Basic Data - Overview
-- Prevalence and Trends
-- Treatment and Problem Use
-- Cannabis and the Criminal Justice System
-- Production and Potency
Marijuana and Physical Health
Marijuana and Psychological Health
-- Psychosis and Schizophrenia
-- IQ and Cognition
Marijuana and Young People
Marijuana and Driving
Laws and Policies
Synthetic Cannabinoids, Spice, and K2
Other & Miscellaneous
Links for Data Tables:
US Arrests, by Year and Crime Category
US Marijuana Arrests Expressed As Percent of Total Drug Arrests
Annual Percent Change in Total, Drug, and Marijuana Arrests, 1996-2010
Average THC, CBD, and CBN Levels of Seized Samples of Domestic Cannabis
THC Potency of Tested Cannabis from Federal Seizure and State and Local Eradication Samples, by Type, 1985-2012
Basic Data - Overview
Is marijuana a “gateway” drug?
"Our results indicate a moderate relation between early teen marijuana use and young adult abuse of other illicit substances; however, this association fades from statistical significance with adjustments for stress and life-course variables. Likewise, our findings show that any causal influence of teen marijuana use on other illicit substance use is contingent upon employment status and is short-term, subsiding entirely by the age of 21. In light of these findings, we urge U.S. drug control policymakers to consider stress and life-course approaches in their pursuit of solutions to the 'drug problem.'"Source:Source: Van Gundy, Karen and Rebellon, Cesar J., "Life-course Perspective on the “Gateway Hypothesis” Journal of Health and Social Behavior (Thousand Oaks, CA: American Sociological Association, September 2010), p. 244.
- See more at: http://www.drugwarfacts.org/cms/Gateway_Theory#sthash.chdjHsdF.dpuf
"The gateway effect, if it exists, has at least two potential and quite different sources (MacCoun, 1998). One interpretation is that it is an effect of the drug use itself (e.g., trying marijuana increases the taste for other drugs or leads users to believe that other substances are more pleasurable or less risky than previously supposed). A second interpretation stresses peer groups and social interactions. Acquiring and using marijuana regularly may lead to differentially associating with peers who have attitudes and behaviors that are prodrug generally, not only with respect to marijuana. One version of this is the possibility that those peers will include people who sell other drugs, reducing the difficulty of locating potential supplies. If the latter is the explanation, then legalization might reduce the likelihood of moving on to harder drugs compared to the current situation."Source:Source: Kilmer, Beau; Caulkins, Jonathan P.; Pacula, Rosalie Liccardo; MacCoun, Robert J.; Reuter, Peter H., "Altered State? Assessing How Marijuana Legalization in California Could Influence Marijuana Consumption and Public Budgets" Drug Policy Research Center (Santa Monica, CA: RAND Corporation, 2010), p. 42.
- See more at: http://www.drugwarfacts.org/cms/Gateway_Theory#sthash.chdjHsdF.dpuf
Is marijuana dangerous?
"Tetrahydrocannabinol is a very safe drug. Laboratory animals (rats, mice, dogs, monkeys) can tolerate doses of up to 1,000 mg/kg (milligrams per kilogram). This would be equivalent to a 70 kg person swallowing 70 grams of the drug—about 5,000 times more than is required to produce a high. Despite the widespread illicit use of cannabis there are very few if any instances of people dying from an overdose. In Britain, official government statistics listed five deaths from cannabis in the period 1993-1995 but on closer examination these proved to have been deaths due to inhalation of vomit that could not be directly attributed to cannabis (House of Lords Report, 1998). By comparison with other commonly used recreational drugs these statistics are impressive."Source:Source: Iversen, Leslie L., PhD, FRS, "The Science of Marijuana" (London, England: Oxford University Press, 2000), p. 178, citing House of Lords, Select Committee on Science and Technology, "Cannabis — The Scientific and Medical Evidence" (London, England: The Stationery Office, Parliament, 1998).
- See more at: http://www.drugwarfacts.org/cms/Overdose#Cannabis
How does marijuana compare with other drugs?
"The public health burden of cannabis use is probably modest compared with that of alcohol, tobacco, and other illicit drugs. A recent Australian study96 estimated that cannabis use caused 0·2% of total disease burden in Australia—a country with one of the highest reported rates of cannabis use. Cannabis accounted for 10% of the burden attributable to all illicit drugs (including heroin, cocaine, and amphetamines). It also accounted for around 10% of the proportion of disease burden attributed to alcohol (2·3%), but only 2·5% of that attributable to tobacco (7·8%)."Source:Source: Hall, Wayne and Degenhardt, Louise, "Adverse health effects of non-medical cannabis use," The Lancet (London, United Kingdom: October 17, 2009) Vol. 374, p. 1389.
- See more at: http://www.drugwarfacts.org/cms/Marijuana#Effects
How did marijuana become illegal?
"Marijuana essentially became illegal in 1937 pursuant to the Marijuana Tax Act.39 The use of marijuana required the payment of a tax for usage; failure to pay the tax resulted in a large fine or stiff prison time for tax evasion.40 Drug prohibition was elevated to another level by targeting 'marijuana,' a plant that had never demonstrated any harm to anyone.41
"Anslinger’s [Harry J. Anslinger, the first Commissioner of the Federal Bureau of Narcotics] efforts to eradicate marijuana continued when Anslinger sought similar anti-narcotic laws against marijuana at the state level.42 Guided by Anslinger’s policy direction, states began passing their own laws or adopting more strident versions of federal laws.43 By 1952, nearly all states had anti-narcotic laws in place.44"Source:Source: Gilmore, Brian, "Again and Again We Suffer: the Poor and the Endurance of the 'War on Drugs,'" University of the District of Columbia Law Review (Washington, DC: The University of the District of Columbia David A. Clarke School of Law, 2011) Volume 15, Number 1, p. 64.
- See more at: http://www.drugwarfacts.org/cms/Marijuana#sthash.4MGmqQ7O.dpuf
What is hemp?
"Industrial hemp can be grown as a fiber, seed, or dual-purpose crop.15 The interior of the stalk has short woody fibers called hurds; the outer portion has long bast fibers. Hemp seed/grains are smooth and about one-eighth to one-fourth of an inch long.16
"Although hemp is not grown in the United States, both finished hemp products and raw material inputs are imported and sold for use in manufacturing for a wide range of product categories (Figure 1). Hemp fibers are used in a wide range of products, including fabrics and textiles, yarns and spun fibers, paper, carpeting, home furnishings, construction and insulation materials, auto parts, and composites. Hurds are used in various applications such as animal bedding, material inputs, papermaking, and composites. Hemp seed and oilcake are used in a range of foods and beverages, and can be an alternative food protein source. Oil from the crushed hemp seed is used as an ingredient in a range of body-care products and nutritional supplements.17 Hemp seed is also used for industrial oils, cosmetics and personal care products, and pharmaceuticals, among other composites."Source:Source: Johnson, Renée, "Hemp As An Agricultural Commodity," Congressional Research Service (Washington, DC: Library of Congress, July 24, 2013), p. 4.
- See more at: http://www.drugwarfacts.org/cms/Hemp#sthash.7Mc42Aho.dpuf
What states allow medical marijuana?
As of August 1, 2013, a total of 20 states plus the District of Columbia have what are called "effective" state medical marijuana laws, and one more state has created an academic program which may in the future help that state's patients. These states include: Alaska, Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Massachusetts, Michigan, Montana, Nevada, New Hampshire, New Jersey, New Mexico, Oregon, Rhode Island, Vermont, and Washington. Maryland has adopted a partially effective law. The state of New Hampshire's medical marijuana law was signed into law by NH Governor Maggie Hassan on July 23, 2013. The state of Illinois became the 20th state with an effective state medical marijuana law on August 1, 2013, when Governor Pat Quinn signed The Compassionate Use of Medical Cannabis Act into law.
What about marijuana and driving?
"Cannabis use impairs cognitive, memory and psycho-motor performance in ways that may impair driving.10 Recent data suggest that approximately 5% of Canadian drivers/adults report driving after cannabis use in the past year.39 Large-scale epidemiological studies using different methodologies (e.g., retrospective epidemiological and case control studies) have found that cannabis use acutely increases the risk of motor vehicle accident (MVA) involvement and fatal crashes among drivers.40,41 Recent reviews have found the increase in risk to be approximately 1.5-3.0, an increase which is substantially lower, however, than that in alcohol-impaired drivers. The impairment from concurrent alcohol and cannabis use may be multiplicative, so individuals who drive under the influence of both drugs may be at higher risk for MVAs.42 An expert consensus view was that a THC concentration of 7-10 nanograms per millilitre in serum would produce impairment equivalent to that of 0.05% blood alcohol content (BAC). It was suggested that this level could serve as a 'per se' limit to define cannabis-impaired driving.43 Current research suggests that acute impairment from cannabis typically clears 3-4 hours after use.44
"This time span could be recommended to users as a minimum wait period before driving. The required wait before driving would need to be longer for higher doses, and would also vary on the basis of individual variation."Source:Source: Fischer, Benedikt; Jeffries, Victoria; Hall, Wayne; Room, Robin; Goldner, Elliot; Rehm, Jürgen, "Lower Risk Cannabis Use Guidelines for Canada (LRCUG): A Narrative Review of Evidence and Recommendations," Canadian Journal of Public Health (Ottawa, Ontario: Canadian Public Health Association, September/October 2011) Vol. 102, No. 5, p. 325.
- See more at: http://www.drugwarfacts.org/cms/Marijuana#Driving
What's happening with reform in the US?
On November 6, 2012, a majority of the voters in the states of Colorado and Washington voted in favor of ballot measures which legalized the adult social use of marijuana.Source:Source: Colorado: "Amendment 64 - Legalize Marijuana Election Results," Denver Post, last accessed Nov. 9, 2012.
Washington: "Initiative Measure No. 502 Concerns marijuana," Washington Secretary of State's Office, last accessed May 24, 2013.
- See more at: http://www.drugwarfacts.org/cms/Marijuana#Law
How do people get marijuana in states where it's not legal?
"Despite continuing increases in the amount of cannabis produced domestically, much of the marijuana available within the United States is foreign-produced. The two primary foreign source areas for marijuana distributed within the United States are Canada and Mexico. Mexican drug trafficking organizations (DTOs) have relocated many of their outdoor cannabis cultivation operations in Mexico from traditional growing areas to more remote locations in central and northern Mexico, primarily to reduce the risk of eradication and gain easier access to U.S. drug markets. Asian criminal groups are the primary producers of high-potency marijuana in Canada."
Do people in the US still get arrested for marijuana?
Although the intent of a 'War on Drugs' may have been to target drug smugglers and 'King Pins,' according to the FBI's annual Uniform Crime Reports, of the 1,552,432 arrests for drug law violations in 2012, 82.2% (1,276,099) were for mere possession of a controlled substance. Only 17.8% (276,333) were for the sale or manufacturing of a drug. Further, nearly half (48.3%) of drug arrests in 2012 were for marijuana -- a total of 749,825. Of those, an estimated 658,231 arrests (42.4% of all drug arrests) were for marijuana possession alone. By contrast in 2000, a total of 734,497 Americans were arrested for marijuana offenses, of which 646,042 (40.9%) were for possession alone.
What's happening in the Netherlands?
"Police and Public Prosecutor give low priority to the investigation of possession of small amounts of a drug for own use. The Opium Act Directive of the Public Prosecutor state that, if the offence concerns possession of small amounts for own use of a hard drug, the drugs will be seized, but normally there will be no custody or prosecution. Diversion to care is the primary aim of custody or prosecution in cases of possession of hard drugs (Directive Opium Act 2011A021 2012, www.om.nl). ‘Small amounts’ of a hard drug are defined as one tablet, ample, wrapple or ball of the drug and in any case an amount of no more than 0,5 grams. With regards to cannabis (categorized as ‘soft drug’) small amounts are defined as no more than 5 grams and no more than 5 cannabis plants – under the condition that there is no professional or commercial cultivation of the plants (Stc. 2011 – 22936). For hallucinogenic mushrooms, also categorized as soft drugs, the small amounts for own use are defined as 0,5 grams (dried mushrooms) and 5 grams (fresh ones). In cases of possession of small amounts of soft drugs, the drugs will be seized but a dismissal by the police will normally (‘in principle’) follow, without custody or prosecution."Source:Source: Van Laar, M.W., Cruts, A.A.N., Van Ooyen-Houben, M.M.J., Van Gageldonk, A., Croes, E.A., Meijer, R.F., et al. (2013). The Netherlands drug situation 2012: report to the EMCDDA by the Reitox National Focal Point. Trimbos-instituut/WODC, Utrecht/Den Haag, p. 118.
- See more at: http://www.drugwarfacts.org/cms/?q=node/1212#sthash.n1MLmG64.dpuf
"All recent policy documents state that the Dutch drug policy has two cornerstones - and this was confirmed by the Minister of Health, Welfare and Sport during the major drug debate in the House of Representatives in March 2012: to protect public health and to combat public nuisance and drug-related crime (TK 24077-259; TK Handelingen 69-28 maart 2012). In the current Opium Act Directive the objective of the drug policy is described as: 'The [new] Dutch drugs policy is aimed to discourage and reduce drug use, certainly in so far as it causes damage to health and to society, and to prevent and reduce the damage associated with drug use, drug production and the drugs trade' (Stc 2011-11134)."Source:Source: Van Laar, M.W., Cruts, A.A.N., Van Ooyen-Houben, M.M.J., Van Gageldonk, A., Croes, E.A., Meijer, R.F., et al. (2013). The Netherlands drug situation 2012: report to the EMCDDA by the Reitox National Focal Point. Trimbos-instituut/WODC, Utrecht/Den Haag, p. 16.
- See more at: http://www.drugwarfacts.org/cms/?q=node/1212#sthash.n1MLmG64.dpuf
What's happening in Uruguay?
“President José Mujica has quietly signed into law the government’s plan to create a regulated, legal market for marijuana, the president’s spokesman said Tuesday. The presidential secretary Diego Canepa said Mr. Mujica signed the legislation on Monday night. That was the last formal step for the law to take effect. Officials now have until April 9 to write the fine print for regulating every aspect of the marijuana market, from growing to selling in a network of pharmacies. They hope to have the whole system in place by the middle of next year. But as of Tuesday, growing marijuana at home was legal, up to six plants per family and an annual harvest of 480 grams, or about one pound.”
(Prevalence of Marijuana Use in the US, 2012)
" In 2012, marijuana was the most commonly used illicit drug, with 18.9 million users. It was used by 79.0 percent of current illicit drug users. About two thirds (62.8 percent) of illicit drug users used only marijuana in the past month. Also, in 2012, 8.9 million persons aged 12 or older were current users of illicit drugs other than marijuana (or 37.2 percent of illicit drug users aged 12 or older). Current use of other drugs but not marijuana was reported by 21.0 percent, and 16.2 percent of illicit drug users reported using both marijuana and other drugs.
"The number and percentage of persons aged 12 or older who were current users of marijuana in 2012 (18.9 million or 7.3 percent) were similar to the estimates for 2011 (18.1 million or 7.0 percent). The 2012 rate of current marijuana use also was similar to the rate in 2010 (6.9 percent), but it was higher than rates from 2002 to 2009. Between 2007 and 2012, for example, the rate of use increased from 5.8 to 7.3 percent, and the number of users increased from 14.5 million to 18.9 million."Source:Substance Abuse and Mental Health Services Administration, Results from the 2012 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-46, HHS Publication No. (SMA) 13-4795. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2013, pp. 13-14.
(Community Epidemiology Working Group Assessment of Cannabis Use in the US, 2012) "One area representative, from New York City, reported the continuing predominance in indicators and serious consequences of marijuana (as well as heroin and cocaine) and changes in marijuana trends as a key finding in that area for this reporting period. Marijuana indicator levels continued to be reported as high relative to other drugs, however, across all CEWG areas, based on treatment admissions and reports identified as marijuana/cannabis among drug items seized and analyzed. New marijuana/cannabis laws legalizing both medical and recreational marijuana use were expected by area representatives to be influencing indicators in several areas currently and in the future. Representatives from Texas and Chicago reported a shift in trafficking and marketing away from Mexican marijuana (due to a drought and poor quality Mexican marijuana) to local markets and local 'grow' operations."Source:"Epidemiologic Trends in Drug Abuse: Proceedings of the Community Epidemiology Work Group, Advance Report, June 2013" (Bethesda, MD: National Institute on Drug Abuse, December 2013), p. 18.
(Prevalence of Marijuana Use in the US, by State, 2009-2010) "In 2009-2010, past month marijuana use was reported by 6.8 percent of the U.S. population aged 12 years or older, an increase from 6.4 percent in 2008-2009 (Table C.3). Nine States that were in the top fifth for past month illicit drug use among persons aged 12 or older also were ranked in the top fifth for past month marijuana use: Alaska, Colorado, District of Columbia, Maine, Massachusetts, New Hampshire, Oregon, Rhode Island, and Vermont (Figures 2.1 and 2.9).
"Seven States were ranked in the top fifth for past month marijuana use in age groups 12 to 17, 18 to 25, 26 or older, and 12 or older: Colorado, Maine, Massachusetts, New Hampshire, Oregon, Rhode Island, and Vermont (Figures 2.9 to 2.12). The rate of past month marijuana use in the 12 or older population ranged from 3.1 percent in Utah to 11.8 percent in Alaska (Table B.3). Utah had the lowest rate in all age groups. Between 2008-2009 and 2009-2010, past month marijuana use among persons 12 or older increased in 10 States: Colorado, District of Columbia, Idaho, Illinois, Massachusetts, Michigan, New Mexico, Oklahoma, Texas, and Washington (Table C.3). During the same time period, past month marijuana use increased in one State among 12 to 17 year olds (District of Columbia), eight States among 18 to 25 year olds (Florida, Illinois, Iowa, New Mexico, North Carolina, Oklahoma, Pennsylvania, and Washington), and four States among persons aged 26 or older (District of Columbia, Idaho, Michigan, and Texas). Decreases only occurred in two States: Tennessee, among persons aged 12 or older, and Utah, among youths aged 12 to 17. All four census regions had higher rates of past month marijuana use among persons aged 12 or older in 2009-2010 compared with 2008-2009."Source:Substance Abuse and Mental Health Services Administration, State Estimates of Substance Use and Mental Disorders from the 2009-2010 National Surveys on Drug Use and Health, NSDUH Series H-43, HHS Publication No. (SMA) 12-4703. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2012.
(Early Initiation of Substance Use) “When initiation of substance use occurs in preadolescence or early in adolescence, the risk of addiction is magnified.8 CASA’s analysis of national data finds that individuals‡ who first used any addictive substance before age 15 are six and a half times as likely to have a substance use disorder as those who did not use any addictive substance until age 21 or older (28.1 percent vs. 4.3 percent).”Source:"Adolescent Substance Use: America’s #1 Public Health Problem," The National Center on Addiction and Substance Abuse at Columbia University (New York, NY: National Center on Addiction and Substance Abuse at Columbia University, June 2011), p. 38
(Marijuana Use in the US by Race/Ethnicity, 2012)
Marijuana Use in Lifetime, Past Year, and Past Month among Persons in the US Aged 12 or Older, by Demographic Characteristics: Number in Thousands, 2012
111,239 31,513 18,855
12-17 4,232 3,363 1,800 18-25 18,052 10,887 6,485 26 or Older 88,955 17,263 10,571
Male 60,056 19.193 12,085 Female 51,183 12,320 6,770
HISPANIC ORIGIN AND RACE
Not Hispanic or Latino 97,803 27,026 16,340 White 79,911 20,778 12,468 Black or African American 12,549 4,413 2,800 American Indian or Alaska Native 710 235 136 Native Hawaiian or Other Pacific Islander * 177 73 Asian 2,253 643 318 Two or More Races 1,978 779 545
Hispanic or Latino
13,435 4,488 2,515
*Low precision; no estimate reported.Source:Substance Abuse and Mental Health Services Administration, Results from the 2012 National Survey on Drug Use and Health: Detailed Tables. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2013, Table 1.24A.
(Marijuana Use Among 50-Year-Olds in the US, 2012) "Among 50-year-old high school graduates in 2012, we estimate that about three quarters (74%) have tried marijuana, and that about two thirds (64%) have tried an illicit drug other than marijuana. (These estimates are adjusted to correct for panel attrition, as described in chapter 4 of Volume II.)
"Their current behavior is far less extreme than those statistics might suggest, but it is not by any means negligible. One in eight (12%) indicates using marijuana in the last 12 months, and one in ten (10%) indicates using any other illicit drug in the same period. Their past-month prevalence rates are lower—7.3% and 6.2%, respectively, for marijuana and any other illicit drug. About 1 in 43 (2.3%) is a current daily marijuana user, though substantially more indicate that they have used marijuana daily at some time in the past."Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., and Schulenberg, J. E., (2013). Monitoring the Future national survey results on drug use, 1975–2012: Volume 2, College students and adults ages 19–50. Ann Arbor: Institute for Social Research, The University of Michigan, p. 37.
(Prevalence of Daily Marijuana Use Among US Adults Aged 19-30, 2012)
Thirty-Day Prevalence of Daily Marijuana Use Among 19-30 Year Olds in the US, 2012
(Figures in Percent)
Modal Age Daily Marijuana Use 19-30 5.5 19-20 6.2 21-22 6.1 23-24 5.7 25-26 5.1 27-28 5.1 29-30 4.5Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., and Schulenberg, J. E., (2013). Monitoring the Future national survey results on drug use, 1975–2012: Volume 2, College students and adults ages 19–50. Ann Arbor: Institute for Social Research, The University of Michigan, p. 107, Table 4-5.
(Estimated Prevalence of Cannabis Dependence) "Some 4.3 percent of Americans have been dependent on marijuana, as defined in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR; American Psychiatric Association, 2000), at some time in their lives. Marijuana produces dependence less readily than most other illicit drugs. Some 9 percent of those who try marijuana develop dependence compared to, for example, 15 percent of people who try cocaine and 24 percent of those who try heroin. However, because so many people use marijuana, cannabis dependence is twice as prevalent as dependence on any other illicit psychoactive substance (cocaine, 1.8 percent; heroin, 0.7 percent; Anthony and Helzer, 1991; Anthony, Warner, and Kessler, 1994)."Source:Budney A, Roffman R, Stephens R, Walker D. Marijuana dependence and its treatment. Addiction Science and Clinical Practice. 2007;4(1):4–16.
(Estimated Prevalence of Cannabis Dependence or Abuse in the US, 2012)
" Marijuana was the illicit drug with the largest number of persons with past year dependence or abuse in 2012, followed by pain relievers, then by cocaine. Of the 7.3 million persons aged 12 or older classified with illicit drug dependence or abuse in 2012, 4.3 million persons had marijuana dependence or abuse (representing 1.7 percent of the total population aged 12 or older, and 58.9 percent of all those classified with illicit drug dependence or abuse), 2.1 million persons had pain reliever dependence or abuse, and 1.1 million persons had cocaine dependence or abuse (Figure 7.2).
" The number of persons who had marijuana dependence or abuse remained similar between 2002 (4.3 million) and 2012 (4.3 million) and between 2011 (4.2 million) and 2012 (Figure 7.3). The rate of marijuana dependence or abuse in 2012 (1.7 percent) was similar to the rate in each year from 2005 through 2011 (ranging from 1.6 to 1.8 percent)."Source:Substance Abuse and Mental Health Services Administration, Results from the 2012 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-46, HHS Publication No. (SMA) 13-4795. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2013, p. 77.
(Daily/Frequent Marijuana Use, 2011) "In 2011, an estimated 16.7 percent of past year marijuana users aged 12 or older used marijuana on 300 or more days within the past 12 months. This translates into nearly 5.0 million persons using marijuana on a daily or almost daily basis over a 12-month period.
"• In 2011, an estimated 39.1 percent (7.1 million) of current marijuana users aged 12 or older used marijuana on 20 or more days in the past month. This was similar to the 2010 estimate of 39.8 percent or 6.9 million users."Source:Substance Abuse and Mental Health Services Administration, Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-44, HHS Publication No. (SMA) 12-4713. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2012, p. 27.
(California Marijuana Arrestees) "In 1990, half of California’s marijuana possession arrestees were African-American, Latino, Asian, or other nonwhite and 35% were under age 20. In 2010, 64% were nonwhite and 52% were under age 20. Marijuana possession arrests of teenagers of color rose from 3,100 in 1990 to 16,400 in 2010 – an arrest surge 300% greater than population growth in that group."Source:Males, Mike, "Misdemeanor marijuana arrests are skyrocketing and other California marijuana enforcement disparities," Center on Juvenile and Criminal Justice (San Francisco, CA: November 2011), p. 2.
(Estimated Risk of Arrest for Marijuana Possession) "To provide a sense of the intensity of enforcement, we calculated the risk a marijuana user faces of being arrested for possession. If calculated per joint consumed, the figure nationally is trivial—perhaps one arrest for every 11,000–12,000 joints.4 However, the relevant risk may be the probability of being arrested during a year of normal consumption. Since marijuana is mostly consumed by individuals who use it at least once a month,5 we estimated the risk that such individuals face. We know from prior studies (e.g., Reuter, Hirschfield, and Davies, 2001) that these risks are higher for youth. Table 2.2 presents separate estimates for those aged 12–17 and for the entire population 12 and over. We observe that the annual risk of misdemeanor arrest for those 12–17 (6.6 percent) is more than twice the rate for the full population (3.0 percent)."Source:Kilmer, Beau; Caulkins, Jonathan P.; Pacula, Rosalie Liccardo; MacCoun, Robert J.; Reuter, Peter H., "Altered State? Assessing How Marijuana Legalization in California Could Influence Marijuana Consumption and Public Budgets" Drug Policy Research Center (Santa Monica, CA: RAND Corporation, 2010), p. 8.
(Impact of Medical Marijuana Legalization (MML) on Crime Rates in States That Have Legalized Medical Cannabis) "The central finding gleaned from the present study was that MML is not predictive of higher crime rates and may be related to reductions in rates of homicide and assault. Interestingly, robbery and burglary rates were unaffected by medicinal marijuana legislation, which runs counter to the claim that dispensaries and grow houses lead to an increase in victimization due to the opportunity structures linked to the amount of drugs and cash that are present. Although, this is in line with prior research suggesting that medical marijuana dispensaries may actually reduce crime in the immediate vicinity ."Source:Robert G. Morris, Michael TenEyck, JC Barnes, and Tomislav V. Kovandzic, "The Effect of Medical Marijuana Laws On Crime: Evidence From State Panel Data, 1990-2006," PLoS ONE 9(3): e92816. March 2014. doi: 10.1371/journal.pone.0092816
(Effect of Medical Marijuana Legalization On Crime Rates) "In sum, these findings run counter to arguments suggesting the legalization of marijuana for medical purposes poses a danger to public health in terms of exposure to violent crime and property crimes. To be sure, medical marijuana laws were not found to have a crime exacerbating effect on any of the seven crime types. On the contrary, our findings indicated that MML precedes a reduction in homicide and assault. While it is important to remain cautious when interpreting these findings as evidence that MML reduces crime, these results do fall in line with recent evidence  and they conform to the longstanding notion that marijuana legalization may lead to a reduction in alcohol use due to individuals substituting marijuana for alcohol [see generally 29, 30]. Given the relationship between alcohol and violent crime , it may turn out that substituting marijuana for alcohol leads to minor reductions in violent crimes that can be detected at the state level. That said, it also remains possible that these associations are statistical artifacts (recall that only the homicide effect holds up when a Bonferroni correction is made)."Source:Robert G. Morris, Michael TenEyck, JC Barnes, and Tomislav V. Kovandzic, "The Effect of Medical Marijuana Laws On Crime: Evidence From State Panel Data, 1990-2006," PLoS ONE 9(3): e92816. March 2014. doi: 10.1371/journal.pone.0092816
(Effect Of Medical Marijuana Legalization On Crime Rates And Limitations Of Data) "Given that the current results failed to uncover a crime exacerbating effect attributable to MML, it is important to examine the findings with a critical eye. While we report no positive association between MML and any crime type, this does not prove MML has no effect on crime (or even that it reduces crime). It may be the case that an omitted variable, or set of variables, has confounded the associations and masked the true positive effect of MML on crime. If this were the case, such a variable would need to be something that was restricted to the states that have passed MML, it would need to have emerged in close temporal proximity to the passage of MML in all of those states (all of which had different dates of passage for the marijuana law), and it would need to be something that decreased crime to such an extent that it ‘‘masked’’ the true positive effect of MML (i.e., it must be something that has an opposite sign effect between MML [e.g., a positive correlation] and crime [e.g., a negative correlation]). Perhaps the more likely explanation of the current findings is that MML laws reflect behaviors and attitudes that have been established in the local communities. If these attitudes and behaviors reflect a more tolerant approach to one another’s personal rights, we are unlikely to expect an increase in crime and might even anticipate a slight reduction in personal crimes.
"Moreover, the present findings should also be taken in context with the nature of the data at hand. They are based on official arrest records (UCR), which do not account for crimes not reported to the police and do not account for all charges that may underlie an arrest. In any case, this longitudinal assessment of medical marijuana laws on state crime rates suggests that these laws do not appear to have any negative (i.e., crime exacerbating) impact on officially reported criminality during the years in which the laws are in effect, at least when it comes to the types of offending explored here. It is also important to keep in mind that the UCR data used here did not account for juvenile offending, which may or may not be empirically tethered to MML in some form or another; an assessment of which is beyond the scope of this study."Source:Robert G. Morris, Michael TenEyck, JC Barnes, and Tomislav V. Kovandzic, "The Effect of Medical Marijuana Laws On Crime: Evidence From State Panel Data, 1990-2006," PLoS ONE 9(3): e92816. March 2014. doi: 10.1371/journal.pone.0092816
(Admissions to Treatment for Marijuana, 2011) According to the federal Treatment Episode Data Set, in 2011 there were 333,578 admissions to treatment with marijuana reported as the primary substance of abuse out of the total 1,844,719 admissions for all substances that year.
According to the TEDS report:
" Marijuana was reported as the primary substance of abuse by 18 percent of TEDS admissions aged 12 and older in 2011 [Table 1.1b].
" The average age at admission for primary marijuana admissions was 24 years [Table 2.1a], although the peak age at admission for both genders in all race/ethnicities was 15 to 17 years [Figure 12]. Forty percent of marijuana admissions were under age 20 (vs. 11 percent of all admissions), and primary marijuana abuse accounted for 74 percent of all admissions aged 12 to 14 years and 76 percent of admissions aged 15 to 17 years [Tables 2.1a-b].
" Non-Hispanic Whites accounted for 45 percent of primary marijuana admissions (32 percent males and 13 percent females), and non-Hispanic Black males accounted for 24 percent [Table 2.3a].
" Twenty-five percent of primary marijuana admissions had first used marijuana by age 12 and another 32 percent by age 14 [Table 2.5].
" Primary marijuana admissions were less likely than all admissions combined to be self- or individually referred to treatment (16 percent vs. 35 percent). Primary marijuana admissions were most likely to be referred by a criminal justice/DUI source (52 percent) [Table 2.6].
" More than 4 in 5 marijuana admissions (85 percent) received ambulatory treatment compared with about 3 in 5 of all admissions combined (62 percent) [Table 2.7].
" Fifty-six percent of primary marijuana admissions reported abuse of additional substances. Alcohol was reported by 41 percent [Table 3.8]."Source:Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. Treatment Episode Data Set (TEDS): 2001-2011. National Admissions to Substance Abuse Treatment Services. BHSIS Series S-65, HHS Publication No. (SMA) 13-4772. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2013, p. 19; and p. 43, Table 1.1a.
(Treatment Admissions with Marijuana as a Primary Substance, 2011)
" Admissions for primary marijuana increased from 15 percent of admissions aged 12 or older in 2001 to 18 percent in 2011 [Table 1.1b].
" Nearly three-quarters (73 percent) of primary marijuana admissions were male [Table 2.1a].
" For primary marijuana admissions, the average age at admission was 24 years [Table 2.1a].
" Slightly less than half (45 percent) of primary marijuana admissions were non-Hispanic White,"Source:Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. Treatment Episode Data Set (TEDS): 2001-2011. National Admissions to Substance Abuse Treatment Services. BHSIS Series S-65, HHS Publication No. (SMA) 13-4772. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2013, p. 2.
(Treatment Admissions for Marijuana in the US, 1992-2002) " A recent issue of The DASIS Report2 examined marijuana treatment admissions between 1992 and 2002 and found that between these years [1992 and 2002] the rate of substance abuse treatment admissions reporting marijuana as their primary substance of abuse3 per 100,000 population increased 162 percent. Similarly, the proportion of marijuana admissions increased from 6 percent of all admissions in 1992 to 15 percent of all admissions reported to the Treatment Episode Data Set (TEDS) in 2002.
"During this time period, the percentage of marijuana treatment admissions that were referred from the criminal justice system increased from 48 percent of all marijuana admissions in 1992 to 58 percent of all marijuana admissions in 2002."Source:"Differences in Marijuana Admissions Based on Source of Referral: 2002," The DASIS Report (Rockville, MD: Substance Abuse and Mental Health Services Administration, Office of Applied Studies, June 5, 2005), pp. 1-2.
(State and Federal Marijuana Prisoners)
Total Federal Prisoners 2004 = 170,535
Total State Prisoners 2004 = 1,244,311
Percent of federal prisoners held for drug law violations = 55%
Percent of state prisoners held for drug law violations = 21%
Marijuana/hashish, Percent of federal drug offenders, 2004 = 12.4%
Marijuana/hashish, Percent of state drug offenders, 2004 = 12.7%
(Total prisoners x percent drug law) x percent marijuana = "marijuana prisoners"
Federal marijuana prisoners in 2004 = 11,630
State marijuana prisoners in 2004 = 33,186
Total federal and state marijuana prisoners in 2004 = 44,816
Note: These data only address people in prisons and thus exclude the 700,000+ offenders who may be in local jails because of a marijuana conviction.Source:Mumola , Christopher J. and Karberg, Jennifer C., "Drug Use and Dependence, State and Federal Prisoners, 2004," Bureau of Justice Statistics (Washington, DC: U.S. Department of Justice, January 2007) NCJ 213530, p. 4.
Harrison, Paige M. and Beck, Allan J., "Prisoners in 2004," Bureau of Justice Statistics, (Washington, DC: US Department of Justice, October 2005), NCJ 210677, Table 1, page 2.
Production & Potency
(Primary Cultivation States) "California, Hawaii, Kentucky, Oregon, Tennessee, Washington, and West Virginia are the primary marijuana cultivation states (M7 states). Domestic Cannabis Eradication/Suppression Program (DCE/SP) data show that more than 8 million plants were eradicated in 2008, 89 percent (7,136,133 plants of 8,013,308 plants) of which were eradicated in the M7 States."
(Marijuana Potency) "Although marijuana grown in the United States was once considered inferior because of a low concentration of THC, advancements in plant selection and cultivation have resulted in higher THC-containing domestic marijuana. In 1974, the average THC content of illicit marijuana was less than one percent. Today most commercial grade marijuana from Mexico/Columbia and domestic outdoor cultivated marijuana has an average THC content of about 4 to 6 percent. Between 1998 and 2002, NIDA-sponsored Marijuana Potency Monitoring System (MPMP) analyzed 4,603 domestic samples. Of those samples, 379 tested over 15 percent THC, 69 samples tested between 20 and 25 percent THC and four samples tested over 25 percent THC."
(Sources of Marijuana) "Despite continuing increases in the amount of cannabis produced domestically, much of the marijuana available within the United States is foreign-produced. The two primary foreign source areas for marijuana distributed within the United States are Canada and Mexico. Mexican drug trafficking organizations (DTOs) have relocated many of their outdoor cannabis cultivation operations in Mexico from traditional growing areas to more remote locations in central and northern Mexico, primarily to reduce the risk of eradication and gain easier access to U.S. drug markets. Asian criminal groups are the primary producers of high-potency marijuana in Canada."
Arithmetic Cannabinoid Averages of Domestic Cannabis Samples by Year Seized Year Number of Samples Percent THC Percent CBD Percent CBC Percent CBN
1988 651 2.56 .43 .14 .14 1989 511 2.00 .59 .12 .08 1990 475 2.58 .67 .19 .03 1991 943 2.57 .87 .21 .03 1992 1025 2.96 .45 .30 .03 1993 1346 2.75 .48 .20 .01 1994 1210 3.02 .50 .25 .02 1995 997 2.93 .41 .25 .03 1996 1025 3.48 .49 .27 .02 1997 1117 3.95 .40 .32 .03 1998 920 3.76 .40 .26 .02 1999 831 4.45 .46 .29 .02 2000 1186 4.10 .33 .26 .06 2001 1007 3.98 .32 .28 .07 2002 701 4.30 .31 .32 .08 2003 625 3.65 .41 .31 .04 2004 694 4.20 .29 .30 .07 2005 657 4.23 .32 .30 .06 2006 778 4.16 .61 .26 .08 2007 882 4.85 .44 .26 .06 2008 653 4.80 .46 .29 .06
Notes:THC = Delta-9-Tetrahydrocannabinol, CBN = Cannabidiol, CBC = Cannabichromene and CBN = Cannabinol.Source:Quarterly Report #104, Dec. 16, 2008 - March 15, 2009, University of Mississippi Potency Monitoring Project (Oxford, MS: National Center for Natural Products Research, a Division of the Research Institute of Pharmaceutical Sciences, 2008), Mahmoud A. ElSohly, PhD, Director, NIDA Marijuana Project (NIDA Contract #N01DA-5-7746), pp. 8 and 10.
THC Potency of Tested Cannabis from Federal Seizure and State and Local Eradication Samples, by Type, 1985-2012 Year Non-Domestic Samples (Federal Seizures) Domestic Samples (State and Local Eradication) Type of Cannabis All Types1 Type of Cannabis All Types1 Marijuana Sinsemilla Marijuana Sinsemilla Potency2 Number3 Potency2 Number3 Potency2 Number3 Potency2 Number3 Potency2 Number3 Potency2 Number3 1985 3.44% 745 7.95% 12 3.48% 767 2.19% 703 7.07% 40 2.22% 845 1986 2.75% 711 8.78% 14 2.80% 753 1.95% 661 8.16% 18 1.84% 803 1987 3.16% 1,110 8.29% 17 3.20% 1,147 2.46% 441 7.69% 26 2.38% 553 1988 3.62% 1,127 8.30% 29 3.70% 1,171 2.20% 513 7.33% 69 2.56% 651 1989 3.68% 725 7.13% 29 3.78% 761 1.71% 350 6.86% 57 2.00% 511 1990 3.78% 756 9.59% 16 3.82% 788 2.09% 352 10.29% 45 2.58% 475 1991 3.18% 1,498 11.20% 29 3.26% 1,564 2.90% 651 10.10% 46 2.57% 943 1992 3.09% 2,461 9.67% 33 3.16% 2,515 3.05% 875 7.72% 43 2.96% 1,025 1993 3.67% 1,994 4.64% 5 3.65% 2,010 2.83% 1,039 5.82% 118 2.75% 1,346 1994 3.76% 2,052 6.92% 10 3.75% 2,074 2.95% 980 7.55% 94 3.02% 1,210 1995 3.95% 3,730 9.64% 17 3.98% 3,747 2.55% 701 7.26% 147 2.92% 999 1996 4.41% 1,377 11.30% 22 4.51% 1,399 2.90% 767 8.94% 146 3.48% 1,029 1997 4.93% 1,313 12.02% 18 5.03% 1,331 3.34% 954 11.50% 104 3.99% 1,119 1998 4.73% 1,298 11.88% 87 4.93% 1,335 3.36% 778 12.58% 64 3.75% 922 1999 4.36% 1,749 13.49% 55 4.63% 1,804 3.76% 691 13.31% 81 4.43% 833 2000 5.10% 1,861 12.87% 62 5.35% 1,923 3.96% 1,057 12.72% 51 4.10% 1,185 2001 5.77% 1,587 12.05% 95 6.13% 1,682 3.58% 805 7.86% 140 3.97% 1,009 2002 5.66% 1,380 14.41% 302 7.23% 1,682 3.27% 409 7.29% 226 4.29% 703 2003 5.62% 1,516 14.00% 347 7.18% 1,863 2.38% 377 7.21% 191 3.67% 625 2004 6.17% 1,418 14.06% 485 8.18% 1,903 2.55% 395 7.67% 246 4.20% 694 2005 5.92% 1,608 13.04% 681 8.04% 2,289 2.25% 354 7.78% 250 4.21% 656 2006 6.49% 1,409 13.59% 668 8.77% 2,077 1.99% 362 6.81% 364 4.15% 775 2007 7.19% 1,303 13.40% 833 9.61% 2,136 1.92% 340 7.21% 503 4.86% 883 2008 7.16% 1,054 13.08% 942 9.95% 1,997 1.82% 302 7.53% 370 4.84% 701 2009 7.13% 1,026 12.36% 1,043 9.77% 2,069 2.43% 435 7.37% 490 4.89% 962 2010 6.69% 892 12.81% 1,360 10.38% 2,252 2.79% 290 11.84% 97 4.89% 405 2011 5.60% 712 13.47% 1,558 11.00% 2,270 NA 0 NA 0 NA 0 20124 6.73% 240 16.19% 518 13.19% 758 NA 0 NA 0 NA 0
Beginning in 2011, no domestic samples were tested.
1 The category "All Types" of cannabis tested includes ditchweed and a small number of Thai sticks.
2 These percentages, indicating potency, are based on simple arithmetic means calculated by dividing the sum of the delta-9 THC.
3 Number of tested samples that yield the potency in prior column.
4 Data for 2012 are preliminary.Source:"National Drug Control Strategy Data Supplement 2013," Executive Office of the President, Office of National Drug Control Policy, 2013, Table 66, p. 79, citing as its sources: University of Mississippi, National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences. Quarterly Report #120, Potency Monitoring Program (March 26, 2013), for data from 1995 to 2012; Quarterly Report 107 (January 12, 2010) for data from 1985 to 1994.
(Average Potency of Seized Cannabis in the UK, 2008)
" Twenty-three Police Forces in England and Wales participated in the study. Forces were requested to submit samples confiscated from street-level users. In early 2008, they submitted 2,921 samples for analysis to either the Forensic Science Service Ltd (FSS) or LGC Forensics at Culham (LGC F).
" Initial laboratory examination showed that 80.8% were herbal cannabis and 15.3% were cannabis resin. The remaining 3.9% were either indeterminate or not cannabis.
" Microscopic examination of around two-thirds of the samples showed that over 97% of the herbal cannabis had been grown by intensive methods (sinsemilla). The remainder was classed as traditional imported herbal cannabis.
" Regional variations were found in the market share of herbal cannabis. Thus North Wales, South Wales, Cleveland and Devon and Cornwall submitted proportionately fewer herbal cannabis samples, whereas Essex, Metropolitan and Avon and Somerset submitted proportionately more. These differences were statistically significant at the 0.1% confidence interval.
" The mean THC concentration (potency) of the sinsemilla samples was 16.2% (range = 4.1 to 46%). The median potency was 15.0%, close to values reported by others in the past few years.
" The mean THC concentration (potency) of the traditional imported herbal cannabis samples was 8.4% (range = 0.3 to 22%); median = 9.0%. Only a very small number of samples were received and analysed.
" The mean potency of cannabis resin was 5.9% (range = 1.3 to 27.8%). The median = 5.0% was typical of values reported by others over many years.
" Cannabis resin had a mean CBD content of 3.5% (range = 0.1 to 7.3%), but the CBD content of herbal cannabis was less than 0.1% in nearly all cases.
" There was a weak, but statistically-significant, correlation (r = 0.48; N = 112; P < 0.001) between the THC and the CBD content of resin."Source:Hardwick, Sheila; King, Leslie, "Home Office Cannabis Potency Study 2008," Home Office Scientific Development Branch (Sandridge, St Albans, UK: May 2008), p. 1.
(Trends in Cannabis Potency in the US, 1980-1995 ) "Data on the THC content of cannabis products in the USA have been collected by ElSohly et al. (1984, 2000) for many years as part of the University of Mississippi Potency Monitoring Project. Samples were submitted by law enforcement agencies and it has to be assumed that they were representative of the market. Mean THC values are shown in Figure 16 for normal herbal cannabis, sinsemilla and resin. The anomalously high value for resin in 1997 (19.24 %) has been excluded; it was based on only five values and is over nine standard deviations above the mean potency for the period 1980–1996. Although there has been an increase in the potency of herbal cannabis over the twenty-five-year period, cannabis resin (and hash oil) showed no long-term trends since 1980 when data were first collected. Although the potency of sinsemilla showed a clear upward trend in the final three years of the study, no such trend was obvious when the longer period of 1980–1995 is examined, particularly in view of the wide variations in potency that occurred from year to year (ElSohly et al., 2000). The THC content of herbal cannabis increased from around 1% before 1980 to around 4% in 1997. This increase, when seen in the European context, is deceptive. Before 1980, all mean herbal cannabis THC levels in the ElSohly study were less than 2.4%. By contrast, and as shown in Figure 10, comparable levels at that time in the United Kingdom were twice as great. In other words, it must be assumed that the quality of herbal cannabis consumed in the USA more than twenty years ago was unusually poor, but that in recent years it has risen to levels typical of Europe. So even the modest increase found by ElSohly et al. (2000) may be less significant than it seems. A recent analysis of cannabis seized in Florida in 2002 (Newell, 2003) showed amounts of THC found in samples ranging from 1.41% to 12.62%; the average THC content was 6.20%, which is almost identical to the 2002 value reported by the University of Mississippi Potency Monitoring Project."Source:EMCDDA Insights #6: An Overview of Cannabis Potency in Europe, European Monitoring Centre for Drugs and Drug Addiction (Luxembourg: Office for Official Publications of the European Communities, 2004), p. 52.
(Average Cannabis Potency) "Statements in the popular media that the potency of cannabis has increased by ten times or more in recent decades are not support by the data from either the USA or Europe. As discussed in the body of this report, systematic data are not available in Europe on long-term trends and analytical and methodological issues complicate the interpretation of the information that is available. Data are stronger for medium and short-term trends where no major differences are apparent in Europe, although some modest increases are found in some countries. The greatest long-term changes in potency appear to have occurred in the USA. It should be noted here that before 1980 herbal cannabis potency in the USA was, according to the available data, very low by European standards."Source:King, Leslie A., European Monitoring Centre for Drugs and Drug Addiction, "EMCDDA Insights - An Overview of Cannabis Potency in Europe" (Luxembourg: Office for Official Publications of the European Communities, 2004), p. 14.
Marijuana and Physical Health
(Estimated Lethal Dose of Cannabis) "Tetrahydrocannabinol is a very safe drug. Laboratory animals (rats, mice, dogs, monkeys) can tolerate doses of up to 1000 mg/kg (milligrams per kilogram). This would be equivalent to a 70 kg person swallowing 70 grams of the drug —about 5,000 times more than is required to produce a high. Despite the widespread illicit use of cannabis there are very few if any instances of people dying from an overdose."
(Public Health Impact of Marijuana) "The public health burden of cannabis use is probably modest compared with that of alcohol, tobacco, and other illicit drugs. A recent Australian study96 estimated that cannabis use caused 0·2% of total disease burden in Australia—a country with one of the highest reported rates of cannabis use. Cannabis accounted for 10% of the burden attributable to all illicit drugs (including heroin, cocaine, and amphetamines). It also accounted for around 10% of the proportion of disease burden attributed to alcohol (2·3%), but only 2·5% of that attributable to tobacco (7·8%)."Source:Hall, Wayne and Degenhardt, Louise, "Adverse health effects of non-medical cannabis use," The Lancet (London, United Kingdom: October 17, 2009) Vol. 374, p. 1389.
(Relative Public Health Risk of Cannabis Use) "There are health risks of cannabis use, most particularly when it is used daily over a period of years or decades. Considerable uncertainty remains about whether these effects are attributable to cannabis use alone, and about what the quantitative relationship is between frequency, quantity and duration of cannabis use and the risk of experiencing these effects.
"On existing patterns of use, cannabis poses a much less serious public health problem than is currently posed by alcohol and tobacco in Western societies."Source:Hall, W., Room, R. & Bondy, S., "WHO Project on Health Implications of Cannabis Use: A Comparative Appraisal of the Health and Psychological Consequences of Alcohol, Cannabis, Nicotine and Opiate Use," (Geneva, Switzerland: World Health Organization, March 1998).
An exhaustive search of the literature finds no deaths induced by marijuana. The US Drug Abuse Warning Network (DAWN) records instances of drug mentions in medical examiners' reports, and though marijuana is mentioned, it is usually in combination with alcohol or other drugs. Marijuana alone has not been shown to cause an overdose death.Source:Drug Abuse Warning Network (DAWN), available on the web at http://www.samhsa.gov/ ; also see Janet E. Joy, Stanley J. Watson, Jr., and John A. Benson, Jr., "Marijuana and Medicine: Assessing the Science Base," Division of Neuroscience and Behavioral Research, Institute of Medicine (Washington, DC: National Academy Press, 1999), available on the web at http://www.nap.edu/html/marimed/ ; and US Department of Justice, Drug Enforcement Administration, "In the Matter of Marijuana Rescheduling Petition" (Docket #86-22), September 6, 1988, p. 57.
(Safety of Medical Cannabis) In 1988, the DEA's Administrative Law Judge, Francis Young, concluded: "In strict medical terms marijuana is far safer than many foods we commonly consume. For example, eating 10 raw potatoes can result in a toxic response. By comparison, it is physically impossible to eat enough marijuana to induce death. Marijuana in its natural form is one of the safest therapeutically active substances known to man. By any measure of rational analysis marijuana can be safely used within the supervised routine of medical care."Source:US Department of Justice, Drug Enforcement Administration, "In the Matter of Marijuana Rescheduling Petition," [Docket #86-22], (September 6, 1988), p. 57.
(Shafer Commission on Marijuana's Relative Safety) "A careful search of the literature and testimony of the nation's health officials has not revealed a single human fatality in the United States proven to have resulted solely from ingestion of marihuana. Experiments with the drug in monkeys demonstrated that the dose required for overdose death was enormous and for all practical purposes unachievable by humans smoking marihuana. This is in marked contrast to other substances in common use, most notably alcohol and barbiturate sleeping pills."Source:Shafer, Raymond P., et al, Marihuana: A Signal of Misunderstanding, Ch. III, (Washington DC: National Commission on Marihuana and Drug Abuse, 1972).
(Pulmonary Effects of Cannabis) "For physiological and pharmacological reasons,61 smoking cannabinoid herbals does not seem to have a similar health hazard profile as tobacco smoking, aside from the potential for bronchial irritation and bronchitis. Smoking cannabis was not associated with an increased risk of developing chronic obstructive pulmonary disease ..."Source:Aggarwal, Sunil K., "Cannabinergic Pain Medicine: A Concise Clinical Primer and Survey of Randomized-controlled Trial Results," Clinical Journal of Pain (Philadelphia, PA: February 23, 2012), p. 4.
(Cannabis Smoking and Pulmonary Function) "In this 20-year study of marijuana and pulmonary function, we confirmed the expected reductions in FEV1 [Forced expiratory volume in the first second of expiration] and FVC [forced vital capacity] from tobacco use. In contrast, marijuana use was associated with higher FEV1 and FVC at the low levels of exposure typical for most marijuana users. With up to 7 joint-years of lifetime exposure (eg, 1 joint/d for 7 years or 1 joint/wk for 49 years), we found no evidence that increasing exposure to marijuana adversely affects pulmonary function. This association, however, was nonlinear: at higher exposure levels, we found a leveling off or even a reversal in this association, especially for FEV1. Although our sample contained insufficient numbers of heavy users to confirm a detrimental effect of very heavy marijuana use on pulmonary function, our findings suggest this possibility."Source:Pletcher, Mark J., et al., "Association Between Marijuana Exposure and Pulmonary Function Over 20 Years," Journal of the American Medical Association, Jan. 11, 2012, Vol. 307, No. 2, p. 177.
(Lung Cancer Risk from Cannabis Use) "Despite these findings, the small number of observational studies fail to demonstrate a clear association between marijuana smoking and diagnoses of lung cancer. Therefore, we must conclude that no convincing evidence exists for an association between marijuana smoking and lung cancer based on existing data. Nonetheless, certain logistic properties of marijuana smoking may increase the risk of carcinogenic exposure compared with conventional tobacco smoking, raising questions as to why observational studies have not demonstrated an association with lung cancer."Source:Mehra, Reena; Moore, Brent A.; Crothers, Kristina; Tetrault, Jeanette; Fiellin, David A., "The Association Between Marijuana Smoking and Lung Cancer: A Systemic Review," Archives of Internal Medicine, (Chicago, IL: American Medical Association, July 10, 2006), Vol. 166, p. 1365.
(Head and Neck Squamous Cell Carcinoma) "We found that moderate marijuana use was significantly associated with reduced risk of HNSCC [head and neck squamous cell carcinoma]. This association was consistent across different measures of marijuana use (marijuana use status, duration, and frequency of use). Diminished risk of HNSCC did not differ across tumor sites, or by HPV [human papillomavirus] 16 antibody status. Further, we observed that marijuana use modified the interaction between alcohol and cigarette smoking, resulting in a decreased HNSCC risk among moderate smokers and light drinkers, and attenuated risk among the heaviest smokers and drinkers."Source:Liang, Caihua; McClean, Michael D.; Marsit, Carmen; Christensen, Brock; Peters, Edward; Nelson, Heather H.; Kelsey, Karl T, "A Population-Based Case-Control Study of Marijuana Use and Head and Neck Squamous Cell Carcinoma," Cancer Research Prevention (New Milford, CT: American Association for Cancer Research, August 2009), p. 766.
(Cancer Risk from Marijuana Use) "Nonetheless, and contrary to our expectations, we found no positive associations between marijuana use and lung or UAT cancers. Although we observed positive dose-response relations of marijuana use to oral and laryngeal cancers in the crude analyses, the trend was no longer observed when adjusting for potential confounders, especially cigarette smoking. In fact, we observed ORs <1 for all cancers except for oral cancer, and a consistent monotonic association was not apparent for any outcome. Similar findings were found when the analyses were restricted to subjects who never smoked cigarettes. The 95% confidence intervals for the adjusted ORs did not extend far above 1 (e.g., were under 2 for marijuana and lung cancer), which suggests that associations of marijuana use with the study cancers are not strong and may be below detectable limits for this type of study."Source:Mia Hashibe, Hal Morgenstern, Yan Cui, Donald P. Tashkin, Zuo-Feng Zhang, Wendy Cozen, Thomas M. Mack, and Sander Greenland, "Marijuana Use and the Risk of Lung and Upper Aerodigestive Tract Cancers: Results of a Population-Based Case-Control Study," Cancer Epidemiology, Biomarkers & Prevention (October 2006), p. 1833.
(Cannabis and Lung Cancer) "Despite several lines of evidence suggesting the biological plausibility of marijuana use being carcinogenic (1), it is possible that marijuana use does not increase cancer risk, as suggested in the recent commentary by Melamede (26). Although the adjusted ORs <1 may be chance findings, they were observed for all non-reference exposure categories with all outcomes except oral cancer. Although purely speculative, it is possible that such inverse associations may reflect a protective effect of marijuana. There is recent evidence from cell culture systems and animal models that 9-tetrahydrocannabinol, the principal psychoactive ingredient in marijuana, and other cannabinoids may inhibit the growth of some tumors by modulating key signaling pathways leading to growth arrest and cell death, as well as by inhibiting tumor angiogenesis (27-29). These antitumoral associations have been observed for several types of malignancies including brain, prostate, thyroid, lung, and breast."Source:Mia Hashibe, Hal Morgenstern, Yan Cui, Donald P. Tashkin, Zuo-Feng Zhang, Wendy Cozen, Thomas M. Mack, and Sander Greenland, "Marijuana Use and the Risk of Lung and Upper Aerodigestive Tract Cancers: Results of a Population-Based Case-Control Study," Cancer Epidemiology, Biomarkers & Prevention (October 2006), p. 1833.
(Cannabis and Diabetes) "In the current study, we demonstrated that chronic cannabis smokers had relative visceral adiposity and adipose tissue insulin resistance but not hepatic steatosis, glucose insulin insensitivity, impaired pancreatic b-cell function, glucose intolerance, or dyslipidemia compared with age-, sex-, ethnicity-, and BMI-matched control individuals. Our study results suggest that chronic, daily cannabis use may have differential tissue-specific effects on insulin sensitivity, but these effects appear to have minimal impact on glucose or lipid metabolism."Source:Muniyappa, Ranganath, MD, PhD, et al., "Metabolic Effects of Chronic Cannabis Smoking," Diabetes Care, e-published before print on March 25, 2013. DOI: 10.2337/dc12-2303. Clinical trial reg. no. NCT00428987, clinicaltrials.gov.
(Cannabis and Diabetes) "Our analyses of adults aged 20-59 years in the NHANES [National Health and Nutrition Examination Survey] III database showed that participants who used marijuana had lower prevalence of DM [Diabetes Mellitus] and had lower odds of DM relative to non-marijuana users. We did not find an association between the use of marijuana and other chronic diseases, such as hypertension, stroke, myocardial infarction and heart failure. This could be due to the smaller prevalence of stroke, myocardial infarction and heart failure in the examined age group.
"We noted the lowest prevalence of DM in current light marijuana users, with current heavy marijuana users and past users also having a lower prevalence of DM than non-marijuana users. The finding that past marijuana users had lower odds of prevalent DM than non-users suggests that early exposure to marijuana may affect the development of DM and a window of time of marijuana exposure earlier in life could be a factor to study. Similarly, our findings of a significant association between marijuana use and DM was only found in those aged $40 years suggest that the possibility of some protection from marijuana use may require many years before they become manifested. By contrast, it could reflect the increased prevalence of DM with age and the ability to detect an association with a lesser sample size when there is a greater cohort at risk for DM. The possible association of light marijuana use with decreased DM is similar to that of alcohol on DM and the metabolic syndrome, in which mild alcohol use was associated with lower prevalence of DM and the metabolic syndrome,14 15 and higher alcohol use associated with higher prevalence of DM and the metabolic syndrome.14 16"Source:Shaheen M, Norris KC, et al., "Decreased prevalence of diabetes in marijuana users: cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) III." BMJ Open 2012;2:e000494. doi:10.1136/bmjopen-2011-000494.
(Cannabis Use and Diet) Marijuana use is associated with higher daily caloric intake. In the NHANES III and CARDIA study, heavy cannabis users had ;20% higher calorie intake than nonusers (25,26). The increase in calories was from higher intake of all macronutrients. Specifically, the frequency and amount of consumption of soda, cheese, salty snacks, pork, and alcohol was higher in cannabis users. Consistent with other studies, the quality of diets consumed by cannabis users was poor (27). Furthermore, the percent of daily calories derived from carbohydrates relatively rich in simple sugars was significantly higher in marijuana smokers. These findings are consistent with human and animal studies demonstrating that cannabinoids stimulate food intake, specifically highly palatable sweet-tasting foods (28). Cannabis smokers in our study exhibited characteristics typically observed in marijuana smokers in the general population."Source:Muniyappa, Ranganath, MD, PhD, et al., "Metabolic Effects of Chronic Cannabis Smoking," Diabetes Care, e-published before print on March 25, 2013. DOI: 10.2337/dc12-2303. Clinical trial reg. no. NCT00428987, clinicaltrials.gov.
(Cannabis and Dependence) "People who develop problems with marijuana may indeed be different from those who do not, but this phenomenon has been observed with other substances of abuse. A comparison with alcohol use and dependence provides a case in point. The great majority of Americans have tried alcohol and continue to drink alcoholic beverages regularly. However, only an estimated 10 to 15 percent of alcohol drinkers develop problems, and only some of these problem drinkers seek treatment. This is also true of those who have tried cocaine or heroin (Anthony, Warner, and Kessler, 1994).
"That said, the experience of dependence on marijuana tends to be less severe than that observed with cocaine, opiates, and alcohol (Budney, 2006; Budney et al., 1998). On average, individuals with marijuana dependence meet fewer DSM dependence criteria; the withdrawal experience is not as dramatic; and the severity of the associated consequences is not as extreme. However, the apparently less severe nature of marijuana dependence does not necessarily mean that marijuana addiction is easier to overcome. Many factors besides a drug’s physiological effects—including availability, frequency and pattern of use, perception of harm, and cost—can contribute to cessation outcomes and the strength of addiction. The low cost of marijuana, the typical pattern of multiple daily use by those addicted, the less dramatic consequences, and ambivalence may increase the difficulty of quitting. Although determining the relative difficulty of quitting various substances of abuse is complex, the treatment literature reviewed here suggests that the experience of marijuana abusers rivals that of those addicted to other substances."Source:Budney A, Roffman R, Stephens R, Walker D. Marijuana dependence and its treatment. Addiction Science and Clinical Practice. 2007;4(1):4–16.
(Pharmacologic Treatments for Cannabis Use Disorder (CUD)) "As research on pharmacological treatments for CUD continues, a few key findings are of note. First, cannabinoid agonists (nabilone, dronabinol in combination with lofexidine, and lofexidine alone), were the only drugs that decreased drug-taking in a human laboratory model of relapse, supporting the notion that agonist replacement and attenuation of noradrenergic activity show promise for relapse prevention. Although dronabinol alone failed to clinically reduce cannabis use, a higher dose might have been more effective. Further, that study was designed to evaluate the initiation of abstinence; dronabinol or the more bioavailable agonist nabilone, might have greater utility in the prevention of relapse [25•]. These studies also support further testing of lofexidine in combination with other drugs, and generally illustrate the utility that can be gained from combining medications.
"Second, gabapentin and NAC were the only drugs tested in placebo-controlled clinical trials that decreased cannabis use (abstinence induction). Third, the ability of a drug to reduce cannabis withdrawal symptoms is not predictive of its ability to alter drug-taking behaviors (reduce use or prevent relapse). However, all the studies that reported positive changes in drug use also reported a reduction in withdrawal during early abstinence, suggesting that this feature is an important component of an efficacious medication."Source:Rebecca E. Balter, Ziva D. Cooper, and Margaret Haney, "Novel Pharmacologic Approaches to Treating Cannabis Use Disorder," Current Addiction Reports, March 1, 2014, DOI 10.1007/s40429-014-0011-1.
(Cannabis Use Disorder (CUD) Definition and Symptoms) "CUD is defined in the DSM-5 as a problematic pattern of cannabis use leading to clinically significant impairment or distress occurring within a 12-month period as manifested by cannabinoid tolerance and withdrawal; increasing amounts of cannabis use over time; inability to control consumption; craving; and recurrent cannabis use having negative implications on social, professional and educational life . Withdrawal symptoms usually appear approximately 24 hours after abstinence initiation, peak within two to six days and remit within two weeks . Symptoms may include irritability, anger or aggression; nervousness or anxiety; sleep difficulty (insomnia, disturbing dreams); decreased appetite or weight loss; restlessness; depressed mood; or physical discomforts (abdominal pain, shakiness/tremors, fever, chills or headache) [5, 6, 7•]. Withdrawal is diagnosed if at least three of these symptoms develop. A week after cessation of use, additional symptoms may appear such as fatigue, yawning, difficulty in concentration, and rebound periods of increased appetite or hypersomnia ."Source:Rebecca E. Balter, Ziva D. Cooper, and Margaret Haney, "Novel Pharmacologic Approaches to Treating Cannabis Use Disorder," Current Addiction Reports, March 1, 2014, DOI 10.1007/s40429-014-0011-1.
(Alcohol v Marijuana - Displacement Effects) "Note that there is no evidence that the 13-year decline in marijuana use observed between 1979 and 1992 led to any accompanying increase in alcohol use, as many observers suggested would happen. In fact, through 1992 there was some parallel decline in annual, monthly, and daily alcohol use, as well as in occasions of heavy drinking among 12th graders. Earlier, when marijuana use rose in the late 1970s, alcohol use moved up along with it. As marijuana use rose again in the 1990s, alcohol use again rose with it, although certainly not as sharply. In sum, there has been little evidence from MTF over the years that supports what we have termed 'the displacement hypothesis,' which asserts that an increase in marijuana use will somehow lead to a decline in alcohol use, or vice versa. Instead, both substances appear to move more in harmony, perhaps both reflecting changes in a more general construct, such as the tendency to use psychoactive substances, whether licit or illicit, or the frequency with which teens “party” or not. However, with alcohol use decreasing and marijuana use increasing over the past few years, it is possible that the displacement hypothesis is gaining support, highlighting the reality of historical change in types as well as causes of substance use. Our continued monitoring will provide the needed evidence about the displacement hypothesis in this current historical period."Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E., Monitoring the Future national survey results on drug use, 1975–2011: Volume I, Secondary school students," Institute for Social Research (Ann Arbor, Michigan: The University of Michigan, 2012), p. 159.
(Smoking Behavior and Potential for Developing Dependence on Cannabis) "Differences in cannabis smoking behaviour may also represent different risks for cannabis dependence independently of total THC exposure. Similar to cigarette smokers [16,21–24], cannabis smokers typically gradually decrease the puff volume and puff duration during the course of one joint, whereas puff velocity and interpuff interval gradually increase . Interestingly, in a 2-year prospective study, nicotine dependence has been shown to develop more rapidly in tobacco smokers who smoke with stable or increasing puff volume and increasing puff duration ('atypical' smoking) . One interpretation of this finding is that the risk of becoming nicotine-dependent is lower in smokers who reach nicotine saturation before the cigarette is finished and decrease their pace of smoking. If this mechanism also applies to cannabis smoking, one may expect that the risk for and the severity of cannabis dependence is associated with 'atypical' cannabis smoking."Source:Peggy van der Pol, Nienke Liebregts, Tibor Brunt, Jan van Amsterdam, Ron de Graaf, Dirk J. Korf, Wim van den Brink & Margriet van Laar, "Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: an ecological study," Addiction, March 16, 2014, doi:10.1111/add.12508.
(Medical Cannabis Patients and Other Drug Use) "Analysis of the demographic and social characteristics of a large sample of applicants seeking approval to use marijuana medically in California supports an interpretation of long term non problematic use by many who had first tried it as adolescents, and then either continued to use it or later resumed its use as adults. In general, they have used it at modest levels and in consistent patterns which anecdotally-often assisted their educational achievement, employment performance, and establishment of a more stable life-style. These data suggest that rather than acting as a gateway to other drugs, (which many had also tried), cannabis has been exerting a beneficial influence on most."Source:Thomas J O'Connell and Ché B Bou-Matar, "Long term marijuana users seeking medical cannabis in California (2001–2007): demographics, social characteristics, patterns of cannabis and other drug use of 4117 applicants," Harm Reduction Journal, (November 2007).
(High-Potency Cannabis and Potential For Developing Dependence) "This study among 98 experienced cannabis smokers is the first naturalistic study to examine whether users of cannabis with high THC concentration titrate the psychoactive effects by using lower doses and/or by reduced inhalation, and whether cannabis smoking behaviour (topography) predicts cannabis dependence severity independently of total THC exposure.
"In contrast to our hypothesis, there was a positive association between cannabis THC concentration and cannabis dose, indicating that users of stronger cannabis generally used larger amounts of cannabis to prepare their regular joint. However, in line with our hypothesis, the negative association between THC concentration of joints and total inhaled smoke volume indicates that users of stronger joints inhaled smaller smoke volumes, thus resulting in partial titration of the total THC exposure. Overall, as exemplified by the comparison of the average user with the user with the maximum THC concentration, users of high-potency cannabis will generally be exposed to higher total doses of THC (at least in this sample). This is in line with Cappell et al.’s observations through a one-way mirror experiment in 1973 where users only partly adapted their intake . Indeed, increased THC concentrations of cannabis have recently been linked to increased internal THC exposure assessed in blood ."Source:Peggy van der Pol, Nienke Liebregts, Tibor Brunt, Jan van Amsterdam, Ron de Graaf, Dirk J. Korf, Wim van den Brink & Margriet van Laar, "Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: an ecological study," Addiction, March 16, 2014, doi:10.1111/add.12508.
(High-Potency Cannabis and Titration of Dosage Among Experienced Users) "Although experienced young adult cannabis users with a preference for stronger joints titrated their THC exposure to some extent by inhaling less smoke, in general more potent cannabis was used in higher dosages leading to a higher THC exposure compared to users preferring lower potency cannabis. None the less, in our population of frequent cannabis users, total THC exposure was only a weak predictor of dependence severity, and did not remain significant after adjustment for baseline dependence severity. However, cannabis smoking behaviours predicted cannabis dependence severity independently of baseline THC exposure and baseline cannabis dependence severity. As the amount of explained variance was low, due possibly to the multifactorial aetiology of dependence, future studies should include other predictors, such as genetic variations, early traumatic experiences and — most importantly — time-dependent variables representing the dynamic nature of personal and dependence development. Meanwhile, smoking variables, such as smoking topography and completely finishing high-dose/high-potent joints in one smoking session, may be helpful to identify people at risk of escalating cannabis dependence severity."Source:Peggy van der Pol, Nienke Liebregts, Tibor Brunt, Jan van Amsterdam, Ron de Graaf, Dirk J. Korf, Wim van den Brink & Margriet van Laar, "Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: an ecological study," Addiction, March 16, 2014, doi:10.1111/add.12508.
(Cannabinoid Withdrawal) "The withdrawal syndrome associated with dronabinol, the API [Active Pharmaceutical Ingredient] in Marinol®, produces symptoms in humans such as restlessness, irritability, mild agitation, anxiety, anger, insomnia, sleep EEG disturbances, nausea, decreased appetite, and decreased weight. Since a withdrawal syndrome is indicative of physical dependence, it is reasonable to conclude that generic dronabinol products (both naturally-derived [from the cannabis plant] or synthetically produced, and in hard or soft gelatin capsules) in sesame oil, will also produce physical dependence similar to those produced by Marinol®."Source:Federal Register, "Listing of Approved Drug Products Containing Dronabinol in Schedule III," Vol. 75, No. 210, Monday, November 1, 2010, pp. 67054 to 67059.
"MARINOL® (dronabinol) Capsules," (Abbott Laboratories: Abbott Park, IL, July 2006), pp. 11.
(Marinol Withdrawal) "An abstinence syndrome has been reported after the abrupt discontinuation of dronabinol [Marinol®] in volunteers receiving dosages of 210 mg/day for 12 to 16 consecutive days. Within 12 hours after discontinuation, these volunteers manifested symptoms such as irritability, insomnia, and restlessness. By approximately 24 hours post-dronabinol discontinuation, withdrawal symptoms intensified to include 'hot flashes', sweating, rhinorrhea, loose stools, hiccoughs and anorexia.
"These withdrawal symptoms gradually dissipated over the next 48 hours. Electroencephalographic changes consistent with the effects of drug withdrawal (hyperexcitation) were recorded in patients after abrupt dechallenge. Patients also complained of disturbed sleep for several weeks after discontinuing therapy with high dosages of dronabinol."
(Marijuana Use as a Gateway to Other Drug Use) "There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other illicit drugs."Source:Janet E. Joy, Stanley J. Watson, Jr., and John A Benson, Jr., "Marijuana and Medicine: Assessing the Science Base," Division of Neuroscience and Behavioral Research, Institute of Medicine (Washington, DC: National Academy Press, 1999), p. 6.
(Patterns in Progression of Drug Use) "Patterns in progression of drug use from adolescence to adulthood are strikingly regular. Because it is the most widely used illicit drug, marijuana is predictably the first illicit drug most people encounter. Not surprisingly, most users of other illicit drugs have used marijuana first. In fact, most drug users begin with alcohol and nicotine before marijuana, usually before they are of legal age."Source:Janet E. Joy, Stanley J. Watson, Jr., and John A Benson, Jr., "Marijuana and Medicine: Assessing the Science Base," Division of Neuroscience and Behavioral Research, Institute of Medicine (Washington, DC: National Academy Press, 1999), p. 99.
(IQ Decline Among Adolescent-Onset Marijuana Users) "In the present study, the most persistent adolescent-onset cannabis users evidenced an average 8-point IQ decline from childhood to adulthood. Quitting, however, may have beneficial effects, preventing additional impairment for adolescent-onset users. Prevention and policy efforts should focus on delivering to the public the message that cannabis use during adolescence can have harmful effects on neuropsychological functioning, delaying the onset of cannabis use at least until adulthood, and encouraging cessation of cannabis use particularly for those who began using cannabis in adolescence."Source:Madeline H. Meier, Avshalom Caspi, Antony Ambler, HonaLee Harrington, Renate Houts, Richard S. E. Keefe, Kay McDonald, Aimee Ward, Richie Poulton, and Terrie E. Moffitt, "Persistent Cannabis Users Show Neuropsychological Decline from Childhood to Midlife, Proceedings of the National Academy of Sciences, www.pnas.org/cgi/doi/10.1073/pnas.1206820109, 2012, p. 6.
(Marijuana Use and IQ) "Although the heavy current users experienced a decrease in IQ score, their scores were still above average at the young adult assessment (mean 105.1). If we had not assessed preteen IQ, these subjects would have appeared to be functioning normally. Only with knowledge of the change in IQ score does the negative impact of current heavy use become apparent."Source:Fried, Peter, Barbara Watkinson, Deborah James, and Robert Gray, "Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults," Canadian Medical Association Journal, April 2, 2002, 166(7), p. 890.
(Cannabis and Cognition) "The results of our meta-analytic study failed to reveal a substantial, systematic effect of long-term, regular cannabis consumption on the neurocognitive functioning of users who were not acutely intoxicated. For six of the eight neurocognitive ability areas that were surveyed. the confidence intervals for the average effect sizes across studies overlapped zero in each instance, indicating that the effect size could not be distinguished from zero. The two exceptions were in the domains of learning and forgetting."Source:Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, p. 685.
(Marijuana Use and Cognition) "In conclusion, our meta-analysis of studies that have attempted to address the question of longer term neurocognitive disturbance in moderate and heavy cannabis users has failed to demonstrate a substantial, systematic, and detrimental effect of cannabis use on neuropsychological performance. It was surprising to find such few and small effects given that most of the potential biases inherent in our analyses actually increased the likelihood of finding a cannabis effect."Source:Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, p. 687.
(Cognitive Deficit Among Adolescent-Onset Marijuana Users) "Our findings suggest that regular cannabis use before age 18 y predicts impairment, but others have found effects only for younger ages (10, 15). Given that the brain undergoes dynamic changes from the onset of puberty through early adulthood (37, 38), this developmental period should be the focus of future research on the age(s) at which harm occurs."Source:Madeline H. Meier, Avshalom Caspi, Antony Ambler, HonaLee Harrington, Renate Houts, Richard S. E. Keefe, Kay McDonald, Aimee Ward, Richie Poulton, and Terrie E. Moffitt, "Persistent Cannabis Users Show Neuropsychological Decline from Childhood to Midlife, Proceedings of the National Academy of Sciences, www.pnas.org/cgi/doi/10.1073/pnas.1206820109, 2012, p. 1.
(Cannabis and Memory) "Nevertheless, when considering all 15 studies (i.e., those that met both strict and more relaxed criteria) we only noted that regular cannabis users performed worse on memory tests, but that the magnitude of the effect was very small. The small magnitude of effect sizes from observations of chronic users of cannabis suggests that cannabis compounds, if found to have therapeutic value, should have a good margin of safety from a neurocognitive standpoint under the more limited conditions of exposure that would likely obtain in a medical setting."Source:Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, pp. 687-8.
(Marijuana Use and Cognition) "Current marijuana use had a negative effect on global IQ score only in subjects who smoked 5 or more joints per week. A negative effect was not observed among subjects who had previously been heavy users but were no longer using the substance. We conclude that marijuana does not have a long-term negative impact on global intelligence. Whether the absence of a residual marijuana effect would also be evident in more specific cognitive domains such as memory and attention remains to be ascertained."Source:Fried, Peter, Barbara Watkinson, Deborah James, and Robert Gray, "Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults," Canadian Medical Association Journal, April 2, 2002, 166(7), p. 887.
(Marijuana Use and Cognition) "Other studies have found short term residual effects of cannabis use on memory and cognition (34, 35) that are more severe among women (36) and heavy users (37). However, our data suggest that over the long term cannabis use is not associated with greater declines in cognition among men, women, or heavy users. The study design we used included several of the features proposed by Pope et al. (34) as critical to addressing the long term effects of cannabis on cognition: naturalistic follow-up, a large sample size, a population basis, comparison of light cannabis use with heavy use, and the construction of models accounting for the effects of gender and use of illicit drugs, alcohol, and tobacco. Therefore, these results would seem to provide strong evidence of the absence of a long term residual effect of cannabis use on cognition."Source:Constantine G. Lyketsos, Elizabeth Garrett, Kung-Yee Liang, and James C. Anthony. (1999). "Cannabis Use and Cognitive Decline in Persons under 65 Years of Age," American Journal of Epidemiology, Vol. 149, No. 9.
(Marijuana Use and Memory) "These results can be interpreted in several ways. A statistically reliable negative effect was observed in the domain of learning and forgetting, suggesting that chronic long-term cannabis use results in a selective memory defect. While the results are compatible with this conclusion, the effect size for both domains was of a very small magnitude. The "real life" impact of such a small and selective effect is questionable. In addition, it is important to note that most users across studies had histories of heavy longterm cannabis consumption. Therefore, these findings are not likely to generalize to more limited administration of cannabis compounds, as would be seen in a medical setting."Source:Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, p. 686.
(Psychological Effects of Cannabis Compared With Exercise) "The [endo] cannabinoids produce psychological states that closely parallel several experiences described as being related to the runner’s high. Compared with the opioid analgesics, the analgesia produced by the endocannabinoid system is more consistent with exercise induced analgesia. Activation of the endocannabinoid system also produces sedation, anxiolysis, a sense of wellbeing, reduced attentional capacity, impaired working memory ability, and difficulty in time estimation. This behavioural profile is similar to the psychological experiences reported by long distance runners."Source:Dietrich, A and McDaniel, W, "Endocannabinoids and exercise," British Journal of Sports Medicine (Middlesex, United Kingdom: British Association of Sport and Exercise Medicine, October 2004), Volume 38, pp. 539-540.
(Marijuana Use and "Amotivational Syndrome") "One of the major concerns about the psychological effects of chronic heavy cannabis use has been that it impairs adult motivation. The evidence for an 'amotivational syndrome' among adults consists largely of case histories and observational reports (e.g. Kolansky and Moore, 1971; Millman and Sbriglio, 1986). The small number of controlled field and laboratory studies have not found compelling evidence for such a syndrome (Dornbush, 1974; Negrete, 1983; Hollister, 1986). The evidential value of the field studies is limited by their small sample sizes, and the limited sociodemographic characteristics of their samples, while the evidential value of the laboratory studies is limited by the short periods of drug use, the youthful good health of the volunteers, and minimal demands made on volunteers in the laboratory (Cohen, 1982). Some regular cannabis users report a loss of ambition and impaired school and occupational performance as adverse effects of their use (e.g. Hendin et al, 1987) and that some ex-cannabis users give impaired occupational performance as a reason for stopping (Jones, 1984). Nonetheless, it is doubtful that cannabis use produces a well defined amotivational syndrome. It may be more parsimonious to regard the symptoms of impaired motivation as symptoms of chronic cannabis intoxication rather than inventing a new psychiatric syndrome."Source:Hall, W., Room, R. & Bondy, S., WHO Project on Health Implications of Cannabis Use: A Comparative Appraisal of the Health and Psychological Consequences of Alcohol, Cannabis, Nicotine and Opiate Use, August 28, 1995 (Geneva, Switzerland: World Health Organization, March 1998).
(Overall Psychological Safety of Cannabis) "A review of the literature suggests that the majority of cannabis users, who use the drug occasionally rather than on a daily basis, will not suffer any lasting physical or mental harm. Conversely, as with other 'recreational' drugs, there will be some who suffer adverse consequences from their use of cannabis. Some individuals who have psychotic thought tendencies might risk precipitating psychotic illness. Those who consume large doses of the drug on a regular basis are likely to have lower educational achievement and lower income, and may suffer physical damage to the airways. They also run a significant risk of becoming dependent upon continuing use of the drug. There is little evidence, however, that these adverse effects persist after drug use stops or that any direct cause and effect relationships are involved."
(Cannabis and Psychotic Experiences) "This 10 year follow-up study showed that incident cannabis use significantly increased the risk of incident psychotic experiences. The association was independent of age, sex, socioeconomic status, use of other drugs, urban/rural environment, and childhood trauma; additional adjustment for other psychiatric diagnoses similarly did not change the results. There was no evidence for self medication effects as psychotic experiences did not predict later cannabis use. The results thus help to clarify the temporal association between cannabis use and psychotic experiences by systematically addressing the issue of reverse causality, given that the long follow-up period allowed exclusion of all individuals with pre-existing psychotic experiences or pre-existing cannabis use. In addition, cannabis use was confirmed as an environmental risk factor impacting on the risk of persistence of psychotic experiences (fig 3)."Source:Keupper, Rebecca, van Os, Jim, et al., "Continued Cannabis Use and Risk of Incidence and Persistence of Psychotic Symptoms: 10-Year Follow-Up Cohort Study, British Medical Journal, 2011;342:d738 doi:10.1136/bmj.d738
(Cannabis and Diagnoses of Schizophrenia and Psychoses) "In terms of the model set out in the Introduction, the expected rise in diagnoses of schizophrenia and psychoses did not occur over a 10 year period. This study does not therefore support the specific causal link between cannabis use and the incidence of psychotic disorders based on the 3 assumptions described in the Introduction. This concurs with other reports indicating that increases in population cannabis use have not been followed by increases in psychotic incidence (Macleod et al., 2006; Arsenault et al., 2004; Rey and Tennant, 2002). However, it is not in line with findings of a rise in first admission rates for psychotic disorders among young people in Zurich following increases in cannabis availability and consumption (Ajdacic-Gross et al., 2007). One factor involved in this discrepancy may be the potency of the cannabis consumed, which varies considerably within Europe (EMCDDA, 2008). In addition, a Netherlands study found that high-potency cannabis obtained from ‘coffee shops’ led to higher levels of tetrahydrocannabinol (THC) in the blood, with young males aged 18–45 at particular risk for excessive consumption (Mensinga et al., 2006)."Source:Frisher, Martin; Crome, Ilana; Orsolina, Martino; and Croft, Peter, "Assessing the impact of cannabis use on trends in diagnosed schizophrenia in the United Kingdom from 1996 to 2005," Schizophrenia Research (Nashville, Tennessee: Schizophrenia International Research Society, September 2009) Vol. 113, Issue 2, p. 126.
(Cannabis and Psychosis) "Although individual lifetime risk of chronic psychotic disorders such as schizophrenia, even in people who use cannabis regularly, is likely to be low (less than 3%), cannabis use can be expected to have a substantial effect on psychotic disorders at a population level because exposure to this drug is so common."Source:Moore, Theresa H M; Zammit, Stanley; Lingford-Hughes, Anne; Barnes, Thomas R E; Jones, Peter B; Burke, Margaret; Lewis, Glyn, "Cannabis use and risk of psychotic or aff ective mental health outcomes: a systematic review," The Lancet (London, United Kingdom: July 28, 2007) Vol 370, p. 327.
(Cannabis and Psychosis) "First, the use of cannabis and rates of psychotic symptoms were related to each other, independently of observed/non-observed fixed covariates and observed time dynamic factors (Table 2). Secondly, the results of structural equation modeling suggest that the direction of causation is that the use of cannabis leads to increases in levels of psychotic symptoms rather than psychotic symptoms increasing the use of cannabis. Indeed, there is a suggestion from the model results that increases in psychotic symptoms may inhibit the use of cannabis."Source:Fergusson, David M., John Horwood & Elizabeth M. Ridder, "Tests of Causal Linkages Between Cannabis Use and Psychotic Symptoms," Addiction, Vol. 100, No. 3, March 2005, p. 363.
(Cannabis and Psychosis) "The lead researcher in the Christchurch study, Professor David Fergusson, said the role of cannabis in psychosis was not sufficient on its own to guide legislation. 'The result suggests heavy use can result in adverse side-effects,' he said. 'That can occur with ( heavy use of ) any substance. It can occur with milk.' Fergusson's research, released this month, concluded that heavy cannabis smokers were 1.5 times more likely to suffer symptoms of psychosis that non-users. The study was the latest in several reports based on a cohort of about 1000 people born in Christchurch over a four-month period in 1977. An effective way to deal with cannabis use would be to incrementally reduce penalties and carefully evaluate its impact, Fergusson said. 'Reduce the penalty, like a parking fine. You could then monitor ( the impact ) after five or six years. If it did not change, you might want to take another step.'Source:Bleakley, Louise, "NZ Study Used in UK Drug Review," The Press (Christchurch, New Zealand: March 22, 2005), from the web at http://www.mapinc.org/newscsdp/v05/n490/a08.html, last accessed October 3, 2011.
(Marijuana Use and Violent Behavior) "Laboratory studies also find no link between THC intoxication and violence. Most people who ingest THC before performing a competitive task in the laboratory do not show more aggression than people who receive placebos; occasionally they show decreased hostility. Numerous scientific panels sponsored by various governments invariably report that marijuana does not lead to violence.(751)"Source:Carter, Gregory T.; Earleywine, Mitchell; McGill, Jason T., "Exhibit B: Statement of Grounds," Rulemaking petition to reclassify cannabis for medical use from a Schedule I controlled substance to a Schedule II (Office of Lincoln D. Chafee, Governor Rhode Island and Office of Christine O. Gregoire, Governor of Washington: Letter to Michelle Leonhard, Administrator of the Drug Enforcement Administration, November 30, 2011), p. 38.
Young People and Marijuana
(Vulnerability of Teens to Effects of Drugs) "The teen brain is a work in progress, making it more vulnerable than the mature brain to the physical effects of drugs. The potential for developing substance abuse and dependence is substantially greater when an individual’s first exposure to alcohol, nicotine and illicit drugs occurs during adolescence than in adulthood."Source:Steinberg, L., Distinguished University Professor and Laura H. Carnell Professor of Psychology, Department of Psychology, Temple University and author of You and Your Adolescent: The Essential guide for ages 10 to 25 (personal communication, June 9, 2011), as quoted in "Adolescent Substance Use: America’s #1 Public Health Problem," The National Center on Addiction and Substance Abuse at Columbia University (New York, NY: National Center on Addiction and Substance Abuse at Columbia University, June 2011), p. 13.
(Early Use of Marijuana) "The younger and more often teens use marijuana, the more likely they are to engage in other substance use and the higher their risk of developing a substance use disorder. Among high school students, 7.5 percent used marijuana for the first time before the age of 13. CASA’s analysis of national data finds that the average age of initiation of marijuana use among high school students is 14.3 years old. Compared to those who began using marijuana after age 21, those who first used it before age 15 are:
More likely to have ever smoked a cigarette (93.3 percent vs. 86.4 percent);
More than twice as likely to have ever misused controlled prescription drugs (56.5 percent vs. 22.9 percent); and
Two and a half times as likely to have ever used other illicit drugs (70.2 percent vs. 27.8 percent)."Source:"Adolescent Substance Abuse: America's #1 Public Health Problem," National Center on Addiction and Substance Abuse at Columbia University, June 2011, p. 27.
(Prevalence and Perceived Risk of Marijuana Use) "Marijuana use, which had been rising among teens for the past four years, continued to rise in 2011 in all prevalence periods for 10th and 12th graders; but in 2012 these increases halted. The recent rise in use stood in stark contrast to the long, gradual decline that had been occurring over the preceding decade. (Although use among 8th graders had been rising, annual prevalence decreased after 2010.) It is relevant that perceived risk for marijuana has been falling for the past six years, and disapproval declined for the past three to four years. These changes would normally portend a further increase in use."Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2013). Monitoring the Future national results on adolescent drug use: Overview of key findings, 2012. Ann Arbor: Institute for Social Research, The University of Michigan, p. 5.
(Marijuana Use vs. Tobacco Use) "High school students are more likely to use marijuana than to smoke cigarettes. High school students are:
" More likely to have tried marijuana than tobacco (24 percent vs. 15 percent); and
" More likely to say their close friends use marijuana than smoke cigarettes (51 percent vs. 39 percent)."Source:QEV Analytics, LTD., "National Survey of American Attitudes on Substance Abuse XVII: Teens," The National Center on Addiction and Substance Abuse at Columbia University (New York, NY: National Center on Addiction and Substance Abuse at Columbia University, August 2012), p. 30.
(Marijuana Use by Peers and Perception of Harm) "Teens also say they are seeing more peers in school smoking marijuana and more teens (73 percent) report having friends who smoke marijuana regularly (71 percent) – significantly higher than four years ago. Since 2008, there have also been significant declines in teen perceptions that they will lose respect, harm themselves, or mess up their lives if they use marijuana."Source:"The Partnership Attitude Tracking Study: 2011 Parents and Teens Full Report," MetLife Foundation and The Partnership at Drugfree.org (New York, NY: May 2, 2012), p. 7.
(12th Graders and Attitudes Toward Legalizing Marijuana) "Despite the fact that many 12th graders in 2011 reported ever having used marijuana themselves (46%), and many do not judge it to be as dangerous as other drugs, nearly two-thirds (64%) favor legally prohibiting marijuana use in public places. Only about one-third (34%) favor prohibiting marijuana use in private, however."
Note: Only 34% of 12th graders favored prohibiting marijuana use in private, and 39.2% agreed that using marijuana should be entirely legal.Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E., Monitoring the Future national survey results on drug use, 1975–2011: Volume I, Secondary school students," Institute for Social Research (Ann Arbor, Michigan: The University of Michigan, 2012), p. 377 and Table 8-8, p. 393.
(Disapproval of Marijuana Use Among Youth in the US) "The proportion of students seeing great risk from using marijuana regularly fell during the rise in use in the 1970s, and again during the subsequent rise in the 1990s. Indeed, at 10th and 12th grades, perceived risk declined a year before use rose in the upturn of the 1990s, making perceived risk a leading indicator of change in use. (The same may have happened at 8th grade as well, but we lack data starting early enough to know.) The decline in perceived risk halted in 1996 in 8th and 10th grades; the increases in use ended a year or two later, again making perceived risk a leading indicator. From 1996 to 2000, perceived risk held fairly steady and the decline in use in the upper grades stalled. After some decline prior to 2002, perceived risk increased in all grades through 2004 as use decreased. Perceived risk fell after 2004 and 2005 in 8th and 12th grades respectively, (and since 2008 in 10th grade) presaging the more recent increase in use. In 2011 perceived risk continued to decline in grades 10 and 12 and leveled in grade 8."Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2012). Monitoring the Future national results on adolescent drug use: Overview of key findings, 2011. Ann Arbor: Institute for Social Research, The University of Michigan, p. 12.
(Support for Legalized Sale of Marijuana in the US Among Youth, 2011) "Asked whether they thought it should be legal to sell marijuana if it were legal to use it, about three in five (62%) said 'yes.' However, about 80% of those answering 'yes' (51% of all respondents) would permit sale only to adults. A small minority (11%) favored the sale to anyone, regardless of age, while 28% said that sale should not be legal even if use were made legal, and 10% said they 'don’t know.'"Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E., Monitoring the Future national survey results on drug use, 1975–2011: Volume I, Secondary school students," Institute for Social Research (Ann Arbor, Michigan: The University of Michigan, 2012), p. 379.
(Adolescent Motivation) "The apparent strength of these relationships in cross-sectional studies (e.g. Kandel, 1984) has been exaggerated because those adolescents who are most likely to use cannabis have lower academic aspirations and poorer high school performance prior to using cannabis than their peers who do not (Newcombe and Bentler, 1988). It remains possible that factors other than the marijuana use account for apparent causal relations. To the extent they may exist, these adverse effects of cannabis and other drug use upon development over and above the effect of pre-existing nonconformity may cascade throughout young adult life, affecting choice of occupation, level of income, choice of mate, and the quality of life of the user and his or her children."Source:Hall, W., Room, R., & Bondy, S., WHO Project on Health Implications of Cannabis Use: A Comparative Appraisal of the Health and Psychological Consequences of Alcohol, Cannabis, Nicotine and Opiate Use August 28, 1995 (Geneva, Switzerland: World Health Organization, 1998).
Other Specific Research Findings on Cannabis and Driving
(Thresholds for Serum THC Level Compared With Blood Alcohol Content) "Risk thresholds could be formulated only for THC which was the most prevalent illicit drug in the general driving population and in injured/killed drivers. The prevalence of THC across all countries that participated in DRUID is 1.37%. This is about one third of the alcohol prevalence. The epidemiological, the experimental and the meta-analytical approaches result in rather low risk estimations. Epidemiological case-control studies assess at maximum a 2.4-fold risk for injury, experimental studies and meta-analysis rank the risk between 0.5 and 2 times than that of sober driving. So THC seems to be much less impairing and risky than most of the other examined substances. Although a relationship between THC concentration and accident risk was found in the epidemiological studies, it was only possible to set an exact THC cut-off by a meta-analysis of experimental studies. Thereby it was found that the serum concentration of 3.8ng/mL THC (≈2ng/mL in whole blood) causes the same amount of impairment as 0.5g/L alcohol. This value could be an empirical basis for a threshold discussion. The meta-analysis could also be used to define limits comparable to lower BAC levels."Source:Schulze, Horst, et al., "DRUID (Driving under the Influence of Drugs, Alcohol and Medicines) Final Report: Work performed, main results and recommendations," Project Funded by the European Commission under the Transport RTD Programme of the 6th Framework Program, Project No: TREN-05-FP6TR-S07.61320-518404-DRUID (Federal Highway Research Institute, Germany, Aug. 1, 2012), p. 84.
(Marijuana, Alcohol, and Driving) "As with cannabis, alcohol use increased variability in lane position and headway (Casswell, 1979; Ramaekers et al., 2000; Smiley et al., 1981; Stein et al., 1983) but caused faster speeds (Casswell, 1977; Krueger & Vollrath, 2000; Peck et al., 1986; Smiley et al., 1987; Stein et al., 1983). Some studies also showed that alcohol use alone and in combination with cannabis affected visual search behavior (Lamers & Ramaekers, 2001; Moskowitz, Ziedman, & Sharma, 1976). Alcohol consumption combined with cannabis use also worsened driver performance relative to use of either substance alone. Lane position and headway variability were more exaggerated (Attwood et al., 1981; Ramaekers et al., 2000; Robbe, 1998) and speeds were faster (Peck et al., 1986).
"Both simulator and road studies showed that relative to alcohol use alone, participants who used cannabis alone or in combination with alcohol were more aware of their intoxication. Robbe (1998) found that participants who consumed 100 g/kg of cannabis rated their performance worse and the amount of effort required greater compared to those who consumed alcohol (0.05 BAC). Ramaekers et al. (2000) showed that cannabis use alone and in combination with alcohol consumption increased self-ratings of intoxication and decreased self-ratings of performance. Lamers and Ramaekers (2001) found that cannabis use alone (100 g/kg) and in combination with alcohol consumption resulted in lower ratings of alertness, greater perceptions of effort, and worse ratings of performance."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues, Dec. 2004, pp. 978.
(Cannabis Use and Motor Vehicle Accident Risk) "Our primary analysis looked at the risk of a motor vehicle collision while under the influence of cannabis and included all nine studies (relating to 49 411 participants). The pooled risk of a motor vehicle collision while driving under the influence of cannabis was almost twice the risk while driving unimpaired (odds ratio 1.92 (95% confidence interval 1.35 to 2.73); P=0.0003); we noted heterogeneity among the individual study effects (I2=81%).
"We also assessed culpability and non-culpability studies separately and explored differences between motor vehicle collisions resulting in deaths and non-fatal injuries. Meta-analyses on subgroups of studies explored the potential effect of specific features related to study design and potential biases: case-control studies versus culpability studies, fatal collisions versus non-fatal collisions, and high quality studies versus medium quality studies (fig 3⇓).
"High quality studies had a pooled odds ratio that was higher than that for medium quality studies, although both results showed a significant association at the 0.05 level. Furthermore, case-control studies (2.79 (1.23 to 6.33); P=0.01) estimated the effect of cannabis use on crash risk to be higher than that estimated by culpability studies (1.65 (1.11 to 2.46); P=0.07). Studies of fatal collisions (2.10 (1.31 to 3.36); P=0.002) had a pooled odds ratio that was statistically significant, but studies of non-fatal collisions (1.74 (0.88 to 3.46); P=0.11) did not show significant results.
"In all studies assessing cannabis use in conjunction with alcohol, the estimated odds ratio for cannabis and alcohol combined was higher than for cannabis use alone, suggesting the presence of a synergistic effect."Source:Asbridge, Mark, et al., "Acute Cannabis Consumption and Motor Vehicle Collision Risk: Systematic Review of Observational Studies and Meta-analysis," British Medical Journal, 2012;344:e536 doi: 10.1136/bmj.e536 (Published 9 February 2012).
(Estimated Prevalence Of Substance Use Among Drivers In Fatal Auto Accidents) "Overall, 23,591 (90.9%) of the 25,951 drivers who died within 1 hour of a crash in these 6 states underwent toxicological testing. Drivers who were tested for drugs were similar in crash circumstances to those who were not tested, but they appeared to be slightly younger (mean age = 39.4 (standard deviation, 19.4) years vs. 43.4 (standard deviation, 27.7) years), more likely to be male (77.7% vs. 75.8%), more likely to be involved in nighttime crashes (51.4% vs. 47.0%), and more likely to have been involved in a crash in the previous 3 years (15.7% vs. 13.9%) than those who were not tested.
"Of the 23,591 drivers tested, 39.7% were positive for alcohol, and 24.8% tested positive for other drugs. The prevalence of alcohol involvement was stable at approximately 39% from 1999 to 2010 (Z = −1.4, P = 0.16). Alcohol involvement was more prevalent in men (43.6%) than in women (26.1%), but trends were stable for both sexes (Table 1). In contrast, the prevalence of nonalcohol drugs showed a statistically significant increasing trend over the study period, rising from 16.6% (95% confidence interval (CI): 14.8, 18.4) in 1999 to 28.3% (95% CI: 26.0, 30.7) in 2010 (Z = −10.19, P < 0.0001). The prevalence rates of non-alcohol drugs and 2 or more nonalcohol drugs increased significantly over the study period in both sexes (Table 1). The prevalence of nonalcohol drug use increased significantly across all age groups (Figure 1)."Source:Joanne E. Brady and Guohua Li. "Trends in Alcohol and Other Drugs Detected in Fatally Injured Drivers in the United States, 1999–2010." American Journal of Epidemiology. (2014) 179 (6): 692-699. doi: 10.1093/aje/kwt327.
(Cannabis Use, Alcohol Use, Smartphone Use, and Accident Risk) "Although for the mobile phone conversation and cannabis studies the reaction times were slightly different, they were still comparable. The same visual stimulus was used and was presented in the same visual scene. When reaction times under each condition were compared with the baseline reaction times measured, alcohol gave a 12.5% increase in reaction times, cannabis a 21% increase, a hands-free mobile phone conversation increased reaction times by 26.5%, texting by 37.4%, using a smartphone for social networking by 37.6% and using a mobile phone for a hand-held mobile phone conversation increased reaction times by 45.9% compared to the baseline condition. Thus, using a smartphone for social networking resulted in a greater impairment to reaction times than alcohol, cannabis, hand held mobile phone conversations and texting, but less than a hand held mobile conversation."Source:Basacik, D.; Reed N. & Robbins, R., "Smartphone use while driving: A simulator study," Institute of Advanced Motorists (London, United Kingdom: Transport Research Laboratory, 2011), pp. 37-38.
(Times for THC Absorption, Bioavailability, and Excretion) "Absorption is slower following the oral route of administration with lower, more delayed peak THC levels. Bioavailability is reduced following oral ingestion due to extensive first pass metabolism. Smoking marijuana results in rapid absorption with peak THC plasma concentrations occurring prior to the end of smoking. Concentrations vary depending on the potency of marijuana and the manner in which the drug is smoked, however, peak plasma concentrations of 100-200 ng/mL are routinely encountered. Plasma THC concentrations generally fall below 5 ng/mL less than 3 hours after smoking. THC is highly lipid soluble, and plasma and urinary elimination half-lives are best estimated at 3-4 days, where the rate-limiting step is the slow redistribution to plasma of THC sequestered in the tissues. Shorter half-lives are generally reported due to limited collection intervals and less sensitive analytical methods. Plasma THC concentrations in occasional users rapidly fall below limits of quantitation within 8 to 12 h. THC is rapidly and extensively metabolized with very little THC being excreted unchanged from the body. THC is primarily metabolized to 11-hydroxy-THC which has equipotent psychoactivity. The 11-hydroxy-THC is then rapidly metabolized to the 11-nor-9-carboxy-THC (THC-COOH) which is not psychoactive. A majority of THC is excreted via the feces (~65%) with approximately 30% of the THC being eliminated in the urine as conjugated glucuronic acids and free THC hydroxylated metabolites."Source:Couper, Fiona J., Logan, Barry K., et al., "Drugs and Human Performance Fact Sheets," (Washington, DC: National Highway Traffic Safety Administration, April 2004), p. 8.
http://www.nhtsa.gov/People/injury/research/job185drugs/cannabis.htm, last accessed April 12, 2014.
(Cannabis Use and Motor Vehicle Accident Risk) "We found only limited evidence to support the claim that cannabis use increases accident risk. Participants who had driven under the influence of cannabis in the previous year appeared to be no more likely than drug-free drivers to report that they had had an accident in the previous 12 months. Prima facie, this would seem to suggest that cannabis-intoxicated driving is not a risk factor for non-fatal accidents. In this sense, the results would support those of Longo et al. (2000b) who found no relationship between recent cannabis use and driver culpability for non-fatal accidents."Source:Jones, Craig; Donnelly, Neil; Swift, Wendy; Weatherburn, Don, "Driving under the influence of cannabis: The problem and potential countermeasures," Crime and Justice Bulletin, NSW Bureau of Crime Statistics and Research (Syndey, Australia: September 2005). p. 11.
(THC and Cannabis Dosages) "THC is the major psychoactive constituent of cannabis. Potency is dependent on THC concentration and is usually expressed as %THC per dry weight of material. Average THC concentration in marijuana is 1-5%, hashish 5-15%, and hashish oil ³ 20%. The form of marijuana known as sinsemilla is derived from the unpollinated female cannabis plant and is preferred for its high THC content (up to 17% THC). Recreational doses are highly variable and users often titer their own dose. A single intake of smoke from a pipe or joint is called a hit (approximately 1/20th of a gram). The lower the potency or THC content the more hits are needed to achieve the desired effects; 1-3 hits of high potency sinsemilla is typically enough to produce the desired effects. In terms of its psychoactive effect, a drop or two of hash oil on a cigarette is equal to a single “joint” of marijuana. Medicinally, the initial starting dose of Marinol® is 2.5 mg, twice daily."Source:Couper, Fiona J., Logan, Barry K., et al., "Drugs and Human Performance Fact Sheets," (Washington, DC: National Highway Traffic Safety Administration, April 2004), p. 7.
http://www.nhtsa.gov/People/injury/research/job185drugs/cannabis.htm, last accessed April 12, 2014.
(Odds Of Involvement In Fatal Auto Accidents Associated With Use Of Various Substances) "The prevalence of drugs detected in cases was higher than in controls across the drug categories (Table 3). Marijuana, narcotics, stimulants, and depressants were each associated with a significantly increased risk of fatal crash involvement, with estimated odds ratios ranging from 1.83 for marijuana to 4.83 for depressants (Table 3). Polydrug use, defined as use of two or more non-alcohol drugs, was associated with a 3.4-fold increased risk of fatal crash involvement (Table 3).
"About one-fifth (20.5%) of the cases tested positive for alcohol and one or more drugs, compared with 2.2% of the controls. Relative to drivers who tested positive for neither alcohol nor drugs, the estimated odds of fatal crash involvement increased over 13 folds for those who were alcohol-positive but drug-negative, more than two folds for those who were alcohol-negative but drug-positive, and 23 folds for those who were positive for both alcohol and drugs (Table 4)."Source:Guohua Li, Joanne E. Brady, and Qixuan Chen. Drug use and fatal motor vehicle crashes: A case-control study. Accident Analysis and Prevention 60 (2013) 205–210. http://dx.doi.org/10.1016/j.aap.2013.09.001.
(Cannabis Use and Accident Risk) "Cannabis use impairs cognitive, memory and psycho-motor performance in ways that may impair driving.10 Recent data suggest that approximately 5% of Canadian drivers/adults report driving after cannabis use in the past year.39 Large-scale epidemiological studies using different methodologies (e.g., retrospective epidemiological and case control studies) have found that cannabis use acutely increases the risk of motor vehicle accident (MVA) involvement and fatal crashes among drivers.40,41 Recent reviews have found the increase in risk to be approximately 1.5-3.0, an increase which is substantially lower, however, than that in alcohol-impaired drivers. The impairment from concurrent alcohol and cannabis use may be multiplicative, so individuals who drive under the influence of both drugs may be at higher risk for MVAs.42 An expert consensus view was that a THC concentration of 7-10 nanograms per millilitre in serum would produce impairment equivalent to that of 0.05% blood alcohol content (BAC). It was suggested that this level could serve as a 'per se' limit to define cannabis-impaired driving.43 Current research suggests that acute impairment from cannabis typically clears 3-4 hours after use.44
"This time span could be recommended to users as a minimum wait period before driving. The required wait before driving would need to be longer for higher doses, and would also vary on the basis of individual variation."Source:Fischer, Benedikt; Jeffries, Victoria; Hall, Wayne; Room, Robin; Goldner, Elliot; Rehm, Jürgen, "Lower Risk Cannabis Use Guidelines for Canada (LRCUG): A Narrative Review of Evidence and Recommendations," Canadian Journal of Public Health (Ottawa, Ontario: Canadian Public Health Association, September/October 2011) Vol. 102, No. 5, p. 325.
(Cannabis Use and Accident Risk) "A review of over a dozen of these [laboratory] experiments reveals three findings. First, after using marijuana, people drive more slowly. In addition, they increase the distance between their cars and the car in front of them. Third, they are less likely to attempt to pass other vehicles on the road. All of these practices can decrease the chance of crashes and certainly limit the probability of injury or death if an accident does occur. These three habits may explain the slightly lower risk of accidents that appears in the epidemiological studies. These results contrast dramatically to those found for alcohol. Alcohol intoxication often increases speed and passing while decreasing following distance, and markedly raises the chance of crashes.(632)"Source:"Rulemaking petition to reclassify cannabis for medical use from a Schedule I controlled substance to a Schedule II, Exhibit B: Statement of Grounds," Prepared by Carter, Gregory T.; Earleywine, Mitchell; and McGill, Jason T. (Office of Lincoln D. Chafee, Governor Rhode Island and Office of Christine O. Gregoire, Governor of Washington, November 30, 2011), Filed With US Drug Enforcement Administration on November 30, 2011, p. 37.
(Cannabis Use and Driving Impairment) "There is considerable evidence from laboratory studies that cannabis (marijuana) impairs reaction time, attention, tracking, hand-eye coordination, and concentration, although not all of these impairments were equally detected by all studies (Couper & Logan, 2004a; Heishman, Stitzer, & Yingling, 1989; Gieringer, 1988; Moskowitz, 1985). In reviewing the literature on marijuana, Smiley (1998) concluded that marijuana impairs performance in divided attention tasks (i.e., a poorer performance on subsidiary tasks). Jones et al. (2003) adds that Smiley’s finding is relevant to the multitasking essence of driving, in particular by making marijuana impaired drivers perhaps less able to handle unexpected events. Interestingly, there is also evidence showing that, unlike alcohol, marijuana enhances rather than mitigates the individual’s perception of impairment (Lamers & Ramaekers, 1999; Robbe & O'Hanlon, 1993; Perez-Reyes, Hicks, Bumberry, Jeffcoat, & Cook, 1988). Robbe and O'Hanlon (1993) reported that in laboratory conditions, drivers under the influence of marijuana were aware of their impairment, which led them to decrease speed, avoid passing other vehicles, and reduce other risk-taking behaviors. Such was not the case with alcohol; for the authors reported that alcohol-impaired drivers were generally not aware of impairment, and therefore did not adjust their driving accordingly."Source:Lacey, John H.; Kelley-Baker, Tara; Furr-Holden, Debra; Voas, Robert B.; Romano, Eduardo; Ramirez, Anthony; Brainard, Katharine; Moore, Christine; Torres, Pedro; and Berning, Amy , "2007 National Roadside Survey of Alcohol and Drug Use by Drivers," Pacific Institute for Research and Evaluation (Calverton, MD: National Highway Traffic Safety Administration, December 2009), p. 9.
(Driving After Cannabis Consumption) "Cannabis is only considered a risk factor for traffic accidents if drivers operate vehicles after consuming the drug. Robbe (1994) found that 30% to 90% of his participants were willing to drive after consuming a typical dose of cannabis. This is consistent with a recent Australian survey in which more than 50% of users drove after consuming cannabis (Lenne, Fry, Dietze, & Rumbold, 2000). A self administered questionnaire given to 508 students in grades 10 to 13 in Ontario, Canada, found that 19.7% reported driving within an hour after using cannabis (Adlaf, Mann, & Paglia, 2003)."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues (Tallahassee, FL: School of Criminology & Criminal Justice, Florida State University, 2004) Volume 34, Number 4, pp. 974-5.
(Impairment) "Participants receiving active marijuana decreased their speed more so than those receiving the placebo cigarette during a distracted section of the drive, An overall effect of marijuana was seen for the mean speed during the distracted driving (PASAT [Paced Auditory Serial-Addition Test] section), While no other changes in driving performance were found, marijuana appeared to hinder practice effects on the PASAT task, suggesting individuals may not be able to adequately use information and experience previously acquired while under the influence of marijuana, While only minimal differences in driving performance were found, this failure to benefit from prior practice may be detrimental to driving performance. Research has shown that graduated driver's licensing programs in which participants receive more on the road training results in a decrease in fatal crashes in 16-year-olds (Baker, Chen & Li 2006), If marijuana indeed impairs one's ability to use prior experience to improve performance, this will likely impair driving under pretrained conditions (e,g,, steering into a skid, allowing increased stopping time on slippery roads, etc)."Source:Anderson, Beth M.; Rizzo, Matthew; Block, Robert I.; Pearlson, Godfrey D.; O'Leary, Daniel S., "Sex differences in the effects of marijuana on simulated driving performance," Journal of Psychoactive Drugs (San Francisco, CA: Haight Ashbury Publications, March 1, 2010), Vol. 42, No. 1.
(Cannabis and Driving Impairment) "The present study's subtle finding of decreased speed under the influence of acute marijuana is generally consistent with the literature, which has found that marijuana's effects on driving can be subtle. In Berghaus's review of the literature prior to 1995, 45% of driving simulator studies showed no impairment from marijuana within the first hour after use (Berghaus, Scheer & Schmidt 1995), More cautious driving behaviors were found in several studies (Lamers & Ramaekers 2001; Stein et al, 1983; Ellingstad, McFarling & Struckman 1973; Rafaelsen, Bech & Rafaelsen 1973; Dott 1972), while an increased reaction time for stopping was the most common finding (Liguori, Gatto & Robinson 1998; Rafaelsen, Bech & Rafaelsen 1973), Moskowitz, Ziedman and Sharma (1976) also found slowed reaction times for a visual choice-reaction time task administered while driving and Smiley, Moskowitz and Zeidman (1981) found increased variability in velocity and lateral position while following curves and while controlling the car in gusts of wind with a high dose of marijuana (200 mcg/kg THC) but not with a lower dose (100 mcg/kg THC), They also found an increase in variability of headway and lateral position while following other cars."Source:Anderson, Beth M.; Rizzo, Matthew; Block, Robert I.; Pearlson, Godfrey D.; O'Leary, Daniel S., "Sex differences in the effects of marijuana on simulated driving performance," Journal of Psychoactive Drugs (San Francisco, CA: Haight Ashbury Publications, March 1, 2010), Vol. 42, No. 1.
(More Data Needed) "The decreased speed during the simulated drive could be interpreted as an attempt to compensate for perceived cognitive impairment, Alternatively, marijuana may not have affected decision making and judgment and the reduction in speed would improve safety margins, While the clinical significance of a 3% to 5% decrease in speed may be questioned, previous research suggests such a decrease will result in approximately a 7% decrease in all injuries and a 15% decrease in fatalities (Nilsson 1981), Use of an alternate task design in which subjects are requested to drive as quickly and as safely as possible rather than following a posted speed limit may provide more insight into compensatory strategies employed while driving under the influence of marijuana, Use of a more challenging road paradigm (e.g., icy or gravel roads) which capitalizes on the use of practice effects may aid in identifying differences in driving performance under the influence of marijuana, There was significant between-subject variability in driving measures and future studies would be further strengthened by using a within-subjects design."Source:Anderson, Beth M.; Rizzo, Matthew; Block, Robert I.; Pearlson, Godfrey D.; O'Leary, Daniel S., "Sex differences in the effects of marijuana on simulated driving performance," Journal of Psychoactive Drugs (San Francisco, CA: Haight Ashbury Publications, March 1, 2010), Vol. 42, No. 1.
(Driving) "Epidemiological studies have been inconclusive regarding whether cannabis use causes an increased risk of motor vehicle accidents; in contrast, unanimity exists that alcohol use increases crash risk.30 In tests using driving simulation, neurocognitive impairment varies in a dose-related fashion, and symptoms are more pronounced with highly automatic driving functions than with more complex tasks that require conscious control.31 Cannabis smokers tend to over-estimate their impairment and compensate effectively while driving by utilizing a variety of behavioral strategies."Source:"Cannabis and the Regulatory Void: Background Paper and Recommendations," California Medical Association (Sacramento, CA: 2011), p. 10
(Marijuana, Alcohol, and Driving) "When compared to alcohol, cannabis is detected far less often in accident-involved drivers. Drummer et al. (2003) cited several studies and found that alcohol was detected in 12.5% to 79% of drivers involved in accidents. With regard to crash risk, a large study conducted by Borkenstein, Crowther, Shumate, Zeil and Zylman (1964) compared BAC in approximately 6,000 accident-involved drivers and 7,600 nonaccident controls. They determined the crash risk for each BAC by comparing the number of accident-involved drivers with detected levels of alcohol at each BAC to the number of nonaccident control drivers with the same BAC. They found that crash risk increased sharply as BAC increased. More specifically, at a BAC of 0.10, drivers were approximately five times more likely to be involved in an accident.
"Similar crash risk results were obtained when data for culpable drivers were evaluated. Drummer (1995) found that drivers with detected levels of alcohol were 7.6 times more likely to be culpable. Longo et al. (2000) showed that drivers who tested positive for alcohol were 8.0 times more culpable, and alcohol consumption in combination with cannabis use produced an odds ratio of 5.4. Similar results were also noted by Swann (2000) and Drummer et al. (2003)."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues, Dec. 2004, pp. 981.
(Driving and THC Levels) "Most of the research on cannabis use has been conducted under laboratory conditions. The literature reviews by Robbe (1994), Hall, Solowij, and Lemon (1994), Border and Norton (1996), and Solowij (1998) agreed that the most extensive effect of cannabis is to impair memory and attention. Additional deficits include problems with temporal processing, (complex) reaction times, and dynamic tracking. These conclusions are generally consistent with the psychopharmacological effects of cannabis mentioned above, including problems with attention, memory, motor coordination, and alertness.
"A meta-analysis by Krüger and Berghaus (1995) profiled the effects of cannabis and alcohol. They reviewed 197 published studies of alcohol and 60 studies of cannabis. Their analysis showed that 50% of the reported effects were significant at a BAC of 0.073 g/dl and a THC level of 11 ng/ml. This implies that if the legal BAC threshold for alcohol is 0.08 g/dl, the corresponding level of THC that would impair the same percentage of tests would be approximately 11 ng/ml."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues (Tallahassee, FL: School of Criminology & Criminal Justice, Florida State University, 2004) Volume 34, Number 4, pp. 974-5.
(Driving Performance) "Several studies have examined cannabis use in driving simulator and on-road situations. The most comprehensive review was done by Smiley in 1986 and then again in 1999. Several trends are evident and can be described by three general performance characteristics:
"1. Cannabis increased variability of speed and headway as well as lane position (Attwood, Williams, McBurney, & Frecker, 1981; Ramaekers, Robbe, & O'Hanlon, 2000; Robbe, 1998; Sexton et al., 2000; Smiley, Moskowitz, & Zeidman, 1981; Smiley, Noy, & Tostowaryk, 1987). This was more pronounced under high workload and unexpected conditions, such as curves and wind gusts.
"2. Cannabis increased the time needed to overtake another vehicle (Dott, 1972 [as cited in Smiley, 1986]) and delayed responses to both secondary and tracking tasks (Casswell, 1977; Moskowitz, Hulbert, & McGlothlin,
1976; Sexton et al., 2000; Smiley et al., 1981).
"3. Cannabis resulted in fewer attempts to overtake another vehicle(Dott, 1972) and larger distances required to pass (Ellingstad et al., 1973 [as cited in Smiley, 1986]). Evidence of increased caution also included slower speeds (Casswell, 1977; Hansteen, Miller, Lonero, Reid, & Jones, 1976; Krueger & Vollrath, 2000; Peck, Biasotti, Boland, Mallory, & Reeve, 1986; Sexton et al., 2000; Smiley et al., 1981; Stein, Allen, Cook, & Karl, 1983) and larger headways (Robbe, 1998; Smiley et al., 1987)."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues (Tallahassee, FL: School of Criminology & Criminal Justice, Florida State University, 2004) Volume 34, Number 4, pp. 974-5.
(Driving Behavioral Compensation) "Both Australian studies suggest cannabis may actually reduce the responsibility rate and lower crash risk. Put another way, cannabis consumption either increases driving ability or, more likely, drivers who use cannabis make adjustments in driving style to compensate for any loss of skill (Drummer, 1995). This is consistent with simulator and road studies that show drivers who consumed cannabis slowed down and drove more cautiously (see Ward & Dye, 1999; Smiley, 1999. This compensation could help reduce the probability of being at fault in a motor vehicle accident since drivers have more time to respond and avoid a collision. However, it must be noted that any behavioral compensation may not be sufficient to cope with the reduced safety margin resulting from the impairment of driver functioning and capacity."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues (Tallahassee, FL: School of Criminology & Criminal Justice, Florida State University, 2004) Volume 34, Number 4, pp. 974-5.
(Cannabis Substitution Effects) "Another paradigm used to assess crash risk is to use cross-sectional surveys of reported nonfatal accidents that can be related to the presence of risk factors, such as alcohol and cannabis consumption. Such a methodology was employed in a provocative dissertation by Laixuthai (1994). This study used data from two large surveys that were nationally representative of high school students in the United States during 1982 and 1989. Results showed that cannabis use was negatively correlated with nonfatal accidents, but these results can be attributed to changes in the amount of alcohol consumed. More specifically, the decriminalization of cannabis and the subsequent reduction in penalty cost, as well as a reduced purchase price of cannabis, made cannabis more appealing and affordable for young consumers. This resulted in more cannabis use, which substituted for alcohol consumption, leading to less frequent and less heavy drinking. The reduction in the amount of alcohol consumed resulted in fewer nonfatal accidents."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues (Tallahassee, FL: School of Criminology & Criminal Justice, Florida State University, 2004) Volume 34, Number 4, pp. 974-5.
(Intoxication Self-Ratings) "Both simulator and road studies showed that relative to alcohol use alone, participants who used cannabis alone or in combination with alcohol were more aware of their intoxication. Robbe (1998) found that participants who consumed 100 g/kg of cannabis rated their performance worse and the amount of effort required greater compared to those who consumed alcohol (0.05 BAC). Ramaekers et al. (2000) showed that cannabis use alone and in combination with alcohol consumption increased self-ratings of intoxication and decreased self-ratings of performance. Lamers and Ramaekers (2001) found that cannabis use alone (100 g/kg) and in combination with alcohol consumption resulted in lower ratings of alertness, greater perceptions of effort, and worse ratings of performance."Source:Laberge, Jason C., Nicholas J. Ward, "Research Note: Cannabis and Driving -- Research Needs and Issues for Transportation Policy," Journal of Drug Issues (Tallahassee, FL: School of Criminology & Criminal Justice, Florida State University, 2004) Volume 34, Number 4, pp. 974-5.
(Mediation of Impairment) "In conclusion, cannabis impairs driving behaviour. However, this impairment is mediated in that subjects under cannabis treatment appear to perceive that they are indeed impaired. Where they can compensate, they do, for example, by not overtaking, by slowing down and by focusing their attention when they know a response will be required. However, such compensation is not possible where events are unexpected or where continuous attention is required. Effects of driving behaviour are present up to an hour after smoking but do not continue for extended periods."
"Thus, not only is it problematic to estimate the percentage of accident involvements associated with cannabis use alone, there is no evidence that impairment resulting from cannabis use causes accidents. Attempts to alleviate these problems by calculating risk of culpability for an accident (rather than the risk of having an accident) suggest that cannabis may actually reduce responsibility for accidents."
On November 6, 2012, a majority of the voters in the states of Colorado and Washington voted in favor of ballot measures which legalized the adult social use of marijuana.Source:Colorado: "Amendment 64 - Legalize Marijuana Election Results," Denver Post, last accessed Nov. 9, 2012.
Washington: "Initiative Measure No. 502 Concerns marijuana," Washington Secretary of State's Office, last accessed May 24, 2013.
Marijuana - Law and Policy
The U.S. Penal Code violations for marijuana and possible sentences:
Violation: "1000 kilograms or more of a mixture or substance containing a detectable amount of marihuana, or 1,000 or more marihuana plants regardless of weight."
Sentence: not "less than 10 years or more than life" "No person sentenced under this subparagraph shall be eligible for parole during the term of imprisonment imposed therein."
Violation: "100 kilograms or more of a mixture or substance containing a detectable amount of marihuana, or 100 or more marihuana plants regardless of weight."
Sentence: not "less than 5 years and not more than 40 years" "No person sentenced under this subparagraph shall be eligible for parole during the term of imprisonment imposed therein."
Violation: "less than 50 kilograms of marihuana, except in the case of 50 or more marihuana plants regardless of weight, 10 kilograms of hashish, or one kilogram of hashish oil"
Sentence: "not more than 5 years, a fine not to exceed the greater of that authorized in accordance with the provisions of title 18 or $250,000 if the defendant is an individual or $1,000,000 if the defendant is other than an individual, or both."Source:U.S. Code. Title 21, Chapter 13 -- Drug Abuse Prevention and Control -- Section 841, Prohibited Acts, pp. 406-407.
"Based on the research to date, the harms associated with the actual use of cannabis likely pale in comparison with the widely observed harms attributable to cannabis prohibition. As such, policymakers should integrate the scientific research conducted on the likely impacts of current prohibitive approaches to cannabis use into the process of optimising cannabis policy."Source:Werb, Daniel; Fischer, Benedikt; and Wood, Evan, "Cannabis policy: Time to move beyond the psychosis debate," International Journal of Drug Policy (London, United Kingdom: International Harm Reduction Association: July 2010) Vol. 21, Issue 4, p. 262.
"1. The severity of punishment for a cannabis possession charge should be reduced. Specifically, cannabis possession should be converted to a civil violation under the Contraventions Act.
"The current law involves considerable enforcement and other criminal justice costs, as well as adverse consequences to individual drug offenders, with little evidence of a substantial deterrent impact on cannabis use, and at best marginal benefits to the public health and safety of Canadians. As a minimal measure, jail should be removed as a sentencing option for cannabis possession. The available evidence indicates that removal of jail as a sentencing option would lead to considerable cost savings without leading to increases in rates of cannabis use. Punishing cannabis possession with a fine only would be consistent with current practices and prevailing public opinion."Source:Single, Eric, "Cannabis Control in Canada: Options Regarding Possession" National Working Group on Addictions Policy (Ottawa, Canada: Canadian Centre on Substance Abuse, May 1998).
(The Netherlands and Depenalization of Cannabis Use) "There is no evidence that the depenalization component of the 1976 policy, per se, increased levels of cannabis use. On the other hand, the later growth in commercial access to cannabis, after de facto legalization, was accompanied by steep increases in use, even among youth. In interpreting that association, three points deserve emphasis. First, the association may not be causal; we have already seen that recent increases occurred in the United States and Oslo despite very different policies. Second, throughout most of the first two decades of the 1976 policy, Dutch use levels have remained at or below those in the United States. And third, it remains to be seen whether prevalence levels will drop again in response to the reduction to a 5-g limit, and to recent government efforts to close down coffee shops and more aggressively enforce the regulations."Source:MacCoun, Robert and Reuter, Peter, "Interpreting Dutch Cannabis Policy: Reasoning by Analogy in the Legalization Debate," Science (New York, NY: American Association for the Advancement of Science, October 3, 1997), pp. 50-51.
(Real Risk of Arrest for Marijuana Possession) "It is also important to point out that in no Western country is a user at much risk of being criminally penalized for using marijuana. The rates of arrest for past-year marijuana users in Western countries are typically less than or equal to 3 percent (Kilmer, 2002; Room et al., 2010). More important, almost none of those convicted of simple possession is incarcerated or receives a fine exceeding $1,000 (Pacula, MacCoun, et al., 2005)."Source:Kilmer, Beau; Caulkins, Jonathan P.; Pacula, Rosalie Liccardo; MacCoun, Robert J.; Reuter, Peter H., "Altered State? Assessing How Marijuana Legalization in California Could Influence Marijuana Consumption and Public Budgets" Drug Policy Research Center (Santa Monica, CA: RAND Corporation, 2010), p. 13.
(Use Rates and Decriminalization) "In California and Ohio, surveys before and after decriminalisation showed that cannabis use increased, but not at a greater rate than in US states which had not decriminalised cannabis. Single (1989) also reviewed data from two large US national surveys of drug use in the 1970s that compared rates of cannabis use in states which had and had not decriminalised cannabis. He found that the prevalence of cannabis use increased in all states, with a larger increase in those states which had not decriminalised (Single, 1989)."Source:Donnelly, Neil; Hall, Wayne; Christie, Paul, "Cannabis Expiation Notice Scheme on levels and patterns of cannabis use in South Australia: evidence from the National Drug Strategy Household Surveys 1985–1995," Department of Health and Aged Care (Canberra, Australia: May 1998), p. 12.
(Federal Source of Legal Cannabis) "In 1968, the National Institute of Mental Health began funding a Drug Supply Program to provide researchers with compounds necessary to conduct biomedical research. Initially, the program focused on THC and other naturally occurring cannabinoids, and then gradually expanded to a wide range of compounds. (Since its beginning, the program has synthesized or obtained over 1,500 different compounds that have been supplied to over 2,500 researchers.) Cannabis was among the first substances to be made available through the Drug Supply Program for use by scientists conducting both nonhuman research and human research under a variety of investigational new drug protocols. It was grown through a contract with the University of Mississippi. With its establishment in 1974, NIDA became the successor to NIMH as the administrator of the cannabis contract and the sole U.S. source for legal cannabis."Source:"Provision of Marijuana and Other Compounds For Scientific Research - Recommendations of The National Institute on Drug Abuse National Advisory Council," National Institute on Drug Abuse (Bethesda, MD: Department of Health and Human Services, National Institutes of Health, January 1998).
(Recommendation by the Canadian Senate's Special Committee on Illegal Drugs) "... the Government of Canada amend the Controlled Drugs and Substances Act to create a criminal exemption scheme. This legislation should stipulate the conditions for obtaining licenses as well as for producing and selling cannabis; criminal penalties for illegal trafficking and export; and the preservation of criminal penalties for all activities falling outside the scope of the exemption scheme."Source:"Cannabis: Our Position for a Canadian Public Policy," report of the Canadian Senate Special Committee on Illegal Drugs (Ottawa, Canada: Senate of Canada, September 2002), p. 46.
(UK Police Foundation) "Our conclusion is that the present law on cannabis produces more harm than it prevents. It is very expensive of the time and resources of the criminal justice system and especially of the police. It inevitably bears more heavily on young people in the streets of inner cities, who are also more likely to be from minority ethnic communities, and as such is inimical to police-community relations. It criminalizes large numbers of otherwise law-abiding, mainly young, people to the detriment of their futures. It has become a proxy for the control of public order; and it inhibits accurate education about the relative risks of different drugs including the risks of cannabis itself."Source:Police Foundation of the United Kingdom, "Drugs and the Law: Report of the Independent Inquiry into the Misuse of Drugs Act of 1971", April 4, 2000. The Police Foundation, based in London, England, is a nonprofit organization presided over by Charles, Crown Prince of Wales, which promotes research, debate and publication to improve the efficiency and effectiveness of policing in the UK.
(1972 National Commission on Marihuana and Drug Abuse) "Rather than inducing violent or aggressive behavior through its purported effects of lowering inhibitions, weakening impulse control and heightening aggressive tendencies, marihuana was usually found to inhibit the expression of aggressive impulses by pacifying the user, interfering with muscular coordination, reducing psychomotor activities and generally producing states of drowsiness lethargy, timidity and passivity."Source:Shafer, Raymond P., et al, Marihuana: A Signal of Misunderstanding, Ch. III, (Washington DC: National Commission on Marihuana and Drug Abuse, 1972).
(1972 National Commission on Marihuana and Drug Abuse) "Marihuana's relative potential for harm to the vast majority of individual users and its actual impact on society does not justify a social policy designed to seek out and firmly punish those who use it. This judgment is based on prevalent use patterns, on behavior exhibited by the vast majority of users and on our interpretations of existing medical and scientific data. This position also is consistent with the estimate by law enforcement personnel that the elimination of use is unattainable."Source:Shafer, Raymond P., et al, Marihuana: A Signal of Misunderstanding, Ch. V, (Washington DC: National Commission on Marihuana and Drug Abuse, 1972).
(Decriminalization and Prevalence of Use) "Proponents of criminalization attribute to their preferred drug-control regime a special power to affect user behavior. Our findings cast doubt on such attributions. Despite widespread lawful availability of cannabis in Amsterdam, there were no differences between the 2 cities [Amsterdam and San Francisco] in age at onset of use, age at first regular use, or age at the start of maximum use."
"Our findings do not support claims that criminalization reduces cannabis use and that decriminalization increases cannabis use."Source:Reinarman, Craig; Cohen, Peter D.A.; Kaal, Hendrien L., "The Limited Relevance of Drug Policy: Cannabis in Amsterdam and in San Francisco," American Journal of Public Health (Washington, DC: American Public Health Association, May 2004) Vol 94, No. 5, pp. 840 and 841.
(Decriminalization and Use) "... our results indicate that the increase in participation was due to individuals over 30 delaying giving up cannabis use as a result of its changed legal status, not an increase in use by younger people. This finding provides an explanation of why US studies based on youth fail to find that decriminalization has an impact on the probability of cannabis use, while studies based on adults and youth, or just adults, do find a positive association between decriminalization and participation in cannabis use."Source:Cameron, Lisa & Williams, Jenny, "Cannabis, Alcohol and Cigarettes: Substitutes or Complements?" The Economic Record (Hawthorn, Victoria, Australia: The Economic Society of Australia, March 2001), p. 32.
(Cannabis Substitution Treatment) "Only orally given THC and, to a lesser extent, nefazodone have shown promise [in treating marijuana dependence]. THC reduced craving and ratings of anxiety, feelings of misery, difficulty sleeping, and chills (Haney et al., 2004). In addition, participants could not distinguish active THC from placebo. These findings were replicated in an outpatient study, which found that a moderate oral dosage of THC (10 mg, three times daily) suppressed many marijuana withdrawal symptoms and that a higher dosage (30 mg, three times daily) almost completely abolished withdrawal symptoms (Budney et al., 2007)."Source:Budney, Alan J.; Roffman, Roger; Stephens, Robert S.; Walker, Denise, "Marijuana Dependence and Its Treatment," Addiction Science & Clinical Practice (Rockville, MD: National Institute on Drug Abuse, December 2007), p. 11.
(Decriminalization and Use Rates) "The available evidence suggests that removal of the prohibition against possession itself (decriminalization) does not increase cannabis use. In addition to the Dutch experience from 1976 to 1983, we have similar findings from analysis of weaker decriminalization (with fines retained for the offense of simple possession of small quantities) in 12 US states (Single, 1989) and South Australia and the Australian Capital Territory (Hall, 1997; McGeorge & Aitken, 1997). The fact that Italy and Spain, which have decriminalized possession for all psychoactive drugs, have marijuana use rates comparable to those of neighboring countries provides further support."Source:MacCoun, Robert and Reuter, Peter, "Evaluating alternative cannabis regimes," British Journal of Psychiatry (London, United Kingdom: American Royal College of Psychiatrists, February, 2001) Vol. 178, p. 127.
(NIDA Cannabis for Research, 1998) "Under the current contract with the University of Mississippi for any given year NIDA [National Institute on Drug Abuse] has the option to grow either 1.5 or 6.5 acres of cannabis, or to not grow any at all, depending on research demand. Generally, 1.5 acres are grown in alternate years. The number of cannabis cigarettes produced from 1.5 acres is about 50,000-60,000, although it can be higher. Cigarettes are produced in three potencies: strength 1 - 3-4 %; strength 2 - 1.8-2.2 %; and strength 3 - placebo, as close to 0% as possible. During the past three years, the following quantities have been shipped: 1994 - 24,000 cigarettes; 1995 - 23, 100 - cigarettes; and 1996 17,700 cigarettes. Virtually all of the cigarettes shipped in the last three years have been for single patient INDs. As of March 1997 there were 278, 100 cigarettes in stock. The cigarettes are maintained in frozen storage and have a useful life of approximately five years."Source:"Provision of Marijuana and Other Compounds For Scientific Research - Recommendations of The National Institute on Drug Abuse National Advisory Council," National Institute on Drug Abuse (Bethesda, MD: Department of Health and Human Services, National Institutes of Health, January 1998)
"Synthetic cannabinoids are substances chemically produced to mimic tetrahydrocannabinol (THC), the active ingredient in marijuana. When these substances are sprayed onto dried herbs and then consumed through smoking or oral ingestion, they can produce psychoactive effects similar to those of marijuana."Source:Sacco, Lisa N. and Finklea, Kristin M., "Synthetic Drugs: Overview and Issues for Congress," Congressional Research Service (Washington, DC: Library of Congress, October 28, 2011), p. 5.
"Synthetic cannabinoids are functionally similar to delta9-tetrahydrocannabinol (THC), the psychoactive principle of cannabis, and bind to the same cannabinoid receptors in the brain and peripheral organs."Source:Fattore, Liana and Fratta, Walter "Beyond THC: the new generation of cannabinoid designer drugs," Frontiers in Behaviorial Neuroscience (Lausanne, Switzerland: September 2011) Volume 5, Article 60, p. 1.
(Spice Use Among 12 Graders) "Synthetic marijuana, which goes by such names as Spice and K-2, is an herbal drug mixture that usually contains designer chemicals that fall into the cannibinoid family. Until March of 2011 these drugs were not scheduled by the Drug Enforcement Administration, so they were readily available on the internet and in head shops, gas stations, etc. The DEA did schedule them under its emergency authority for one year, beginning March 1, 2011, making their possession and sale no longer legal. MTF first addressed the use of synthetic marijuana in its 2011 survey, asking 12th graders about use in the prior 12 months, which would have covered a considerable period of time prior to the drugs being scheduled. Some 11.4% indicated use in the prior 12 months. Next year’s survey results should reflect any effects of the scheduling by the DEA."Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2012). Monitoring the Future national results on adolescent drug use: Overview of key findings, 2011. Ann Arbor: Institute for Social Research, The University of Michigan, p. 5.
(Spice) "Despite its [marijuana's] long history of use and abuse for both medical and recreational purposes, a new generation of synthetic cannabinoids has recently emerged on the market, which are sold on the Internet as herbal mixtures under the brand names of 'Spice,' 'Spice Gold,' 'Spice Diamond,' 'Arctic Spice,' 'Silver,' 'Aroma,' 'K2,' 'Genie,' 'Scene' or 'Dream,' and advertised as incense products, meditation potpourris, bath additives, or air fresheners. These products are often referred to as 'herbal highs' or 'legal highs' because of their legal status and purported natural herbal make-up."Source:Fattore, Liana and Fratta, Walter "Beyond THC: the new generation of cannabinoid designer drugs," Frontiers in Behaviorial Neuroscience (Lausanne, Switzerland: September 2011) Volume 5, Article 60, p. 1.
(Spice) "‘Spice’ and other ‘herbal’ products are often referred to as ‘legal highs’ or ‘herbal highs’, in reference to their legal status and purported natural herbal make-up (McLachlan, 2009; Lindigkeit et al., 2009; Zimmermann et al., 2009). However, albeit not controlled, it appears that most of the ingredients listed on the packaging are actually not present in the ‘Spice’ products and it is seems likely that the psychoactive effects reported are most probably due to added synthetic cannabinoids, which are not shown on the label. There is no evidence that JWH, CP and/or HU [three chemically distinct groups of synthetic cannabinoids] compounds are present in all ‘Spice’ products or even batches of the same product. Different amounts or combinations of these substances seem to have been used in different ‘Spice’ products to produce cannabis-like effects. It is possible that substances from these or other chemical groups with a cannabinoid agonist or other pharmacological activity could be added to any herbal mixture (17) (Griffiths et al., 2009).
"The emergence of new, smokable herbal products laced with synthetic cannabinoids can also be seen as a significant new development in the field of so-called ‘designer drugs’. With the appearance, for the first time, of new synthetic cannabinoids, it can be anticipated that the concept of ‘designer drugs’ being almost exclusively linked to the large series of compounds with phenethylamine and tryptamine nucleus will change significantly (18). There are more than 100 known compounds with cannabinoid receptor activity and it can be assumed that further such substances from different chemical groups will appear (with direct or indirect stimulation of CB1 receptors)."Source:"Understanding the 'Spice' phenomenon," European Monitoring Centre for Drugs and Drug Addiction (Luxembourg: Office for Official Publications of the European Communities, 2009), p. 21.
(K2 and Spice) "Clemson University Professor John Huffman is credited with first synthesizing some of the cannabinoids, such as JWH-018, now used in 'fake pot' substances such as K2. The effects of JWH-018 can be 10 times stronger than those of THC. Dr. Huffman is quoted as saying, 'These things are dangerous—anybody who uses them is playing Russian roulette. They have profound psychological effects. We never intended them for human consumption.'"Source:Sacco, Lisa N. and Finklea, Kristin M., "Synthetic Drugs: Overview and Issues for Congress, Congressional Research Service (Washington, DC: Library of Congress, October 28, 2011), p. 5.
(Prevalence of Synthetic Cannabinoid Use Among US Youth) "Synthetic marijuana, so named because it contains synthetic versions of some of the cannabinoids found in marijuana, is a recent and important addition to the smorgasbord of drugs available to American young people. These designer chemicals are sprayed onto herbal materials that are then sold in small packets under such brand names as Spice and K-2. They have been readily available as over-the-counter drugs on the Internet, in head shops and gas stations, etc. While many of the most widely used chemicals were scheduled by the Drug Enforcement Administration in March of 2011, making their sale no longer legal, purveyors of these products have skirted the restrictions by making small changes in the chemical composition of the cannabinoids used. Use of these products was first measured in MTF in 2011 in a tripwire question for 12th graders, asking about their frequency of use in the prior 12 months. Annual prevalence was found to be 11.4%, making synthetic marijuana the second most widely used class of illicit drug after marijuana. In spite of the DEA’s scheduling of the most common ingredients, use among 12th graders remained unchanged in 2012, with 11.3% annual prevalence. Eighth and 10th graders were also asked about use of these drugs in 2012, and their annual prevalence rates were 4.4% and 8.8%, respectively, making synthetic marijuana the second most widely used illicit drug among 10th graders, as well, and the third among 8th graders behind marijuana and inhalants. There is a relatively low level of perceived risk for trying synthetic marijuana once or twice, despite growing evidence of serious problems resulting from the use of these drugs."Source:Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2013). "Monitoring the Future national survey results on drug use, 1975–2012: Volume I, Secondary school students." Ann Arbor: Institute for Social Research, The University of Michigan, p. 15.
(Spice Prohibition) "Because of health concerns and the abuse potential of herbal incense products, many have been banned in several European countries, 18 U.S. states, and the U.S. military.33,38 In March 2011, the FDA placed 5 synthetic cannabinoids (JWH-018, JWH-073, JWH-200, CP-47,497, and cannabicyclohexanol) on Schedule I, making them illegal to possess or sell in the United States.38"Source:Pierre, Joseph M., "Cannabis, synthetic cannabinoids, and psychosis risk: What the evidence says," Current Psychiatry (Parsippany, NJ: September 2011) Vol. 10, No. 9, p. 56.
(Scheduling of Spice) "On March 1, 2011, the DEA used its temporary scheduling authority and issued a final rule to place five synthetic cannabinoids on the list of controlled substances under Schedule I of the CSA.26 The five substances are
"• 1-pentyl-3-(1-naphthoyl)indole (JWH-018);
"• 1-butyl-3-(1-naphthoyl)indole (JWH-073);
"• 1-[2-(4-morpholinyl)ethyl]-3-(1-naphthoyl)indole (JWH-200);
"• 5-(1,1-dimethylheptyl)-2-[(1R,3S)-3-hydroxycyclohexyl]-phenol (CP-47,497); and
"• 5-(1,1-dimethyloctyl)-2-[(1R,3S)-3-hydroxycyclohexyl]-phenol (cannabicyclohexanol; CP-47,497 C8 homologue).
"Pursuant to the temporary scheduling authority, these substances will remain on the list of Schedule I controlled substances for one year, and then may be given one six-month temporary extension. To remain on Schedule I thereafter, the substances would need to be permanently scheduled within the CSA."Source:Sacco, Lisa N. and Finklea, Kristin M., "Synthetic Drugs: Overview and Issues for Congress, Congressional Research Service (Washington, DC: Library of Congress, October 28, 2011), p. 6.
(State Bans on Synthetic Cannabinoids) "At this time, forty-six (46) states and the federal government have scheduled one or more synthetic cannabinoids by statute or regulation and twenty-nine (29) states have some form of the generic language. Of the four states that have not scheduled one or more of the synthetic cannabinoids, Louisiana and Nebraska include the generic language. The only two states that have not yet scheduled any of the synthetic cannabinoids or the generic language are Maryland and Rhode Island. Maryland had four bills pending this legislative session, but was unable to get legislation passed before the session adjourned. There is still a regulation pending in Maryland that would schedule certain cannabinoids. The District of Columbia also has legislation pending. Rhode Island, however, does not have anything pending at this time."Source:Gray, Heather, "An Introduction to Synthetic Drugs," National Alliiance for Model State Drug Laws (Santa Fe, NM: June 2012), p. 11.
(Limits on Research) "There is shared concern among researchers that adding these substances to Schedule I could hinder medical research. As previously mentioned, Professor Huffman did not intend for K2 to be consumed by humans. He is, however, against adding synthetic cannabinoids to Schedule I, asserting that there is still much to learn about synthetic cannabinoids and that placing them on Schedule I would create too many hurdles for researchers who need to access these drugs.58 Professor Huffman has created several synthetic cannabinoids that are seen as showing promise in treating skin cancers, pain, and inflammation."Source:Sacco, Lisa N. and Finklea, Kristin M., "Synthetic Drugs: Overview and Issues for Congress, Congressional Research Service (Washington, DC: Library of Congress, October 28, 2011), p. 13.
(Testing for Use of Synthetics) "Most of the synthetic cannabinoids added as not-listed ingredients to Spice products are very difficult to detect by commonly used drug screening procedures. Apart from the analogs of THC such as HU-210, the structure of these new synthetic cannabinoids differs from that of THC, so that they probably will not trigger a positive test for cannabinoids in immunoassays of body fluids."Source:Fattore, Liana and Fratta, Walter "Beyond THC: the new generation of cannabinoid designer drugs," Frontiers in Behaviorial Neuroscience (Lausanne, Switzerland: September 2011) Volume 5, Article 60, p. 4.
(Monitoring of New Drugs) "A dramatic online snapshot of the Spice phenomenon as an emerging trend has been recently given by an important web mapping program, the Psychonaut Web Mapping Project, a European Commission-funded project involving researchers from seven European countries (Belgium, Finland, Germany, Italy, Norway, Spain, and UK), which aims to develop a web scanning system to identify newly marketed psychoactive compounds, and their combinations (e.g., ketamine and Spice, cannabis and Spice), on the basis of the information available on the Internet (Psychonaut Web Mapping Research Group, 2010). As a major result of the Project, a new and updated web-based database is now widely accessible to implement a regular monitoring of the web for novel and recreational drugs."Source:Fattore, Liana and Fratta, Walter "Beyond THC: the new generation of cannabinoid designer drugs," Frontiers in Behaviorial Neuroscience (Lausanne, Switzerland: September 2011) Volume 5, Article 60, p. 3.
Marijuana - Other & Miscellaneous
(Effects of Cannabis Prohibition) "Increased funding for cannabis prohibition has increased cannabis seizures and arrests, but the assumption that this reduces cannabis potency, increases price or meaningfully reduces availability or use is inconsistent with surveillance data the US federal government has itself collected."Source:International Centre for Science in Drug Policy, "Tools for Debate: US Federal Government Data on Cannabis Prohibition" (Vancouver, British Columbia: 2010), p. 21
(Taxonomy) "The biological (reproductive) definition of a species states that all specimens of a population are of a single species if they are naturally able to sexually reproduce, generating fertile offspring. This is the case throughout the genus Cannabis, and by this definition, therefore, there are no clear biological grounds to separate it into different species.However, within the species Cannabis sativa L., several subspecies are sometimes identified (Small and Cronquist, 1976).
"Despite this, modern Cannabis taxonomy remains confused, as a scientific minority prefers to define species according to their typological or morphological characteristics. In 1974, Schultes et al. described three putative species, Cannabis sativa L. (a typically tall species used for fibre, seed or psychoactive use), Cannabis indica Lam. (a short, wide-leafed plant from Afghanistan, used to produce resin) and Cannabis ruderalis Jan. (a short unbranched roadside plant with minimal drug content)."Source:"EMCDDA Insights: Cannabis production and markets in Europe," European Monitoring Centre for Drugs and Drug Addiction (Lisbon, Portugal: 2012), p. 21.
(THC Content) "The secretion of THC is most abundant in the flowering heads and surrounding leaves. The amount of resin secreted is influenced by environmental conditions during growth (light, temperature and humidity), sex of the plant, and time of harvest. The THC content varies between parts of the plant: from 10-12 % in flowers, 1-2 % in leaves, 0.1-0.3 % in stalks, to less than 0.03 % in the roots."
(History) "There are indications that cannabis was used as early as 4000 B.C. in Central Asia and north-western China, with written evidence going back to 2700 B.C. in the pharmacopeia of emperor Chen-Nong. It then gradually spread across the globe, to India (some 1500 B.C., also mentioned in Altharva Veda, one of four holy books about 1400 B.C.1), the Near and Middle East (some 900 B.C.), Europe (some 800 B.C.), various parts of South-East Asia (2nd century A.D.), Africa (as of the 11th century A.D.) to the Americas (19th century) and the rest of the world.2"
(Political History) "The identification of cannabis as a potentially dangerous psychoactive substance did not, however, prevent a substantial number of these enquiries to explore the issue of whether current legislation reflected the real dangers posed by cannabis. Already in 1944, the La Guardia Committee Report on Marihuana concluded that ‘the practice of smoking marihuana does not lead to addiction in the medical sense of the word’ and that ‘the use of marihuana does not lead to morphine or heroin or cocaine addiction’ (Zimmer and Morgan, 1997). In 1968 the Wootton Report stated that ‘the dangers of cannabis use as commonly accepted in the past and the risk of progression to opiates have been overstated’ and ‘cannabis is less harmful than other substances (amphetamines, barbiturates, codeine-like compounds)’. A similar conclusion was arrived at 34 years later in 2002 when the Advisory Committee on Drug Dependence proposed the reclassification of cannabis from Class B to Class C (enforced by law in 2004 and confirmed in 2005). These views were reiterated by other enquiries, such as the Baan Committee in the Netherlands, which affirmed in 1971 that ‘cannabis use does not lead directly to other drug use’ (16) or by the US National Commission on Marihuana and Drug Abuse, which in 1973 stated that ‘the existing social and legal policy is out of proportion to the individual and social harm engendered by the use of the drug [cannabis]’ (17). The Canadian Le Dain Commission saw ‘the UN Single Convention of 1961 as responsible’ for such a situation which ‘might have reinforced the erroneous impression that cannabis is to be assimilated to the opiate narcotics’. The same commission, however, suggested that the UN Convention did ‘not prevent domestic legislation from correcting this impression’ (18)."Source:EMCDDA (2008), "A cannabis reader: global issues and local experiences," Monograph series 8, Volume 1, European Monitoring Centre for Drugs and Drug Addiction, Lisbon, p. 108.
"Cultivated Sinsemilla: Female cannabis plant which has not been pollinated. May grow from cutting or from seed. May contain some seed (if un-pollinated the seed will be sterile). Common illicit indoor grow technique.
"Cultivated Non Sinsemilla: Male or Female cannabis plant commonly grown for illicit drug use.
"Cultivated Ditchweed: Male or Female cannabis plant which grows wild in many states that has in some way been tended by man. Examples of tending are: weeding, watering, topping, fertilizing, harvesting.
"Ditchweed: Unattended, wild male or female cannabis that is native to many states.
"Cannabis Bud: Flowering top of a female cannabis plant. The Bud may contain seed. Most valuable portion of a cannabis plant to the illicit grower. Bud formation occurs late in plant development.
"Leaf: Cannabis leaf potency tends to correlate to position on the plant. The most potent part of the plant is the new leaves at the top of the plant. As you move downward on the plant potency decreases. The least potent leaves on the plant are the large leaves at the bottom of the plant.
"Mature Cannabis: Mature cannabis plants have a higher potency than immature plants. Determination of plant maturity should be made using all available contextual factors. For example, is the plant outdoors and it only June or July, if so, then the plant is likely immature. However, if the growing season is near an end, such as September or October, then the plant is probably mature. Note male cannabis plants are mature as early as August when grown outdoors. It is more difficult to generalize regarding maturity of indoor grows. “Spike” cannabis plants can mature in as little as 6-8 weeks whereas an indoor grow with plants 3-4 feet in height may take 60-120 days to mature.
"Already Harvested: Cannabis plant material recently dried or packaged. May be either bud or leaf.
"Average Plant Canopy Diameter: Record the diameter of a typical mature cannabis plant at its broadest point through the center. Diameter data can be used to predict usable yield with good accuracy."
(Effects of Prohibition) "Prohibition has two effects: on one hand it raises supplier costs, disrupts market functioning and prevents open promotion of the product; on the other, it sacrifices the authorities’ ability to tax transactions and regulate operation of the market, product characteristics and promotional activity of suppliers. The cannabis prevalence rates presented in Figure 1 show clearly that prohibition has failed to prevent widespread use of the drug and leaves open the possibility that it might be easier to control the harmful use of cannabis by regulation of a legal market than to control illicit consumption under prohibition. The contrast between the general welcome for tobacco regulation (including bans on smoking in public places) and the deep suspicion of prohibition policy on cannabis is striking and suggests that a middle course of legalised but limited consumption may find a public consensus."Source:"Pudney, Stephen, "Drugs Policy – What Should We Do About Cannabis?" Centre for Economic Policy Research (London, United Kingdom: April 2009), p. 23.
(Marijuana Tax Act) "Marijuana essentially became illegal in 1937 pursuant to the Marijuana Tax Act.39 The use of marijuana required the payment of a tax for usage; failure to pay the tax resulted in a large fine or stiff prison time for tax evasion.40 Drug prohibition was elevated to another level by targeting 'marijuana,' a plant that had never demonstrated any harm to anyone.41
"Anslinger’s [Harry J. Anslinger, the first Commissioner of the Federal Bureau of Narcotics] efforts to eradicate marijuana continued when Anslinger sought similar anti-narcotic laws against marijuana at the state level.42 Guided by Anslinger’s policy direction, states began passing their own laws or adopting more strident versions of federal laws.43 By 1952, nearly all states had anti-narcotic laws in place.44"Source:Gilmore, Brian, "Again and Again We Suffer: the Poor and the Endurance of the 'War on Drugs,'" University of the District of Columbia Law Review (Washington, DC: The University of the District of Columbia David A. Clarke School of Law, 2011) Volume 15, Number 1, p. 64.
(Total Annual Arrests by Year and Category) Although the intent of a 'War on Drugs' may have been to target drug smugglers and 'King Pins,' according to the FBI's annual Uniform Crime Reports, of the 1,552,432 arrests for drug law violations in 2012, 82.2% (1,276,099) were for mere possession of a controlled substance. Only 17.8% (276,333) were for the sale or manufacturing of a drug. Further, nearly half (48.3%) of drug arrests in 2012 were for marijuana -- a total of 749,825. Of those, an estimated 658,231 arrests (42.4% of all drug arrests) were for marijuana possession alone. By contrast in 2000, a total of 734,497 Americans were arrested for marijuana offenses, of which 646,042 (40.9%) were for possession alone.
US Arrests As Reported By FBI UCR Program Year Total Arrests Total Drug Arrests Total Marijuana Arrests Marijuana Trafficking/Sale Arrests Marijuana Possession Arrests Total Violent Crime Arrests Total Property Crime Arrests 2012 12,196,959 1,552,432 749,825 91,593 658,231 521,196 1,646,212 2011 12,408,899 1,531,251 757,969 94,937 663,032 534,704 1,639,883 2010 13,120,947 1,638,846 853,839 103,247 750,591 552,077 1,643,962 2009 13,687,241 1,663,582 858,408 99,815 758,593 581,765 1,728,285 2008 14,005,615 1,702,537 847,863 93,640 754,224 594,911 1,687,345 2007 14,209,365 1,841,182 872,720 97,583 775,137 597,447 1,610,088 2006 14,380,370 1,889,810 829,627 90,711 738,916 611,523 1,540,297 2005 14,094,186 1,846,351 786,545 90,471 696,074 603,503 1,609,327 2004 13,938,071 1,746,570 773,731 87,329 686,402 586,558 1,644,197 2003 13,639,479 1,678,192 755,186 92,300 662,886 597,026 1,605,127 2002 13,741,438 1,538,813 697,082 83,096 613,986 620,510 1,613,954 2001 13,699,254 1,586,902 723,628 82,519 641,109 627,132 1,618,465 2000 13,980,297 1,579,566 734,497 88,455 646,042 625,132 1,620,928 1999 14,355,600 1,557,100 716,266 85,641 630,626 644,770 1,676,100 1998 14,528,300 1,559,100 682,885 84,191 598,694 675,900 1,805,600 1997 15,284,300 1,583,600 695,201 88,682 606,519 717,750 2,015,600 1996 15,168,100 1,506,200 641,642 94,891 546,751 729,900 2,045,600 1995 15,119,800 1,476,100 588,964 85,614 503,350 796,250 2,128,600 1990 14,195,100 1,089,500 326,850 66,460 260,390 705,500 2,217,800 1980 10,441,000 580,900 401,982 63,318 338,664 475,160 1,863,300 Total
236,438,421 28,002,034 12,318,682 1,549,101 11,427,813 10,421,804 28,750,970Source:"Crime in the United States 2012 - Arrests," FBI Uniform Crime Report (Washington, DC: US Dept. of Justice, September 2013), p. 1.
"Crime in the United States 2011 - Arrests," FBI Uniform Crime Report (Washington, DC: US Dept. of Justice, October 2012), p. 1.
Arrests for Drug Abuse Violations: http://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2011/crime-in-the-...
"Crime in the United States 2010," FBI Uniform Crime Report (Washington, DC: US Dept. of Justice, September 2011), Table 29.
Arrests for Drug Abuse Violations: http://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2010/crime-in-the-...
"Crime in the United States 2009," FBI Uniform Crime Report (Washington, DC: US Dept. of Justice, September 2010), Table 29.
Arrests for Drug Abuse Violations: http://www2.fbi.gov/ucr/cius2009/arrests/index.html.
"2008 Crime in the United States," FBI Uniform Crime Reports (Washington, DC: US Dept. of Justice, September 2009), Table 29.
Arrests for Drug Abuse Violations: http://www2.fbi.gov/ucr/cius2008/arrests/index.html.
"2007 Crime in the United States," (Washington, DC: US Dept. of Justice, September 2008), Table 29.
Arrests for Drug Abuse Violations: http://www2.fbi.gov/ucr/cius2007/arrests/index.html
"2006 Crime in the United States," (Washington, DC: US Dept. of Justice, September 2007), Table 29.
Arrests for Drug Abuse Violations: http://www2.fbi.gov/ucr/cius2006/arrests/index.html
"Crime in the United States 2005," FBI Uniform Crime Reports (Washington, DC: US Dept. of Justice, September 2006), Table 29.
Arrests for Drug Abuse Violations: http://www2.fbi.gov/ucr/05cius/arrests/index.html
"Crime in the United States 2004," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 2005) Table 29.
Arrests for Drug Abuse Violations: http://www2.fbi.gov/ucr/cius_04/persons_arrested/index.html
"Crime in the United States 2003," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 2004), p. 269, Table 4.1 & and p. 270, Table 29.
"Crime in the United States 2002," FBI Uniform Crime Reports (Washington, DC: US Dept. of Justice, 2003).
"Crime in the United States 2001," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 2002), p. 232, Table 4.1 & and p. 233, Table 29. http://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2001/01sec4.pdf
"Crime in the United States - 2000," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 2001), p. 216, Tables 29 and 4.1.
"Crime in the United States - 1999," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 2000), pp. 211-212.
"Crime in the United States - 1998," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 1999), pp. 209-219.
"Crime in the United States - 1997," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 1998), p. 221, Table 4.1 & p. 222, Table 29.
"Uniform Crime Reports for the United States 1996" Federal Bureau of Investigation (Washington, DC: US Government Printing Office, 1997), p. 213, Table 4.1 & p. 214, Table 29.
"Crime in the United States - 1995," FBI Uniform Crime Reports (Washington, DC: US Government Printing Office, 1996), pp. 207-208.
FBI, UCR for the US 1990 (Washington, DC: US Government Printing Office, 1991), pp. 173-174.
FBI, UCR for the US 1980 (Washington, DC: US Government Printing Office, 1981), pp. 189-191.
US Marijuana Arrests Percentage Share of Total Drug Arrests - Year - Marijuana
% of Total Drug Arrests
Marijuana Manufacturing & Sale
% of Total Drug Arrests
% of Total Drug Arrests
2012 48.3% 5.9% 42.4% 2011 49.5% 6.2% 43.3% 2010 52.1% 6.3% 45.8% 2009 51.6% 6.0% 45.6% 2008 49.8% 5.5% 44.3% 2007 47.4% 5.3% 42.1% 2006 43.9% 4.8% 39.1% 2005 42.6% 4.9% 37.7% 2004 44.3% 5.0% 39.3% 2003 45.0% 5.5% 39.5% 2002 45.3% 5.4% 39.9% 2001 45.6% 5.2% 40.4% 2000 46.5% 5.6% 40.9% 1999 46.0% 5.5% 40.5% 1998 43.8% 5.4% 38.4% 1997 43.9% 5.6% 38.3% 1996 42.6% 6.3% 36.3% 1995 39.9% 5.8% 34.1%Source:FBI Uniform Crime Reports 1970-2011. Please see sources cited above in US Arrests table. Annual Percent Change in Total, Drug, and Marijuana Arrests, 1996-2010 Year Total Arrests Total Drug Arrests Total Marijuana Arrests Marijuana Trafficking & Sale Arrests Marijuana Possession Arrests 2010 -4.1% -1.5% -0.5% 3.4% -1.1% 2009 -2.3% -2.3% 1.2% 6.6% 0.6% 2008 -1.4% -7.5% -2.8% -4.0% -2.7% 2007 -1.2% -2.6% 5.2% 7.6% 4.9% 2006 2.0% 2.4% 5.5% 0.3% 6.2% 2005 1.1% 5.7% 1.7% 5.7% 1.7% 2004 2.2% 4.1% 2.5% -5.4% 3.5% 2003 -0.7% 9.1% 8.3% 11.1% 8.0% 2002 0.3% -3.0% -3.7% 0.7% -4.2% 2001 -2.0% 0.5% -1.5% -6.7% -0.8% 2000 -2.6% 1.4% 2.5% 3.3% 2.4% 1999 -1.2% -0.1% 4.9% 1.7% 5.3% 1998 -4.9% -1.5% -1.8% -5.1% -1.3% 1997 0.8% 5.1% 8.3% -6.5% 10.9% 1996 0.3% 2.0% 8.9% 10.8% 8.6% 15-year Average -0.9% 0.8% 2.6% 1.4% 2.8%Source:FBI Uniform Crime Reports 1970-2010. Please see cite sources for U.S. Arrests table.