"On average, 7% of the ESPAD students stated that they had used marijuana or hashish during the past 30 days. As a proportion of the group reporting lifetime use, this corresponds to roughly four in ten. The highest rates of past-30-days cannabis use are found in the two neighbouring countries of France and Monaco (24% and 21%, respectively), followed by the United States (not an ESPAD country) (18 %) and the Czech Republic and Spain (not an ESPAD country) (15% each).
Statistics and other data regarding drug use and other risk-taking behavior among young people, as well as drug policies related to young people including prevention, education, social development, healthcare, mental health, and criminal justice.
"Overall, supply reduction—that is, reducing the availability of drugs—does not appear to have played as major a role as many had assumed in four of the five most important downturns in illicit drug use that have occurred to date, namely, those for marijuana, cocaine, crack, and ecstasy (see, for example, Figures 8-4, 8-5, and 8-6). The case of cocaine is particularly striking, as perceived availability actually rose during much of the period of downturn in use that began in the mid- 1980s.
"Inhalants rank second among the illicit drugs in lifetime prevalence for 8th graders (8.9%) and third for 10th graders (6.1%); but they rank seventh for 12th graders (4.9%). Inhalants also rank second-highest in 30-day prevalence among the illicit drugs for 8th (2.1%) and third (1.1%) among 10th graders, but they rank much lower for 12th graders (0.8%). Note that the youngest respondents report the highest levels of use; this is the only class of drugs for which current use declines with age during adolescence.3"
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.
(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."
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)."
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."
"Annual marijuana prevalence peaked among 12th graders in 1979 at 51%, following a rise that began during the 1960s. Then use declined fairly steadily for 13 years, bottoming at 22% in 1992—a decline of more than half. The 1990s, however, saw a resurgence of use. After a considerable increase (one that actually began among 8th graders a year earlier than among 10th and 12th graders), annual prevalence rates peaked in 1996 at 8th grade and in 1997 at 10th and 12th grades. After these peak years, use declined among all three grades through 2007 or 2008.
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:
"Teen users are at significantly higher risk of developing an addictive disorder compared to adults, and the earlier they began using, the higher their risk. Nine out of 10 people who meet the clinical criteria for substance use disorders involving nicotine, alcohol or other drugs began smoking, drinking or using other drugs before they turned 18. People who begin using any addictive substance before age 15 are six and a half times as likely to develop a substance use disorder as those who delay use until age 21 or older (28.1 percent vs. 4.3 percent)."