Prevalence of Past-Month (Current) Marijuana Use in the US

"In 2013, marijuana was the most commonly used illicit drug, with 19.8 million current (past month) users. It was used by 80.6 percent of current illicit drug users. Nearly two thirds (64.7 percent) of current illicit drug users used only marijuana in the past month. Also, in 2013, 8.7 million persons aged 12 or older were current users of illicit drugs other than marijuana (or 35.3 percent of illicit drug users aged 12 or older). Current use of other drugs but not marijuana was reported by 19.4 percent of illicit drug users, and 15.9 percent reported using both marijuana and other drugs.
"The number and percentage of persons aged 12 or older who were current users of marijuana in 2013 (19.8 million or 7.5 percent) were similar to the estimates in 2012 (18.9 million or 7.3 percent) (Figure 2.2). The rate of current marijuana use in 2013 was higher than the rates in 2002 to 2011. For example, during the period from 2002 to 2008, the rates varied from 5.8 to 6.2 percent. By 2009, the rate increased to 6.7 percent, then continued to increase to the rate in 2013."


Substance Abuse and Mental Health Services Administration, Results from the 2013 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-48, HHS Publication No. (SMA) 14-4863. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2014, pp. 15-16.