Prevalence of Marijuana Use Among U.S. Adults Doubles Over Past Decade

The percentage of Americans who reported using marijuana in the past year more than doubled between 2001- 2002 and 2012-2013, and the increase in marijuana use disorder during that time was nearly as large. Past year marijuana use rose from 4.1 percent to 9.5 percent of the U.S. adult population, while the prevalence of marijuana use disorder rose from 1.5 percent to 2.9 percent, according to national surveys conducted by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health. Based on the current study, approximately 30 percent of people who used marijuana in the past year met criteria for marijuana use disorder during 2012-2013, as defined by the Diagnostic and Statistical Manual of Mental Disorders. This includes symptoms such as taking the drug in larger amounts or over a longer period than was intended by the user; the persistent desire to cut down or control use/unsuccessful efforts to do so; failure to fulfill major role obligations at work, school or home as a result of marijuana use; and tolerance and/or withdrawal.
http://www.nih.gov/news/health/oct2015/niaaa-21.htm