Marijuana use by adults in the United States has soared, more doubling, over the past decade, 2001-2002 to 2012-2013. Surveys show 9.5 percent of Americans use marijuana; 30 percent of users meet criteria for a disorder.
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 results of our surveys, marijuana use in the United States has risen rapidly over the past decade, with about 3 in 10 people who use marijuana meeting the criteria for addiction. Given these increases, it is important that the scientific community convey information to the public about the potential harms,” said George Koob, Ph.D., director of NIAAA.
Marijuana disorder is 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.
When examined by age, young adults (ages 18 -29) were found to be at highest risk for marijuana use and marijuana use disorder, with use increasing from 10.5 percent to 21.2 percent and disorder increasing from 4.4 percent to 7.5 percent over the past decade.
Studies funded by NIDA and NIAAA have shown that marijuana impairs driving performance, increasing lane weaving, and that since the legalization of medical marijuana in Colorado, drivers involved in fatal motor vehicle crashes are significantly more likely to test positive for marijuana use.