Data from 2 National Institute on Alcohol Abuse and Alcoholism surveys conducted a decade apart shows that the percentage of US adults who use marijuana doubled from 4.1% to 9.5% between 2001-2002 and 2012-2013 (Hasin DS et al. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2015.1858 [published online October 21, 2015]). During that same time span, the prevalence of adults in the United States who met the criteria for marijuana use disorder increased from 1.5% to 2.9%. The percentage of marijuana users categorized as having a marijuana use disorder, however, decreased from 35.6% of users in 2001-2002 to 30.6% of users in 2012-2013.