Marijuana use among adults in the United States more than doubled to 9.5% in 2012-2013 from 4.1% in 2001-2002, according to research published in JAMA Psychiatry.
Marijuana use disorders (abuse or dependence) have also increased to 2.9% in 2012-2013 from 1.5% in 2001-2002. This means that 3 out of 10 marijuana users in the United States (approximately 6.8 million Americans) were diagnosed with a marijuana use disorder from 2012-2013.
To examine the past-year rates of marijuana use, Bridget F. Grant, PhD, from the National Institute on Alcohol Abuse and Alcoholism in Rockville, Md., and colleagues studied data from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III).
The most notable increases in marijuana use were in women, blacks, Hispanics, people living in the South, and those middle-aged or older. The most notable increases in marijuana disorders were in those who were 45 to 64 years old, blacks, Hispanics, those with very low incomes, or those living in the South.
However, the increased number of marijuana disorders does not represent an increased risk — it actually represents a decreased risk. Among marijuana users, disorders decreased to 30.6% in 2012-2013 from 35.6% in 2001-2002. This means that the increase in marijuana disorders is simply due to the increase in users, most likely due to changing laws and attitudes about marijuana. 23 states have laws regarding medical marijuana, and 4 of these states have legalized recreational marijuana.
The researchers conclude that these findings warrant careful and balanced education. “In summary, while many in the United States think prohibition of recreational marijuana should be ended, this study and others suggest caution and the need for public education about the potential harms in marijuana use, including the risk for addiction,” wrote Grant.
“As is the case with alcohol, many individuals can use marijuana without becoming addicted. However, the clear risk for marijuana use disorders among users (approximately 30%) suggests that as the number of US users grows, so will the numbers of those experiencing problems related to such use. This information is important to convey in a balanced manner to health care professionals, policy makers and the public.”
Hasin DS, Saha TD, Kerridge BT, Goldstein RB et al. Prevalence of Marijuana Use Disorders in the United States Between 2001-2002 and 2012-2013. JAMA Psychiatry. 2015; doi:10.1001/jamapsychiatry.2015.1858.