A recent article published in the Journal of the American Academy of Child & Adolescent Psychiatry concluded that survey data between 2002 and 2013 shows a decline in cannabis use disorders among the American youth population.

The article, published by Richard Gruzca et al., analyzed data from the National Survey on Drug Use and Health, which included 216,852 adolescents aged 12 through 17. The survey covered subjects from all 50 states and calculated the average annual change in prevalence of cannabis use disorders.[1]

Richard A. Gruzca, PhD

Richard A. Gruzca, PhD

According to the research, which was conducted following grants from the National Institute on Drug Abuse (NIDA), general cannabis usage and usage disorders among adolescents both dropped substantially between 2002 and 2013.

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Those opposed to cannabis legalization have long claimed that medical and recreational cannabis laws would heighten availability, leading to increased youth exposure and irreparable harm to the adolescent community. According to the data, the opposite has happened during the medical cannabis era.


Between 2002 and 2013, there was a 9.8% decrease in cannabis usage among youths aged 12 to 17. The number of adolescents who had problems directly related to cannabis declined by 24% during that same time.

Christian J. Hopfer, MD

Christian J. Hopfer, MD

Dr. Christian Hopfer of the University of Colorado Denver School of Medicine sees these results as part of something bigger. For Dr. Hopfer, cannabis use among adolescents is incredibly complex, and these reductions in usage and abuse patterns may be due to an overall decline in conduct issues among youths.[2]

Dr. Hopfer is careful to iterate that the results from Gruzca et al. do not provide concrete evidence that cannabis legalization for recreational purposes is harmless on adolescents:

“The relation between the quasi or full legalization of marijuana for medical or recreational purposes for adults and adolescent marijuana use is complex; however, the article by Grucza et al. examines time trends primarily during marijuana medical legalization and cannot be used to infer the effects of adult recreational legalization.”

As in generally the case when it comes to cannabis, more research is necessary for the scientific community to develop a firm grasp on behavioral and usage trends among youths exposed to cannabis.

For instance, since recreational cannabis laws have been instituted, surveys have shown that adult cannabis use has increased from 4.1% and 9.5%, with adult use disorders increasing from 1.5% to 2.9%. This is surprising considering the data regarding adolescent cannabis use shows a separate trend.

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As you can see in the chart above, cannabis use disorders have remained generally stable among those adolescents without comorbid conduct patterns (white box).

The fact that cannabis use disorders (black box) have substantially decreased among those youths with comorbid conduct issues does deserve further investigation, particularly as states begin to legalize adult cannabis use for recreational purposes.


Cannabis Reports encourages the next step of research, and is pleased to see grants from federal agencies such as NIDA being used for unbiased cannabis research.

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[1] Grucza RA, Agrawal A, Krauss MJ, et al. Declining prevalence of marijuana use disorders among adolescents in the United States, 2002 to 2013. J Am Acad Child Adolesc Psychiatry. 2016;55:487-494. DOI: 10.1016/j.jaac.2016.04.002
[2] Hopfer C. Declining Rates of Adolescent Marijuana Use Disorders During the Past Decade May Be Due to Declining Conduct Problems. J AM Acad Child Adolesc Psychiatry 2016; 55:439-440. DOI: 10.1016/j.jaac.2016.03.013