News Release

Recreational marijuana availability in Oregon and use among adolescents

Peer-Reviewed Publication

Pacific Institute for Research and Evaluation

New research from the Prevention Research Center of the Pacific Institute for Research and Evaluation suggests that legalization and greater retail availability of recreational marijuana is positively associated with marijuana use among adolescents.

The researchers investigated whether legalization of recreational marijuana sales in 2015 and retail availability of marijuana in Oregon counties were associated with higher levels of adolescent marijuana use and related beliefs.

Using survey data gathered every other year from 2010 to 2018 from 6th, 8th and 11th graders 35 Oregon counties, this study assessed changes in past-30-day marijuana use and beliefs, including:

  • perceived availability of marijuana,
  • perceived parent approval of marijuana use, and
  • lower levels of perceived risk of marijuana use.

Comparisons were made in counties that allowed recreational marijuana sales compared to counties that did not.

The results of the study show that:

  • Higher rates of past-30-day marijuana use and more favorable beliefs were found in counties that allow recreational marijuana sales both before and after legalization;
  • Prevalence of past-30-day marijuana use increased after legalization both in counties that did and did not allow sales;
  • The relationship between allowing recreational marijuana sales and adolescent marijuana use was accounted for by greater retail marijuana availability and favorable beliefs.

Overall, this study shows that there was a statewide increase in the prevalence of marijuana use among Oregon adolescents after legalization in 2015, and that greater retail availability of marijuana in counties that permit recreational marijuana sales is positively associated with both marijuana use and beliefs favorable toward its use among adolescents.

Said lead author, Dr. Paschall, "Our study indicates that statewide legalization of recreational marijuana use and greater retail availability of marijuana in Oregon communities may be contributing to an increase in marijuana use among adolescents. Greater local restrictions on numbers of licensed marijuana retail outlets, hours of operation and advertising, and higher taxes on marijuana products may help to reduce both retail and social availability of marijuana."


Source: Paschall, Mallie J. and Joel W. Grube. Recreational Marijuana Availability in Oregon and Use Among Adolescents. American Journal of Preventive Medicine. Volume 58, Issue 2, February 2020, Pages e63-e69.

This study was supported by grants from the National Institute on Alcohol Abuse and Alcoholism (NIAAA Grant Nos. R01AA021726 and P60AA006282).

PIRE is an independent, nonprofit organization merging scientific knowledge and proven practice to create solutions that improve the health, safety and well-being of individuals, communities, and nations around the world.

The Prevention Research Center (PRC) of PIRE is one of 16 centers sponsored by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), of the National Institutes of Health, and is the only one that specializes in prevention. PRC's focus is on conducting research to better understand the social and physical environments that influence individual behavior that lead to alcohol and drug misuse.

The Resource Link for Community Action provides information and practical guidance to state and community agencies and organizations, policy makers, and members of the public who are interested in combating alcohol and other drug abuse and misuse.


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