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Medical Marijuana Legalization and Marijuana Use Among Youth in Oregon


While the legalization of marijuana for medical and recreational use has raised concerns about potential influences on marijuana use and beliefs among youth, few empirical studies have addressed this issue. We examined the association between medical marijuana patients and licensed growers per 1000 population in 32 Oregon counties from 2006 to 2015, and marijuana use among youth over the same period. We obtained data on registered medical marijuana patients and licensed growers from the Oregon Medical Marijuana Program and we obtained data on youth marijuana use, perceived parental disapproval, and demographic characteristics from the Oregon Healthy Teens Survey. Across 32 Oregon counties, the mean rate of marijuana patients per 1000 population increased from 2.9 in 2006 to 18.3 in 2015, whereas the grower rate increased from 3.8 to 11.9. Results of multi-level analyses indicated significant positive associations between rates of marijuana patients and growers per 1000 population and the prevalence of past 30-day marijuana use, controlling for youth demographic characteristics. The marijuana patient and grower rates were also inversely associated with parental disapproval of marijuana use, which decreased from 2006 to 2015 and acted as a mediator. These findings suggest that a greater number of registered marijuana patients and growers per 1000 population in Oregon counties was associated with a higher prevalence of marijuana use among youth from 2006 to 2015, and that this relationship was partially attributable to perceived norms favorable towards marijuana use.

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This research and preparation of this paper were supported by a grant from the National Institute on Alcohol Abuse and Alcoholism (R01AA021726). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIAAA or the National Institutes of Health. We would like to thank Emma and Zachary Adler for assisting with the acquisition and compilation of medical marijuana patient and grower data from the Oregon Medical Marijuana Program.

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Correspondence to Mallie J. Paschall.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards

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Paschall, M.J., Grube, J.W. & Biglan, A. Medical Marijuana Legalization and Marijuana Use Among Youth in Oregon. J Primary Prevent 38, 329–341 (2017).

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