Emerging, Hot Topic: Retail Availability of Marijuana in Oregon Counties and Use of Alcohol and Related Beliefs Among Adolescents

Objective: This study investigated whether legalization of recreational marijuana sales in Oregon counties in 2015 was associated with subsequent changes in alcohol use and beliefs related to alcohol use among adolescents.

Method: Biannual data for 6th, 8th and 11th graders from the Student Wellness Survey (SWS) in 35 Oregon counties from 2010 to 2018 (N=240,111) were analyzed to assess relative changes in past-30-day use of alcohol, and alcohol related beliefs in counties that allowed recreational marijuana sales in 2015 compared to counties that did not.

Results: Any past-30-day use of alcohol decreased from 2010 (21.8%) to 2018 (17.2%). Multi-level logistic regression models indicated a significant overall decline in use of alcohol from 2010 to 2018 (OR = 0.90, CI 95% [.88 -.92], p<.001). However, there was not a significant change in past-30-day alcohol use after legalization of recreational marijuana sales in 2015, and there was not a significant difference in past-30-day alcohol use between counties that allow recreational marijuana sales in unincorporated areas and those that do not allow it. Analyses also indicated significant post-legalization increases in perceived risk and parent approval of alcohol use, but no change in the perceived availability of alcohol when controlling for the overall time trend and student demographic characteristics.

Conclusion: There was a decline in past-30-day use of alcohol among Oregon adolescents from 2010 to 2018, but no significant change after legalization of recreational marijuana sales in Oregon in 2015. In addition, perceived risk and normative beliefs changed after legalization of recreational marijuana sales with increases in both perceived risk and perceived parental approval of alcohol use.