Oregon counties with more marijuana and alcohol shops saw more teen co-use after legalization
After Oregon legalized recreational marijuana in 2015, counties with the highest density of both marijuana and alcohol retail outlets saw a significant increase in adolescent co-use of alcohol and marijuana.
Quick Facts
What This Study Found
Post-legalization, there was a significant increase in past-30-day alcohol and marijuana co-use in 2016 in counties with the highest retail outlet density. The relationship between outlet density and co-use was mediated by adolescent beliefs about availability, parent approval, and risk. There were also post-RML increases in perceived risk and perceived parent approval of use.
Key Numbers
71,870 11th graders; 36 Oregon counties; 2010-2018 data; significant co-use increase in 2016 in highest-density counties; beliefs about availability, parent approval, and risk mediated the outlet density-co-use relationship
How They Did This
Multi-level logistic regression of biennial data from the Oregon Student Wellness Survey, 2010-2018, covering 71,870 11th graders across 36 counties. Examined associations between recreational marijuana legalization, county-level outlet density, and adolescent co-use and beliefs.
Why This Research Matters
Understanding how retail density affects adolescent substance use patterns can inform zoning and licensing decisions. The finding that beliefs mediate the outlet density-use relationship suggests both environmental and educational interventions are needed.
The Bigger Picture
This suggests that cannabis legalization effects on adolescents are not uniform across regions but depend on local retail environments. Communities can potentially mitigate adolescent use impacts through outlet density regulations.
What This Study Doesn't Tell Us
Observational ecological design cannot establish individual-level causation. Biennial survey data may miss short-term fluctuations. Oregon may not represent other states. Outlet density is an imperfect proxy for actual accessibility to minors.
Questions This Raises
- ?Is there an outlet density threshold below which adolescent co-use is not affected?
- ?Do delivery services and online sales undermine the protective effect of outlet density limits?
Trust & Context
- Key Stat:
- Co-use increase was significant only in highest outlet density counties
- Evidence Grade:
- Large representative sample with multi-level design and multiple survey waves, though ecological design limits individual-level inference.
- Study Age:
- Published in 2021 using 2010-2018 survey data.
- Original Title:
- Retail Availability of Recreational Marijuana and Alcohol in Oregon Counties and Co-Use of Alcohol and Marijuana and Related Beliefs among Adolescents.
- Published In:
- Substance use & misuse, 56(3), 345-352 (2021)
- Authors:
- García-Ramírez, Grisel(2), Paschall, Mallie J(2), Grube, Joel W(2)
- Database ID:
- RTHC-03145
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Did legalization increase teen marijuana use everywhere?
No. The increase in co-use was concentrated in counties with the highest density of recreational marijuana and alcohol retail outlets. Counties with fewer outlets did not show the same increase.
How did beliefs play a role?
Adolescent beliefs about marijuana and alcohol availability, parent approval, and risk mediated the relationship between outlet density and co-use. In areas with more shops, teens perceived greater availability and social approval, which translated to more co-use.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03145APA
García-Ramírez, Grisel; Paschall, Mallie J; Grube, Joel W. (2021). Retail Availability of Recreational Marijuana and Alcohol in Oregon Counties and Co-Use of Alcohol and Marijuana and Related Beliefs among Adolescents.. Substance use & misuse, 56(3), 345-352. https://doi.org/10.1080/10826084.2020.1858104
MLA
García-Ramírez, Grisel, et al. "Retail Availability of Recreational Marijuana and Alcohol in Oregon Counties and Co-Use of Alcohol and Marijuana and Related Beliefs among Adolescents.." Substance use & misuse, 2021. https://doi.org/10.1080/10826084.2020.1858104
RethinkTHC
RethinkTHC Research Database. "Retail Availability of Recreational Marijuana and Alcohol in..." RTHC-03145. Retrieved from https://rethinkthc.com/research/garcia-ramirez-2021-retail-availability-of-recreational
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.