Recreational Marijuana Legalization and Community Policy in Oregon: Influence on Youth Attitudes, Peer Use, Parent Use, and Youth Use

Introduction: Studies investigating the impact of legalization of medical or recreational marijuana on youth have found little to no changes in adolescent use. We expect that changes in youth marijuana use will not occur immediately following legalization, but changes in other factors that likely impact youth use may be more immediate. We investigated how the implementation of recreational marijuana sales and local regulations on sales influenced youth willingness and intent to use, exposure to peers who use, parent use, and youth use.

 Methods: The implementation of recreational marijuana sales in Oregon coincided with our study on youth substance use. Half of participants transitioned from 8^th to 9^th grade prior to legalization and the other half made this transition during the implementation of legalized recreation marijuana sales (N = 444). Although legal, Oregon cities and counties were allowed to opt out of sales. Logistic regression models estimated the impact of legalized sales and community policy on changes in attitudes, peer use, and parent use. Zero-inflated Poisson growth curve models estimated the effects of legalization and community policy on trajectories of youth marijuana use from 8^th through 9^th grade (4 timepoints).

 Results: Youth who were in the prior to legalization cohort and in communities that opted out of sales were less likely to increase their willingness to try marijuana (p = .02, OR = 0.27 [95% CI 0.09, 0.78]) and intent to use (p = .02, OR = 0.28 [95% CI 0.10, 0.84]). Youth who were in the legalization cohort and in communities that opted out of sales were more likely to increase their intent to use (p = .02, OR = 5.78 [95% CI 1.38, 24.30]). Significant influences on changes in peer and parent use were not detected. No changes were found for legalization and community policy effects on youth who were non-users. For youth who used marijuana, legalization predicted greater increases (b = 0.10, p = .01) in use. In communities that opted out of marijuana sales, youth baseline use was lower (b = -0.36, p < .001) than in those implementing sales. An interaction effect showed that legalization in communities that opted out of sales had lower baseline frequencies (b = -1.01, p = .02) and greater growth (b = 0.28, p = .05) in youth marijuana use compared to the other groups.

 Conclusions: Community attitudes and policy appears to impact youth attitudes towards marijuana. Results suggest that legalization of recreation marijuana did not increase marijuana use for youth who did not use marijuana but did increase the frequency of use in youth who were already using. In states that legalize recreational marijuana, efforts to prevent youth who use marijuana from escalating their use, perhaps to levels of abuse, is indicated.