Perceived prevalence of peer marijuana use: changes among college students before and after Oregon recreational marijuana legalization
This study examined changes in perceived peer marijuana use among college students in Oregon before and after recreational marijuana legalization (RML). Results showed that RML was associated with higher perceived rates of marijuana use by peers, particularly among non-users. This increase in descriptive norms could potentially contribute to future marijuana use initiation among college students.
College of Health researcher(s)
College unit(s)
Highlights
- The study examines the changes in perceived peer use of marijuana among college students in Oregon before and after recreational marijuana legalization (RML).
- Data was collected from 2008 to 2016 from two Oregon institutions and 123 institutions in non-RML states.
- RML was associated with higher perceived rates of marijuana use by peers, particularly among respondents who had never used marijuana.
- The increase in descriptive norms among non-using students could contribute to future marijuana use initiation and may be one mechanism linking RML with higher rates of marijuana use among college students.
Abstract
Background
Oregon students’ rates of marijuana use have increased following recreational marijuana legalization (RML), but the relation between RML and students’ perceived peer use of marijuana – or descriptive norms – is unknown.
Objectives
This study examined whether perceived peer use of marijuana changed more following RML for college students in Oregon than in states without RML.
Methods
Repeated cross-sectional data were collected from the National College Health Assessment-II surveys from 2008 to 2016 to assess changes in descriptive norms (“Within the last 30 days, what percent of students at your school used marijuana?”) among 18–26 year-old undergraduates from two Oregon institutions and 123 institutions in non-RML states (N = 280,006; 66.23% female; 33.19% male) following Oregon RML (7/1/2015). Mixed-effects regressions were used to account for clustering at the institutional level; models controlled for covariates and secular changes in descriptive norms.
Results
RML was associated with higher perceived rates of marijuana use by peers [Percent Increase = 3.09, p < .001]. The effect was significant for respondents who had never used marijuana [Percent Increase = 3.72, p < .001], but not for respondents who recently or ever previously used marijuana. Respondents who had recently used marijuana had higher descriptive norms than those who had never used [Percent Increase = 12.83, p < .001].
Conclusions
Given the association between descriptive norms and personal use, RML-related increases in descriptive norms among non-using students could contribute to future marijuana use initiation and may be one mechanism linking RML with higher rates of marijuana use among college students.