Cannabis is a commonly used drug among young adults with around 40% of young adults age 19-28 reporting use in 2019. Many factors influence cannabis use in this age group including injunctive and descriptive norms, ease of access, and perceptions of harms and risks. In addition, the recent legalization of nonmedical cannabis use in many states may have impacted the prevalence and frequency of cannabis use. The legalization of nonmedical cannabis use may have also affected use of other substances including alcohol. This study examines cannabis- and alcohol-specific risk factors for use following the legalization of nonmedical cannabis use.  

The study’s sample consisted of 12,951 young adults age 18 to 25 who participated in the Washington Young Adult Health Study (YAHS). Descriptive norms were measured by asking participants their perceptions on frequency of past year use of alcohol, medical cannabis, and nonmedical cannabis for a typical person their age. Injunctive norms were assessed by asking participants how acceptable it was for a person their age to use cannabis once or twice and regularly. Participants were also asked how easy it would be to obtain cannabis and alcohol. Lastly, respondents were asked to rate the physical and psychological harm of daily alcohol use, heavy episodic drinking, regular cannabis use, and occasional cannabis use. Data was analyzed using logistic regression models to assess for substance-specific risk factors.  

Results of the data analysis showed that perceptions of past-year use of medical and nonmedical cannabis increased significantly over time. The perception of past-year alcohol use among those under age 21 changed little over time while there was an increase in perception of past year alcohol use for those over age 21. Perceived acceptability of occasional and regular cannabis use remained stable over the years for those under age 21 and increased for those older than 21. Ease of obtaining cannabis increased significantly for those over the age of 21 and remained stable for those under 21. Among those under 21, there was a change in low perceived risk of physical harm from occasional cannabis use. For those over 21 there was a change in low perceived risk of physical and psychological harm from both occasional and regular cannabis use.  

Takeaway: Cannabis-specific risk factors have increased among young adults, especially those aged 21+, since the legalization of nonmedical cannabis use in Washington state.  

Gilson, M.S., Kilmer, J.R., Fleming, C.B., Rhew, I.C., Calhoun, B.H., Guttmannova, K.. Substance-Specific Risk Factors for Cannabis and Alcohol Use Among Young Adults Following Implementation of Nonmedical Cannabis Legalization [published online ahead of print, 2022 Sep 17]. Prevention Science. 2022;10.1007/s11121-022-01435-8. doi:10.1007/s11121-022-01435-8