Grant: Project Grant

On October 17, 2018, recreational cannabis was legalized in Canada. The consequences of this major legislative change are unknown and we have a rare opportunity to evaluate its effects systematically. In the month prior to legalization, we collected data on cannabis perceptions, cannabis use, and other substance use from 1502 adults in Ontario. Our internal funding has permitted subsequent assessments at 6- and 12-months (95% and 93% retention, respectively), and will permit a further assessment at 18-months post-legalization. This Project Grant is to conduct additional follow-up assessments across a five-year period following legalization (24-, 30-, 36-, 42- , 48-, 54-, and 60-months). Specifically, the Primary Aims are to examine: (1) changes in attitudes and perceptions about cannabis; (2) changes in cannabis consumption practices; (3) psychological factors that affect changes following legalization (e.g., initiating, escalating, or reducing use). In addition, for exploratory purposes, the study has two Secondary Aims. The first is to examine how changes in cannabis use following legalization affects the use of other substances, both recreational (e.g., alcohol) and prescription (e.g., opioids). The second is to explore sex/gender differences in all of the preceding domains. Collectively, the proposed study will make substantial contributions to understanding of the effects of recreational cannabis legalization in Canada and will have significant implications for other jurisdictions considering cannabis legalization around the world.