Leveraging an Existing Longitudinal Observational Cohort to Understand the Impacts of Cannabis Legalization and the COVID-19 Pandemic on Alcohol and Cannabis Use in At-risk Young Adults

Over the last five years, two major societal events have taken place in Canada, the legalization of cannabis for non-medical (recreational) purposes and the coronavirus 2019 (COVID-19) pandemic. The impacts of these events on substance use are continuing to unfold and are not well understood, especially in high-risk groups. One such high-risk group is young adults (20-29), both because the twenties are a highly formative developmental period and the rates of substance use, especially alcohol and cannabis, are highest in this age group. Young adulthood is often when individuals leave the family home, complete formal education, launch careers, and enter marriage and parenthood. As a result, substance misuse during this period can have lifelong impacts by disrupting critical psychosocial milestones. Since 2017, we have been funded by CIHR to follow a cohort of at-risk young adults to understand their substance use. The project has generated numerous findings to date, but has also overlapped with both legalization and the COVID-19 pandemic, thus offering a window into the impacts of these events. Participants in the cohort were ~22 at the start of the study and were ~26 at the last full assessment wave. This proposal is to continue to follow these individuals to ~30 to understand the impacts of these major events. The study will use quantitative assessments to using validated instruments and qualitative interviews to hear participants experiences and perspectives in their own words. In addition, the study will examine differences based on sex/gender and in underrepresented subgoups, such as racialized individuals. The results will substantially contribute to our understanding of the impacts of cannabis legalization and the COVID-19 pandemic, and will inform evidence-based healthcare and policy strategies. Collectively, the project will serve as a high-resolution empirical 'time capsule' to understand the impacts of these momentous events in Canada.