2. Patterns of problematic cannabis use among Canadian and US respondents between 2018 and 2020: Findings from the International Cannabis Policy Study

The current study sought to examine trends in problematic cannabis use (PCU) over three consecutive years (2018-2020) from population-based surveys in Canada and the US to provide preliminary evidence of the impact of nonmedical cannabis legalization on population health.

Data came from the first three cycles of the International Cannabis Policy Study which were conducted in Canada and the US in Fall 2018, 2019, and 2020 (N=118,584). Linear regression models will examine factors influencing ASSIST scores, a tool used to objectively evaluate PCU, in Canada and the US; multinomial models will examine changes in use risk categories, and logistic regression models will examine factors contributing to increased scores on the tool.

The current study will provide a description of PCU over the first years of nonmedical cannabis legalization in Canada as well as parallel contexts in US jurisdictions that legalized nonmedical cannabis use and those where its use remained illegal at the time of study. The current study will provide essential information examining ‘high risk’ and disproportionately affected populations including specific challenges experienced among these groups and described along sociodemographic characteristics.

The study findings will inform discussions on the impact of nonmedical cannabis legalization and broader social dynamics and underlying secular trends. The current study intends to highlight the importance of standardizing important cannabis use measures such as PCU and provide initial evidence to serve as a baseline for future work in this area.