Highs and downs: A scoping review of public opinion about cannabis, alcohol and tobacco in Canada

Issues: Since the legalisation of cannabis in October 2018, Canada has emerged as a privileged place for research on the properties of this substance, its health effects, but also on its relation with public opinion. However, this scoping review points out the complexity of tracing the evolution of Canadian public opinion on cannabis based on available scientific data. Approach: This review follows the guidelines of the Joanna Briggs Institute and summarises more than 60 years of research on Canadians' public opinion, perception and knowledge of cannabis. The study also includes alcohol and tobacco in order to provide a meaningful comparison between substances. Key Findings: One hundred and sixty-one references selected from over 30 000 studies, with the oldest dating back to 1956, show that public opinion on cannabis is under-studied in Canada compared to alcohol and tobacco. Young people and students are among the most studied populations, unlike Aboriginal communities, immigrants and elderly people. The study reveals the absence of experts in public opinion and political communication, and calls for an imperative need for theoretical frameworks rooted in the work of social scientists. Implication: These findings do not suggest slowing the rate of publication on alcohol, tobacco, youth or students. Rather, they encourage increasing the rate of publication on other substances used and on other groups also targeted as being particularly at risk of misuse. Conclusion: New studies need to measure and contribute to the understanding of Canadian public opinion on cannabis in comparison with public policies currently in place.