Cannabis remains the most widely produced, trafficked and consumed illicit drug worldwide, and at this time Canada and many other countries are implementing alternative regulatory approaches to cannabis. While research on cannabis has traditionally focused on the harms of cannabis use, an emerging body of evidence suggests that cannabis use can also alter high-risk drug practices, such as reducing cocaine use, opioid use and associated overdose. Much of this work suggests that cannabis is often used as a substitute for harder drugs of abuse which may have important implications for health policy responses to the current opioid epidemic in British Columbia.
However, this evidence has been primarily cross-sectional and ecological in nature, and lacking are rigorous longitudinal studies unpacking the precise impacts of cannabis use and evolving cannabis policy on the development of high-risk drug use behaviours. Further, the impacts of cannabis use on HIV and addiction treatment outcomes remains unclear. In light of the recent legalization of non-medical cannabis, identifying the impacts of cannabis on high-risk substance use and drug treatment outcomes will be important for informing clinical and public health practice, as well as policy.