Using the Severity of Dependence Scale to examine cannabis consumers with impaired control in Canada.

Background: The 2018 Cannabis Act legalizing the production, sale, and use of cannabis for non-medical purposes renewed interest in the importance of ongoing and more detailed monitoring of cannabis consumption and consequences. Some cannabis users will experience impaired control over their use of cannabis, putting them at risk for cannabis use disorder (CUD, sometimes called addiction) and other harms. Including the Severity of Dependence Scale (SDS) in the annual Canadian Community Health Survey (CCHS) would allow for monitoring of one of the more harmful consequences of cannabis use in the post-legalization period.

Data and methods: Data from the nationally representative 2019-2020 CCHS were used to examine cannabis consumers with and without impaired control. Respondents who used cannabis in the past year were categorized according to their SDS scores: those with impaired control (SDS ≥ 4) versus those without impaired control (SDS < 4). Cross-tabulations were used to examine the sociodemographic, mental health, health behaviour and cannabis exposure characteristics of those with impaired control. Multivariable logistic regression models assessed associations between these characteristics and the risk of impaired control. The prevalence of self-reported cannabis-related problems experienced by consumers-with and without impaired control-is also presented.

Results: In 2019-2020, 4.7% of past-year cannabis consumers scored ≥ 4 on the SDS and were considered to have impaired control. Multivariable logistic regression suggested that the odds of having impaired control remained higher for people who were male, were aged 18 to 24 years, were single or never married, were from lower-income households, were diagnosed with an anxiety or a mood disorder, started consuming cannabis at age ≤ 15, and consumed at least monthly.

Interpretation: A better understanding of the characteristics of cannabis consumers experiencing impaired control (a correlate of future CUD or addiction) could help with the development of more effective education, prevention and treatment strategies.