The short-term impacts of the decriminalization of personal possession of select illegal drugs on drug possession criminal incidents and criminal cases in British Columbia, Canada (2013 to 2023).

BACKGROUND

Decriminalization of personal possession of illegal drugs was implemented in British Columbia, Canada on January 31, 2023. We examined the short-term impacts of decriminalization on drug possession criminal incidents and criminal cases in British Columbia.

METHODS

We sourced population-based monthly counts of drug possession incidents, persons charged by police in drug possession incidents, and drug possession cases in British Columbia and other provinces in Canada (2013-2023). Crude and age-standardized rates per 100,000 population were calculated and differenced to generate single time series for the outcomes. Controlled interrupted time series analyses were conducted using generalized additive models that tested immediate effects and trend changes in the outcomes.

RESULTS

Decriminalization resulted in an immediate downshift (β [95% CI]: 0.46 [0.04, 0.88]) in the difference of the crude rates of drug possession incidents between British Columbia and other provinces in Canada. Similar significant effects were not observed in regards to the trend change. These changes corresponded to an overall average reduction of 5.5 (95% CI: 1.1, 11.9) drug possession incidents per 100,000 population per month in British Columbia compared to other provinces in Canada. Decriminalization was not associated with changes in persons charged by police in drug possession incidents or drug possession cases in British Columbia compared to other provinces in Canada.

CONCLUSIONS

Decriminalization was associated with reductions in drug possession incidents, but it was not associated with changes in persons charged by police in drug possession incidents or drug possession cases.