Background: On January 31, 2023, British Columbia became the only Canadian jurisdiction trialling decriminalization of personal possession of illicit drugs. This study investigated temporal trends in policing-related barriers to accessing harm reduction services among young people who use drugs (PWUD) in Vancouver before and after decriminalization.

Methods: Data from 2021-2024 was collected from a cohort of street-involved young PWUD in Vancouver. Logistic regression with generalized estimating equations (GEE) assessed trends in policing-related barriers to harm reduction services pre- and post-decriminalization, with calendar time and decriminalization (plus their interaction) as primary explanatory variables. We conducted a sub-analysis among participants reporting Indigeneity.

Results: Among 319 participants, the baseline median age was 27.8 years and 83 (26%) reported police barriers to harm reduction services. In multivariable GEE analysis, an increasing trend in the odds of experiencing police barriers was observed pre-decriminalization (adjusted odds ratio [AOR]=2.31; 95% confidence interval [CI]: 1.22-4.36). Post-decriminalization, levels of police barriers immediately declined (AOR=0.37; 95% CI: 0.16-0.88), and the trend became non-significant (AOR=1.05; 95% CI: 0.45-2.46). A similar pattern was observed in the sub-analysis among Indigenous participants, but post-decriminalization there was no significant change in level (AOR=0.66; 95% CI: 0.22-1.98), but a significant declining trend (AOR=0.28; 95% CI: 0.08-0.97).

Implications: Among young PWUD, we observed relative reductions in experiencing policing-related barriers to harm reduction services after the implementation of decriminalization, halting the increasing trend observed pre-decriminalization. Findings suggest decriminalization had a positive impact on reducing police barriers to harm reduction services, and this benefit extended to young Indigenous PWUD.