Eight months after German legalization, no significant increase in cannabis use or stoned driving

German cannabis use rose from 12.1% to 14.4%, but this did not significantly differ from Austrian trends (DiD OR 1.18, 95% CI 0.95-1.48). Among monthly+ users, DUIC decreased slightly from 28.5% to 26.8% with no significant difference from Austria (DiD aOR 0.68, 95% CI 0.27-1.68). DUIC combined with alcohol/drugs (DUIC+) accounted for 21.5% of episodes and was most common among weekly users.

Cross-sectional population surveys in Germany and Austria before (November-December 2023) and after legalization (November 2024-January 2025). Difference-in-differences analysis using Austria as control. Cannabis use assessed in adults 18-64 (Germany: ~16,000; Austria: ~4,200). DUIC assessed among monthly+ users.

Germany is the largest European country to legalize cannabis, making its experience crucial for other European nations considering reform. The finding of no significant short-term increase in stoned driving addresses one of the primary safety concerns about legalization, though the 21.5% rate of combined cannabis/alcohol DUIC episodes is concerning.

Published in Lancet Regional Health Europe, this study provides the first rigorous evaluation of Germany's cannabis reform using Austria as a natural control group. The null findings for both use and DUIC at 8 months are consistent with Canadian and US state-level data showing that legalization effects on use and driving are slow to materialize, if they do at all.

Only 8 months post-legalization; effects may take longer to emerge. No legal commercial sales were operating during the study period (only possession and cultivation were legal). Self-reported DUIC may underestimate true prevalence. Austria is an imperfect control (cultural and policy differences).