Prevalence of cannabis use before and in the early period following partial legalisation in Germany

Background

On April 1st, 2024, Germany implemented the Act on the Handling of Cannabis for Non-Medical Use (KCanG), allowing adults to cultivate and possess recreational cannabis, while commercial sale remains prohibited. We assessed whether this was associated with a change in the prevalence of cannabis use. This analysis is essential for understanding the public health implications of the reform and for informing future regulatory decisions.

Methods

A series of 21 repeated surveys between April/May 2022 and October/November 2025 (covering the period approximately two years before and one and a half years after the KCanG). We measured past 12-month cannabis use (at least once; daily or almost daily use). Piecewise binomial logistic regression models used wave dates as predictors, allowing a slope change at the first full wave after April 2024, with a random effect for wave. Analyses covered the total sample and subgroups by gender, age (14-24 vs. 25-64 years), and daily or almost daily use among past 12-month users. Sensitivity analyses used alternate intervention dates (in-time placebo tests). A detailed plan for the current analyses was published prior to data analysis (https://osf.io/w92v5).

Results

Among 32,991 respondents aged 14-64 years, 2,092 (6.3%) reported past 12-month cannabis use. The prevalence and proportion of (almost) daily users remained largely stable before and after the law reform. None of the slope coefficients before the introduction of the KCanG were statistically significant (all p ≥ .08), and none of the coefficients for the change in the slope were statistically significant (all p ≥ .31). Sensitivity analyses supported these findings.

Conclusions

Germany’s 2024 cannabis reform was not associated with changes in 12-month use prevalence or heavy use early (1.5 years) after implementation. Continued monitoring over longer periods and across multiple data sources is recommended, as effects may emerge later.

Key messages

• The partial legalisation of cannabis was neither associated with a short-term change in the prevalence of 12-month cannabis use nor in the proportion of heavy users among past 12-month users.

• As some of the effects of the partial legalisation are likely to have not yet fully unfolded, it is necessary to continue closely monitoring trends over a longer post-implementation period.