No change in cannabis use after Germany’s partial legalisation

Cannabis use in Germany stayed at the same level during the first two years after parts of the ban were lifted. That is shown by a new study in the International Journal of Drug Policy, in which researchers followed 23 survey waves before and after the German cannabis act came into force on 1 April 2024. Neither the share who had used cannabis in the past year nor the share using it daily changed in a way that could be linked to the reform.

What Germany’s cannabis reform involves

The German cannabis legislation, CanG, consists of two parts: the Consumer Cannabis Act (KCanG) and the Medical Cannabis Act (MedCanG). The KCanG gives adults over 18 the right to possess and cultivate limited amounts for personal use and to form non-profit cannabis clubs. Commercial sale remains prohibited. The government itself has called the reform a “partial legalisation” — it differs from the commercial models in Canada and several US states.

In parallel, medical cannabis has been legal in Germany since 2017, but the MedCanG now allows residents to obtain cannabis flowers on prescription via telemedicine for almost any medical purpose. According to the researchers, this has created Europe’s largest commercial cannabis market, with around 200 tonnes of medical cannabis available during 2025.

How use was measured across 23 survey waves

The study draws on DEBRA, an ongoing series of surveys on nicotine, tobacco and cannabis in the German population. The analysis covers survey waves 36 to 58, from April 2022 to March/April 2026 — around two years before and two years after the CanG was introduced. Interviews were conducted face to face in people’s homes, and respondents were recruited either through random stratified sampling or quota sampling. The responses were weighted to match the population in terms of age, gender, household size, level of education and region.

In total, 35,957 people aged 14–64 took part. Of these, 6.4 per cent, corresponding to 2,302 people, reported having used cannabis in the past 12 months — around 100 people per survey wave. Within that group, 11.7 per cent, or 270 people, reported daily or almost daily use. The analysis used piecewise logistic regression, testing for a change in slope at the first full survey wave after April 2024. As a sensitivity analysis, the break point was moved two waves forward and two waves back.

Stable use also among young people and men

Use remained broadly unchanged throughout the study period. Among men, the share rose during the third quarter of 2023, then fell and rose again from the middle of 2024 — a pattern that was clearer in the 14–24 age group. In the group who had used cannabis in the past year, the share of heavy users fluctuated more and declined slightly over time.

None of the slopes before the reform were statistically significant, with the exception of a slightly negative slope among daily or almost daily users in the group who had used cannabis in the past year (−0.091; p = 0.04). Nor was any of the coefficients for a change in slope after the reform significant (all p ≥ 0.15), and the sensitivity analyses gave the same picture. A subsequent analysis that also allowed a level shift at the time of the reform did not change the conclusions, apart from a minor shift in the 25–64 age group, where the p-value for the pre-reform slope went from 0.071 to 0.028.

Consistent with other German measurements

The researchers compare their results with other representative German surveys. A nationwide survey conducted every three years showed a steady increase in 12-month prevalence in the 18–59 age group, from 5.1 per cent in 2012 to 10.0 per cent in 2021. More recent data from the same survey estimated 12-month prevalence among 18–64-year-olds at 8.8 per cent in 2021 and 9.8 per cent in 2024, that is, after the reform — but that increase was not statistically significant and appeared only among men, from 10.7 to 12.3 per cent, not among women, whose level stayed around 7 per cent.

Another population survey focusing on young people showed a steady increase in 12-month prevalence in the 18–25 age group since 2008. There, use among men rose from 26.9 per cent in 2023 to 31.6 per cent in 2025, while the level among women remained around 19 per cent. The share of heavy users among adults who had used cannabis in the past year has also been fairly constant since 1995, at around 10 per cent, with a somewhat higher share in 2021 and no significant difference between 2021 and 2024.

Effects may appear later

Research on commercial cannabis models suggests that use increases modestly in jurisdictions with retail sales, such as most Canadian provinces and many US states. An analysis of survey data among US college students also showed that effects can grow over time, with the largest effect sizes five years after a law change. The researchers therefore argue that shifts in German cannabis use may only appear in the coming years, and that some policy effects — particularly regarding legal access through private and collective cultivation — have not yet fully unfolded.

Limitations of the study

The study is observational and lacks a control group or comparison series, which limits the scope for causal conclusions. The researchers cannot separate effects of the KCanG from those of the MedCanG. The survey also does not capture marginalised groups, so possible changes in use among the most vulnerable are probably not reflected.

The primary outcome — any use in the past 12 months — may to some degree reflect behaviour from before the reform among those who responded during the first year after April 2024. That misclassification is not considered substantial, however, as around 80 per cent of those who reported use in the past year also reported use in the past 30 days. The absolute prevalence is likely underestimated because the interviews were conducted face to face at home, and according to the researchers a changed willingness to disclose cannabis use could produce an artificial increase after the reform. In addition, the number of participants per survey wave was limited, at around 1,500 people.

The researchers want continued monitoring

The study concludes that partial legalisation was probably not associated with any short-term change in the trend for 12-month prevalence, nor with any change in the share of heavy users among those who had used cannabis in the past year. The increase seen since 2012 may continue at a weaker slope. The researchers recommend continued close monitoring of trends using several data sources and over a longer period after the reform.

Source

Cannabis use prevalence before and early after partial legalisation in Germany