Germany’s partial legalisation of cannabis came into effect on 1 April 2024, allowing adults limited possession, home cultivation (up to three plants), and use under certain regulated conditions. Critics feared that making adult use legal would lead to sharp increases, especially among adolescents. But new data suggests the opposite is happening, teen cannabis use has declined.
A recent report, Drogenaffinitätsstudie 2025 by the Bundesinstitut für Öffentliche Gesundheit (BIÖG), surveyed about 7,001 young people aged 12-25 between April and July 2025, and compared with a similar survey from April–June 2023, before legalisation.
Here are the key findings for adolescents (12-17):
- Annual prevalence (i.e. used cannabis at least once in past 12 months) dropped from 6.7% in 2023 to 6.1% in 2025.
- “Regular use” (more than 10 times in past year) fell from 1.3% to 1.1% over the same period.
How This Fits Into Wider Research That Shows Legalisation ≠ Higher Youth Use
The German data is consistent with several peer-reviewed studies and international observations. Here are examples.
- United States – JAMA Pediatrics (2019):
A study titled “Association of Marijuana Laws With Teen Marijuana Use: New Estimates From the Youth Risk Behavior Surveys” found that after recreational legalization in some U.S. states, adolescent use either held steady or declined. The reasoning is partly that licit dispensaries impose age verification, making it harder for minors to access cannabis. - NORML / U.S. longitudinal data:
A 2023 systematic review in Frontiers in Psychiatry showed that teen cannabis use (ages ~13-17) actually dropped in some states following legalization (for recreational use), especially where regulation is strong. - Germany – Epidemiological Survey of Substance Abuse (ESA):
Looking at adults, this study found that cannabis use had been rising for several years before 2024; after legalisation in 2024, usage did rise slightly (from ~8.8% to ~9.8%) compared to 2021—but this increase was not statistically significant. Importantly, the ESA is about adults, but shows that legalisation has not led to runaway increases immediately after reform.
Why Might Teen Use Decline or Remain Stable Post-Legalisation?
Given the fears, why do so many studies show teen use stays flat or declines after legal reform? Some plausible mechanisms:
- Age verification and regulated supply channels make it harder for minors to buy cannabis from legal sources. If legal supply channels are compliant, the black market (where age checks are minimal) may shrink or become a less prevalent source.
- Reduced novelty / stigma effects: Sometimes part of the draw of illicit or tabooed substances is the “forbidden fruit” effect. Once legal, that effect may diminish.
- Better prevention, education, and public health infrastructure: Legalisation often comes with more resources for education, prevention, information campaigns, and harm reduction, which may discourage adolescent uptake.
- Monitoring & research: Legal jurisdictions more often collect data, monitor outcomes, and adjust laws/regulations, meaning negative trends may be spotted and corrected early.
What the German Findings Add: A Positive Signal
Germany’s 2025 study is encouraging for proponents of cannabis legalisation for several reasons:
- The survey is large (7000+ young people) and representative. That gives credibility to findings.
- The decline among youth is observable soon after legalisation. Since Germany’s partial legalisation is quite recent (April 2024), a drop (even modest) in youth prevalence within about a year is significant.
- The reduction is both in any past-12-month use and in more frequent/regular use among teens. Regulation may especially help curb heavier or riskier consumption patterns.
Why This Strengthens the Pro-Legalisation Argument
Putting the German findings together with international literature, here are reasons why these data strengthen the case for legalisation:
- It dispels a major fear: One of the strongest objections to legalisation has been “youth will use more”. If many jurisdictions (including Germany now) show teen use does not rise, and may even fall, that fear becomes much less compelling.
- Public health oriented regulation can work: Legalisation doesn’t mean laissez-faire. The German legalisation is partial and regulated (limits on possession, plant count, clubs, etc.). Combined with good monitoring and prevention, data suggests risk can be managed.
- Legalisation can shift black markets: If legal options are made available and informal channels reduced, then minors may have less exposure to illicit, unregulated sources where potency, contamination, and risk of adulteration are higher.
- Opportunity to invest in youth prevention: The transition to legal status often opens space (legally, politically, financially) for investing in prevention, education, counseling, mental health services. These can help reduce risk among youth.
- Potential for more honest, realistic public discourse: When cannabis is legal in some form, conversations about risks, safer use, effects on brain development, etc., can happen openly and many people are more supportive of health-based messaging.
Conclusion
The Drogenaffinitätsstudie 2025 from Germany offers a hopeful signal: teen cannabis use has fallen slightly in the year after partial legalization, both in occasional and more regular use categories. Combined with research from the U.S. and other countries, this suggests that legalisation, when done with regulation, age limits, and monitoring, does not inevitably lead to more adolescent use, and in many cases may help reduce it.
For those in favour of cannabis reform, these findings strengthen the argument that fears of youth misuse are often overstated, especially under responsible policies. They emphasize that legalisation isn’t just about freedom for adults, it can be paired with strong protections for young people.
