Trial reportBundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz2024
[Effectiveness of a cannabis prevention program in school: results of a randomized prospective study].
Trial report in Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
3 citing papers in PubMed, 2 citations in OpenAlex.
- Risk factors for adolescent cannabis use following partial cannabis legalization in Germany: a cross-sectional study in secondary schools.Substance abuse treatment, prevention, and policy · 2026Article
- Who is at risk? Core mental health symptoms and problematic cannabis use in Germany.Journal of cannabis research · 2026Article
- Cannabis use among adolescents and young adults in Germany: Study results and prevention measures offered by the Federal Institute of Public Health.Journal of health monitoring · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundIn the current debate about legalized access to cannabis for adults in Germany, there is widespread agreement about the need for increased prevention among children and young people. The aim of this work is to examine the effectiveness of a school-based cannabis prevention program on knowledge, attitudes, and behavior.
methodCluster-randomized waiting list control group study with two study arms: "participation in the 'Der grüne Koffer' prevention program", a collection of methods for cannabis prevention, vs. "no participation" and two measurement time points before and four months after the intervention in four German states.
resultsThe mean age of the sample of 3976 adolescents from 280 school classes in grades 8 and 9 was 14.02 years (standard deviation = 0.89). The sex ratio was balanced (49.5% female). Cannabis-related knowledge increased significantly more in the intervention group compared to the control group from the first to the second measurement time point (adjusted beta = 0.25 [95% confidence interval: 0.14-0.37]). Attitudes toward cannabis use did not change significantly in either group. In the 8th grades of the intervention group, significantly fewer adolescents (2.9%) started experimenting with cannabis use for the first time during the observation period than in the control group (5.3%), whereas no group difference was detectable in the 9th grades (interaction grade level x group: odds ratio = 2.17 [1.13-4.15], p = 0.019). DISCUSSION: The evidence of an effect of participation in the "Der grüne Koffer" prevention program on knowledge and first-time use of cannabis in the 8th grade can be considered promising against the background of previous national and international studies, which could not provide evidence of effects of school-based cannabis prevention in middle and late adolescence.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.