Trial reportAddiction (Abingdon, England)2025
Effects of legal access versus illegal market cannabis on use and mental health: A randomized controlled trial.
Trial report in Addiction (Abingdon, England), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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
2 citing papers in PubMed.
- Effects of legal access versus illegal market cannabis on use and mental health: A randomized controlled trial.Addiction (Abingdon, England) · 2025Trial
- Commentary on Baltes-Flueckiger et al.: Rethinking expectations and evidence in cannabis policy.Addiction (Abingdon, England) · 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
10 authors.
Funding
Abstract
aimsWe measured the effects of public health-oriented cannabis access compared with the illegal market on cannabis use and related mental health outcomes in adult cannabis users.
designThis was a two-arm, parallel group, open-label, randomized controlled trial. Follow-up outcome measurement took place after 6 months.
settingThe study was conducted in Basel-Stadt, Switzerland.
participantsA total of 378 adult (aged ≥18 years) cannabis users were enrolled and randomized between August 2022 and March 2023, although only 374 users who completed baseline measures could be included. INTERVENTION AND COMPARATOR: Participants were randomly assigned to the intervention group with public health-oriented recreational cannabis access in pharmacies (regulated cannabis products, safer use information, voluntary counseling, no advertisement; 189/188) or the illegal market control group (continued illicit cannabis sourcing; 189/186). MEASUREMENTS: The primary outcome was self-reported severity of cannabis misuse after 6 months, as measured by the Cannabis Use Disorders Identification Test - Revised (range 0-32). Secondary outcomes involved depressive, anxiety, and psychotic symptoms, cannabis consumption amount, alcohol, and drug use.
findingsTen participants were not followed (2.7%). Primary analysis included those with complete data (182 vs. 182). There was some evidence of a difference in cannabis misuse between the legal cannabis intervention group (mean [M] = 10.1) and the illegal market control group (M = 10.9; β = -0.69, 95% confidence interval [CI] = -1.4 to 0.0, P = 0.052). These results were supported by an intention-to-treat multiple imputation analysis (n = 374). Additional sub-group analysis by whether the participant used other drugs or not suggested that any reduction in cannabis misuse was confined to those in the legal cannabis intervention group who used other drugs (P
conclusionsPublic health-oriented recreational cannabis access may decrease cannabis use and cannabis-related harms, especially among those using other drugs.
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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.