An international expert panel identified modifiable cannabis-related risk factors for psychosis and developed evidence-based harm reduction recommendations, noting that protective effects of CBD remain uncertain.
Read this if you use cannabis and want to understand how to minimize your psychosis risk, or if you are a clinician advising cannabis users.
CBD uncertainExpert panel found the protective effects of CBD against cannabis-related psychosis remain uncertain
What the researchers found
The review identified multiple risk factors: genetic predisposition, mental health/substance use history, early age of first use, frequency of use, high-THC product composition, smoking route, and co-use of other substances. Risk factor combinations amplify odds of psychosis. The protective effects of CBD are uncertain despite popular belief. Continued cannabis use adversely affects psychosis treatment and medication effectiveness. The expert panel developed recommendations for risk reduction short of abstinence.
Why it matters
As cannabis use normalizes globally, a harm-reduction approach to psychosis prevention is practical and necessary. These evidence-graded recommendations give clinicians and public health officials actionable guidance for an increasingly common clinical scenario.
The numbers in context
- Literature search from 2016 onward
- Multiple risk factors identified and quality-graded
- International expert consensus panel
- CBD protective effects: uncertain
- Continued use adversely affects treatment outcomes
How the study worked
Narrative review of primary databases from 2016 onward, focusing on reviews and high-quality studies. Quality-graded evidence summaries. Recommendations developed by international expert consensus.
Who was studied
Cannabis users at risk for psychosis (general population focus)
What this study cannot tell us
Narrative review methodology. Expert consensus may not reflect all perspectives. Many risk factors are interrelated and difficult to isolate. Recommendations for harm reduction short of abstinence may be challenging to implement.
How to read the evidence
Expert consensus based on quality-graded narrative review. Strong clinical authority but dependent on underlying evidence quality.
When this study was published
Published in 2023. Provides current evidence-based guidelines for a rapidly evolving field.
The bigger picture
The shift from "just say no" to evidence-based harm reduction for cannabis mirrors what happened with alcohol and tobacco. These guidelines provide a framework for reducing psychosis risk while acknowledging that many people will continue to use cannabis.
Questions still open
- How effective are these recommendations when implemented in clinical practice?
- Should genetic testing for psychosis risk be offered to cannabis users?
- Can cannabis product regulation (THC caps, CBD requirements) reduce population-level psychosis risk?
Read the original research
Recommendations for Reducing the Risk of Cannabis Use-Related Adverse Psychosis Outcomes: A Public Mental Health-Oriented Evidence Review.
Journal of dual diagnosis, 19(2-3), 71-96
Citation
Fischer, Benedikt; Hall, Wayne; Fidalgo, Thiago M; Hoch, Eva; Le Foll, Bernard; Medina-Mora, Maria-Elena; Reimer, Jens; Tibbo, Philip G; Jutras-Aswad, Didier. (2023). Recommendations for Reducing the Risk of Cannabis Use-Related Adverse Psychosis Outcomes: A Public Mental Health-Oriented Evidence Review.. Journal of dual diagnosis, 19(2-3), 71-96. https://doi.org/10.1080/15504263.2023.2226588