Relationships between cannabis use and mental disorders: assessing the coherence of evidence from studies with different methodologies.
W. Hall, T. Yimer, R. Thorne, Eva Hoch, Chloe Burke, A. Gridley, Y. Hurd, Jack Wilson, Janni Leung, Tom P. Freeman
The Lancet Psychiatry July 1, 2026 DOI: 10.1016/s2215-0366(26)00086-6 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Key findings | The authors conclude there is credible evidence that daily cannabis use is a contributory cause of psychosis. They report that evidence for bipolar disorder is limited by fewer high-quality studies, and that the role of cannabis in depression, anxiety, and suicidality remains uncertain because associations are modest and may reflect self-medication, shared risk factors, or bidirectional relationships. |
Abstract
Cannabis use often begins in adolescence and young adulthood, when anxiety, depression, psychosis, and bipolar disorder typically first develop. Young people aged in their mid-teens to mid-twenties who engage in daily cannabis use and develop a cannabis use disorder have a higher prevalence of these mental disorders. We assessed the coherence of evidence from epidemiological, genetic, experimental, and preclinical studies to assess relationships between daily cannabis use and the increased incidence, prevalence, and persistence of psychosis, bipolar disorder, anxiety, depression, and suicidal behaviours. We found credible evidence that daily cannabis use is a contributory cause of psychosis. There were fewer high quality epidemiological and genetic studies of bipolar disorder. The role of cannabis use in depression, anxiety, and suicidality was less certain because associations were modest and could reflect self-medication, shared risk factors, or bidirectional relationships. A high priority should be given to developing effective interventions for cannabis use disorders in people with mental disorders.
Comparable studies
Other narrative reviews on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Causal association between cannabis and psychosis: examination of the evidence | 2004 | Review | |
| Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history. General (historical and pharmacological review) | 2018 | Review | |
| Psychiatric effects of cannabis | 2001 | Review | |
| Beyond THC: The New Generation of Cannabinoid Designer Drugs | 2011 | Review | |
| Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug | 2006 | Review |
Citations in the library
Cites 15
- Antidepressant-like activity and modulation of brain monoaminergic transmission by blockade of anandamide hydrolysis Proceedings of the National Academy of Sciences December 13, 2005
- Effects of cannabis use on outcomes of psychotic disorders: systematic review The British Journal of Psychiatry October 31, 2008
- Poor medication adherence and risk of relapse associated with continued cannabis use in patients with first-episode psychosis: a prospective analysis The Lancet Psychiatry July 10, 2017
- An Update on the Behavioral and Neurobiological Effects of Cannabis Use in Adolescents: A Translational Perspective. American Journal of Psychiatry July 1, 2025
- Convergence of Cannabis and Psychosis on the Dopamine System JAMA Psychiatry April 9, 2025
and 10 more in the library