A systematic review of longitudinal studies investigating the impact of cannabis use in patients with psychotic disorders
Open accessAbstract
Introduction: Research has established a link between cannabis use and adverse psychotic outcomes in psychosis patients. However, we have yet to determine if this relationship is maintained when controlling for important confounding variables. The following systematic review aims to investigate if the association between cannabis use and psychotic outcomes is preserved when accounting for important confounders, and if discontinued use mitigates any potential negative impacts.Areas covered: The authors conducted an exhaustive search of the MEDLINE database and Google Scholar to identify articles pertaining to the systematic review. Thirty-three articles were retained for meeting the eligibility criteria.Expert opinion: The evidence confirms an overarching pattern of negative psychotic outcomes of cannabis intake in psychosis populations, even when accounting for crucial confounders. Psychosis patients should be informed with evidence-based health information regarding the effects of cannabis use. Clinicians should systematically evaluate cannabis intake patterns in psychosis patients and offer intervention services geared toward reducing problematic consumption. Researchers should record confounding factors in a more systematic manner in future longitudinal investigations while paying careful attention to the potency and dose–response effects of the ingested cannabis. Deciders will need to investigate the impact of cannabis regulations on psychosis populations.
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Continued cannabis use in people with psychosis is associated with longer hospital stays than in non-users.
“A meta-analysis of longitudinal studies [54] found that continued cannabis use in people with psychosis is associated with an increased risk of relapse to psychosis and with longer hospital stays than in non-users [55].”
From Cannabis, cannabinoids and health: a review of evidence on risks and medical benefits (2025) · cites this paper as [55]
Continued cannabis use in people with psychosis is associated with an increased risk of relapse to psychosis.
“A meta-analysis of longitudinal studies [54] found that continued cannabis use in people with psychosis is associated with an increased risk of relapse to psychosis and with longer hospital stays than in non-users [55].”
From Cannabis, cannabinoids and health: a review of evidence on risks and medical benefits (2025) · cites this paper as [55]
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“One study [61] exclusively included patients receiving intramus-”
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Cannabis, cannabinoids and health: a review of evidence on risks and medical benefits
Hoch, E., Volkow, N. D., Friemel, C. M., Lorenzetti, V., Freeman, T. P., & Hall, W. (2025) · European Archives of Psychiatry and Clinical Neuroscience · doi:10.1007/s00406-024-01880-2 · Cited by 139 · see citing works
- Authors
- Athanassiou, M., Dumais, A., Gnanhoue, G., Abdel-Baki, A., Jutras-Aswad, D., & Potvin, S.
- Affiliations
- Institut universitaire en santé mentale de Montréal (CA)
- Institut national de psychiatrie légale Philippe-Pinel (CA)
- Department of Psychiatry and Addiction, Faculty of Medicine, University of Montreal, Montreal, Canada
- Corresponding author
- Potvin, Stéphane
- Venue
- Expert Review of Neurotherapeutics
- Publisher
- Informa UK Limited
- Published
- 2021-06-21
- Volume
- 21
- Issue
- 7
- Pages
- 779-791
- ISSN
- 1473-7175 (ISSN-L)
- 1744-8360
- OpenAlex
- W3168748807
- Cited by
- 29
- References
- 10
- Citations by year
- 2026: 6 · 2025: 3 · 2024: 11 · 2023: 5 · 2022: 4
- FWCI
- 0.63
- Type
- journal article
- Language
- en
- Open access
- green
- figshare.com
- Licence
- cc-by
- Locations
- Expert Review of Neurotherapeutics (publishedVersion)
- PubMed (publishedVersion)
- Figshare (submittedVersion, cc-by)
- Figshare (cc-by)
- Topics
- Health Sciences › Medicine › Pharmacology › Cannabis and Cannabinoid Research
- Health Sciences › Medicine › Psychiatry and Mental health › Schizophrenia research and treatment
- Health Sciences › Medicine › Epidemiology › Substance Abuse Treatment and Outcomes
- Keywords
- cannabis use, psychosis, cannabis withdrawal, confounding variables, cannabis potency, dose-response relationship, cannabis regulation, longitudinal outcomes
- MeSH terms
- Analgesics, Cannabis, Humans, Longitudinal Studies, Psychotic Disorders
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