A Mini-Review Found Suggestive Evidence That Cannabis Use Increases Suicide Risk in People With Schizophrenia | Research

The takeaway

Across 12 studies examining cannabis use and suicide risk in people with schizophrenia spectrum disorders, cohort studies consistently pointed toward increased suicide risk with cannabis exposure, with the strongest signals among men and during first-episode psychosis.

Psychiatrists, psychosis specialists, suicide prevention researchers, mental health clinicians.

Cohort studies consistently linked cannabis to increased suicide risk in schizophrenia

What the researchers found

Three cohort studies agreed that cannabis use was associated with increased suicide risk in schizophrenia patients. Cross-sectional studies and one case-control study yielded contradictory results. Qualitative synthesis suggested a positive correlation, particularly for first-episode psychosis (FEP) and male patients.

Why it matters

Both cannabis use and psychotic disorders independently increase suicide risk. Understanding whether their combination creates additional risk is critical for clinical management, especially during the vulnerable first-episode psychosis period.

The numbers in context

12 studies included. 3 cohort studies showed increased risk. 6 cross-sectional studies yielded mixed results. Male gender and first-episode psychosis identified as key risk modifiers.

How the study worked

Mini-review searching PubMed, Scopus, and PsycInfo from January 2010 to February 2022. Included 6 cross-sectional, 3 cohort, 1 case-control, 1 RCT, and 1 case report.

What this study cannot tell us

Mini-review rather than systematic review with meta-analysis. Small number of included studies (12). Heterogeneous study designs make comparison difficult. Cannot determine causation. Publication bias possible.

How to read the evidence

Mini-review of 12 studies with consistent cohort study findings but mixed cross-sectional results.

When this study was published

Published in 2023 reviewing literature from 2010-2022.

The bigger picture

This review highlights a concerning but still uncertain signal. The consistency of cohort studies (which are methodologically stronger than cross-sectional designs) versus the mixed cross-sectional findings suggests the association may be real but difficult to detect without longitudinal follow-up.

Questions still open

Does cannabis use directly increase suicide risk in psychosis, or is it a marker for other risk factors?
Should cannabis screening be standard in suicide risk assessment for psychosis patients?

Common questions

Does cannabis increase suicide risk in people with schizophrenia?

Cohort studies in this review consistently suggested yes, with the strongest signal among men and during first-episode psychosis. However, cross-sectional studies yielded mixed results, and the evidence is not conclusive.

Who is most at risk?

The review identified male gender and first-episode psychosis as key factors that may amplify the association between cannabis use and suicide risk in schizophrenia.

Read the original research

CANNABIS USE AND SUICIDE IN NON-AFFECTIVE PSYCHOSIS: A MINI-REVIEW OF RECENT LITERATURE.

Psychiatria Danubina, 35(3), 307-319

View on PubMed ↗Publisher’s paper ↗

Citation

Ricci, Valerio; Cristofori, Enrico; Passarello, Erica; Paggi, Andrea; Cavallo, Alex; Ceci, Franca; Martinotti, Giovanni; De Berardis, Domenico; Maina, Giuseppe. (2023). CANNABIS USE AND SUICIDE IN NON-AFFECTIVE PSYCHOSIS: A MINI-REVIEW OF RECENT LITERATURE.. Psychiatria Danubina, 35(3), 307-319. https://doi.org/10.24869/psyd.2023.307