Cannabis Use Significantly Increases Suicide Risk in First-Episode Psychosis Patients

Across 50 studies (12,764 FEP patients), cannabis use consistently elevated suicide risk (OR 1.43-1.84), with daily use showing OR 2.73 (95% CI 1.89-3.94) and high-THC cannabis OR 3.12 (95% CI 2.11-4.62). Mechanisms included neurobiological alterations, depressive symptom exacerbation, impaired cognition, increased duration of untreated psychosis, and reduced treatment adherence. Critical high-risk periods: first month after treatment initiation and post-discharge.

Systematic review following PRISMA guidelines analyzing 50 studies involving 12,764 first-episode psychosis patients. Examined cannabis-suicide relationship, underlying mechanisms, moderating factors, and intervention strategies.

Suicide is the leading cause of premature death in psychosis patients, and this review shows cannabis dramatically amplifies that risk. The dose-response relationship, with daily and high-potency use carrying the most risk, provides specific guidance for clinical risk assessment and intervention timing.

As cannabis potency increases globally, the suicide risk for psychosis patients who use cannabis may be rising. The identification of specific high-risk periods (early treatment, post-discharge) enables targeted intervention protocols that could save lives.

Mostly observational studies. Cannot fully establish causation. Suicide is rare even in high-risk populations, limiting statistical precision. THC potency was not measured directly in most studies. Cannot determine whether cannabis causes suicidality or whether suicidal patients are more likely to use cannabis.