Cannabis, Psychosis, and Mortality: A Cohort Study of 50,373 Swedish Men.
Edison Manrique-Garcia, Antonio Ponce de Leon, Christina Dalman, Sven Andréasson, Peter Allebeck
American Journal of Psychiatry August 1, 2016 DOI: 10.1176/appi.ajp.2016.14050637 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Longitudinal study Peer reviewed |
|---|---|
| Sample size | 50,373 |
| Population | Swedish male military conscripts ages 18-19 |
| Duration | Followed up to around age 60 |
| Topics | Cannabis |
| Key findings | Heavy cannabis use at baseline was associated with a 40% higher risk of death (hazard ratio=1.4); cannabis use did not interact with psychotic disorders to affect mortality. |
Abstract
The authors assessed 1) the overall risk of death among cannabis users compared with nonusers and the extent to which psychosis affects excess mortality; 2) mortality among persons with psychotic disorders and the extent to which cannabis use affects excess mortality; and 3) the interaction effect of cannabis use and diagnosis of psychotic disorders on mortality. This was a longitudinal study of 50,373 Swedish male military conscripts (ages 18-19) who were followed in the National Cause of Death Register up to around age 60. Cox proportional hazard modeling was used to assess risk of death in relation to baseline cannabis use and diagnosis of psychotic disorders. Subjects with a baseline history of heavy cannabis use had a significantly higher risk of death (hazard ratio=1.4, 95% CI=1.1, 1.8) than those without such a history. The authors found an excess mortality among subjects with psychotic disorders, but the level did not differ between those with a history of cannabis use (ever users: hazard ratio=3.8, 95% CI=2.8, 5.0; heavy users: hazard ratio=3.8, 95% CI=2.6, 6.2) and those without such a history (hazard ratio=3.7, 95% CI=3.1, 44). No interaction was observed between cannabis use and diagnosis of psychotic disorders with regard to mortality. The results suggest that individuals with an early history of heavy use of cannabis are at a higher risk of death than those with a history of no use of cannabis. Although the authors adjusted for several confounders at baseline, the results should be interpreted with caution because of a lack of information on confounders in the period after conscription.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |
Citations in the library
Cited by 3
- Comparative Clinical Trajectories Across Cannabis‐Related and Nonsubstance‐Related Psychoses Acta Psychiatrica Scandinavica April 8, 2026
- Mindfulness-Based Interventions for Adolescent Substance Use and Substance Use Disorders: A Systematic Review. Pediatrics February 1, 2026
- Is there a common vulnerability in cannabis phenomenology and schizotypy? The role of the N170 ERP. Schizophrenia Research July 2018