Cannabis use disorder was not linked to violence in people with schizophrenia, but alcohol use disorder was
Among 124 patients with schizophrenia in a high-security hospital, cannabis use disorder was not associated with impulsivity or violence, while alcohol use disorder was nearly four times more likely to be associated with violent behavior.
Quick Facts
What This Study Found
Violent and nonviolent psychotic patients had similar rates of cannabis use disorder. Cannabis was not associated with any dimension of impulsivity. In contrast, alcohol use disorder was associated with impulsive behavior and was nearly 4 times more likely in violent patients (OR=3.96). Cocaine use disorder was associated with proneness to boredom but not violence.
Key Numbers
124 patients; alcohol use disorder OR=3.96 for violence; cannabis use disorder not associated with violence or impulsivity; cocaine linked to proneness to boredom
How They Did This
Cross-sectional retrospective study of 124 patients with schizophrenia spectrum disorders in a high-security hospital, using standardized measures of violence history, impulsivity, psychopathy, substance use, and psychotic symptoms.
Why This Research Matters
The common assumption that cannabis drives violence in people with psychosis is challenged by this data showing alcohol, not cannabis, is the substance associated with violent behavior in this high-risk population.
The Bigger Picture
This finding is important for clinical risk assessment. If practitioners focus on cannabis as a violence risk factor while underweighting alcohol, they may misjudge which patients are at highest risk.
What This Study Doesn't Tell Us
Cross-sectional design in a specialized high-security setting. Patients may underreport substance use. Results may not generalize to community-dwelling psychosis patients. Small sample size.
Questions This Raises
- ?Does this finding hold in community settings?
- ?Should clinical violence risk assessments weight alcohol more heavily than cannabis?
- ?Could cannabis use be a marker for other risk factors without being causal?
Trust & Context
- Key Stat:
- Alcohol, not cannabis, was associated with violence in schizophrenia (OR=3.96)
- Evidence Grade:
- Cross-sectional study in a specialized high-security setting with standardized measures
- Study Age:
- Published in 2021. The relationship between substance use and violence in psychosis remains debated.
- Original Title:
- Lifetime Cannabis Use Disorder Is Not Associated With Lifetime Impulsive Behavior and Severe Violence in Patients With Schizophrenia Spectrum Disorders From a High-Security Hospital.
- Published In:
- Journal of clinical psychopharmacology, 41(6), 623-628 (2021)
- Authors:
- Comai, Stefano(2), Fuamba, Yves, Rivolta, Maria Chiara, Gobbi, Gabriella
- Database ID:
- RTHC-03072
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis make people with schizophrenia violent?
This study found no association between cannabis use disorder and violence or impulsivity in 124 schizophrenia patients. Alcohol use disorder, not cannabis, was the substance associated with violent behavior.
Which substance poses the greatest violence risk in psychosis?
In this high-security hospital study, alcohol use disorder was nearly four times more likely among violent patients. The authors recommend clinicians focus on alcohol abuse when assessing dangerousness in psychotic patients.
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Cite This Study
https://rethinkthc.com/research/RTHC-03072APA
Comai, Stefano; Fuamba, Yves; Rivolta, Maria Chiara; Gobbi, Gabriella. (2021). Lifetime Cannabis Use Disorder Is Not Associated With Lifetime Impulsive Behavior and Severe Violence in Patients With Schizophrenia Spectrum Disorders From a High-Security Hospital.. Journal of clinical psychopharmacology, 41(6), 623-628. https://doi.org/10.1097/JCP.0000000000001493
MLA
Comai, Stefano, et al. "Lifetime Cannabis Use Disorder Is Not Associated With Lifetime Impulsive Behavior and Severe Violence in Patients With Schizophrenia Spectrum Disorders From a High-Security Hospital.." Journal of clinical psychopharmacology, 2021. https://doi.org/10.1097/JCP.0000000000001493
RethinkTHC
RethinkTHC Research Database. "Lifetime Cannabis Use Disorder Is Not Associated With Lifeti..." RTHC-03072. Retrieved from https://rethinkthc.com/research/comai-2021-lifetime-cannabis-use-disorder
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.