Cannabis use was linked to aggression in people with PTSD and psychotic disorders, but causation unproven
A systematic review of 15 studies found associations between cannabis use and aggression or violence in people with PTSD and psychotic-spectrum disorders, but methodological limitations prevent causal conclusions.
Quick Facts
What This Study Found
Cross-sectional associations between cannabis use and aggression/violence were found in PTSD samples. Longitudinal associations were observed in psychotic-spectrum disorders. However, uncontrolled confounding factors in most studies preclude causal conclusions.
Key Numbers
391 papers identified, 15 met inclusion criteria. Cross-sectional associations found in PTSD samples. Longitudinal associations found in psychotic-spectrum disorders.
How They Did This
Systematic review following PRISMA guidelines, searching PubMed, Google Scholar, MEDLINE, and PsycINFO from inception to January 2022. Of 391 papers, 15 met inclusion criteria examining aggression/violence in people with psychiatric diagnoses who use cannabis.
Why This Research Matters
Understanding whether cannabis increases aggression risk in people with psychiatric conditions is critical for clinical decision-making, but this review shows the evidence is not yet strong enough to draw firm conclusions.
The Bigger Picture
As cannabis use becomes more common, including among people with psychiatric conditions, understanding its relationship to aggression and violence becomes increasingly important for clinicians and patients alike.
What This Study Doesn't Tell Us
Only 15 studies met criteria. Most had uncontrolled confounders. The review mixed cross-sectional and longitudinal designs. Different definitions of aggression and violence were used across studies.
Questions This Raises
- ?Does cannabis directly increase aggression in vulnerable populations, or do shared risk factors explain both?
- ?Could certain cannabis products or doses be more problematic?
- ?Would controlled studies show different results?
Trust & Context
- Key Stat:
- Longitudinal association found specifically in psychotic-spectrum disorders
- Evidence Grade:
- Moderate: systematic review with PRISMA methodology, but limited by small number of included studies and their methodological weaknesses.
- Study Age:
- Published in 2022.
- Original Title:
- Does cannabis use predict aggressive or violent behavior in psychiatric populations? A systematic review.
- Published In:
- The American journal of drug and alcohol abuse, 48(6), 631-643 (2022)
- Authors:
- Sorkhou, Maryam(8), Johnstone, Samantha(2), Kivlichan, Ashley E, Castle, David J, George, Tony P
- Database ID:
- RTHC-04240
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does cannabis make people aggressive?
This review found associations between cannabis use and aggression in people with PTSD and psychotic disorders, but the evidence is not strong enough to say cannabis directly causes aggression. Confounding factors were not adequately controlled in most studies.
Which psychiatric conditions showed the strongest link?
Cross-sectional associations were found in PTSD, and longitudinal associations (suggesting a temporal relationship) were found in psychotic-spectrum disorders.
What would it take to prove causation?
The authors call for well-controlled longitudinal studies that account for confounders like alcohol use, medication compliance, symptom severity, and socioeconomic factors.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-04240APA
Sorkhou, Maryam; Johnstone, Samantha; Kivlichan, Ashley E; Castle, David J; George, Tony P. (2022). Does cannabis use predict aggressive or violent behavior in psychiatric populations? A systematic review.. The American journal of drug and alcohol abuse, 48(6), 631-643. https://doi.org/10.1080/00952990.2022.2118060
MLA
Sorkhou, Maryam, et al. "Does cannabis use predict aggressive or violent behavior in psychiatric populations? A systematic review.." The American journal of drug and alcohol abuse, 2022. https://doi.org/10.1080/00952990.2022.2118060
RethinkTHC
RethinkTHC Research Database. "Does cannabis use predict aggressive or violent behavior in ..." RTHC-04240. Retrieved from https://rethinkthc.com/research/sorkhou-2022-does-cannabis-use-predict
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.