Cannabis Use Linked to Higher Risk of Violent Behavior and Victimization
Cannabis users face twice the likelihood of committing violent acts and roughly one and a half times the risk of experiencing violence themselves, according to a large review published in Psychological Medicine and led by researchers at King’s College London.
King’s College London Links Cannabis Use to Doubled Risk of Violence
Researchers at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London analyzed 63 studies involving over 265,000 people. General population cannabis users showed twice the rate of committing violent acts, while psychiatric patients using cannabis displayed roughly two and a half times the rate of non-using psychiatric peers.
Examining the Scope of Physical, Sexual, and Psychological Harm
The research team combined data from 63 studies to examine the WHO-defined scope of physical, sexual, and psychological violence, separating self-reported actions from criminal convictions.
Dr. Marta Di Forti, co-author of the study from the IoPPN and South London and Maudsley NHS Foundation Trust, noted that heavy cannabis use acts as a factor in violence, allowing researchers to speak with greater confidence about these risks while avoiding broader stigmatization.
Longitudinal Findings and Criminal Conviction Rates
Professor Sir Robin Murray, senior author of the study from the IoPPN, stated that the link held in longitudinal studies following people over time, though associations appeared smaller than in cross-sectional studies observing a single point in time.
For violence resulting in criminal convictions, individuals using cannabis displayed three to four times the likelihood of having a conviction. Murray pointed out that as cannabis undergoes global commercialization and legalization, discussions regarding risk must expand beyond the individual user to encompass violence.
Increased Victimization Risks and Demographic Disparities
The review also revealed that cannabis users faced a fifty percent higher risk of becoming victims of violence, with this association proving stronger among women than men. The National Institute for Health and Care Research (NIHR) Biomedical Research Centre: Maudsley and the Medical Research Council supported the investigation.
The review identified an association rather than direct causation, noting that concurrent alcohol use, other drug use, and social circumstances frequently overlap with cannabis consumption.
Public Health Implications and Study Limitations
Regarding public health implications, the study authors advise mental health services to routinely evaluate cannabis use when assessing violence risk, and suggest public health messaging incorporate these findings.
However, the study’s authors emphasize key limitations: most underlying research occurred before high-potency cannabis became prevalent, few studies quantified exact usage amounts or frequency, and criminal conviction data relied on a limited subset of studies.
Patients and families managing complex behavioral health concerns alongside substance use are encouraged to consult qualified mental health professionals and addiction medicine specialists to evaluate risk factors and establish individualized care protocols.
Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.