Journal article
Use of illicit substances and violent behaviour in psychotic disorders: two nationwide case-control studies and meta-analyses
- Abstract:
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Background
Substance use disorder explains most of the excess risk of violent behaviour in psychotic disorders. However, it is unclear to what extent the psychopharmacological properties and subthreshold use of illicit substances are associated with violence.
Methods
Individuals with psychotic disorders were recruited for two nationwide projects: GROUP (N = 871) in the Netherlands and NEDEN (N = 921) in the United Kingdom. Substance use and violent behaviour were assessed with standardized instruments and multiple sources of information. First, we used logistic regression models to estimate the associations of daily and nondaily use with violence for cannabis, stimulants, depressants and hallucinogens in the GROUP and NEDEN samples separately. Adjustments were made for age, sex and educational level. We then combined the results in random-effects meta-analyses.
Results
Daily use, compared with nondaily or no use, and nondaily use increased the pooled odds of violence for all substance categories. The increases were significant for daily use of cannabis (pooled odds ratio [pOR] 1.6, 95% confidence interval [CI] 1.2-2.0), stimulants (pOR 2.8, 95% CI 1.7-4.5) and depressants (pOR 2.2, 95% CI 1.1-4.5) and nondaily use of stimulants (pOR 1.6, 95% CI 1.2-2.0) and hallucinogens (pOR 1.5, 95% CI 1.1-2.1). Daily use of hallucinogens, which could only be analysed in the NEDEN sample, significantly increased the adjusted odds of violence (adjusted odds ratio 3.3, 95% CI 1.2-9.3).
Conclusions
Strategies to prevent violent behaviour in psychotic disorders should target any substance use.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
Actions
Access Document
- Files:
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(Preview, Supplementary materials, pdf, 196.3KB, Terms of use)
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(Preview, Accepted manuscript, pdf, 556.0KB, Terms of use)
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- Publisher copy:
- 10.1176/appi.focus.26024106
Authors
+ Wellcome Trust
More from this funder
- Funder identifier:
- https://ror.org/029chgv08
- Grant:
- 202836/Z/16/Z
+ Department of Health and Social Care
More from this funder
- Funder identifier:
- https://ror.org/03sbpja79
- Grant:
- PO261680
+ ZonMw, The Dutch Organisation for knowledge and innovation in health, healthcare and well-being
More from this funder
- Funder identifier:
- https://ror.org/01yaj9a77
- Grant:
- 10-000-1001
- Publisher:
- Psychiatry Online
- Journal:
- Focus More from this journal
- Volume:
- 24
- Issue:
- 1
- Pages:
- 99-104
- Publication date:
- 2026-01-15
- DOI:
- EISSN:
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1541-4108
- ISSN:
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1541-4094
- Language:
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English
- Keywords:
- Pubs id:
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2361147
- Local pid:
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pubs:2361147
- Deposit date:
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2026-03-02
- ARK identifier:
Terms of use
- Copyright holder:
- Lamsma et al.
- Copyright date:
- 2026
- Notes:
- The author accepted manuscript (AAM) of this paper has been made available under the University of Oxford's Open Access Publications Policy, and a CC BY public copyright licence has been applied.
- Licence:
- CC Attribution (CC BY)
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