Drug Use Disorders and Violence: Associations With Individual Drug Categories.

Although drug use disorders are among the most important modifiable factors for violence perpetration, previous reviews have not investigated links with individual categories of drug use disorders or explored sources of variation in risk estimates between studies. We conducted a systematic review and meta-analysis of studies that examined the link between individual drug categories and violent outcomes. We searched for primary case-control and cohort investigations that reported risk of violence against others in individuals diagnosed with drug use disorders using validated clinical criteria, and followed PRISMA guidelines. We identified 18 studies published from 1990 to 2019 reporting data from 591,411 individuals with drug use disorders. We reported odds ratios (OR) of the violence risk in different categories of drug use disorders compared with those without. We found ORs ranged from 0.8 to 25.0 for most individual drug categories, with generally higher ORs in individuals with polydrug use disorders. In addition, we explored sources of between-study heterogeneity by subgroup and meta-regression analyses. Cohort investigations reported a lower risk of violence than case-control reports (OR = 2.7 [2.1-3.5] vs 6.6 [5.1-8.6]), and associations were stronger when the outcome was any violence rather than intimate partner violence (OR = 5.7 [3.8-8.6] vs 1.7 [1.4-2.1]), which was consistent with results from the meta-regression. Overall, these findings highlight the potential impact of preventing and treating drug use disorders on reducing violence risk and associated morbidities.