Severe Mental Illness and Substance Use Disorders in Prisoners in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis of Prevalence Studies

Background: Although more than two thirds of prisoners are based in low- and middle-income countries (LMIC), the burden of psychiatric disorders is not reliably known. This review provides estimates for the prevalence of severe mental illness and substance use disorders in incarcerated individuals in LMIC. Methods: Systematic literature searches were conducted in 17 electronic databases identifying prevalence studies of psychiatric disorders in prison populations, published between January 1987 and May 2018. We pooled prevalences using random-effects meta-analyses and assessed the sources of heterogeneity by meta-regression. We extracted general population estimates from the Global Burden of Diseases 2016 database to calculate prevalence ratios. The review was registered in PROSPERO (CRD42015020905). Findings: We identified 23 publications reporting estimates for 14,527 prisoners. The pooled one-year prevalence rates were estimated to be 6·2% (95% CI 4·0-8·6) for psychosis, 16·0% (95% CI 11·7-20·8) for major depression, 3·8% (95% CI 1·2-7·6) for alcohol use disorders, and 5·1% (95% CI 2·9-7·8) for drug use disorders. We found elevated prevalences at prison intake and geographic variations for substance use disorders. Prevalence ratios indicated substantially higher rates among prisoners than in the general population. Interpretation: The prevalence of major psychiatric disorders is high in prisoners in LMIC. As these findings are likely to reflect unmet needs, the development of scalable interventions should be a public health priority in resource-poor settings. Funding: This work was funded by CONICYT of the Chilean government (FONDECYT Regular grant number 1160260 to APM) and The Wellcome Trust (grant number 202836/Z/16/Z to SF). Declaration of Interest: We declare no competing interests.