It remains unclear whether children and adolescents in the child welfare system (CWS) exhibit a higher prevalence of mental disorders compared with the general population. The objective of this study was to perform a systematic review and meta-analysis to assess the prevalence of mental disorders in the CWS.
All of the epidemiological surveys assessing the prevalence of mental disorders in children and adolescents in the CWS were included. The pooled prevalence was estimated with random effect models. Potential sources of heterogeneity were explored using meta-regression analyses.
Eight studies provided prevalence estimates that were obtained from 3104 children and adolescents. Nearly 1 child or adolescent of every 2 (49%; 95% confidence interval (CI) 43–54) was identified as meeting criteria for a current mental disorder. The most common mental disorder was disruptive disorder (27%; 95% CI 20–34), including conduct disorder (20%; 95% CI 13–27) and oppositional defiant disorder (12%; 95% CI 10–14). The prevalence of attention-deficit/hyperactivity disorder was estimated to be 11% (95% CI 6–15). The prevalence estimates of anxiety and depressive disorders were 18% (95% CI 12–24) and 11% (95% CI 7–15). Posttraumatic stress disorder had the lowest prevalence (4%; 95% CI 2–6).
High prevalences of mental disorders in the CWS were reported, which highlights the need for the provision of qualified service. The substantial heterogeneity of our findings is indicative of the need for accurate epidemiological data to effectively guide public policy.