Polanczyk · Journal of child psychology and psychiatry, and allied disciplines 2015 · systematic review and meta-analysis · n=41 studies

Annual research review: A meta-analysis of the worldwide prevalence of mental disorders in children and adolescents.

Cited 4060 times in the scientific literature.

Level 1 - systematic review of randomized trials

Systematic review and meta-analysis of epidemiological prevalence studies (design analogy)

PubMed 25649325 · doi:10.1111/jcpp.12381 · record verified 2026-08-29

What was done

Authors systematically searched PubMed, PsycINFO, and EMBASE for prevalence studies of mental disorders in probabilistic community samples of children and adolescents using standardized diagnostic assessments (DSM or ICD). Meta-analyses calculated worldwide pooled prevalence for any mental disorder and specific diagnostic classes. Meta-regression evaluated the influence of population characteristics, study methods, diagnostic tools, functional impairment criteria, geography, and year of data collection on estimate heterogeneity.

What was found

Across 41 studies from 27 countries: - Worldwide pooled prevalence of any mental disorder: 13.4% (95% CI 11.3–15.9) - Any anxiety disorder: 6.5% (95% CI 4.7–9.1) - Any disruptive disorder: 5.7% (95% CI 4.0–8.1) - Attention-deficit hyperactivity disorder (ADHD): 3.4% (95% CI 2.6–4.5) - Any depressive disorder: 2.6% (95% CI 1.7–3.9) Significant heterogeneity was detected for all pooled estimates. Multivariate meta-regression explained 88.89% of heterogeneity, with sample representativeness, sample frame, diagnostic interview type, and functional impairment requirements acting as significant moderators. Estimates did not significantly differ by geographic region or data collection year.

Why it matters

This review provides a global benchmark showing that approximately 1 in 8 youth meet criteria for a mental disorder. It indicates that methodological choices and diagnostic definitions drive prevalence variation far more than geographic differences.

Limits

Total individual participant sample size was not reported in the abstract. Significant residual heterogeneity persisted despite controlling for multiple moderators, and primary studies varied substantially in diagnostic tools and criteria for functional impairment.

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