Age at onset of mental disorders worldwide: large-scale meta-analysis of 192 epidemiological studies.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of 192 observational studies
PubMed 34079068 · doi:10.1038/s41380-021-01161-7
What was done
A PRISMA- and MOOSE-compliant systematic review and meta-analysis of birth cohort, cross-sectional, and cohort studies representative of the general population indexed in PubMed and Web of Science up to May 16, 2020. The authors evaluated age at onset for any ICD- or DSM-defined mental disorder. Co-primary outcomes were the proportion of individuals with onset before age 14, 18, and 25 years, and peak age at onset overall and across ICD-11 diagnostic blocks. Median age at onset for specific disorders was also assessed.
What was found
Across 192 studies including 708,561 individuals: - Any mental disorder: onset before age 14 was 34.6%, before 18 was 48.4%, before 25 was 62.5%; peak age at onset was 14.5 years (median 18, IQR 11–34). - Neurodevelopmental disorders: peak 5.5 years; 61.5% before age 14, 83.2% before 18, 95.8% before 25 (median 12). - Anxiety/fear-related disorders: peak 5.5 years; 38.1% before age 14, 51.8% before 18, 73.3% before 25 (median 17). - Obsessive-compulsive/related disorders: peak 14.5 years; 24.6% before age 14, 45.1% before 18, 64.0% before 25 (median 19). - Feeding/eating disorders: peak 15.5 years; 15.8% before age 14, 48.1% before 18, 82.4% before 25 (median 18). - Stress-associated conditions: peak 15.5 years; 16.9% before age 14, 27.6% before 18, 43.1% before 25 (median 30). - Substance use/addictive disorders: peak 19.5 years; 2.9% before age 14, 15.2% before 18, 48.8% before 25 (median 25). - Schizophrenia-spectrum/psychotic states: peak 20.5 years; 3.0% before age 14, 12.3% before 18, 47.8% before 25 (median 25). - Personality disorders: peak 20.5 years; 1.9% before age 14, 9.6% before 18, 47.7% before 25 (median 25). - Mood disorders: peak 20.5 years; 2.5% before age 14, 11.5% before 18, 34.5% before 25 (median 31). No significant differences emerged by sex or definition of age of onset.
Why it matters
Nearly half of mental disorders worldwide emerge before age 18 and nearly two-thirds by age 25. These data provide empirical benchmarks for targeting prevention and challenge healthcare systems divided strictly at age 18.
Limits
The abstract does not detail geographic distribution, study quality, or statistical heterogeneity. The inclusion of retrospective cross-sectional designs carries an inherent risk of recall bias regarding exact onset age.