Risk and Protective Factors for Suicide Mortality in Youths: A Systematic Review and Meta-Analysis.

Abstract

Risk and protective factors for suicide mortality in youths remain poorly synthesized, as prior reviews have focused on all ages or nonfatal outcomes. To systematically assess factors associated with risk of suicide mortality in youths. MEDLINE, PsycINFO, Embase, and CINAHL from inception to March 7, 2025. Case-control and cohort studies of youths (aged ≤24 years) examining risk and/or protective factors associated with suicide mortality vs living general-population controls were included. Two independent reviewers screened 9497 records. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 2 reviewers independently screened reports; 1 extracted data, verified by a second. Evidence was synthesized using vote counting and random-effects meta-analysis in April 2026. The primary outcome was suicide mortality at age 24 years or younger. Ninety reports from 68 studies, mostly from high-income countries, identified distinct risk and/or protective factors; 54 reports contributed to 30 meta-analyses. The factors associated with the highest odds of suicide risk included schizophrenia (odds ratio [OR], 22.23; 95% CI, 12.05-41.03; I2 = 85.4%; 7 reports), mood disorders (OR, 11.32; 95% CI, 6.11-20.97; I2 = 64.6%; 7 reports), and self-harm (OR, 14.06; 95% CI, 5.58-35.39; I2 = 90.1%; 10 reports). Clinical indicators of health care use were also associated with higher risk, including mental health services use in preceding year (OR, 7.39; 95% CI, 6.45-8.47; I2 = 0.0%; 5 reports) and psychiatric admission (OR, 31.96; 95% CI, 13.83-73.86; I2 = 94.8%; 6 reports). At the socioecological level, several indicators were associated with higher risk, including maltreatment (OR, 4.03; 95% CI, 1.41-11.50; I2 = 67.1%; 5 reports), out-of-home placement (OR, 4.47; 95% CI, 2.15-9.28; I2 = 42.1%; 5 reports), youth justice system involvement (OR, 2.70; 95% CI, 1.94-3.75; I2 = 64.2%; 7 reports), and low educational attainment (OR, 2.95; 95% CI, 1.66-5.24; I2 = 76.0%; 5 reports). In contrast, indicators of family stability were associated with lower risk, including living with both parents (OR, 0.55; 95% CI, 0.48-0.62; I2 = 12.1%; 11 reports). Heterogeneity was substantial across analyses, while Newcastle-Ottawa ratings indicated moderate-to-high study quality. In this systematic review and meta-analysis, suicide mortality in youths was associated with mental disorders, health care contact, and adversity, supporting both clinical care and population-level prevention, with future research needed in underrepresented populations.