Mental disorders as risk factors for suicidal behavior in young people: A meta-analysis and systematic review of longitudinal studies

Background Suicide is the second leading cause of death for young people. Objective: To assess mental disorders as risk factors for suicidal behaviour among adolescents and young adults including population-based longitudinal studies. Method We conducted a systematic literature review. Bibliographic searches undertaken in five international databases and grey literature sources until January 2017 yielded a total of 26,883 potential papers. 1701 full-text articles were assessed for eligibility of which 1677 were excluded because they did not meet our eligibility criteria. Separate meta-analyses were conducted for each outcome (suicide death and suicide attempts). Odds ratio (OR) and 95% confidence intervals (95%CI) and beta coefficients and standard errors were calculated. Results 24 studies were finally included involving 25,354 participants (12–26 years). The presence of any mental disorder was associated with higher risk of suicide death (OR = 10.83, 95%CI = 4.69–25.00) and suicide attempt (OR = 3.56; 95%CI 2.24–5.67). When considering suicidal attempt as the outcome, only affective disorders (OR = 1.54; 95%CI = 1.21–1.96) were significant. Finally, the results revealed that psychiatric comorbidity was a primary risk factor for suicide attempts. Limitations Data were obtained from studies with heterogeneous diagnostic assessments of mental disorders. Nine case-control studies were included and some data were collected in students, not in general population. Conclusions Mental disorders and comorbidity are strong predictors of suicide behaviour in young people. Detection and management of the affective disorders as well as their psychiatric comorbidity could be a crucial strategy to prevent suicidality in this age group.