Research paperGeographical and temporal variations in the prevalence of mental disorders in suicide: Systematic review and meta-analysis

- The prevalence of mental disorders among suicide is the lowest in the East Asia.
- The prevalence of mental disorders among suicide has been decreasing.
- There are substantial heterogeneities among psychological studies.

BackgroundIn contrast to the previous studies reporting that most suicides occur among people with mental disorders, recent studies have reported various rates of mental disorders in suicide in different geographical regions. We aimed to comprehensively investigate the factors influencing the variation in the prevalence of mental disorders reported among suicide victims.MethodThe authors searched Embase, Medline, Web of Science, and the Cochrane Library to identify psychological autopsy studies reporting the prevalence of any mental disorders among suicide victims. A meta-regression analysis was conducted to identify the potential effects of geographical regions, the year of publication, measurements of personality disorder, measurements of comorbidity, and the ratio of females on the prevalence of mental disorders in addition to examining the heterogeneity across studies.ResultsFrom 4475 potentially relevant studies, 48 studies met eligibility criteria, with 6626 suicide victims. The studies from East Asia had a significantly lower mean prevalence (69.6% [95% CI=56.8 to 80.0]) than those in North America (88.2% [95% CI=79.7-93.5]) and South Asia (90.4% [95% CI=71.8-97.2]). The prevalence of any mental disorder decreased according to the year of publication (coefficients=−0.0715, p<0.001).LimitationsSubstantial heterogeneities were identified within all subgroup analyses.ConclusionsThe prevalence of mental disorders among suicide cases seemed relatively low in the East Asia region, and recently published studies tended to report a lower prevalence of mental disorders. The link between the risk factors and suicide in the absence of a mental disorder should be examined in different geographical and sociocultural contexts.