Suicide and prevalence of mental disorders: A systematic review and meta-analysis of world data on case-control psychological autopsy studies

Introduction Suicide is a multifaceted event precipitated by underlying biopsychosocial risk factors. Evidence for various psychiatric morbidities underlying suicidality through Psychological Autopsy (PA) is established in case-control studies. However, considering the possible geographical variations and the limited number of studies from developing countries, the estimates of such risk factors across the world could provide great insight into their comparative prevalence and assist in targeting the prevention of suicide. Methods A systematic review of the literature from 1991 to 2020 in the English language was conducted with the protocol registration on PROSPERO ID (CRD 42021249216) to identify the pooled odds ratio of any psychiatric morbidity as a risk factor for suicide. Results Out of 1144 articles, 43 studies were included in this review. The pooled odds ratio for any psychiatric morbidity measured across 31 studies was 16.71 (95% CI: 12.29 - 22.70, Tau2 = 0.58, I2 = 80.4%, Cochran's Q = 153.36, df = 30, p-value <0.001). The subgroup analysis for affective disorder, previous suicide attempt, WHO region-wise risk distribution, and publication year of study were not significant. Conclusions There is a sixteen-fold increased risk of suicide in persons with mental disorders compared to healthy controls, and the risk is similar across the geographical region and publication time. The international efforts to reduce the common risk factors for suicide would equally be helpful for all countries despite cultural variations. Early identification and treatment of sleep disorders, physical illnesses, anxiety, and personality disorders should be prioritized along with the established mental disorders to reduce suicide rates across the world.