Mental health disorders and suicide mortality in Peru: A propensity score-matched analysis of national registry data between 2017 and 2023

Background: Mental health disorders and suicide associations are well-documented globally, yet exhibit pronounced Global North research bias with limited evidence from Latin America and the Caribbean (LAC) region. Objective: To examine the association between mental health disorders and suicide mortality using Peru's national mortality surveillance system with propensity score matching. Methods: We conducted a cross-sectional analysis of Peru's National Death Information System (SINADEF) from January 2017 to December 2023. Mental health and substance use disorders were identified from contributing and antecedent causes of death, classified into seven categories: unipolar depression, bipolar disorder, schizophrenia, dementia, drug use disorder, alcohol use disorder, and intellectual disability. Propensity score matching (3:1 nearest neighbor) was employed to control for demographic, socioeconomic, and geographic confounders, followed by logistic regression to examine associations between psychiatric diagnosis and suicide mortality. Results: The analysis included 1070,242 individuals. After propensity score matching, demographic characteristics were well-balanced between exposed and unexposed groups. Any mental health disorder was significantly associated with suicide mortality (OR = 4.86, 95% CI: 2.98–7.94). Unipolar depression showed the strongest association (OR = 45.00, 95% CI: 10.62-190.63), followed by schizophrenia and psychosis (OR = 5.02, 95% CI: 1.20–21.05), and substance use disorders (OR = 2.32, 95% CI: 1.01–5.29) driven primary by alcohol use disorder (OR = 2.51, 95% CI: 1.08-5.82). Dementia showed no significant association with suicide mortality (OR = 0.23, 95% CI: 0.01-4.10). Conclusions: Mental health disorders are associated with increased odds of suicide mortality in Peru.