Ethnoracial disparities in suicide following interpersonal violence: A nationwide cohort of over 9 million Brazilian youth.

Background: Interpersonal violence is a known risk factor for suicide, but its impact across racial and ethnic groups, particularly among Black and Indigenous youth, remains underexplored. Methods: We conducted a nationwide longitudinal study involving 9,788,264 individuals aged 10-29 years who were enrolled in the 100 Million Brazilian Cohort and linked to Notifiable Diseases Information System (SINAN), National Hospital Information System (SIH) and Mortality Information System (SIM) (2011-2018). Exposure was any recorded interpersonal violence; the outcome was suicide (ICD-10 X60-X84). Cox models adjusted for demographic, socioeconomic, household factors, prior psychiatric hospitalization, and self-harm. Analyses were stratified by race. Findings: During follow-up, 92,287 (0·94%) individuals had a record of interpersonal violence, and 1,657 suicides were identified. Exposure to violence was associated with a higher risk of suicide (HR 2·92; 95% CI 2·06-4·15). Associations were strongest among Indigenous youth (HR 10.61; 95% CI 4.34-25.94), followed by Black youth (HR 3.14; 95% CI 1.92-5.14). No significant association was observed among White youth. Interpretation: Interpersonal violence is a major risk factor for youth suicide in Brazil, disproportionately affecting Indigenous and Black populations. Addressing systemic racism and structural inequalities is essential for equitable suicide prevention.