Bridging Three Decades: Global Self-Harm Trends From 1990–2021 and Projections to 2040

Abstract

Background: Self-harm, which includes both nonsuicidal self-injury and suicidal behaviors, poses a major global public health challenge. This study provides a comprehensive analysis of trends in self-harm worldwide, the socioeconomic disparities associated with it, and future projections, using data from the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2021.

Methods: Self-harm data were extracted from GBD 2021, including incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years(DALYs) for 204 countries and territories from 1990 to 2021. Age-standardized rates and estimated annual percentage change (EAPC) were calculated. Inequality was assessed using the Slope Index of Inequality (SII) and Concentration Index (CI). Autoregressive Integrated Moving Average (ARIMA) models were employed to generate projections of self-harm burden from 2022 to 2040.

Results: The global burden of self-harm is projected to change substantially by 2040, with deaths estimated to increase to 829,853 (95% Uncertainty Interval (UI), 262,233–1,397,474) and prevalence projected to rise to 35,863,341 (95% UI, 8,079,108–63,647,574) cases (representing a 131.9% increase from the 2021 baseline of 15,467,153 cases). From 1990 to 2021, age-standardized rates of self-harm demonstrated decreasing trends globally and across sociodemographic index (SDI) levels, with the largest declines observed in high-middle SDI countries. Gender disparities were evident, with more pronounced decreases in females. Inequalities in DALYs due to self-harm decreased over time but remained higher among females in lower-SDI populations.

Conclusions: Despite decreasing age-standardized rates, the global burden of self-harm is projected to increase substantially by 2040, with driven by increasing incidence and prevalence in incidence and prevalence. Inequities persist, particularly among females in lower-SDI populations. Implementation of targeted prevention and intervention strategies, strengthening of mental health systems, and addressing social determinants of health are imperative to reduce the growing burden of self-harm worldwide.