Abstract: Objective To describe and analyze the global burden of Years Lived with Disability (YLD) attributable to depressive disorders from 1990 to 2021, examining the equity implications associated with varying levels of social development, with the aim of providing a reference for the prevention and control of depressive disorders. Methods Data pertaining to YLD rates for depressive disorders and the Human Development Index (HDI) for various countries and regions were compiled from the Global Burden of Disease 2021 database and the Human Development Report 2022. Joinpoint regression analysis was employed to assess the temporal trends in age-standardized YLD rates for depressive disorders globally between 1990 and 2021. The correlation between age-standardized YLD rates and the HDI was analyzed, and disparities in these rates across nations with different levels of social development were compared. The Slope Index of Inequality (SII) and the Concentration Index (CIX) were utilized to conduct an equity analysis of the global age-standardized YLD rates for depressive disorders. Results A significant upward trend was observed in the global age-standardized YLD rate for depressive disorders from 1990 to 2021. The Average Annual Percent Change (AAPC) for the total population was 0.43% (95% CI: 0.28%-0.57%), for males was 0.47% (95% CI: 0.30%-0.64%), and for females was 0.40% (95% CI: 0.27%-0.53%) (all P<0.01). A significant negative correlation was identified between the age-standardized YLD burden of depressive disorders and the HDI for the period 1990-2021 (rs=-0.312, P<0.01). Statistically significant differences in age-standardized YLD rates for depressive disorders were found among countries with varying levels of social development in both 1990 and 2021 (both P<0.05). The Slope Index of Inequality was -161.98 (95% CI: -268.80 to -55.16) in 1990 and -269.04 (95% CI: -361.60 to -176.48) in 2021, with the absolute value demonstrating an increasing trend. The Concentration Index was -0.03 (95% CI: -0.05 to -0.02) in 1990 and -0.04 (95% CI: -0.05 to -0.03) in 2021, with its absolute value showing an initial increase followed by a subsequent decrease. Conclusion The global burden of YLDs due to depressive disorders increased from 1990 to 2021, and significant inequities persist. The burden is disproportionately concentrated in countries with lower levels of social development. It is imperative to prioritize the prevention and treatment of depressive disorders in these nations and to implement proactive measures to promote equity in the global burden of YLDs from depression.

Key words: Depressive disorders, Human development index, Year lived with disability, Slope index of inequality, Concentration index