Mapping Disease Burden of Major Depressive Disorder and Its Risk Factors in Low- and Middle-Income Countries

Introduction: Major depressive disorder (MDD) is currently the second leading cause of life expectancy due to disability globally. This study aimed to examine the disease burden, risk factors, and temporal trends of MDD in low- and middle-income countries (LMICs) from 1990 to 2021.

Disability-adjusted life years (DALYs) data for 135 LMICs were obtained from the 2021 Global Burden of Disease (GBD) database. To assess trends in the burden of MDD over the past 3 decades, segmented regression analysis was applied to calculate the estimated annual percentage change. Spearman correlation analysis was conducted to examine the association between gross national income (GNI) and gender disparities in age-standardized DALY rates (ASDR) for MDD. We also explored how key risk factors - intimate partner violence, bullying victimization, and childhood sexual abuse - contributed to observed disparities.

In 2021, LMICs accounted for 80.19% of the global burden of MDD. Age and gender disparities were significant, with DALY rates increasing markedly from adolescence and peaking around age 75. Gender disparities showed a higher burden among females, particularly in countries with higher GNI per capita. Analysis of risk factors revealed that intimate partner violence, bullying victimization, and childhood sexual assault were major contributors to the MDD burden, with notable variations across income levels and age groups. Temporal trends showed a marked increase in MDD burden across all income groups after 2019.

MDD continues to impose a significant health burden in LMICs, disproportionately affecting females, youth, and elderly populations. The significant increase in MDD burden across all income groups after 2019 likely reflects the intensifying effects of global disruptions, with the COVID-19 pandemic being a key contributing factor. Populations with the highest burden also showed greater exposure to key risk factors.