Global Burden and Inequalities in Mental Disorders Across Countries and Territories: 1990 to 2021
TL;DR
The burden of mental disorders remains substantial and unequally distributed worldwide, and persistent and widening disparities over the past three decades highlight the urgent need for strengthened global health policies and coordinated multilevel interventions aimed at reducing inequalities across countries with differing levels of socio-demographic development.
Abstract
Background: Although the global burden of mental disorders has been extensively documented, systematic assessments of cross-country inequalities, particularly regarding how this burden varies across levels of socio-demographic development, remain limited. Methods: Data on disability-adjusted life-years (DALYs) attributable to mental disorders and the socio-demographic index (SDI) were obtained from the 2021 Global Burden of Disease Study. Absolute and relative inequalities were assessed using the slope index of inequality (SII) and concentration index (CI). Results: Between 1990 and 2021, the total number of DALYs attributable to mental disorders increased by 73.4%, with the largest increase observed among adults aged 30 to 54 years. Age-standardized DALY rates increased by 9.4%, primarily driven by anxiety disorders, eating disorders, and depressive disorders. Females exhibited higher age-standardized rates of depressive disorders, anxiety disorders, bipolar disorder, and eating disorders, whereas males had higher rates of schizophrenia, autism spectrum disorder, conduct disorder, attention-deficit/hyperactivity disorder (ADHD), and other mental disorders. Anxiety disorders and depressive disorders were the primary contributors to the increasing burden, particularly among women and adolescents. In 2021, the burden of mental disorders showed substantial geographical variation across countries and territories. Inequality analyses demonstrated that the SII for overall mental disorders increased from 69 to 243, whereas relative inequality remained stable over time. Across SDI strata, high-SDI countries experienced a greater burden of eating disorders, ADHD, schizophrenia, and anxiety disorders, while low-SDI countries experienced a greater burden of depressive disorders and idiopathic developmental intellectual disability. Conclusions: The burden of mental disorders remains substantial and unequally distributed worldwide. Persistent and widening disparities over the past three decades highlight the urgent need for strengthened global health policies and coordinated multilevel interventions aimed at reducing inequalities across countries with differing levels of socio-demographic development.