Sex difference in incidence of major depressive disorder: an analysis from the Global Burden of Disease Study 2019

BACKGROUND: Major depressive disorder (MDD) is a leading mental disorder causing severe impairment. This study was aimed to evaluate sex difference in global MDD incidence by year, age, and socioeconomic status, according to the Global Burden of Disease Study 2019 (GBD 2019). METHODS: Global and national sex-specific incidence estimates of MDD, from 1990 to 2019, in different age groups, were extracted from the GBD 2019. Socioeconomic development index (SDI) as an indicator of national socioeconomic development was used. Absolute (female minus male) and relative (female to male ratio) sex difference in age-standardized incidence rates (ASRs), as well as risk ratios (RR and 95% confidence interval), were computed by year and age. Linear regression analyses were conducted to investigate socioeconomic-associated sex difference in incidence. RESULTS: Absolute and relative sex difference in ASRs showed a slight declining trend during 1990 and 2019, with absolute difference decreasing from 1818.23 to 1602.58, and relative difference decreasing from 1.71 to 1.61. Worldwide, females had a higher risk of MDD than males in 1990 (RR: 1.706 (1.705-1.706)) and 2019 (RR: 1.602 (1.619-1.620)). The highest RRs were observed in the Region of the Americas. Sex difference in incidence rates increased rapidly with age for those under 20 years old. The highest RR (1.913 (1.910-1.915)) was observed in the age group of 10-14. Relative sex difference had a significant positive relationship with SDI (standardized β = 0.267, P < 0.001). CONCLUSIONS: Despite that slight improvement in sex difference in global MDD incidence has been achieved, sex difference still persists in the past decades, with females always having a higher incidence than males. Greater sex difference was found at younger ages and in more developed countries. The findings highlight the importance of making sex-specific health policy to reduce sex difference in MDD incidence.