Global, regional, and national incidence trends of depressive disorder, 1990-2019: An age-period-cohort analysis based on the Global Burden of Disease 2019 study

Background: Depressive disorder is a severe global public health problem. It is crucial to evaluate the global incidence trends of depressive disorder. Methods: The incidence data were drawn from the Global Burden of Disease Study (GBD) 2019. Estimates were presented by global and sociodemographic index (SDI) quintiles, and the age-period-cohort (APC) model was used to estimate the incidence trends. Results: APC analysis indicated a decline in depressive disorder incidence globally (net drift = -0.24%, 95%CI: -0.29, -0.18), except for an increase in SDI regions (net drift = 0.07, 95%CI:0, 0.14). In high SDI regions, depressive disorder incidence increased among the younger and declined among the elder population, whereas the opposite trend was observed in middle and low-middle SDI regions. The depressive disorder incidence increased significantly among people aged 15 to 24 years after adjusting for age effects, decreased since 2000 after adjusting for period effects and increased rapidly in the birth cohort after 1990 in high SDI by adjusting for cohort effects. Conclusion: Globally, there was a declining trend of depressive disorder incidence in 1990 - 2019. Specifically, the incidence was declining globally in younger populations, while increasing in older populations. However, this trend differed depending on the SDI of the region.