Trajectories of major depression in middle-aged and older adults: A population-based study

Objectives This study aimed to examine depression trajectories and correlates in a nationally representative sample of middle-aged and older adults in the United States. Methods The study sample consisted of 15 661 participants aged over 50 years from the US Health and Retirement Study. Major depression was assessed using the Composite International Diagnostic Interview (CIDI-SF). Depression trajectories were identified using a group-based trajectory modeling enhanced to account for nonrandom attrition. Multinomial logistic regression was conducted to investigate predictors of depression trajectories. Results Four depression trajectory groups were identified: "never" (85.8%), "increasing" (6.3%), "decreasing" (3.2%), and "persistently moderate/high" (4.7%). Baseline depressive symptom severity was a strong predictor of depression trajectories. Older age, male sex, and non-Hispanic African American race were associated with a lower risk of the three trajectories with small to high depression burden, whereas chronic disease count was associated with a higher risk of these trajectories. The risk of being on the increasing trajectory increased with mobility difficulties. Difficulties in household activities predicted membership in the persistently moderate/high group. Conclusions A small but nonignorable proportion of middle-aged and older adults have chronic major depression. Initial symptom severity and chronic disease burden are consistent risk factors for unfavorable depression trajectories and potential targets for screening and intervention.