The trajectories of depressive symptoms and subsequent incident dementia, coronary heart diseases, stroke and all-cause mortality

Evidence suggests the occurrence of depressive symptoms in mid- to late-life inflates the risk for ageing-related morbidity compared to people without depressive symptoms. The eventual association between depressive symptoms in mid- to late-life and long-term (over 10-year) risks for incident dementia, coronary heart disease (CHD), stroke, and morbidity is to be established.This longitudinal cohort study utilized Health and Retirement Study (HRS) of U.S residents aged ≥ 50 years who were interviewed every 2-year during follow-up (average follow-up: 11.6 ± 2.85 years). Trajectories of depressive symptoms were assessed by the Center for Epidemiologic Studies Depression (CES-D) scale from 1994 to 2000 at baseline. Incident dementia, CHD, stroke and all-cause mortality were determined from 2000 to 2018.Among 7810 individuals who were free from dementia, CHD and stroke, five trajectories of depressive symptoms were identified: non-depressed (36.7 %), mild (48.8 %), worsening (7.8 %), improving (4.1 %) and persistent (2.7 %). Compared with those in the non-depressed group, participants with mild, worsening and persistent depressive symptoms had significantly greater hazards of incident dementia (multivariable adjusted hazard ratios and 95 % confidence intervals: 1.32 [1.17-1.48], 1.58 [1.30-1.93], 2.82 [2.17-3.67], respectively), CHD (1.13 [1.03-1.24], 1.47 [1.25-1.73], 1.34 [1.03-1.74], respectively), stroke (1.30 [1.12-1.52], 1.58 [1.23-2.04], 1.71 [1.16-2.53], respectively) and all-cause mortality (1.17 [1.07-1.27], 1.46 [1.27-1.68], 1.66 [1.35-2.06], respectively). The hazards of incident events, except for CHD, were not significantly greater in individuals with improving depressive symptoms.The present findings suggest even sub-clinical threshold depressive symptoms were associated with the hazards of ageing related diseases while such associations were not significant with managed depressive symptoms.