Aging
Recent, cumulative depressive symptoms and memory in the Health and Retirement Study Anna M. Pederson* Anna Pederson Pederson Pederson Pederson Pederson Pederson Pederson Pederson Pederson Department of Epidemiology, Boston University School of Public Health
Depressive symptoms are strongly associated with cognitive aging, yet the bidirectionality and time-varying nature complicate estimation of causal effects, especially when separating recent from cumulative exposure. These analyses follow 14,214 Health and Retirement Study participants enrolled 1996-2018 and born <1959. Elevated depressive symptoms were measured using 8 binary items from the Center for Epidemiologic Studies Depression scale (binary indicator, ≥ 3 items endorsed) for up to 12 biennial visits. Cumulative depressive burden was calculated as the proportion of prior waves with elevated symptoms. Cognition was assessed using the sum of immediate and delayed 10-word recall (range: 0-20). Stabilized inverse probability (IP) weights were estimated to account for baseline and time-varying confounding. Weighted and unweighted linear mixed effects models estimated associations of recent and cumulative depressive symptoms with memory, with adjustment for sociodemographics. At baseline, participants were mean [SD] age 57.9 [7.9] years. In unweighted models, prior wave depressive symptoms and cumulative exposure were both associated with worse memory (βprevious= -0.29; 95% CI: -0.35,-0.23 ; βcumulative= -0.67; 95% CI: -0.77, -0.57). In weighted models, estimates for both recent and cumulative symptoms were attenuated, but remained significant (βprevious= -0.13; 95% CI: -0.18, -0.08; βcumulative= -0.38; 95% CI: -0.48, -0.29). Our results suggest that both recent and cumulative exposure to depressive symptoms contribute to lower cognitive function. These results highlight the importance of early depression intervention to reduce adverse cognitive outcomes and suggests reverse causation from incipient dementia to depression is unlikely to account for the association.
