Abstract
Depression is a well-established risk factor for impaired cognitive function, but the mechanisms underlying this relationship remain poorly understood. In this study, we utilized data from the 2017-18 Wave 1 of the Longitudinal Aging Study in India to examine the potentially causal association between depressive symptoms and cognitive performance in middle-aged and older adults using alternative estimation methods to account for observed and unobserved confounding. We also investigated the mediating roles of activities of daily living (ADL), instrumental activities of daily living (IADL), and sleep problems in the pathway linking depressive symptoms to cognitive decline. Our findings indicated significant decline in cognitive function associated with depression, particularly in the domains of language, immediate memory, and orientation. Moreover, we identified substantial mediation effects, with IADL accounting for 26.3%, ADL for 15.5%, and sleep problems for 10.8% of the relationship between depression and cognitive performance. These results suggest that interventions aimed at improving mental health in aging populations could enhance both performance in daily functioning and cognitive outcomes.