Differential Relations among Depressive Symptoms, Global Cognition, and Multiple Measures of Everyday Function in a Sample of Community-Dwelling Older Adults

Abstract Objective Functional assessments for older adults, including questionnaires and performance-based tests, may evaluate different constructs and be differentially influenced by cognitive status or mood. Relative to cognition, less is known about relations between depressive symptoms and everyday function; depression may decrease motivation, impair cognition, and/or bias self-reported functional ability. Furthermore, specific depressive symptoms may differentially influence functional outcomes. The present study evaluated everyday function through multiple methods in a diverse sample of community-dwelling older adults to elucidate depression-cognition-function relations. Method 121 community-dwelling older adults with healthy cognition or mild cognitive impairment completed the Geriatric Depression Scale (GDS-15), cognitive tests, and two everyday function measures: the performance-based Naturalistic Action Test (NAT) and the Instrumental Activities of Daily Living – Compensation (IADL-C) Questionnaire. Study partners also completed the IADL-C. Multivariate regressions examined the influence of depressive symptoms, global cognition, and their interaction on functional outcomes. A principal component analysis of the GDS-15 identified depressive symptom clusters, which were added to the models. Results Global cognition significantly predicted all functional measures (p’s < 0.01). Depressive symptom burden predicted only self-reported everyday function (p < 0.01), driven by “apathy” items (p = 0.02). No depression-cognition interactions were observed across all models. Conclusion Questionnaire- and performance-based functional measures may capture distinct, but related, aspects of function that are differentially influenced by mood and cognition. Performance-based tests may assess cognitive capacity for task execution, while self-report measures may capture actual task engagement influenced by motivation and mood. Comprehensive functional assessments should include multiple measures to improve diagnostic accuracy, inform interventions, and enrich conceptualizations of function in aging.