The link between apathy and depressive symptoms and healthy lifestyles in older community‐dwelling adults

Abstract Background Apathy (loss of motivation or goal‐directed behaviour) and depression each confer risk for dementia, cardiovascular disease and mortality in older adults. The mechanisms by which these neuropsychiatric symptoms are linked with health outcomes are not yet understood. Health behaviours may be one pathway, yet their potential links with apathy have received scant attention, whereas depression has been consistently associated with unhealthier behaviours including physical inactivity. Depression and apathy may be confounded, thus it is critical to determine their potential differential associations with health behaviours. This study thus aims to investigate whether apathy and depressive symptoms in older adults were associated with a broad battery of health behaviours. Method Community‐dwelling participants from the Sydney Memory and Ageing Study (n = 1,030) aged 70‐90 without dementia completed assessments including the Geriatric Depression Scale, from which apathy (GDS‐3A) and depression (GDS‐12D) subscores were obtained. To investigate cross‐sectional associations with self‐reported physical activity, diet, current and lifetime alcohol consumption and smoking, linear or logistic regressions predicted the outcomes from apathy and depression, controlling for age, sex, education, global cognition and chronic conditions. Result Greater apathy (but not depressive symptoms) was significantly associated with current physical inactivity (fewer hours/week weighted by intensity, p < .001) and frequent alcohol consumption (>2x weekly, p <.05). Depressive symptoms alone predicted poorer current adherence to Australian Dietary Guidelines (ADG‐2013, p <.05) and smoking (p <.001). Higher levels of both apathy and depressive symptoms were significantly associated with a past period of “heavier” alcohol consumption (p <.05); neither were related with lifetime history of smoking nor lifetime abstinence from alcohol. Conclusion Apathy and depression were differentially associated with health behaviours. Presence of these symptoms in older adults may act as a barrier to engagement in healthier lifestyle activities, which are known to have numerous benefits for health and cognitive outcomes. These novel findings should be further examined longitudinally and with objective measures and alternative apathy assessment. Apathy should be considered along with depression as key determinants of health behaviours when designing health promotion interventions targeting older adults, and in models of dementia risk reduction.