Depressive symptoms in late life: Associations with apathy, resilience and disability vary between young-old and old-old

Objective: Prior research has found that disability and apathy are associated with late-life depression. However, the effect of age on these associations in "late-life," an ambiguous term encompassing all individuals typically older than 60 years, has not been examined. We investigated the association of depression with disability, apathy and resilience across the age range of late-life. Methods: One hundred and five community-dwelling elderly with moderate levels of disability were assessed using the Geriatric Depression Scale (GDS), Hardy-Gill Resilience Scale, Starkstein Apathy Scale and IADL/ADL questionnaire. Multiple regression analysis was used to assess relationships between depression, disability, apathy and resilience, stratified by age (<80 vs. >80). Results: In the <80 year old subject group, resilience, apathy and disability scores (partial type III R² = 11.1%, 10.4% and 12.8%, respectively) equally contributed to the variability of GDS score. In contrast, in the >80 year old subject group, apathy (partial type III R² = 18.7%) had the greatest contribution to GDS score. Conclusions: In elderly persons under age 80, resilience, apathy and disability all have relatively equal contributions to depression scores, whereas in those over age 80, depression is most highly correlated with apathy. These data suggest that depressive symptoms in elderly persons have different clinical features along the age spectrum from young-old to old-old.