Apathy in early and late-life depression

Background: Late-life depression is thought to differ in clinical presentation from early-life depression. Particularly, late-life depression is considered to be more characterized by apathy than is early-life depression. Lacking convincing evidence, this study examines the presence and associated socio-demographic/clinical characteristics of apathy in older compared to younger depressed persons. Methods: This cross-sectional study used data from two naturalistic cohort studies, i.e. the Netherlands Study of Depression in Older Persons (NESDO) and the Netherlands Study of Depression and Anxiety (NESDA). These studies included 605 persons (aged 18-93 years) with a major depressive disorder, divided into 217 early-life (< 60 years) and 388 late-life (>= 60 years) depressed persons. Apathy was considered present if a score of >= 14 on the Apathy Scale. Results: Apathy was strongly associated with age: it was more frequently present in persons with late-life depression (74.5%) than in those with early-life depression (53.5%). Independent of age, the following characteristics were associated with the presence of apathy: male gender, low education, use of benzodiazepines, chronic diseases, and more severe depression. Of all potential risk factors, only former and current smoking was associated with the presence of apathy in older depressed persons but not in younger depressed persons (p-value for age interaction = 0.01). Limitations: No causal relationships can be drawn due to the cross-sectional design of the study. Conclusions: In depressed individuals, clinically relevant apathy was more frequently present in older compared to younger persons. Both age groups showed largely the same associated risk factors. Apathy was independently associated with older age, male gender and more severe depression.