Presence and correlates of apathy in non-demented depressed and non-depressed older persons

Background and Objectives: Apathy is a behavioral syndrome that often co-occurs with depression. Nonetheless, the etiology of apathy and depression may be different. We hypothesized that apathy occurs more often in depressed compared to non-depressed older persons; and that independent correlates for apathy will be different in depressed and non-depressed older persons. Methods: In this cross-sectional study of Netherlands Study of Depression in Older Persons (NESDO), a total of 350 depressed older persons according to the Composite International Diagnostic Interview (CIDI) and 126 non-depressed older persons, aged at least 60 years were recruited in several Medical Centres and general practices. In both depressed and non-depressed older persons, those with and without apathy as assessed with the Apathy Scale (score ≥ 14) were compared with regard to socio-demographic, clinical, and biological characteristics. Results: Apathy was present in 75% of the depressed and 25% of the non- depressed older persons. Independent correlates of apathy in both depressed and non-depressed older persons were male gender and less education. Furthermore, in depressed older persons, higher scores on the Inventory of Depressive Symptomatology (IDS) and, in non-depressed older persons, a higher C-reactive protein (CRP) level correlated independently with apathy. Conclusions: Apathy occurred frequently among both depressed and non-depressed older persons. Among depressed older persons, apathy appeared to be a symptom of more serious depression, whereas among non-depressed persons apathy was associated with increased CRP being a marker for immune activation, suggesting a different aetiology for apathy in its own right