Is apathy in late-life depressive illness related to age-at-onset, cognitive function or vascular risk?

BACKGROUND: Apathy has been shown to be an important feature of degenerative, vascular or traumatic brain disorder. Its presence is associated with high depression scores, higher age, low performance on frontal tasks, and more severe deep white matter hyperintensities. In late-life depression, lack of interest or motivation are often more prominent than depressed mood, especially in the late-onset type. It was hypothesized that in a heterogeneous sample of elderly depressed patients, apathy is associated with late-onset type of depression, cognitive dysfunction or vascular risk factors.
METHOD: The Apathy Evaluation Scale (AES) was administered to twenty-nine elderly (> or = 60 years) inpatients with a DSM-IV major depression or dysthymic disorder. The severity of the depression was measured with the Montgomery-Asberg Depression Rating Scale (MADRS) and cognitive function with the Mini-mental State Examination (MMSE). The presence of vascular risk factors was traced in the patient's medical records.
RESULTS: Apathy was found in 86% of the patients. The AES-score was correlated with the negative symptom score, but not with total MADRS or MMSE-score. No difference in AES-score between early-onset depressed (n = 16) and late-onset depressed (n = 13) patients was found, and between patients with or without vascular risk.
CONCLUSION: Apathy is a main feature of moderate to severe depressive illness in elderly patients and related to the negative symptoms of the disorder. Further studies should include less severely depressed patients and investigate the relation between depression severity and apathy.