To alert to apathy as a sub-syndrome in the spectrum dementia-depression.

Review of literature relevant in medline database.

The modern concept of apathy implies a reduced volition. Apathy may occur in depression and dementia and the differential diagnosis is difficult. Symptoms of apathy may constitute a sub-syndrome in the spectrum depression-dementia, that are characterized by lack of interest, psychomotor retardation, loss of energy and loss of appetite. Apathy may occur in dementia without depression and is significantly associated with more severe cognitive deficits. In dementia, depression may primarily result from a combination of symptoms of anxiety and apathy. Most patients with dementia and apathy had concomitant depression, but less depressed patients had concomitant apathy. The key to diagnosis may be the mood symptoms: dysthymia could be a negative emotional reaction to the progressive cognitive decline in dementia, whereas major depression could more strongly related to biological factors.

The nosological position of apathy remains obscure, with some studies suggesting that apathy and depression are independent constructs, and other studies showing a significant overlap between apathy and depression. The major interest to the type of syndrome has therapeutics implications.