Apathy: a common psychiatric syndrome in the elderly.

Apathy, or a lack of motivation, has been increasingly recognized as a distinct psychiatric syndrome. Apathy is primarily a dysfunction of the frontal-subcortical circuit and is associated with various neuropsychiatric disorders including Alzheimer's disease. Apathy is associated with a number of adverse outcomes, including apparent cognitive impairment, decreased daily function, poor insight into one's own functional and cognitive impairment, and poor outcome from rehabilitation treatment.