Apathy and cognitive performance in older adults with depression

Recent studies have linked apathy to frontal lobe dysfunction in persons with dementia, but few studies have explored this relationship in older, depressed persons without dementia. We examined the association between apathy and cognitive function in a group of older persons with major depression using standardized neuropsychological tests. We hypothesized that presence of apathy in depression is associated with poorer frontal executive performance.

We analyzed data from 89 older adults with major depression. We defined apathy using four items from the Hamilton Psychiatric Rating Scale for Depression which reflect the clinical state of apathy, including 'diminished work/interest,' 'psychomotor retardation,' 'anergy' and 'lack of insight.'

Apathy most strongly correlated with two verbal executive measures (Stroop C and FAS), a nonverbal executive measure (Wisconsin Card Sorting Test-Other Responses), and a measure of information processing speed (Stroop B). Apathy was not associated with age, sex, education, medical illness burden, Mini-Mental State Examination score and Full Scale IQ score. Stepwise regression analyses of significant cognitive tests showed that apathy alone or apathy plus depression severity, age, or education accounted for a significant amount of the variance.

The results of this study provide support for an apathy syndrome associated with poorer executive function in older adults with major depression.