Cognitive function over the treatment course of depression in middle-aged patients: correlation with brain MRI signal hyperintensities.

INTRODUCTION: It has been proposed that the often found hyperintensities on MRI representing vascular changes might be correlated with a worse outcome of cognitive malfunction in depression. The purpose of this study was to evaluate neuropsychological status in the acute depressed state and following remission and to investigate the potential relationship between MRI hyperintensities and neuropsychological functioning through the treatment course in a group of middle-aged depressed patients.
MATERIALS AND METHODS: Twenty-seven depressed patients were assessed by a series of neuropsychological tests at the beginning of the depressive episode and again after an euthymic phase of 6 months following treatment. Thirty healthy controls were tested at comparable intervals. In all patients and controls a MRI was performed to identify hyperintensities representing a possible correlation with test performance during treatment course.
RESULTS: At the onset of a depressive episode patients performed significantly worse than the controls in all tests. After sustained remission the patient group still performed significantly worse in verbal memory and verbal fluency compared to controls. There were no significant correlations between number of presence of vascular risk factors, or presence of hyperintensities on MRI, and cognitive abilities at either time point. DISCUSSION: These findings favor the hypothesis that some neuropsychological deficits might persist following treatment for depression, even in middle-aged patients. We found, however, that any residual cognitive deficit is not associated with MRI-hyperintensities in this age-group.