Neuropsychological function in nonpsychotic unipolar major depression

Objective: To examine neuropsychological deficits in unmedicated patients w ith a nonpsychotic unipolar major depressive disorder. Background: Although cognitive deficits in depression have been reported in several studies, mo st previous studies have concentrated on a few areas of cognition in more o r less heterogenous groups of depressives. Method: Twenty-two nonhospitaliz ed patients with a DSM-III-R defined nonpsychotic unipolar major depressive disorder were compared with 30 healthy controls. Neuropsychological tests were organized in the following functions: motor function, selective attent ion, mental flexibility, visuomotor tracking, working memory, short-term me mory, verbal long-term memory, nonverbal long-term memory, verbal fluency, and visuospatial function. Results: There emerged an overall group differen ce in neuropsychological test performance. with patients scoring significan tly lower than controls. Bonferroni corrected univariate analyses of varian ce showed that patients performed significantly below controls in the follo wing areas: selective attention, working memory, verbal long-term memory, a nd verbal fluency, Two functions were areas of differential deficits in the depressed group: selective attention and working memory. Impaired verbal l ong-term memory seemed to reflect an underlying working memory deficit. Con clusions: Nonhospitalized patients with a nonpsychotic unipolar major depre ssive disorder exhibited an overall neuropsychological deficit and they per formed disproportionately worse in the two domains of selective attention a nd working memory. The neurobiological implications of the present results are in accordance with the hypothesis that there is a global-diffuse impair ment of brain function with particular involvement of the frontal lobes in nonpsychotic unipolar major depressive disorder.