Hemispheric asymmetries of function in patients with major affective disorders.

Several investigators have suggested that affectively disordered patients have dysfunction of the nondominant cerebral hemisphere. The present study tested this hypothesis using psychometrically matched measures of verbal and visual-spatial skills. A sample of 64 psychiatric in-patients and out-patients was interviewed using an expanded and modified version of the NIMH Diagnostic Interview Schedule and diagnosed using the criteria of DSM-III-R, the Research Diagnostic Criteria, and the Feighner et al. system. Patients diagnosed as affectively disordered by at least one system were administered a pair of psychometrically matched measures: a measure of Word-Finding modeled after the Boston Naming Test, and a measure of visual-spatial functioning adapted from the Dot-Localization task. Patients with diagnoses of major depression by any of the three systems showed significantly poorer performance on Dot Localization than on Word Finding. Differences for patients with bipolar diagnoses were in the same direction but fell short of significance. These results support the hypothesis that patients with major depressive disorders may show impaired right-hemisphere functioning.