EFFECTS OF MAJOR DEPRESSION ON ESTIMATES OF INTELLIGENCE

This study examined whether patients with major depressive disorder ma nifest deficits in intelligence during affective episodes and followin g clinical improvement. WAIS-R scores were contrasted in 100 patients in an episode of major depression with 50 normal controls, matched to the patient sample in terms of demographic variables and estimates of premorbid IQ. The groups were equivalent in verbal IQ, but, in line wi th previous studies, the depressed patients had a pronounced deficit i n performance IQ. A patient subsample was administered the WAIS-R unde r unlimited time conditions to determine whether the time constraints of performance IQ subtests contributed to the magnitude of the verbal- performance IQ discrepancy. This discrepancy was only slightly reduced with untimed scoring. Subgroups of depressed patients were retested w ith the WAIS-R within one week (n = 26) or two months (n = 33) followi ng treatment with electroconvulsive therapy. In both subsamples, IQ sc ores were improved at posttreatment testing relative to pretreatment, but with little change in the verbal-performance IQ discrepancy. These and related findings suggested that a performance IQ deficit is chara cteristic of depressed patients regardless of affective state.