Frontal lobe impairment in schizophrenia: relationship to intellectual functioning.

Schizophrenic subjects (N = 48) and individually matched healthy controls were administered the Verbal Scale of the Wechsler Adult Intelligence Scale (VIQ) and a test of verbal fluency. The verbal fluency and VIQ scores of the schizophrenic subjects were significantly lower than the scores of the control subjects. An additional sample of healthy subjects (N = 144) was used to generate a regression equation for the prediction of verbal fluency scores from Verbal IQ and age. The verbal fluency scores obtained by the schizophrenic subjects were significantly lower than the scores predicted from the regression equation, whereas a significant difference was not obtained in the matched controls. These results provide further evidence of frontal lobe dysfunction in schizophrenia.