RESTING EEG IN FIRST-EPISODE AND CHRONIC-SCHIZOPHRENIA

We examined the frequency characteristics of the electroencephalogram (EEG) in 102 schizophrenic patients (44 first-episode and 58 chronic p atients) and 102 normal comparison subjects. EEGs of schizophrenic pat ients had more delta (1-3 Hz) and theta (3.125-8 Hz) activity and less alpha (8.125-13 Hz) activity than normal comparison subjects. There w ere no significant differences in the EEG frequency composition of fir st-episode and chronic patients. Because first-episode and chronic pat ients were characterized by different disorder durations and treatment histories, the similarity of their EEGs suggests that EEG abnormaliti es are stable characteristics of schizophrenia and are not treatment-r elated epiphenomena. A principal components analysis of EEG power band s identified an augmented low frequency-diminished alpha component and a beta component. Schizophrenic patients had significantly higher sco res on the augmented low frequency-diminished alpha component than did normal comparison subjects, and there was no significant group differ ence in scores on the beta component. The findings of this investigati on suggest that EEG abnormalities in schizophrenia reflect aspects of brain dysfunction.