EVOKED-POTENTIAL CORRELATES OF PSYCHOSIS

Abstract

Evoked potential (EP) correlates of several psychiatric disorders were investigated by applying a comprehensive EP procedure to 102 psychiatric patients and 28 nonpatients. EP to left and right median nerve shocks, visual pattern flashes, and auditory clicks were recorded from 1 EOG [electrooculogram] and 14 monopolar scalp derivations. Nine age- and sex-matched groups were compared. EP of overtly psychotic patients (schizophrenics, depressives, manics) differed markedly from normal, while those of patients without overy psychosis (neurotics, personality disorders, latent schizophrenics) did not; in the overtly psychotic, later EP events (100 ms or more poststimulus) were attenuated. EP of neurotic depressives differed greatly from those of psychotic depressives. A somatosensory negative peak occurring 60-ms poststimulus was more posteriorly distributed in chronic schizophrenics (paranoid, undifferentiated) than in any other subject group. The attenuated later EP activity associated with overt psychosis was interpreted as a concomitant of cognitive (attention?) impairment, rather than of emotional disturbance.