PAROXYSMAL EEG ACTIVITY AND PSYCHOPATHOLOGY DURING THE TREATMENT WITH CLOZAPINE

EEG effects and psychopathological changes during treatment with clozapine and haloperidol were compared. Thirty-nine acute schizophrenic patients (20 clozapine and 19 haloperidol) were treated with doses adjusted to the patients' needs. Data was collected on days 0, 3, 10, 20 and 30. Paroxysmal EEG patterns during a 20-minute recording were counted (blind evaluation) in 6 scalp areas. Twelve psychopathological syndromes were assessed using a standardized rating scale (AMP System). Several schizophrenic and depressive syndromes showed a similar response to both drugs. On the days 3, 10 and 20, more clozapine patients showed paroxysmal EEG patterns than haloperidol patients (p < .05). Clozapine patients with paroxysmal EEG patterns had received a lower clozapine dosage on day 10 than those without paroxysms (p < .02). Also, clozapine patients with EEG paroxysms showed a greater reduction of the retarded depressive syndrome on day 20 than patients without paroxysms (p < .05). Furthermore there was a negative correlation (p < .02) between frequency of EEG paroxysms and intensity of the depressive syndrome: and a positive correlation (p < .01) between frequency of EEG paroxysms and reduction of the depressive syndrome with time. The results demonstrate a relation between clozapine-induced paroxysmal EEG patterns and psychopathological effects, reminiscent of a similar relation in patients with epileptic psychosis, suggesting the hypothesis of a common neurophysiological mechanism.