Electroconvulsive treatment--indications, benefits, and limitations.

Multiple variables were examined in relation to outcome of ECT in a complete population of 261 patients treated over a four-year period. Sixty-three percent were rated as much improved. Response to ECT was not predicted by identifying data, DSM-III Axes I, II and III, Research Diagnostic Categories (RDC) or the majority of the "blind" clinical ratings and neuropsychological and EEG data. ECT response was significantly associated with DSM-III Axis IV and V, history of substance abuse and the Brief Psychiatric Rating Scale (BPRS) withdrawal-retardation factor. Ratings of psychopathology and measures of intelligence improved with ECT, more in the patients who responded favorably than in those who did not. Scores on the neuropsychological test battery were better after ECT but remained within the brain-damaged range. Schizophrenic patients received the greatest number of treatments and showed the least variability in seizure duration. Electrical energy required for seizure induction was highest in depressed patients. Bilateral electrode placement was preferred for the majority of patients.