Electroconvulsive therapy is widely used for treatment-resistant psychiatric patients, with remission rates close to 50% and response rates between 60–70%. Post ictal suppression index (PISI) has been positively correlated with clinical outcome.

Characterize the treatment results of the electroconvulsive therapy unit of CHPL; find a correlation between improvement on HAM-D, PANSS and PSAS and PISI.

The patient data was collected and divided according to ICD-10 diagnosis. Evaluation scales were applied at the beginning and end of treatment: depressed patients (F31.3–5; F33; F20.4; F25.1) - HAM-D; schizophrenic/ schizoaffective/ bipolar-manic or mixed patients (F20.X, F25.X, F31.0, F31.6) - PANSS; with any of these diagnosis - PSAS. A correlation between the points of improvement on each scale and PISI was investigated using the Pearson product-moment correlation coefficient.

Of 101 depressed patients, 33,7% showed remission and 49,5% showed response, over 11 sessions (average). The reduction on HAM-D score was significantly greater for patients with initial HAM-D score > 18 versus HAM-D ≤ 18 (52,9% versus 37,75%). Patients with unipolar depression (N = 72) and bipolar depression (N = 22) showed comparable results (response:47,2% versus 52,4%; remission: 30,6% versus 40,1%). Schizophrenic patients (N = 43) had higher response rates: 88%. No correlation was found between PISI and HAM-D, PANSS or PSAS improvement (r = -0,1;-0,01;-0,07).

Response and remission rates in depressed patients were inferior to other ECT studies, except in patients with higher severity. Those rates were comparable for schizophrenic patients. PISI did not correlate with clinical outcome.