Similar clinical improvement of depression using 0.5-ms and 1-ms pulse widths in bilateral electroconvulsive therapy

There is a lack of research regarding 0.5-ms pulse width (PW) in bilateral electroconvulsive therapy (ECT). The aim of this study was to compare the efficacy and number of treatment sessions between groups receiving 0.5-ms and 1-ms PW ECT. Ninety-four patients with unipolar major depression treated with acute bilateral ECT were analysed retrospectively, grouped as consecutive patients treated with 0.5-ms PW ECT (n = 47), and age- and sex-matched patients treated with 1-ms PW ECT. Clinical and ECT data were extracted from clinical records. Symptom evaluations and global cognitive screening at baseline and post-ECT were administered by trained psychiatrists. The Hamilton Rating Scale for Depression (HDRS-21) was rated weekly. Efficacy and number of treatment sessions were compared between groups. PW was explored as a predictor of mean decrease in HDRS and number of treatment sessions by regression models. Group characteristics did not differ at baseline. The mean decrease in HDRS in the 0.5- and 1-ms PW [25.85 (7.79) vs. 24.33 (6.99), respectively], response (95.7% vs. 97.9%), remission (87.2% vs. 80.9%) and mean number of treatment sessions [11.28 (3.85) vs. 11.34 (3.36)] were not significantly different. Episode duration and severity, and previous ECT predicted HDRS decrease. Severity at baseline and the 6th session, the dosing method and the last ECT treatment dose predicted the number of treatment sessions needed. PW was not significant in the regressions models. The results suggest that both PWs perform similarly in bilateral ECT for depression, resulting in equivalent antidepressant efficacy and number of treatment sessions needed.