Summary

This meta-analysis examined short-term efficacy of ECT. ECT was significantly more effective than either drug therapy or simulated ECT. Bilateral ECT was more effective than unilateral, and high dose was more effective than low dose.

Design

• Meta-analysis of 73 randomized trials that compared various aspects of ECT (dose, frequency, electrode placement, wave form), and compared ECT to drug therapy or placebo.
• Most trials were small (about 40-60 participants), and quality of reporting was described as poor.
• Primary outcome: change in symptoms on a continuous depressive symptom scale at end of ECT course, to estimate efficacy of ECT. Change in symptoms at 6 months also examined.

Results

• 6 trials (n=256) compared ECT with simulated ECT procedure (including anesthesia). Real ECT was significantly more effective than placebo in treating depressive symptoms, with an advantage on the Hamilton depression rating scale (HDRS) averaging 9.7 (95% CI, 5.7-13.5).
• 18 trials (n=1,144) compared ECT with drug therapy, including imipramine, amitriptyline, tryptophan, paroxetine, lithium, and phenelzine. Treatment duration ranged from 3-12 weeks. ECT was significantly more effective than drug therapy, with a HDRS advantage of 5.2 points (95% CI, 1.4-8.9).
• 28 trials (n=1,408) compared bilateral with unilateral electrode placement. Bilateral ECT was more effective than unilateral, with an HDRS advantage of 3.6 points (95% CI, 2.2-5.2). Bilateral ECT was associated with greater impairment in retrograde memory.
• 6 trials (n=210) compared frequency of ECT (once, twice, or three times per week). No significant difference in depressive symptom improvement.
• 7 trials (n=342) compared dose of electrical stimulus. High dose ECT was significantly more effective than low dose, with an HDRS advantage of 4.1 points (95% CI, 2.4-5.9).
• 8 trials (n=296) compared stimulus wave form (brief pulse with sinewave). No significant difference was noted.

Reference

UK ECT Review Group. Efficacy and safety of electroconvulsive therapy in depressive disorders: a systematic review and meta-analysis. Lancet. 2003;361(9360):799-808. doi:10.1016/S0140-6736(03)12705-5.