Fifty-one trials were included in the review.
ECT in bipolar mania: There were 28 clinical trials (1,651 participants). The three controlled/comparative prospective trials (one double blind) showed that ECT with or without chlorpromazine was more effective than simulated ECT or lithium. Of the six controlled/comparative retrospective trials, two reported significant benefit from ECT compared to no treatment or lithium. Overall, the non-comparative studies showed significant improvements with ECT.
ECT in bipolar depression: There were nine clinical trials (364 participants). Four retrospective comparative trials showed no significant benefit from ECT compared to antidepressants. Four of five non-comparative studies showed significant improvements with ECT.
ECT in patients with bipolar versus unipolar depression: There were 10 clinical trials (five prospective and five retrospective, 1,373 participants, 325 bipolar and 1,048 unipolar). Nine trials showed no significant differences in treatment effect.
ECT in mixed states: There were four clinical trials (121 participants). The two prospective and two retrospective non-comparative trials showed significant improvement with ECT.
ECT in patients with manic and bipolar depression: There were three clinical trials (127 participants). The two retrospective comparative/controlled trials and one retrospective non-comparative trial indicated improved outcomes with ECT.
Results from studies that compared different ECT techniques were reported in the review. The effects of ECT on patients’ cognitive abilities were reported.