Electroconvulsive therapy (ECT) appears to be far more effective than algorithm-based drug therapy for treatment-resistant bipolar depression in what is believed to be the first randomized, controlled trial of ECT in bipolar depression.
However, remission rates were "modest" in both groups, highlighting the need for new and more effective treatment options for this "challenging clinical condition," the authors, led by Helle K. Schoeyen, MD, PhD, Division of Psychiatry, Stavanger University Hospital, in Norway, note.
"It's important to run studies where there is a lack of evidence. This is the first randomized, controlled study assessing the effect of ECT compared to pharmacological treatment in bipolar depression. Thus, the results may be of importance to clinicians when they have to choose among treatment options to this severely ill patient population," Dr Schoeyen told Medscape Medical News.
The study was published in the January issue of the American Journal of Psychiatry.
Most Effective Treatment?
Despite the lack of randomized, controlled trials, ECT is regarded by many clinicians as "the most effective treatment" for treatment-resistant bipolar depression.
The study included 73 acutely ill inpatients with bipolar disorder who were experiencing treatment-resistant depression; the patients had a Montgomery-Åsberg Depression Rating Scale (MADRS) score of 25 or higher.
The patients were randomly assigned to receive either ECT for three sessions per week for up to 6 weeks, using right unilateral placement of stimulus electrodes and brief pulse stimulation, or standard algorithm-based pharmacologic treatment for bipolar depression.
ECT was significantly more effective than drug therapy in the linear mixed effects modeling analysis, Dr Schoeyen and colleagues report.
The mean MADRS score at the end of the 6-week treatment period was 6.6 points lower in the ECT group (95% confidence interval [CI], 2.5 - 10.6; P = .002) compared with the drug treatment group.
Similarly, the mean score on the 30-item version of the Inventory of Depressive Symptomatology at 6 weeks was 9.4 points lower in the ECT group (95% CI, 4.6 - 14.3; P = .0001). For the Clinical Global Impression for Bipolar Disorder, the mean score was 0.7 points lower in the ECT group (95% CI, 0.13 - 1.36; P = .02) at the end of the treatment period.
More than twice as many ECT patients had a significant response (73.9% vs 35.0%; P = .01), but the remission rate did not differ between the groups (34.8% vs 30.0%; P = .74).
"The study tells us that ECT is the most potent treatment option compared to pharmacological treatment. The low remission rates may reflect the severity of illness both in symptoms and chronicity of the patient group included in this study," Dr Schoeyen said.
"Bipolar depression is undoubtedly one of the psychiatric conditions with the most unmet medical need," write Mauricio Tohen, MD, and Christopher Abbott, MD, of the Department of Psychiatry and Behavioral Sciences, University of New Mexico Health Sciences Center, in Albuquerque, in a linked editorial.
Despite several limitations, the study "adds major value to the evidence-based data on the use of ECT as a treatment option for bipolar depression," they write.
ECT is "definitely an option to be considered for acute treatment; however, we need to learn more about its value added in maintenance treatment," Dr Tohen told Medscape Medical News.
Data on ECT in maintenance treatment of bipolar depression are "desperately needed," Dr Tohen and Dr Abbott point out in their editorial. Studies suggest that relapse rates after ECT are as high as 50%, most occurring 6 to 9 weeks after completing an ECT series.
The investigators plan to follow the study participants in both arms for 21 weeks, which will provide information on sustained response and relapse. "The field looks forward to the findings of the 21-week follow up results," Dr Tohen and Dr Abbott say.
The study received no commercial funding. Several authors have disclosed relevant financial relationships, all of which are listed in the original article.
Am J Psychiatry. 2015;172:3-5, 41-51