ECT beyond unipolar major depression: systematic review and meta‐analysis of electroconvulsive therapy in bipolar depression

Abstract

ECT beyond unipolar major depression: systematic review and metaanalysis of electroconvulsive therapy in bipolar depression.Objective: In this systematic review and meta-analysis, the response, remission, and speed of response in adults with major depressive disorder (MDD) and bipolar disorder in depressive episode (BDD) receiving an acute course of electroconvulsive therapy (ECT) were quantitatively analyzed. Methods: Using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, 1660 citations were identified through five electronic databases. Nineteen articles met final inclusion criteria for meta-analysis. Results: The pooled response and remission rates with ECT in MDD were 74.2% (n = 1246/1680) and 52.3% (n = 850/1626), respectively. In BDD, they were 77.1% (n = 437/567) and 52.3% (n = 275/377), respectively. Although response rates to ECT were statistically higher in BDD (OR = 0.73, 95% CI: 0.56-0.95, P = 0.02), remission rates were similar (OR = 0.91, 95% CI: 0.65-1.26, P = 0.56). Individuals with BDD vs. MDD required fewer number of ECT sessions to achieve response (SMD = À0.23, 95% CI: À0.44 to À0.023, P = 0.03). There were no significant moderator effects identified. Conclusion: Response rates and speed of response are higher in individuals with BDD; however, remission rates are equivalent. These findings support increased utilization of ECT in individuals with treatment-refractory BDD. Summations• Electroconvulsive therapy is more effective for treating individuals with bipolar vs. unipolar major depression in terms of clinical response, but it was found to be equally effective for achieving remission. Moreover, a smaller number of ECT sessions was needed to achieve clinical response in BDD vs. MDD patients. Considerations• Studies reporting on remission rates were generally heterogeneous in assessing clinical outcomes. A variety of rating scales were applied for measuring response and remission rates. As well, there was a lack of data on outpatients. Furthermore, this meta-analysis synthesized non-randomized study designs rather than randomized controlled trials.

Caution should be advised when recommending increased use ofECTbased on low‐quality evidence

“…Patients can choose their treatment, but they cannot choose their condition. Even if, in contrast to the meta-analysis by Bahji et al, 1 such comparisons were based on evidence from randomized trials, the relative measure of outcomes in one patient population compared to another offers no information on the absolute benefits of the treatment in either population. Thus, one could theoretically compare two populations with different conditions where one is given a treatment that has no effect and arrive at a conclusion similar to that of Bahji et al 1 : that outcomes were superior in the treated group.…”

“…On the basis of a meta-analysis that compared patients with unipolar depression against patients with bipolar depression who received electroconvulsive treatment (ECT), Bahji et al 1 concluded that their findings supported increased utilization of ECT in patients with treatment-refractory bipolar depression and urged for more clinicians to use ECT in both unipolar and bipolar depression. However, due to several methodological limitations in their meta-analysis their recommendations do not seem supported by the evidence.…”

“…Such a difference is likely below a clinically important difference. 4 Third, Bahji et al 1 did not investigate any harms outcomes. An assessment of the usefulness of a treatment relies on balancing benefits against harms and by omitting an investigation of harms, Bahji et al 1 did not provide the necessary evidence to make any recommendations.…”

“…4 Third, Bahji et al 1 did not investigate any harms outcomes. An assessment of the usefulness of a treatment relies on balancing benefits against harms and by omitting an investigation of harms, Bahji et al 1 did not provide the necessary evidence to make any recommendations. Importantly, there are known harms of ECT treatment, such as anterograde and retrograde amnesia, and ECT can result in permanent memory loss.…”

“…5 Fourth, the assessment of the quality of the studies did not account for missing information and it underestimated the risk of bias. While Bahji et al 1 assessed the study quality using a quality assessment tool for observational studies, they summed up scores of individual items to arrive at a total score, which is not recommended and specifically advised against in the assessment tool they used. 6 Instead, a critical appraisal of observational studies should involve consideration of how each of many factors may introduce bias and to what extent this affects the internal validity of the studies.…”