The Efficacy and Tolerability of Continuation and Maintenance Electroconvulsive Therapy for Depression A Systematic Review of Randomized and Observational Studies

Abstract

Electroconvulsive therapy (ECT) is a highly effective treatment for severe and treatment-resistant depression, but relapse rates remain high despite maintenance pharmacotherapy. Continuation or maintenance ECT (C/M-ECT) offers the potential to prevent relapses in the most unwell patients, but there remains disagreement among guidelines regarding its efficacy and tolerability. This review aims to summarize and assess the current evidence for the efficacy and tolerability of continuation and maintenance ECT for depression, including data from randomized and observational studies, which included an appropriate control group. Twenty studies were found meeting inclusion criteria. There was evidence from 14 studies suggesting that relapse rates are reduced in those receiving C/M-ECT. There was evidence from 6 studies suggesting that C/M-ECT had no effect on global cognitive function. Detailed neuropsychological testing was limited, but within studies that assessed specific cognitive domains, there was not consistent evidence for deficits in C/M-ECT compared with the control group. The certainty of evidence across outcomes was low or very low because of inclusion of observational studies, heterogeneity of study design, and patient populations. The findings add further weight to evidence suggesting that C/M-ECT is a viable treatment option to prevent relapse in severe depression and provides clinicians with further evidence for the benefits and risks of C/M-ECT when discussing treatment options with patients. Future research should focus on randomized or well-designed prospective studies with sufficient follow-up to determine longer-term outcomes, while including a standardized, detailed neurocognitive battery to assess potential adverse effects.