Influence of an adjuvant antidepressant on the efficacy of electroconvulsive therapy: A systematic review and meta-analysis

Objective: The primary indication for electroconvulsive therapy is medication-resistant major depression. There is some evidence that combining electroconvulsive therapy with an antidepressant, instead of electroconvulsive therapy monotherapy, might improve remission rates. However, data on this topic have not been systematically studied. We undertook a systematic review and meta-analysis to determine the effectiveness of an adjuvant antidepressant during electroconvulsive therapy for major depression. Methods: Embase, Medline Ovid, Web of Science, Cochrane Central, PsychINFO Ovid and Google Scholar were searched up to January 2019. Randomized controlled trials and cohort studies reporting on the influence of an adjuvant antidepressant on the efficacy of electroconvulsive therapy for major depression were included. Authors independently screened records, extracted data and assessed study quality. We reported this systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Nine studies were included in the meta-analysis. The meta-analysis revealed a significant advantage of adjuvant antidepressants versus placebo. The overall effect size per category of antidepressant was as follows: tricyclic antidepressants: Hedges’ g 0.32 (95% confidence interval: [0.14, 0.51]) (k = 6) with low heterogeneity (I²: 4%, p = 0.39); selective serotonin reuptake inhibitors/serotonin noradrenaline reuptake inhibitors: Hedges’ g 0.27 (95% confidence interval: [0.03, 0.52]) (k = 2) with a lack of heterogeneity (I²: 0%, p = 0.89); and monoamine oxidase inhibitors: Hedges’ g 0.35 (95% confidence interval: [−0.07, 0.77]) with moderate heterogeneity (I²: 43%, p = 0.17) (k = 3). Conclusion: An adjuvant antidepressant enhances the efficacy of electroconvulsive therapy for major depression. Tricyclic antidepressants, selective serotonin reuptake inhibitors/serotonin noradrenaline reuptake inhibitors and monoamine oxidase inhibitors showed the same effect size. However, the effect sizes of tricyclic antidepressants and monoamine oxidase inhibitors are most likely underestimated, due to insufficient doses in most of the included studies. We recommend the routine use of an adequately dosed antidepressant during electroconvulsive therapy for major depression.