BACKGROUND: Electroconvulsive therapy (ECT) is an effective intervention for major depressive disorder, especially for subsets of depression that resist more common therapies. However, ECT use is limited by its significant risk for adverse cognitive side effects. Shortening the pulse width of the current used has been demonstrated to lower this risk; however, the shorter pulse may not sufficiently elicit therapeutic effects. A systematic review was performed to determine if UBP ECT is as efficacious as BP ECT, and therefore would be a valid treatment for managing depression. METHODS: We conducted a literature search of MedLine/PubMed, Embase, Cochrane CENTRAL, and Google Scholars databases in October 2017 with the terms “depression”, “major depressive disorder”, “electroconvulsive therapy”, “ECT”, “brief”, “ultrabrief”, and “sine wave”. Studies were selected using inclusion criteria and exclusion criteria. Effects sizes were calculated from formalized mood rating pre-ECT and post-ECT, response rates and remission rates. Heterogeneity and reporting bias of the articles were also assessed. Data were analyzed using meta-analysis tools provided by the Erasmus Research Institute of Management. RESULTS: Data from 9 studies resulted in a pooled Cohen’s d = 0.16 (CI = -0.08 to 0.43, p = 0.149). The effect size alone favors BP ECT over UBP ECT in improving mood as per MADRS/HRSD ratings, but if given p > 0.05, results were non-significant. BP ECT was determined to be more efficacious then UBP ECT in terms of both achieving response and achieving remission, with a pooled ORresponse = 0.72 (CI – 0.49 to 1.05, p = 0.027) and pooled ORremission = 0.65 (CI = 0.42 to 0.98, p = 0.011). CONCLUSION: The choice to use BP ECT or UBP ECT is a balance between the burden of side effects and efficacy. These data suggest that patients with a lower risk of developing cognitive side effect and/or need urgent intervention receive BP ECT. Conversely, patients with a higher risk of developing adverse cognitive side effects and/or are not in need of urgent intervention may benefit UBP ECT. Additional studies are recommended to confirm these findings and clarify the optimal use of these two modalities of ECT.