Efficacy and safety of zuranolone in major depressive disorder: a meta-analysis of factor effect and dose-response analyses.

Background: Zuranolone is recognised as a promising antidepressant agent. Our study aimed to investigate the efficacy and safety of zuranolone in treating major depressive disorder (MDD). Methods: A systematic review was conducted by searching major databases from inception to August 20, 2023 (INPLASY: 202360087). A meta-analysis was performed by using a random-effects model to calculate effect sizes, expressed as standardised mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs). The primary outcome was improvement in depressive symptoms, while secondary outcomes included response and remission rates of depression, improvement in anxiety symptoms, incidence of dropouts, and any side effects. We conducted subgroup analyses for general MDD and postpartum-onset MDD and a dose-response meta-analysis to estimate the relationship between zuranolone dose and outcomes. Findings: The study included seven randomised control trials involving 1789 patients. Zuranolone reduced depressive symptoms (SMD = -0.37, 95% CIs = -0.51 to -0.23), increased response rate (OR = 2.06, 95% CIs = 1.48-2.85) and remission rate (OR = 2.04, 95% CIs = 1.38-3.02), and reduced anxiety symptoms (SMD = -0.26, 95% CIs = -0.39 to -0.14). Furthermore, zuranolone-treated patients experienced more side effects than those in the control group (OR = 1.40, 95% CIs = 1.10-1.78), although dropout rate did not significantly differ between the two groups (OR = 1.13, 95% CIs = 0.85-1.49). According to the dose-response meta-analysis, zuranolone could effectively improve depression and anxiety at increasing doses up to a maximum daily dose of 30 mg; however, side effects increased with doses exceeding 30 mg. Based on subgroup analyses, zuranolone showed greater efficacy in treatment of postpartum-onset MDD than general MDD, but the difference did not reach statistical significance. Interpretation: Our findings suggested that zuranolone is effective in alleviating depression and anxiety. Nevertheless, there is a potential risk of adverse effects. Given its therapeutic efficacy and risk of side effects, a daily dose of 30 mg appears to be the optimal choice. Funding: Chang Gung Medical Foundation.