Rapidity of Symptom Improvement With Intranasal Esketamine for Major Depressive Disorder

Objective: Rapid-acting treatment options are needed for major depressive disorder (MDD). The objective of this systematic review and meta-analysis was to estimate the magnitude of the treatment effect for intranasal esketamine over placebo at 24 hours after the first dose and at endpoint. Data Sources: PubMed, abstracts of major psychiatric meetings, and ClinicalTrials.gov were searched up to November 2020 with no language constraints, cross-referencing the term intranasal with esketamine and randomized. Study Selection: Of 27 studies reviewed, 8 articles, with a total of 1,437 patients with MDD, met study criteria and were included in the meta-analysis. Data Extraction: Randomized, double-blind clinical trials comparing adjunctive treatment of standard antidepressants with intranasal esketamine for MDD, using intranasal placebo augmentation as a comparator, were selected. Results: Estimates of the standardized mean difference (SMD) in change scores were pooled after examining for homogeneity using the test statistic proposed by DerSimonian and Laird. Findings of the random effects model were presented. Augmentation of standard antidepressants with intranasal esketamine resulted in greater Montgomery-Asberg Depression Rating Scale (MADRS) score reduction than adjunctive intranasal placebo at 24 hours. Across the trials, the SMD was 0.34 (95% CI = 0.11 to 0.46, P < .0001) with a 2.9-point greater mean MADRS score reduction following intranasal esketamine versus active control plus intranasal saline. A similar finding was evident at endpoint. Conclusions: This updated systematic review and meta-analysis found that augmentation of antidepressants with intranasal esketamine was statistically and clinically more effective in reducing depression severity than augmentation with placebo, at both 24 hours and study endpoint. Future studies are needed to evaluate dose-response relationship for esketamine.