Systematic Reviews and Meta-Analyses of Ketamine Therapy for Depression (2020–2024): A Comparative Evidence Summary

This report synthesizes findings from over 25 systematic reviews and meta-analyses published between 2020 and 2024 on the use of ketamine-based treatments for depression, including intravenous ketamine, esketamine nasal spray (Spravato), and oral ketamine. It answers the most pressing questions patients and clinicians face: How effective is each route of administration? How fast does it work? What are the real-world response and remission rates? 

For those seeking a patient-focused summary of the findings, this report is also available on KetamineTherapyForDepression.org, a nonprofit site dedicated to translating ketamine research into accessible, evidence-based guidance.

Drawing exclusively from high-level evidence, this report highlights the superior efficacy and rapid onset of IV ketamine, contrasts it with the more modest benefits of esketamine, and reviews the slower and less reliable outcomes of oral formulations. It also examines early research on the combination of ketamine and psychotherapy. Designed for patients, clinicians, journalists, and policymakers, this summary translates dense scientific research into clear, comparative insights.