Efficacy of single and repeated administration of ketamine in unipolar and bipolar depression: a meta-analysis of randomized clinical trials
Pharmacological Reports April 16, 2020 J. Kryst, P. Kawalec, Alicja Mikrut Mitoraj et al. 157 citations
A meta-analysis of 20 randomized controlled trials found that a single dose of ketamine produces a rapid and robust antidepressant effect in patients with major depression, with the largest reduction in depressive symptoms observed at 24 hours and effects lasting up to 7 days. The effect was significant in treatment-resistant patients and when ketamine was added to ongoing antidepressant treatment, but not when used as monotherapy at 7 days. Repeated ketamine administration sustained the initial antidepressant effects over 2–3 weeks, with significant reductions in depression severity scores compared to placebo.