Assessing the Efficacy of Single-Dose Ketamine for Major Depression

Researchers assessed the efficacy of single-dose ketamine in subgroups of those with major depression to determine if recurrent use of ketamine could be a feasible strategy to uphold therapeutic gains. They searched through electronic databases for published peer-reviewed randomized controlled trials through February 22, 2019 that contained single and repeated ketamine use in patients with major depression. From their search, 20 studies were selected for the meta-analysis. The greatest impact of ketamine compared with controls in lessening depressive symptoms was seen at 24 hours (standardized mean difference [SMD] = − 0.89; 95% CI − 1.24; − 0.53; p <.00001), but a considerable difference was seen for up to 7 days following a single dose. At 2 to 3 weeks of recurrent treatment of ketamine, a considerable decrease of depression severity scores was seen (SMD = − 0.70; 95% CI − 1.15; − 0.25 or SMD = − 0.81; 95% CI − 1.41; − 0.20 [depending on the used dosing regimen]; p ≤.009)vs placebo. From their assessment of the randomized controlled trials, researchers found that recurrent administration of ketamine is effective in tolerating primary antidepressant effects seen following single dosing.


Kryst J, Kawalec P, Mitoraj AM, Pilc A, Lasoń W, Brzostek T. Efficacy of single and repeated administration of ketamine in unipolar and bipolar depression: a meta-analysis of randomized clinical trials. Pharmacol Rep. 2020;72(3):543-562. doi:10.1007/s43440-020-00097-z

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