Fava, M., Freeman, M.P., Flynn, M. et al. Double-blind, placebo-controlled, dose-ranging trial of intravenous ketamine as adjunctive therapy in treatment-resistant depression (TRD). Mol Psychiatry 25, 1592–1603 (2020).

Highlights:

• Question: What is the optimal, rapid antidepressant dose of intravenous (IV) ketamine, an NMDA receptor antagonist?
• Findings: Our results suggest that there is evidence for the efficacy of the 0.5 mg/kg and 1.0 mg/kg subanesthetic doses of IV ketamine and no clear or consistent evidence for clinically meaningful efficacy of lower doses of IV ketamine. Most of the effect was due to differences at day 1.
• Meaning: Our results suggest that there is a range of effective, subanesthetic doses of IV ketamine in TRD.

Takeaways:

0.5 to 1.0 mg/kg of IV ketamine appears to be the ideal range for the treatment of treatment-resistant depression.  Lower doses may likely not be as effective.  Doses should be patient-specific, as some patients may require a smaller dose, while others require higher doses.