Effectiveness of ketamine therapy among patients with treatment-resistant depression: a double-blind, randomised, controlled trial

Randomised, double-blind RCT phase: subcutaneous ketamine (100 mg/mL) given twice weekly for 4 weeks; participants screened 1 month after RCT for eligibility to enter a 4-week open-label extension after a 1-month break.

Dosing is weight-based by volume (0.22–0.53 mL starting volumes depending on body weight) with the possibility of dose increases up to 0.91 mL; adherence ensured by staff-administered injections. Primary outcome: remission at end of RCT phase (MADRS <10); MADRS change also assessed.