Randomized, double-blind, parallel study (withdrawn) testing IV ketamine 0.5 mg/kg infusion over 40 min in adults with treatment-resistant major depressive disorder (actual n=0).
This randomized, double-blind, parallel study aimed to test whether IV ketamine acutely activates endogenous µ-opioid neurotransmission in adults with treatment-resistant major depressive disorder.
Participants received a single 40-minute infusion of ketamine (0.5 mg/kg total, infused at 0.75 mg/kg/hr) or matching saline; outcomes included PET/neuroimaging measures of µ-opioid system activation and clinical depression ratings.
IV ketamine infusion (active experimental arm).
Infused over 40 minutes at 0.75 mg/kg/hr (total 0.5 mg/kg).
Normal saline infusion (placebo comparator).
Normal saline infusion matching ketamine (0.75 mg/kg/hr over 40 minutes).