Double-blind, randomised crossover trial (n=16 actual) testing whether naltrexone 50 mg (vs placebo) given 45 min prior blocks the antidepressant effect of ketamine 0.5 mg/kg IV in adults with treatment-resistant major depressive disorder.
Randomised, triple-blind crossover study in adults with treatment-resistant MDD comparing ketamine infusions preceded by naltrexone 50 mg or matched placebo; two infusion phases separated by ~30 days.
Primary outcome is change on the 6-item Hamilton Rating Scale for Depression (HAM-D-6); secondary outcomes include CADSS for dissociation and a visual analog craving scale for ketamine.
Safety and tolerability monitored with vitals, labs and ECG; naltrexone or placebo given 45 minutes prior to each ketamine infusion.
Randomised crossover: each participant receives two ketamine infusions (0.5 mg/kg) in two phases separated by ~30 days; pretreated with naltrexone 50 mg or matched placebo 45 min prior.
Ketamine 0.5 mg/kg IV infusion; two sessions separated by ~30 days.
Naltrexone 50 mg orally given 45 min prior (or matched placebo).