Glutamate and Opioid Mechanisms of Antidepressant Response to Ketamine
Randomised, double-blind, quadruple-masked crossover study (n=27) in adults with treatment-resistant depression testing IV ketamine 0.5 mg/kg (40 min) with oral naltrexone 50 mg or placebo pretreatment to assess acute glutamate, functional connectivity and cerebral blood flow effects.
Details
This randomised, double-blind, quadruple-masked crossover study examines the acute neurobiological effects of intravenous ketamine (0.5 mg/kg over 40 minutes) on brain glutamate, functional connectivity and cerebral blood flow in adults with treatment-resistant depression. Each participant undergoes two imaging sessions receiving ketamine after oral naltrexone 50 mg or matched placebo administered 45 minutes prior.
Primary aims are to determine whether naltrexone attenuates ketamine-induced glutamatergic and imaging changes and whether these neurobiological measures relate to antidepressant response; outcomes include imaging-based glutamate measures, functional connectivity, CBF, clinical rating scales and safety/tolerability.