Ketamine’s Actions on Rumination Mechanisms as an Antidepressant

This double-blind, randomised crossover study examines acute (2-hour) antidepressant effects of a single 0.5 mg/kg IV ketamine infusion versus saline in remitted depressed participants using fMRI tasks probing autobiographical emotional memory (rumination) and monetary reward (anhedonia).

Outcomes include changes in limbic and striatal activation during tasks, with secondary assessment of safety and tolerability; sessions are separated by a minimum 1-week washout.