Yoon G, et al. - Researchers suggest the possible efficacy of opiate receptor antagonism combined with ketamine in reducing addiction risk among patients with depression at risk for substance abuse. While ketamine has rapid and robust antidepressant effects, the abuse liability of ketamine is concerning, even more so with a preliminary report suggesting that antidepressant effects of ketamine might depend on opiate receptor stimulation. The presented pilot data suggest that naltrexone pretreatment does not reduce the antidepressant effects of ketamine.