Stress-sensitive antidepressant-like effects of ketamine in the mouse forced swim test.

Major depression is a stress-linked disease with significant morbidity and the anesthetic drug ketamine is of growing interest in the treatment of depression, since in responsive individuals a single dose has rapid (within hours) antidepressant effects that can be sustained for over a week in some instances. This combination of fast action and a therapeutic effect that lasts far beyond the drug's half-life points to a unique mechanism of action. In this reverse translational study, we investigate the degree to which ketamine counteracts stress-related depression-like behavioral responses by determining whether it affects unstressed animals similarly to stressed mice.