A chemical byproduct, or metabolite, created as the body breaks down ketamine likely holds the secret to its rapid antidepressant action. This metabolite singularly reversed depression-like behaviors in mice without triggering any of the anesthetic, dissociative, or addictive side effects associated with ketamine. The discovery fundamentally changes scientists' understanding of how this rapid antidepressant mechanism works and holds promise for improved treatments. https://www.sciencedaily.com/releases/2016/05/160504141131.htm https://en.wikipedia.org/wiki/Hydroxynorketamine