#Esketamine #FDA #Ketamine #Depression The FDA has approved esketamine for clinical use in cases of treatment-resistant depression, or depression that fails to respond to more than one antidepressant medication. Esketamine is a molecule derived from the anesthetic ketamine, which has itself gained steam as a novel depression treatment. The approval, which the agency announced on March 5, was widely expected after an advisory panel recommended 14 to 2 in favor in early February. But the decision is significant, the drug’s developers say, because unlike other antidepressants on the market, esketamine works through the brain’s glutamate pathways—making it the first new mechanism of action approved by the FDA to treat depression in 30 years. “This really promises a completely new and different treatment for many patients,” says David Hough, a psychiatrist who led the clinical trials of esketamine for Janssen Pharmaceuticals, the pharmaceutical arm of Johnson and Johnson and the d