Doctors love ketamine , the hallucinogenic drug that can relieve pain at lower doses and function as anesthesia at higher ones. Ketamine can also help treat suicidal ideation , and some people are using it off-label for pain and treatment-resistant depression. It's an enticing medication as far as depression is concerned because it can start working in as little as 40 minutes , whereas traditional antidepressants can take weeks to kick in. But evidence of its antidepressant effects comes from anecdotes and studies involving fewer than people—there has never been a large-scale clinical trial to test the safety and effectiveness of putting depressed people in a K-hole. The FDA approved ketamine as an anesthetic in But instead of looking for the negative things that people reported, the team was on the hunt for a lack of certain symptoms, specifically depression symptoms.