Dawn Ionescu, MD, a psychiatrist at Massachusetts General Hospital, will never forget the first time she saw the drug ketamine in action. “Within hours, a severely depressed patient was talking to other people in the dayroom, eating dinner, and looking brighter,” says Dr. Ionescu. “I decided: I want to know how this is working.”
Ketamine was FDA-approved in the 1970s as an anesthetic and has since been hijacked as a hallucinogenic “club drug.” Recently, researchers noticed it can lift depression quickly, possibly by fixing damaged neurocircuits. “If you think of neurons as trees, depression looks like branches in winter—thin and unhealthy. After treatment with ketamine, the branches look like spring—flowering and plump,” says Dr. Ionescu, based on her observations of animal studies.
The grand research plan: Scan the brains of depressed patients (and search for these hidden symptoms) before and after ketamine triggers relief. “If we can see the brain changing, we may be able to understand the actual neurobiology of depression and discover new antidepressants,” Dr. Ionescu says. “I would say it’s one of the most hopeful times we’ve had in decades.”