For decades, scientists have searched for a new type of antidepressant, one that works differently from the 20-plus drugs already on the market. Finding a new option is crucial, since a third of people don’t respond to available depression treatments.

They haven’t had much luck — except for the discovery that IV infusions of ketamine hydrochloride, an FDA-approved anesthetic, can cause rapid antidepressant effects in many people with stubborn depression.

Figuring out exactly how ketamine has these effects has been a researcher’s dream, since ketamine is too problematic a drug to currently be considered a mainstream depression treatment. It’s illicitly used — and abused — as a psychedelic club drug and can cause hallucinations. Ketamine can also have negative side effects when used off-label to treat depression, including unexpected changes in heart functioning, cognition and respiration. Its antidepressant effects fade, so it typically has to be given over and over again, and it’s not yet clear how safe or effective it is when taken long-term. Developing a drug that works like ketamine, but without all the baggage, is the holy grail — but scientists haven’t known quite what to target.

[Read the Full Article Here]