Ketamine: can it really be an antidepressant?

A version of the club drug licensed in the US could usher in a wave of fast-acting treatments, but experts are worried

Claudia Kieffer remembers the first time she encountered the drug she describes as having "saved my life". Eight years ago, Kieffer, who had suffered from treatment-resistant depression for decades, was given ketamine as a routine anaesthetic, as part of a post-mastectomy breast reconstruction procedure.

But as well as alleviating the pain, Kieffer noticed an instantaneous change in her state of mind.