[https://www.nature.com/articles/d41586-021-00187-9](https://www.nature.com/articles/d41586-021-00187-9) “Regulators will soon grapple with how to safely administer powerful psychedelics for treating depression and post-traumatic stress disorder.”

The Imperial study was one of a spate of clinical trials launched over the past few years using illicit psychedelic drugs such as psilocybin, lysergic acid diethylamide (LSD) and MDMA (3,4-methylenedioxymethamphetamine, also known as molly or ecstasy) to treat mental-health disorders, generally with the close guidance of a psychiatrist or psychotherapist. The idea has been around for decades — or centuries in some cultures — but the momentum has picked up drastically over the past few years as investors and scientists have begun to champion the approach again (see ‘Psychedelics take flight’).

But many researchers are excited. Several trials show dramatic results: in a study published in November 2020, for example, 71% of people who took psilocybin for major depressive disorder showed a greater than 50% reduction in symptoms after four weeks, and half of the participants entered remission. Some follow-up studies after therapy, although small, have shown lasting benefits.

“I think I knew this was going to be unpacking a lot — I was carrying a bit of a load at the time,” Rutter says.