A phase I clinical trial for psilocybin concluded that the shroomy compound was incredibly safe for human subjects, opening the doors for phase II of the trial.

The clinical trial was conducted through a partnership between King’s College London’s Psychedelic Trials Group at the Centre for Affective Disorders and Compass Pathways, a drug company focused on finding new medicines for treatment-resistant depression. (Full disclosure: I was published through King’s College London in 2012.) 

The study involved 89 healthy volunteers who were administered 10mg or 25mg of COMP360 — Compass’s psilocybin drug — or a placebo. Up to six volunteers received the drug at a time, and specialized psychotherapists stuck around to talk the subjects through their trips in case things got… challenging.

“Sometimes that can be a little bit frightening or a little bit intense and the therapist is just there to hold your hand if that’s what’s required and just provide some support or just to kind of say it’s all right, I’m here,” Compass Pathways’ communications director, Tracy Cheung, told Endpoints News.

Anyway, here’s what the researchers found. 

First, they reported that not one subject experienced “serious adverse events.” Furthermore, the researchers observed “no negative effects on cognitive and emotional functioning,” though they noted that subjects dosed on psilocybin showed “changes in sensory perception and positive mood alteration.” Finally, when things did get bumpy, the therapists on-hand always got the subjects back on track. 

“This study is part of our overall clinical development program in treatment-resistant depression. We wanted to look at the safety and tolerability profile of our psilocybin, and to look at the feasibility of a model where up to six one-on-one sessions are held at the same time,” said Dr. Ekaterina Malievskaia, Compass Pathways’ co-founder and chief innovation officer, in a press release. “We are focused on getting psilocybin therapy safely to as many patients who would benefit from it as possible.”

Last year, Compass Pathways became the first US pharmaceutical company to receive a fast-track “breakthrough therapy” designation for psilocybin by the FDA. The FDA only approves “breakthrough” drugs if clinical evidence already exists for the compound’s medical efficacy, and if there’s an urgent public health need for the treatment. A few weeks ago, the FDA granted breakthrough therapy designation to a US-based non-profit, Usona, to study psilocybin as a treatment for major depressive disorder. 

While shroomers won’t be surprised by this latest research, this clinical trial confirms similar findings from previous studies. In 2017, the Global Drug Survey found that of all intoxicating “recreational” drugs, psilocybin mushrooms led to the fewest emergency room visits compared to substances like alcohol, cocaine, and even weed.  

The Compass/King’s College study did not assess whether psilocybin could effectively treat severe depression, only whether psilocybin could be safely administered to humans. Phase II of the clinical trial has already started in the US and EU, with results available sometime in early 2021.

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