Psilocybin Study

About psilocybin

Psilocybin is a naturally occurring chemical found in several species of mushrooms, sometimes referred to as ‘magic mushrooms’. It is one of a group of drugs known as ‘psychedelics’ which are being studied as potential treatments for several mental health conditions including depression, anxiety, OCD, and addiction.

Thousands of psilocybin sessions have been conducted in modern scientific studies on patients and healthy volunteers and hundreds of patients were treated with psilocybin in the 1950s and 60s1. A preliminary small-scale open-label study2 in 20 patients with treatment-resistant depression demonstrated significant reductions in depressive symptoms at all measured time points after baseline. In this study, symptom improvements appeared rapidly after just two psilocybin treatment sessions and remained significant six months post-treatment. In October 2018, the FDA3 gave Breakthrough Therapy status to COMPASS Pathways’ programme of psilocybin therapy for treatment-resistant depression. The FDA designates a programme as a Breakthrough Therapy if preliminary clinical evidence shows that it may demonstrate substantial improvement over available therapy.

To view a video on psilocybin therapy for treatment-resistant depression from our CPD event, click here.

The study

Newcastle took part in the largest randomised, controlled, double-blind psilocybin therapy study ever completed. This worldwide multi-centre study showed a rapid and sustained response for patients with treatment-resistant depression receiving a single dose of COMP360 psilocybin with psychological support. The study was sponsored by COMPASS Pathways and listed on

The study analysed the effects of a single administration of psilocybin at three doses (1mg, 10mg, 25mg) in 233 patients, in conjunction with psychological support from specially trained therapists. The trial compared two active doses, 25mg and 10mg, against a comparator of 1 mg. All patients on antidepressants were tapered off them prior to dosing. The study included 13-16 visits, two of which could be done remotely, over a 15–18-week period.

It was found that the 25mg group, compared to the 1mg group, showed a -6.6 difference on the MADRS (The Montgomery–Åsberg Depression Rating Scale) at the primary endpoint of week 3 (p<0.001). The 10mg group, compared to the 1mg group, did not show a significant difference at week 3 (p=0.184).

There were at least double the number of MADRS responders, remitters, and sustained responders with 25mg vs 1mg. 36.7% (29 patients) in 25mg group showed a response at week 3, compared with 17.7% (14 patients) in 1mg group. 29.1% (23 patients) in 25mg group were in remission at week 3, compared with 7.6% (6 patients) in 1mg group. 24.1% (19 patients) in 25mg group were sustained responders (meaning that they met response at week 3 and all subsequent visits) at week 12, compared with 10.1% (8 patients) in 1mg group.

COMP360 was generally well tolerated, with more than 90% of treatment-emergent adverse events (TEAEs) mild or moderate in severity. The most common were headache, nausea, fatigue and insomnia.

In terms of serious Adverse Events (SAEs), these were split into two timeframes. [HT(1] From day 2 to week 3, the SAEs included suicidal ideation and intentional self-injury (25-mg group and the 10-mg group). Additionally, there was one event of hospitalization (for severe depression) in the 10-mg group. No SAEs were reported in the 1-mg group. Between week 3 and week 12, SAEs in the 25-mg group were suicidal behaviour, codeine withdrawal syndrome, and adjustment disorder with anxiety and depressed mood; in the 10-mg group were intentional self-injury, depression, and suicidal ideation; and in the 1-mg group were intentional self-injury (in one participant).

The objective of the trial was to find the appropriate dose for a larger, phase 3 programme, which COMPASS expects to begin in 2023.

To find out more head to

1Nichols et al (2016);2Carhart-Harris et al (2017);3US Food and Drug Administration;4Diagnostic and Statistical Manual of Mental Disorders;5Electroconvulsive therapy