News release

From: The Lancet

The Lancet Regional Health – Europe: Psilocybin linked to a reduction in depression symptoms in small real-world study

A study of 19 patients with treatment-resistant depression treated with psilocybin in Switzerland found psilocybin was associated with a significant reduction in depression symptoms. The study is published in The Lancet Regional Health – Europe journal.

Psilocybin - a naturally occurring psychedelic compound found in some species of mushrooms - has demonstrated promising antidepressant effects in depression and treatment-resistant depression in controlled clinical trials. However, its effectiveness and safety in real-world treatment settings remain largely unknown.  

This study analysed the medical records of 19 patients in Switzerland* who received one to four clinical dosing sessions of psilocybin at the Psychiatric University Hospital Zurich as treatment for treatment-resistant mild to severe depression.  

On average, the clinician-reported depression rating scores decreased from approximately 31/60 before psilocybin treatment to 20/60 within 42 days after the final dosing session. The patient-reported depression scores decreased from an average of 32/63 to 23/63. Side effects were reported in 30/40 psilocybin dosing sessions, with the most common being fatigue, headache and tearfulness, but no serious or sustained side effects were documented. 

The authors say their findings suggest that results from clinical trials may translate into routine clinical practice, although outcomes appear smaller in scale. They highlight that the small sample size of this study limits generalisability and as there was no longer term follow up it is not known if the improvements in depression symptoms were maintained. They call for larger real-world studies.