Inflammatory response to psilocybin in treatment-resistant depression
Research type
Research Study
Full title
Measurement of blood inflammatory marker levels in samples collected as part of a clinical trial of psilocybin for treatment-resistant depression
IRAS ID
357453
Contact name
Luke Baxter
Contact email
Sponsor organisation
King's College London
Clinicaltrials.gov Identifier
NCT07164755, NCT number
Duration of Study in the UK
1 years, 0 months, 1 days
Research summary
About a third of people with clinical depression will be affected by treatment-resistant depression, which means that their symptoms do not improve with the antidepressants that are currently available. People with treatment-resistant depression tend to be more unwell, for longer. They also are at greater risk of severe complications of depression, such as suicide.
When the body responds to disease or injury, it produces signals that activate the immune system. This process is known as ‘inflammation’. Inflammation is important for keeping the body safe, but it can be harmful if it happens excessively, or at the wrong time or place. There is evidence to suggest that inflammation contributes to the development of treatment-resistant depression.
Psilocybin is a psychedelic drug – at higher doses it causes people to hallucinate and have unusual thoughts. In clinical trials, a moderate dose has also been found to improve the symptoms of treatment-resistant depression. One of the ways it may do this is by reducing inflammation and we know that psilocybin has this effect from previous studies using animals. However, the relationship between inflammation and changes in symptoms of depression in humans following psilocybin treatment remain unclear.
In a recent clinical trial (called PsiDeR), blood samples were collected from patients with treatment-resistant depression both before and after they were given psilocybin.
My project would involve testing this samples for levels of key inflammatory markers in blood. This would help us determine: 1) whether the levels of inflammatory markers can predict which people with treatment-resistant depression have the most benefit from psilocybin, 2) whether the levels of inflammatory markers are altered following psilocybin treatment, and 3) whether the change in inflammatory markers is correlated with the change in depression symptoms.
REC name
North West - Preston Research Ethics Committee
REC reference
25/NW/0335
Date of REC Opinion
1 Dec 2025
REC opinion
Further Information Favourable Opinion