Show/hide main menu

Centre for Affective Disorders

Psilocybin Trials

The Centre for Affective Disorders is currently running 2 randomised, controlled trials of psilocybin. We are also likely to be starting a further study in March 2019. More information can be found below.

General Information

The Centre for Affective Disorders has recently been awarded a large grant from the National Institute for Health Research (NIHR) to investigate the safety, feasibility and efficacy of psilocybin as a treatment for clinical depression that has not improved with standard treatments, using the gold standard design of a randomised, placebo-controlled trial. This study will be led by Dr James Rucker and, subject to trial approvals, will recruit up to 60 participants with current depression unresponsive to the usual treatments.

The aim of the research is to determine whether psilocybin delivered with psychological support and medical supervision is a safe treatment for people with difficult to treat depression. To determine this, the trial will collect detailed data on adverse events as well as comparing participant’s ratings of their depression symptoms before and after treatment and between different doses of psilocybin. We will also investigate which form of psychological support best meets the needs of those receiving psilocybin and whether we can use cognitive tests, blood tests and brain scans to understand how psilocybin works in the brain and who it might suit best.

The Centre has also been awarded funding from a commercial life sciences company, COMPASS Pathways Ltd., to undertake a study of the effects of psilocybin on cognitive and emotional processing in healthy volunteers.  The Centre is also participating in COMPASS’ international randomised controlled trial of psilocybin for difficult-to-treat depression that is taking place in multiple centres throughout Europe. Recruitment will start in Summer 2018.  Both studies will be led by Prof. Allan Young.

The need for new directions in depression therapies

Difficult-to-treat, or ‘treatment resistant’ depression is clinical depression that does not respond to standard treatments. It is a major health concern for patients, carers, society and governments, but historically has been under-researched relative to other less common conditions. It is associated with high rates of suicide and worsens outcomes in a wide variety of other health problems.

Two safe and effective treatments for depression - selective serotonergic antidepressants (e.g. Prozac (fluoxetine)) and cognitive behavioural therapy - were introduced over 30 years ago, but there have been no new breakthrough treatments since then. Up to 50% of patients find they achieve little or no benefit from established treatments, suggesting an urgent need to develop alternative paradigms of therapy.

The history of psychedelics in treating depression

Prior to 1970, and the UN Conventions on Drugs, the classical psychedelics psilocybin, mescaline and d-lysergic acid diethylamide (LSD) were used as treatments in psychiatry for resistant forms of depression, anxiety and additions. Research at that time, which was suboptimal by modern standards, suggested that they may help some people who were psychologically ’stuck’ in the process of therapy to attain new perspectives on their difficulties within a safe and supportive context. This, in turn, could lead to enduring, positive behavioural change. Delivered within a medically controlled environment and with a trusted therapist, the risk of serious adverse events was thought to be relatively low. However, the classical psychedelics were thought not to be safe for people with psychotic disorders such as schizophrenia, or for people who were predisposed to developing these conditions.

After 1970, and caught up in the US-led ‘war on drugs’, LSD, psilocybin and mescaline were designated ‘Schedule 1’ substances in the UN Conventions on Drugs, meaning that they could not be prescribed by medical doctors outside of an authorised research study. Funding for such studies dried up in the wake of hardening socio-political attitudes towards psychoactive substances. As a consequence, this area of clinical research in psychiatry came to a standstill without a clear view about whether the drugs were safe and effective when compared to placebo or other treatments.

After a 30 year pause there has been a slow but steady resurgence of clinical research interest into psilocybin, which is the active component of so-called ‘magic mushrooms’. An open label pilot study of psilocybin delivered with psychological support to 20 patients with difficult-to-treat depression suggested that this paradigm of treatment was feasible when delivered in a medically controlled setting. This is now being investigated further through the current trials at the Centre for Affective Disorders.

The Safety and Efficacy of Psilocybin in Participants with Treatment-Resistant Depression (P-TRD)

We are looking for people over the age of 18 with current depression that has not responded to the usual antidepressant treatments. Psilocybin is a controlled drug and one of the ingredients of so-called ‘magic mushrooms’. Recent research has suggested that psilocybin may help in treating depression and we wish to investigate this further.

For more information contact

Psilocybin in Depression Resistant to Standard Treatments (PsiDeR)

This study does not yet have regulatory approval, however we are anticipating a start date of around March 2019.

This study has a dedicated webpage at You can also register your interest at


The Effects of Psilocybin on Cognitive Function in Healthy Participants

We have recently completed a study to test the effects of Psilocybin on cognitive function. Cognitive function is the way the brain processes knowledge, memory, judgement and problem solving. The most recent studies have indicated that psilocybin might facilitate improvement on cognitive function; however, these effects have not been fully evaluated and we are investigating this further. We are no longer recruiting for this study, but to register interest in any future studies with healthy participants, please email 


Sitemap Site help Terms and conditions  Privacy policy  Accessibility  Modern slavery statement  Contact us

© 2019 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454