Psilocybin for OCD (Obsessive Compulsive Disorder)

Could psilocybin be used for the treatment of OCD?

Psilocybin is currently being researched as a treatment for OCD by Drug Science founder, Prof David Nutt, at the Centre for Psychedelic Research. In this Drug Science webinar, Dr Nick Sireau provides an overview of OCD and the new research being launched into psilocybin as a potential treatment.


What is OCD?

OCD stands for obsessive-compulsive disorder. It affects 2-3% of the population (up to 1.5 million people in the UK), and the WHO has classified it as one of the 10 leading causes of disability worldwide. Unfortunately, 40-50% of OCD patients will not respond to current treatments. In fact, most current medications take 2-3 months to have any effect and are normally prescribed alongside antipsychotic drugs. Despite this, OCD is the least funded of all mental health disorders.

A variety of obsessions and compulsions characterise OCD, and the different types of OCD include:

  • Contamination-based OCD in which people have an overriding phobia of contamination.
  • Pure OCD, where the obsessions and compulsions are entirely mental, such as the fear of harming people if they lose control.
  • False memory OCD, in which a false memory is fabricated and then plagues the person, despite being entirely fictional.


New clinical trial of psilocybin for OCD

The first UK trial of psilocybin for OCD, will assess 20 patients, who will receive 2 sessions of psilocybin therapy and will be investigated with the YBOCS OCD test and a variety of other technical measures. The study was funded by Orchard, a charity set up by Dr Sireau to fund research into new OCD treatments such as psilocybin therapy. In this webinar, Dr Sireau also explains the other research into psilocybin for OCD which is taking place at research centres around the world.


What published research supports psilocybin as a treatment for OCD?

While research on psilocybin therapy for OCD is limited, a 2006 study led by Dr Francisco Moreno investigated the Safety, Tolerability, and Efficacy of Psilocybin in 9 Patients with Obsessive-Compulsive Disorder.

The authors discuss how existing medications and therapies are not very effective, and the need to identify new treatment options. They mention anecdotal reports of how psychedelic agents may relieve the symptoms of OCD. Although the mechanisms underlying OCD remain poorly understood, a large body of clinical data indicates a central role of 5-HT (serotonin). Serotonin is a neurotransmitter: a chemical that alters the signals between neurons (nerve cells in the brain). Those medications that do alleviate symptoms function by increasing synaptic 5-HT (the amount of serotonin in the brain). As a 5-HT receptor agonist, psilocybin (and it’s more active form psilocin) stimulates nerve cells by binding to serotonin receptors and thus psilocybin might be effective in the treatment of OCD.

The results of this study supported the hypothesis: among the nine subjects with OCD, all experienced reductions in OCD symptoms when psilocybin was administered in a controlled clinical environment. Additionally, the treatment proved safe with no serious adverse effects.


Why is there so little research on psilocybin for OCD?

This was a small study, and further research is needed to back up its findings. Despite 15 years having elapsed since the study was performed, no further research has been done on psilocybin for OCD. The reason, according to Dr Moreno, was that the culture and stigma against psychedelic drugs did not allow for it.

While the evidence base has developed slowly, there is now greater awareness of the potential for psychedelic drugs such as psilocybin to be used as treatments for mental disorders, and larger studies meet with less cultural resistance. In fact, a recent YouGov poll by Drug Science found that the majority of the British public support research into psilocybin in the treatment of mental health. However, the schedule 1 status of psilocybin forms a significant barrier to research – something which urgently needs to change to support further research into psilocybin for OCD.


This webinar was recorded during the Student Psychedelic Conference and included a live Q&A session from the audience. If you want to ensure that you don’t miss any of our events, so that you can ask your questions live, all you need to do is join the Drug Science Mailing List.

Drug Science is the leading independent scientific body on drugs in the UK. We rely on donations to provide clear, evidence-based information without political or commercial interference. Drug Science webinars are free, and always will be, so if you’d like to support us then please consider joining the Drug Science Community.