CompletedNot ApplicableInterventional

Psilocybin as a treatment for anorexia nervosa

Anorexia nervosa is a serious eating disorder where people feel compelled to keep their weight dangerously low. There are currently no approved medications to treat it, and many people find existing therapies do not lead to a full recovery. Researchers at Imperial College London are running a study to find out if psilocybin—the active substance in magic mushrooms—can help. In a calm hospital setting, participants receive psilocybin alongside close guidance from trained therapists. Researchers also use brain scans to learn how the treatment affects brain pathways linked to rigid habits and low mood. The study involves 8 clinic visits over 6 weeks, including 3 dosing days, preparation and reflection sessions, and brain scans. Participants are then followed up for 12 months. The goal is to see if this approach is safe, practical, and helpful for women living with long-term anorexia.

At a glance

Status

Completed

Phase

Not Applicable

Sponsor

Imperial College London

Enrolment target

Start

15 Apr 2021

Estimated completion

01 Apr 2023

Anorexia nervosa

What is this study about?

Anorexia nervosa is a difficult and often life-threatening condition. People with anorexia severely limit what they eat, often exercise excessively, and view their body shape in a distorted way. Even when very underweight, they may still feel overweight. Despite how common and dangerous the condition is, there are currently no licensed medications to treat it, and fewer than half of people make a full recovery with talking therapies alone.

Psilocybin is a natural psychedelic compound found in certain mushrooms. In recent years, medical studies have shown that psilocybin, when taken in a carefully controlled clinical environment with psychological support, may help reset rigid patterns of thinking. It has already shown promising results in treating severe depression, anxiety, and obsessive-compulsive disorder. Scientists believe it may also help soften the rigid thoughts and overwhelming anxiety that keep people trapped in anorexia.

In this study, researchers want to see whether psilocybin is practical and effective for women who have had anorexia for several years and have not found relief from standard treatments. To see how the medicine works in the brain, participants will have non-invasive brain scans (MRI) and brainwave recordings (EEG) before and after their treatment sessions.

Because this is an early-stage pilot study, the main aim is to test safety and see if a larger clinical trial is worthwhile. It provides hope for developing brand new treatment options for people who currently have very limited medical choices.

Key takeaways

Tests whether psilocybin (magic mushroom extract) can help treat long-term anorexia nervosa.
Aimed at UK women aged 21 to 65 whose previous treatments have not worked.
Involves 8 clinic visits in London over 6 weeks, including 3 supported dosing sessions.
Includes brain scans (MRI and EEG) to see how psilocybin changes brain activity.
Requires participants to safely taper off antidepressants with support from their care team.
Includes 12 months of follow-up monitoring to track long-term recovery and well-being.

Who may be eligible?

This study is open to women aged between 21 and 65 who live in the UK and have had a diagnosis of anorexia nervosa for at least 3 years. To be considered, previous standard treatments must not have helped you recover, and you must currently be looked after by a specialist NHS eating disorder team and have a UK GP.

Participants must have a body mass index (BMI) of at least 14 kg/m² and be medically stable. You must also be willing to stop taking any antidepressant medications before starting the study, as these can interfere with psilocybin. The study doctors and your regular care team will help you do this slowly and safely.

You cannot take part if you or a close family member (such as a parent or sibling) have ever had a psychotic disorder like schizophrenia or bipolar disorder. People with unstable physical health, such as rapid weight loss of more than 2kg in the past month, or problems with their heart, liver, or kidneys, will also not be able to join for safety reasons.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am a woman aged between 21 and 65 living in the UK.
I have had an anorexia nervosa diagnosis for at least 3 years.
Previous treatments have not led to lasting recovery.
I am currently receiving care from a specialist eating disorder team and have a UK GP.
My BMI is 14 kg/m² or higher and my health is reasonably stable.
Neither I nor my immediate family have a history of psychotic disorders (like schizophrenia).

Answer every question to see your result.

What does participation involve?

Taking part lasts around 6 weeks for the active treatment, followed by check-ins over 12 months. In total, you will attend 8 study visits at Imperial College London.

During the 6 weeks, you will have 3 dosing days where you take psilocybin in a quiet, comfortable room with two trained guides present the entire time. Before each dose, you will have 'preparation' sessions with your guides to talk through what to expect. Afterwards, you will have 'integration' sessions to talk about your thoughts, feelings, and experiences.

Alongside the dosing days, you will have 2 MRI scans (which take pictures of your brain using magnets) and 5 EEG tests (where small sensors placed on your scalp measure brainwaves). You will also complete regular questionnaires and interviews about your mood and eating disorder thoughts. After the 8 visits, the team will keep in touch with you for 12 months to see how you are getting on.

Potential risks and benefits

You may experience improvements in your mood, well-being, and a reduction in eating disorder thoughts, although direct benefit cannot be guaranteed. The main risks include temporary side effects during the dosing day, such as feeling sick (nausea), a mild headache, a temporary rise in heart rate or blood pressure, or feelings of anxiety during the experience. These effects are closely managed by your guides and doctors. Safely tapering off existing antidepressants can also be difficult and may temporarily lower your mood. Taking part is completely voluntary, and you are free to leave the study at any time without your regular NHS medical care being affected.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Imperial College Healthcare Trust Clinical Research Facility
City only
London, England

Common questions

Will I be left alone after taking the medicine?

No. Two trained guides will stay with you throughout the entire dosing session in a calm, supportive room to ensure you feel safe and looked after.

Is psilocybin addictive?

Medical research shows that psilocybin does not cause physical addiction or drug dependence, especially when given in a few controlled hospital doses.

Do I have to come off my regular antidepressants?

Yes. Most antidepressants block the effects of psilocybin. If you decide to join, your care team and study doctors will help you taper off them safely.

Will taking part cure my anorexia?

This is an early research trial, so researchers cannot promise a cure. The aim is to see if psilocybin can help loosen eating disorder thoughts and improve recovery rates.

Can I leave the study if I feel it is too much?

Yes, taking part is entirely voluntary. You can withdraw at any point without giving a reason, and your regular eating disorder care will continue as normal.

How to find out more

Meg Spriggs

m.spriggs@imperial.ac.uk - Official trial record

Always speak to your GP or specialist before deciding to take part in a study.