Psilocybin as a Treatment for Anorexia Nervosa: A Pilot Study

Inclusion Criteria: 1. Primary DSM-V diagnosis of Anorexia Nervosa 2. Current diagnosis of Anorexia Nervosa, established by specialist eating disorder care team to have likely been present for \>3 years 3. Current or past treatments have not been successful to maintain remission from anorexia 4. Be in the care of a GP and specialist eating disorder team in the UK 5. Have a GP and specialist eating disorder team in the UK who can confirm diagnosis 6. Sufficiently competent in English and mental capacity to provide written informed consent 7. BMI ≥14kg/m2 and medically stable 8. Capacity to consent 9. Agree to have us maintain contact with an identified next-of-kin for the duration of the study 10. Agree to have us maintain contact with GP and/or specialist eating disorder team as required, for the duration of the study Exclusion Criteria: 1. Current or previously diagnosed psychotic disorder 2. Immediate family member with a diagnosed psychotic disorder 3. Unstable physical condition e.g., rapid weight loss \> 2kg in the prior month 4. Abnormal serum electrolytes, raised cardiac enzymes, hepatic or renal dysfunction 5. MRI or EEG contraindications 6. A history of laxative abuse in the last 3 months (more than twice a week for 3 months) 7. History of serious suicide attempts or presence of a suicide/ serious self-harm risk at screening 8. Currently an involuntary patient 9. Emotionally unstable personality, history of mania, or other psychiatric problem that the screening clinician feels may jeopardise the therapeutic alliance and/or safe exposure to psilocybin 10. Blood or needle phobia 11. Positive pregnancy test at screening or during the study, or woman who are breastfeeding 12. If sexually active, participants who lack appropriate contraceptive measures 13. Drug or alcohol dependence within the last 6 months 14. No email access 15. Patients presenting with abnormal QT interval prolongation at screening or with a history of this (QTc at screening above 470ms) 16. Patients who are currently, or have recently (within 3 months) been enrolled in another CTIMP.