Anorexia nervosa is the most fatal of all psychiatric conditions. With the current paucity of effective pharmacological and psychological treatments, and fewer than half of those diagnosed making a full recovery, there is a great need for new treatment avenues to be explored. For this study, we will recruit patients who have a primary diagnosis of anorexia nervosa as defined by DSM-V criteria, which has been established by their specialist ED team to have been present for at least 3 years, and who have found other forms of treatment ineffective. Over a period of 6 weeks, participants who are deemed eligible at screening will partake in 8 study visits, including three psilocybin dosing sessions with varying doses. The maximum dose of psilocybin a participant will receive in a single session is 25 mg. Across these 8 visits, there will also be 2 MRI scans, up to 5 EEG recordings and a range of psychological measures (questionnaires and interviews). There will be a follow-up period of 12 months following the final study visit.
The primary aim of this study is to assess the acceptability and efficacy of treating anorexia nervosa with psilocybin. The secondary aim of this study is to use Magnetic Resonance Imaging (MRI) and Electroencephalography (EEG) to examine the neuronal underpinnings of treatment with psilocybin in this patient group.