Short answer: not yet known. A Swedish team has published the psiAN phase IIa open-label randomized controlled trial protocol to test whether adding two 25 mg psilocybin sessions with structured psychological support to usual care is safe and feasible for adolescents and young adults with recurrent anorexia nervosa. No outcomes have been reported.
The primary endpoint is safety and tolerability, with close monitoring of adverse events and clinical parameters. Secondary measures track eating disorder symptoms, relapse, mood, and wellbeing for up to 12 months. The design also includes 7 Tesla fMRI tasks and blood BDNF to explore mechanisms. Because blinding is not possible, expectancy effects are a limitation. An overview of the protocol is available at this page.
Enrollment spans ages 16 to 35, with minors included only after an adult safety review and with required consents. A small earlier study in adults with anorexia nervosa suggested tolerability, but that does not establish safety or feasibility in youth.
In sum, this approach remains investigational until trial results are published.