Can psilocybin treat anorexia?

A single dose of psilocybin, administered alongside psychological support, is a safe and acceptable treatment for patients with anorexia nervosa, according to findings from a small phase 1 clinical trial published in Nature Medicine.

In this US trial involving 10 adult women with anorexia, most participants self-reported positive changes three months after their experience.

Four participants’ eating disorder scores decreased substantially at three-month check-in, qualifying them for being in remission of an eating disorder.

The study, by researchers from the University of California - San Diego, and the University of Michigan Medical School, is said to be the first-ever data report of using psilocybin, the key psychoactive ingredient in magic mushrooms, in anorexia nervosa in a clinical research trial.

A promising finding

The researchers highlight that their study is preliminary and they call for more extensive research, but say it’s a promising finding for a deadly and difficult-to-treat illness.

Stephanie Knatz Peck and colleagues’ investigation generated qualitative, self-reported responses from the patients, revealing that 90% regarded the psilocybin treatment as meaningful and positive, endorsing additional treatments if available.

The authors note that the results were based on a small sample size and did not include a placebo group, so they should be interpreted with caution.

They conclude that although they found psilocybin therapy to be a safe and acceptable treatment, further randomised controlled trials are needed to validate the findings.

The next phase

Dr Trevor Steward, Senior Research Fellow in the School of Psychological Sciences at the University of Melbourne, said, “This study represents an important first step towards determining how safe and well tolerated psilocybin therapy is for adult patients with anorexia nervosa. It opens the door for the next phase of clinical trials to assess the effectiveness of psilocybin therapy in improving anorexia nervosa symptoms.

“Psilocybin therapy has provided glimmers of hope in other mental health disorders, notably by providing evidence that it can improve anxiety, cognitive flexibility and self-acceptance for some people. These are all features of anorexia nervosa, and the rationale for exploring psilocybin therapy as an option in the case of anorexia is strong.

“However, this study does not demonstrate that psilocybin therapy can be used to treat anorexia nervosa. Larger-scale clinical trials are a fundamental requirement to confirm whether psilocybin therapy can indeed be considered a viable treatment for anorexia nervosa. While these results show this psilocybin therapy is safe under controlled conditions, it’s essential not to let the hype around psychedelics outpace the scientific evidence. Continued research and caution are of the utmost importance to ensure we make informed decisions about the potential of psilocybin therapy in tackling this deadly illness.

“The field is only beginning to scratch the surface in terms of understanding how psilocybin impacts the brain, and dedicated funding to exploring how it specifically acts to target anorexia nervosa symptoms is crucial to advancing this important avenue of research. As there are no approved medications available specifically for anorexia nervosa treatment, psilocybin therapy may prove to be a promising option, though additional research is needed to test this.”

Larger-scale research

Associate Professor Gemma Sharp, leader of the Body Image & Eating Disorders Research Group at Monash University and a Senior Clinical Psychologist at Alfred Health, highlighted that there are currently no approved pharmacological interventions for anorexia nervosa and these are very much needed to save lives.

“My own eating disorder patients have expressed interest in psilocybin therapy for a number of years and I am glad that there are gradually more opportunities for them to participate in research. Having said that, this published research is very preliminary. It involved only 10 women with anorexia nervosa, five in partial remission and an average BMI in the normal weight range rather than underweight.

“Nevertheless, the research suggested that a single dose of psilocybin together with psychological support was safe, tolerable and acceptable. The number of people involved in the research was too small to thoroughly examine the impacts on eating disorders and broader mental health symptoms. However, the women generally reported improvements in their quality of life, which is so important in eating disorder recovery.

“This research provides an important platform for larger-scale research. A crucial goal for future research is understanding exactly how psilocybin might assist people with anorexia nervosa (the biological mechanisms) as this will allow us as clinicians and researchers to optimise any treatment strategies.”

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