Psilocybin Therapy Shows Promise for Anorexia Nervosa in Early-Stage Trial
核心洞察
A pilot trial of 21 women with long-standing anorexia nervosa (搜索) found that three doses of psilocybin combined with talk therapy reduced eating disorder symptoms, with 48% achieving scores comparable to those without an eating disorder at three months.
Participants reported increased motivation to recover that persisted for up to one year after the trial ended, though no meaningful change in body mass index was observed.
The study lacked a control group, and researchers caution that further rigorous trials are needed before psilocybin therapy could become widely available for anorexia.
A small pilot study from Imperial College London suggests that psilocybin—the psychoactive compound in magic mushrooms—may offer a new therapeutic avenue for anorexia nervosa (搜索), one of the deadliest and most treatment-resistant psychiatric disorders. The findings, while preliminary, provide an early signal that psychedelic-assisted therapy could help patients break free from the rigid thought patterns that characterize the illness.
The study enrolled 21 women who had lived with anorexia nervosa (搜索) for an average of 11 years and had not found lasting relief from conventional treatments. Participants had an average age of 32 and a mean body mass index (BMI) of 16.4, well below the healthy adult range of 18.5 to 24.9.
Over six weeks, each participant received three oral doses of psilocybin in a carefully controlled therapeutic setting: one 1-mg dose (described as "assumed inactive") followed by two 25-mg doses, each spaced two weeks apart. The dosing was accompanied by intensive talk therapy before and after each session. Notably, the protocol did not include nutritional intervention or a focus on weight gain.
Symptom Reduction and Lasting Motivation
The researchers tracked participants at two weeks, three months, six months, and one year after the final dosing session. Eating disorder symptom scores were lower at every follow-up point. At three months, 48% of participants had scores comparable to those seen in individuals without an eating disorder diagnosis.
"These are people who've tried everything, and nothing's worked," said Robin Carhart-Harris, Ralph Metzner Distinguished Professor of Neurology and Psychiatry at the University of California, San Francisco, and a co-author of the study. "Getting half of them in remission at three months was impressive."
Participants also reported a stronger motivation to recover—a change that endured for a full year after the trial concluded. The treatment did not, however, produce a meaningful change in BMI, which researchers said was unsurprising given the short weight-tracking period.
Safety Profile and Adverse Events
Psilocybin was generally well tolerated in the study. The most common side effects were headaches and nausea. One participant withdrew after her second dose.
The research team also reported that one participant attempted suicide twice, at seven and nine months after receiving psilocybin. After review, both the study team and outside experts determined these events were unrelated to the treatment. The researchers stressed that the case must be viewed in the context of anorexia's known risks: people with the disorder are more than 18 times more likely to die by suicide than the general population, making it the psychiatric condition with the highest mortality rate.
Mechanism and Therapeutic Rationale
Carhart-Harris likened psilocybin therapy to "shaking a snow globe," describing how the drug may weaken entrenched problematic thought patterns and create opportunities for new perspectives. Both animal and human studies suggest psychedelics can increase cognitive flexibility and emotional connectedness—features often impaired in people with eating disorders.
"Anorexia often serves as a protective mechanism for people, and we saw participants be able to explore their relationship with the illness and gain some new perspectives," said Jennifer Danby, a systemic psychotherapist and eating disorders specialist who served as lead therapist on the trial. "By laying fertile ground for change, even minor adjustments can lead to promising change longer term."
The psychedelic experience itself can be psychologically challenging. One participant, identified by the pseudonym Christina, described her sessions as "horrific," with visions of blood and distorted faces. Yet she credits the trial with transforming her life. "In terms of the quality of my life, it's unrecognizable," she said. "I can feel again. I attribute 95 percent of where I am today to the trial."
Limitations and Cautious Interpretation
The study had significant limitations. With only 21 participants and no drug-free comparison group, it is difficult to determine whether psilocybin itself drove the improvements. David Hellerstein, a professor of clinical psychiatry at Columbia University Irving Medical Center, who was not involved in the study, characterized the findings as "modestly encouraging" while emphasizing the need for controlled trials.
Claire Finkelstein, a clinical psychologist at Swinburne University of Technology in Australia, also not involved in the trial, called the results "profound" but added: "The data, while promising, has shown us that it isn't working for everyone. We need more research to learn who it helps, why and how to improve treatment for those who aren't responding."
"Our results in individuals living with anorexia nervosa (搜索) are encouraging, especially given that these participants had found previous treatments unsuccessful in maintaining their remission," said Dr. Hannah Douglass, who led the study while completing her Ph.D. at Imperial College London. "However, further research is needed to assess how these findings might apply to a broader, more diverse population."
The Unmet Need
Current treatments for anorexia nervosa (搜索)—including cognitive-behavioral therapy and antidepressants such as SSRIs—work in only about half of patients. Research suggests approximately one-third of people with anorexia do not recover even after receiving treatment. The disorder is rarely just about food or weight; as Danby's colleague Meg Vardy, a researcher and chairperson of the New Zealand–based charity JourneyED Eating Disorder Support Aotearoa, explained, "The symptoms of anorexia are a language of pain."
Carhart-Harris predicts that the U.S. Food and Drug Administration could approve psilocybin for treating depression or eating disorders within five years, though he and other experts caution that people should not self-medicate with psychedelics outside of supervised clinical settings. "People's expectations and hopes have far outstripped the evidence," Hellerstein warned.