Psilocybin Trial Shows Lower Anorexia Symptoms but No BMI Change in Small Study

A study at the Center for Psychedelic Research at Imperial College London tested psilocybin as a treatment for anorexia nervosa and recorded lower eating disorder symptom scores at every follow-up point. com reported that researchers recruited 21 women who had lived with anorexia for an average of 11 years.

The participants averaged 32 years old and entered the study with a mean BMI of 16.4.

Each woman received three oral doses over six weeks: one 1 mg dose followed by two 25 mg doses spaced two weeks apart. The 1 mg dose served as an assumed inactive placebo. Researchers tracked participants at two weeks, three months, six months, and one year after the final session.

Nearly all participants showed symptom improvement two weeks after the last dose. At three months, 48 percent had scores comparable to people without an eating disorder. Reported motivation to recover rose and remained elevated for one year.

BMI did not change noticeably during the six-week tracking window. The most common side effects were headaches and nausea. One participant withdrew after the second dose. One participant attempted suicide twice, at seven and nine months after treatment.

The study team and outside experts concluded the attempts were unrelated to psilocybin. “Our results in individuals living with anorexia nervosa are encouraging, especially given that these participants had found previous treatments unsuccessful in maintaining their remission,” Dr. Hannah Douglass said.

She added that further research is required to test the findings in a broader population. Jennifer Danby, a systemic psychotherapist who served as lead therapist on the trial, said she had worked in eating disorders for more than 15 years and found it encouraging that participants could explore their relationship with the illness from a different angle.