A new Phase 1 study looking at psilocybin in combination with psychological support as a treatment for females with anorexia nervosa has shown positive results.
Eating disorders have increased 140% over the last decade, however, treatment for conditions such as anorexia nervosa often falls short of success. With 31% of anorexia nervosa patients experiencing relapse, there is a desperate need for new treatments.
Now, in the first study of its kind study, published in the journal Nature, researchers have investigated the safety, tolerability and exploratory efficacy of a single 25-mg dose of psilocybin in conjunction with psychological support as a treatment for anorexia nervosa.
The authors write: “There have been minimal advancements in novel treatment strategies and stagnant outcomes over the past several decades, resulting in a ‘crisis in care’4,5. Novel and innovative treatment methods are urgently needed to improve treatment engagement and outcomes. One such avenue may be psilocybin therapy.”
The results show that the treatment was tolerated by participants with no serious adverse effects observed and no clinically significant changes were observed in vital signs or ECG.
However, two participants that were required to eat breakfast before the treatment developed hypoglycemia, although this resolved within 24 hours. Additionally, one participant with a history of major depressive disorder (MDD) and suicidal ideation reported an increase in suicidal ideation during the three-month follow-up, however, the researchers note that this did not appear to be related to study participation.
Mild adverse reactions among participants included headache, nausea and fatigue.
Regarding weight concerns, tests showed that they were significantly decreased from baseline to the one-month and three month follow-ups, and shape concerns also significantly decreased at the one-month. However, the researchers say these were no longer significant at the three-month follow-up.
Additionally, changes in the eating concern and dietary restraint subscales were not significant, but changes in eating concerns approached significance at the three-month follow-up.
The authors write: “Effects of treatment were, however, highly variable among participants…
“Four participants (40% of sample) demonstrated global EDE scores that decreased to within 1 s.d. of community norms (mean 0.93, s.d. 0.80)34 at 3-month follow-up (Extended Data Fig. 2), which we interpret to be clinically significant. No correlations were observed between any assessed participant characteristics and outcomes. Three of four responders met criteria for AN (versus pAN), and one had a diagnosis of anorexia nervosa binge–purge (AN-BP).”
Dr Trevor Steward, Senior Research Fellow in the School of Psychological Sciences, University of Melbourne, who was not involved with the study, commented: “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.”
Dr Alexandra Pike, Lecturer in Mental Health, University of York, who was also not involved with the study, said:
“The authors report the results of a small Phase 1 clinical trial of psilocybin (the active ingredient in ‘magic mushrooms’) in 10 people with the eating disorder anorexia nervosa (though some participants were in partial recovery). Notably, Phase 1 trials are not designed to test the efficacy of an intervention on symptoms: instead, a Phase 1 study is performed to assess whether an intervention is safe and tolerable in a sample of the people it might be used in.
“In this small and self-selecting sample, there were no serious adverse events, but two participants experienced a brief period of low blood sugar. The changes found in eating disorder symptoms were very subtle, and only appeared in a few of the many questionnaires participants completed – in contrast to more unambiguous results in disorders such as major depressive disorder. Limitations include the fact that there was no control group, so any improvement might be a ‘placebo effect’, and were self-selecting, so may already have felt positive about psychedelics and expected psilocybin to work.
“Additionally, the protocol includes sessions with psychologists alongside the delivery of psilocybin, which may also have caused effects on symptoms.
“It is also worth noting that two authors (SKP and WHK) have financial and scientific relationships with COMPASS Pathways, the company which manufactures this form of psilocybin. In sum, this study is a first step in showing that psilocybin may be a safe treatment for those with anorexia nervosa, but we cannot conclude from this work that it will be effective in this chronic, complex illness.”
