Treatments are urgently needed for anorexia nervosa. The eating disorder has one of the highest death rates of all mental illnesses yet there are no approved medications to specifically tackle its symptoms. Now, there is reason to hope that the psychedelic drug psilocybin might help some sufferers in their recovery.
Psilocybin is a compound found in some species of mushroom and tends to be used recreationally for its hallucinogenic effect. Increasingly, it is also being recognised for its potential as a medicine. Since July, psychiatrists in Australia have been permitted to prescribe it to patients with treatment-resistant depression (“High Hopes”, June 24).
There are some sound reasons to believe it may also be useful for anorexia, says Stephanie Knatz Peck, a California-based clinical psychologist who specialises in eating disorders. She has conducted a small preliminary trial that showed promising results for psilocybin. A single dose of the psychoactive drug was given to 10 adult women with anorexia and most reported positive changes. Four participants qualified as being in remission at the three-month check-in.
The impact of this psychedelic drug on brain chemicals is thought to be responsible, at least in part.”There are pretty significant serotonin disturbances implicated in anorexia, along with dopamine disturbances,” says Knatz Peck. “Psilocybin stimulates the serotonin receptors and also seems to have an effect on dopamine.”
This effect on neurotransmitters is why the drug is being used as an antidepressant, but Knatz Peck believes there is another compelling reason why it might be helpful for the eating disorder.
“Anorexia is an illness where people feel very stuck in their behaviours,” she says. “Sometimes, even when they try their hardest, there is a big difficulty in changing rigid, repetitive behaviours. The current understanding is that psilocybin might help the brain connect in ways that it doesn’t normally, and this may persist afterwards. That might translate to more malleability and plasticity. People may have new perspectives and less difficulty changing entrenched thoughts and behavioural patterns.”
There are challenges involved when administering any psychoactive drug. The participants in Knatz Peck’s trial had to be carefully screened then monitored while they were experiencing the effects of the single, 25mg dose of synthetic psilocybin. Some experienced hypoglycaemia, most likely because there is a reduction in appetite while on the drug and anorexia sufferers may already have very low blood sugar.
There wasn’t a significant amount of weight gained as a result of the treatment but most women found the experience meaningful and positive. Almost everyone – aside from one “super-responder” – thought a single dosing session wasn’t enough.
Knatz Peck hopes that in future, psilocybin may provide a more autonomous and less-prescriptive route to anorexia recovery, which tends to be managed with a mix of therapy and supervised weight gain.
“I spent a lot of time with every participant and a lot of them said they’d been to a restaurant and for the first time didn’t feel they were trying to order the lowest-calorie foods on the menu,” she says.
It is likely psilocybin will work better for some anorexia sufferers than others. Knatz Peck believes the super-responder in her group was particularly highly motivated to make the most of this opportunity for behavioural change, believing it was a time when this would be easier to manage.
“She went into clinical remission and gained almost two BMI points in a three-month period.”
The next step is a larger randomised trial, sponsored by Compass Pathways, the company that developed the synthetic psilocybin formulation. It will involve 60 people in five different centres.
In the meantime, Knatz Peck is watching with interest the situation in Australia, the first country to classify psychedelics as medicines.
“There are so many limitations with the current treatments and this is a forward-thinking approach,” she says. “Inevitably, there will be problems to solve along the way. You need highly skilled therapists who are trained in how to safely do these treatments, along with clinics that are well-equipped and have the appropriate settings and space. I look forward to seeing how it plays out.”
