Eating disorders like Anorexia nervosa (AN) are the second deadliest mental illness after opioid addiction. Almost 10 percent of the human population is affected. Despite its severity and intensive treatment centers that support patients, there is still no proven treatment for AN. Estimates show that not even half of patients recover. From that pool of victories, about 50 percent relapse. But it’s not all bad news, a recent clinical trial suggests psilocybin could help.

Research has shown that AN patients’ brain serotonin function is altered in both the receptors and secretors. It just so happens that serotonin-2A is the main psychoactive compound in psilocybin mushrooms.

RELATED: Research shows that running high is more fun

This has led researchers to wonder whether psychedelic mushrooms could impact the brain function of someone with AN. Nature Medicine recently published a study testing the theory . The main objective was to understand the safety of psilocybin for anorexia, and also to learn if more research is warranted.

This study did have limitations, though no conflict of interest was noted. The small sample size and lack of diversity in the participating cohort were listed as a possible issue. All ten female participants were also self-referred, which could have created some bias.

Additionally, the sensationalized news coverage of the potential of psychedelics paired with the prestige of the eating disorder clinic that housed the study could have impacted self-reported data sets.

What it took to participate

To be accepted, patients had to have a Body Mass Index (BMI) under 16 without cardiac ailments or significant illnesses. Pregnant patients were not allowed to sign up.

The researchers avoided mental illness, but exclusions were made for participants like suicidal ideations, borderline personality disorder, substance abuse within the last year, and a history of mania.

Participants on serotonergic medications before starting this trial were asked to stop. They were titrated off of their prescribed dose with the assistance of personalized integrated therapy.

RELATED: Anatomy of the come up – what psychedelics taught me about cannabis-induced anxiety

Before dosing, participants met with study psychologists on two occasions. On dosing day, they arrived early to measure vitals, get a urine sample, and test hypoglycemia over breakfast.

Patients then received one 25mg dose of COMP360, a synthetic psilocybin compound, in five 5mg capsules. Two therapists remained with patients throughout the eight-hour psilocybin sessions.

Researchers used the Five Dimensional Altered State of Consciousness Scale (5D-ASC) before liftoff and when the patients started coming down to understand their “trip” and ascertain if they were safe to head out.

Patients returned the day after their dose for a 60 to 90-minute integration session, working the lessons learned on their journey into their lives. The next follow-up visits came one week (this visit also included an integration session), one month, and three months after the big dose. Seven participants moved during the post-dose period, so seven meetings were held via telehealth.

Here’s what researchers found out

At its heart, this study aimed to understand any adverse effects of psilocybin therapy for AN. To measure this outcome, researchers documented vital signs, ECGs, changes in lab tests, and suicidality in each meeting.

An Eating Disorder Examination (EDE) was crucial to understanding the patient’s evolving feelings concerning weight, shape, eating, and dietary restraints. These were administered at the one and three-month interviews.

Participants were also prompted to complete a self-reported questionnaire and an Eating Disorder Inventory. Other behaviors related to AN were monitored, including rituals around eating, anxiety, and body image.

The results were varied but interesting. One oft-used indicator that AN treatment is working is a rise in body mass index. While there was no perceived impact on BMI from the psilocybin treatment, 40 percent of participants (or four) showed a decrease in psychopathy related to AN.

RELATED: Anatomy of the come up – what psychedelics taught me about cannabis-induced anxiety

Of these four, two had a rise in BMI, one remained the same, and the final participant saw a decrease– but they remained optimistic.

“The irony is that now that I want to recover, I can eat intuitively, but that is not enough to support physical recovery,” one participant reported to the treatment center.

These results suggest that more time between dosing and assessment must pass to see a positive trending BMI resulting from psilocybin therapy.

As mentioned, this study had limitations. Though results are interesting, they should be “interpreted with caution.” But the research did prove its concept, opening the door for additional trials featuring larger, more diverse cohorts. With COMP360 and other precise psilocybin dosing methods now available for approved research, studies continue to explore how the compound could impact a growing number of conditions.