YA advisors expressed fear that they would be tricked or coerced into eating during their psilocybin dosing sessions when they were in an altered state YA advisors agreed that having limited options for nutritional intake would be preferred as having more options could be anxiety provoking for YA participants.

Both YAs and parent advisors expressed wariness and an emphasis on not repeating family- based treatment (FBT), the current first line therapy for AN in which parents take over all aspects of feeding the patient. The YA advisors said that YA participants would need clarity on the role of parents in the trial, specifically how the psychotherapy differed from FBT. One YA advisor expressed concern over disclosure, fearing they would say something that would upset their family member. The YA advisors suggested that the research team make clear that the YA participants in the trial can confidentiality speak with their study psychotherapists and choose what to disclose to their participating family member.

Regarding family participation, the YA advisors discussed offering examples of what support might look like. The YA advisors reported that YA participants would need to know that a support person should be someone who has been actively engaged in helping the participant access care for their eating disorder for at least the past year. YA advisors suggested examples of different family members or support people could be helpful during the consent process (e.g. parents, adult siblings, spouses, long-term close friends if family is not available).

Parent advisors expressed uncertainty about how to support a YA participant during a psychedelic therapy trial. Like YA advisors, parent advisors wanted clarification over their role in psychedelic therapy and clarity about how it differed from FBT approaches. Although both YAs and parents are to be enrolled in the trial and considered participants, it was important to YA advisors to clarify with both YA participants and parent participants that YAs are the target participants. The YA advisors offered feedback on elements of the screening and consent process. They talked about building in assessments about a YA participant’s motivation to participate in the trial and having multiple team members along the consent process evaluate motivation to ensure enrollment was not driven primarily by family members. YA advisors provided possible questions for use during the screening process.

Discussion Given the information gathered above, the following modifications were made to the SPANYA trial. The role of family involvement will be clarified beginning in the screening and consent process, including examples of possible family members and support people who could enroll with the young adult. During the screening and enrollment process participants will receive a detailed calendar that lays out key dates and expectations for the length of the trial.

Additional screening questions have been added to assess intrinsic vs extrinsic motivations for participating in the trial. The study team has developed a handout to explain expectations related to eating and hydration on doing days, including instances in which participants may be asked to take in additional nutrition such as episodes of dizziness or hypoglycemia. The options for nutritional intake on dosing days will be limited to two choices which are also detailed in this participant handout. There will be an emphasis on the participant centered approach to the therapy sessions and clarity that the study does not include an overarching nutrition plan.