Trip sitting or just sitting? Session facilitators substantially influence psychedelic experiences in clinical trials but not in healthy ones

In psychedelic clinical trials, facilitators accounted for about 13.6% of the variance in participants’ subjective acute experiences, highlighting their influence in clinical populations.

In this new review Goldy et al. (2026) show that session facilitators have a measurable and meaningful influence on psychedelic experiences in clinical populations, but not in healthy participants. In trials involving individuals with mental health conditions, facilitators accounted for a notable proportion of variability (around 13.6%) in acute subjective experiences, such as emotional intensity, insight, and overall experience quality, indicating that who guides the session can significantly shape how the drug is experienced.

By contrast, in healthy volunteers, these facilitator effects were minimal, suggesting that psychedelic experiences are more stable when baseline psychological distress is absent. The findings highlight that interpersonal and contextual factors (“set and setting”) are especially important in therapeutic contexts, and they underscore the need for standardised facilitator training and consideration of facilitator effects in clinical trial design and interpretation.

Abstract

“Psychedelics' characteristic acute subjective effects predict therapeutic benefits, such as decreases in depression and anxiety. Thus, optimizing treatment involves better understanding which factors shape subjective effects. Session facilitators, who support participants before, during, and after psychedelic administration sessions, form an important part of the setting of these experiences.

Yet, the extent to which session facilitators influence participants' acute subjective effects is unknown. To address this gap, we analyzed data from 9 psilocybin administration studies involving 298 participants, 670 dosing sessions, and 60 facilitators-the largest dataset of its kind. Using multilevel models, we examined whether facilitators contributed to variance in participants' acute subjective effects. Results showed that facilitators accounted for negligible variance (0.8 %) in healthy volunteers, but greater variance in clinical samples (13.6 %), after controlling for study and participant differences.

These findings reveal that facilitators may play a clinically meaningful role in shaping psychedelic treatment outcomes in patient populations, relative to non-patients, comparable to or exceeding therapist effects in traditional psychotherapy (∼8 %). These results have direct implications for clinical trial design, training protocols, and the implementation of psychedelic treatments as they continue to scale.”

Goldy SP, Sepeda ND, Hilbert SN, Bari BA, Garcia-Romeu A, Gukasyan N, Barrett FS, Yaden DB, Nayak SM. Trip sitting or just sitting? Session facilitators substantially influence psychedelic experiences in clinical trials but not in healthy ones. Psychiatry Res. 2026 May;359:117010. doi: 10.1016/j.psychres.2026.117010. Epub 2026 Feb 13. PMID: 41747432. Read Paper

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