A Field-Wide Review and Analysis of Study Materials Used in Psilocybin Trials: Assessment of Two Decades of Research

Serotonergic psychedelics, serotonin 2A receptor agonists such as psilocybin that can result in substantially altered states of consciousness, are used in recreational and research settings. The safety of psychedelic experiences in research settings is supported by controlled physical environments, presence of clinical and medical staff to address emergent issues, screening for personal and family history of potential contraindications, and psychoeducational preparation with psychological support. Research settings typically provide psychoeducation to participants verbally and in writing (e.g., informed consent), and such documents and conversations can provide safety-related information-but may also introduce a wide range of expectancies. Such expectancies might involve the specific character of the acute subjective effects of psychedelics, possible side effects, and anticipated outcomes.

To better understand the content of this psychoeducation, we gathered study materials from many psilocybin studies conducted in the past two decades in healthy and therapeutic populations. We conducted a reflexive thematic analysis to better understand these documents.

While these documents varied substantially between studies, we identified themes intended to lower levels of risk and optimize therapeutic effects from psychedelic treatments. The most frequently coded themes related to (1) biological and physical safety, (2) psychological safety and well-being, (3) aspects of setting, and (4) potential for expectancies. Prioritizing biological and psychological safety was evident in the materials from all sites. Furthermore, we identify potential contributors to expectancy unrelated to safety and suggest that these extrapharmacological elements be studied systematically in future research.

Ideally, future research should strive to maximize safety while attempting to minimize extraneous expectancies.