Investigating Psilocybin and Context in Healthy Volunteers

This study is looking at how psilocybin (a drug) interacts with the environment and support (called 'context') during its use. It involves 120 healthy volunteers, aged 21 to 70, who have lower-than-average mental well-being. Participants will receive either up to 25 mg of psilocybin or an inactive placebo. The drug will be given in one of two different contexts, which are expected to change how the drug affects people. Researchers will measure changes in mental well-being and feelings of connectedness up to 28 days after treatment, and challenging experiences eight hours after the dose. The study is currently unclear on its recruitment status.

Study design
This is a double-blind, randomized study with 120 participants, divided into four groups. It uses a 2x2 factorial design.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed for 28 days after receiving the dose.

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NCT06626139

Investigating the Interaction of Psilocybin and Context of Its Administration in Healthy Volunteers

Recruiting
PHASE2Ages 21–70InterventionalBasic science
Robin Carhart-Harris, PhD, MA
~120 participants
Updated 2026-06-04 on ClinicalTrials.gov
What's tested:PsilocybinContext 1Context 2Placebo

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Challenging Experience Questionnaire (CEQ) subscales score
Measured over Eight hours post-dose.
+3 more outcomes measured
Healthy Participants With Lower-than-average Mental Well-being
1 sites across 1 states
California1
  • Robin Carhart-Harris, PhD · PRINCIPAL_INVESTIGATOR · University of California, San Francisco
  • Jennifer Mitchell, PhD · PRINCIPAL_INVESTIGATOR · University of California, San Francisco

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  • Challenging Experience Questionnaire (CEQ) subscales scoreEight hours post-dose.

    The Challenging Experience Questionnaire is designed to measure challenging psychological experiences associated with the acute effects of psilocybin. For this study, the combined score across four our of its seven subscales will be used as a primary outcome: Fear, Insanity, Isolation, and Paranoia, excluding Grief, Physical Distress, and Death subscales. Scaled scores range from 0 to 100. Higher scores indicate higher levels of challenging experience (worse outcome).

  • Change in Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS) score from Baseline to 28 days post-doseBaseline to 28 days post-dose.

    The Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS) was developed to enable the monitoring of mental wellbeing in the general population and the evaluation of projects, programmes and policies which aim to improve mental wellbeing. Scores range form 14 to 70. Higher scores indicate higher levels of mental well-being (better outcome).

  • Change in Watts Connectedness Scale (WCS) scores from Baseline to 28 days post-doseBaseline to 28 days post-dose.

    The WCS is a 3-dimensional index of felt connectedness that may sensitively measure therapeutically relevant psychological changes post-psychedelic use. Scores range from 0 to 100. Higher scores indicate higher levels of connectedness (better outcome).

  • Emotional Breakthrough Inventory (EBI) scoreEight hours post-dose.

    The Emotional Breakthrough Inventory was developed to assess emotional breakthrough, an important and distinct component of the acute psychedelic experience. Scores range from 0 to 100. Higher scores indicate higher levels of emotional breakthrough (better outcome).