Effects of Psilocybin on Shared Experience

Not Applicable

Not yet recruiting

• Conditions: Disorders of Consciousness; Psychedelic Experiences
• Interventions: Drug: Psilocybin; Other: Placebo

• Registration Number: NCT06529939
• Lead Sponsor: Western University, Canada

Brief Summary

The goal of this clinical trial is to learn whether our methods of detecting awareness in vegetative or minimally conscious patients (using neuroimaging) are sensitive to the effects of psilocybin (a psychedelic drug). One of these methods includes scanning people's brains while they watch a film. When different individuals watch a film, their brain's become synchronized with each other as they watch the plot unfold. Most importantly, if a seemingly unconscious patient also shows the same brain-synchronization, it means they might actually be conscious and aware.

To approach our goal, we will be carrying out this trial in healthy volunteers. This will help us better understand whether psilocybin may be a potential treatment for restoring awareness in these patients. The main questions it aims to answer are:

* Does psilocybin enhance or diminish brain synchrony during a film?

* Do changes in brain synchrony reflect differences in each individual's conscious experience?

Participants will be asked to:

* Attend two brain scanning sessions and watch a series of film clips, perform a brief mental imagery task, and listen to music - once under a placebo, and once under psilocybin.

* Play a series of games that assess their cognition (memory, reasoning, planning, etc.).

* Perform a series of visual illusions tasks.

Detailed Description

Not available

Study Timeline

• Status Verified: 2024-07
• Study First Submitted: 2024-07-18
• Study First Submitted QC: 2024-07-26
• Last Update Submitted: 2024-07-26
• Study First Posted: 2024-07-31
• Last Update Posted: 2024-07-31
• Study Start: 2024-09
• Primary Completion: 2025-09
• Study Completion: 2025-09

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

Participants must:

• Have access to an internet connection
• Be in good general health
• Be 19 years of age, or older
• Be willing to follow the study protocol

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Exclusion Criteria

The following people will be excluded from the study. Those who:

• Are unable to read English
• Have high blood pressure
• Are pregnant (determined by a urine pregnancy test at in-person screening)
• Are not using effective methods of contraception with their partner(s) (e.g. oral contraceptive pill, injection, implant, patch, vaginal ring, intrauterine coil, intrauterine device, tubal ligation, or barrier method)
• Are taking chronic administration of tricyclic antidepressants and/or lithium
• Are taking acute administration of serotonin reuptake inhibitors
• Are currently using the antipsychotic medication haloperidol
• Are currently using monoamine oxidase inhibitors
• Have any current or past history of meeting the Diagnostic and Statistical Manual of Mental Illnesses (DSM-V) criteria for schizophrenia, bipolar I, bipolar II, or psychotic symptoms
• Have any first or second-degree relatives with history of above disorders/symptoms
• Have any other diagnosed and/or extreme psychiatric disorders, such as anxiety, depression, post-traumatic stress disorder (PTSD), addiction, obsessive-compulsive disorder (OCD), etc.
• Have any history of suicidal behaviour or current/recent suicidal ideation (determined by the Columbia-Suicide Severity Rating Scale [C-SSRS] at in-person screening)

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Psilocybin First	Psilocybin	Individuals in this arm will be given psilocybin for their first scanning session. For their second scanning session (at least two weeks later), they will receive the placebo.
Placebo First	Psilocybin	Individuals in this arm will be given the placebo for their first scanning session. For their second scanning session (at least two weeks later), they will receive psilocybin.
Psilocybin First	Placebo	Individuals in this arm will be given psilocybin for their first scanning session. For their second scanning session (at least two weeks later), they will receive the placebo.
Placebo First	Placebo	Individuals in this arm will be given the placebo for their first scanning session. For their second scanning session (at least two weeks later), they will receive psilocybin.

Primary Outcome Measures

Name	Time	Method
Interpretive Phenomenological Analysis	Through study completion, an average of 2 weeks. Analyzed following second scan (from interview data).	An analysis of the different themes that emerge (e.g. "feeling joy") when interviewing participants about their experience under the placebo or psilocybin. These themes will be correlated against ISC scores for each drug condition. Not scored on any scale; each theme's prevalence will be reported as a ratio and/or percentage.
Intersubject Correlation (ISC)	Through study completion, an average of 2 weeks. ISC for each drug/task condition is computed and analyzed following second scan (from neuroimaging data).	The degree to which different participants' brain activity is correlated with one another (or synchronized) across the time-course of an in-scanner task (e.g. during a resting state, while watching film clips, while listening to music, etc.). Higher ISC scores indicate greater brain synchronization between individuals (minimum value=0, indicating no ISC/synchronization).

Secondary Outcome Measures

Name	Time	Method
Reasoning Skills	Through study completion, an average of 2 weeks. Analyzed following second scan (from Creyos cognitive scores).	An assessment of the logical reasoning skills of each participant. These scores are computed by the Creyos online cognitive testing platform, from each participants' performance on the suite of web-based games (which assess memory, spatial/verbal reasoning, planning, and concentration). Data will likely be reported as a normalized score with no min/max value (higher scores will indicate a better outcome).
Short-Term Memory	Through study completion, an average of 2 weeks. Analyzed following second scan (from Creyos cognitive scores).	An assessment of the short-term memory abilities of each participant. These scores are computed by the Creyos online cognitive testing platform, from each participants' performance on the suite of web-based games (which assess memory, spatial/verbal reasoning, planning, and concentration). Data will likely be reported as a normalized score with no min/max value (higher scores will indicate a better outcome).
Verbal Reasoning	Through study completion, an average of 2 weeks. Analyzed following second scan (from Creyos cognitive scores).	An assessment of the verbal reasoning abilities of each participant. These scores are computed by the Creyos online cognitive testing platform, from each participants' performance on the suite of web-based games (which assess memory, spatial/verbal reasoning, planning, and concentration). Data will likely be reported as a normalized score with no min/max value (higher scores will indicate a better outcome).