Neural and Physiological Correlates of Psychedelic Sub-states

Summary

The main purpose of this study is to gain a better understanding of the distinct mental states and physical reactions that can arise during a psychedelic experience. By repeatedly assessing the same participants in an MRI while under the effects of psilocybin, the investigators want to identify reliable brain and body reactions arising during these psychedelic experiences. It is hoped that this will provide an insight to inspire future research on psilocybin and related psychedelics as well as inform on their therapeutic action. This study will involve up to 12 healthy volunteers with previous psychedelic experience. Participants in this study will be given four doses of psilocybin, with breaks of at least seven days in between dosing visits. The first dosing visit will feature a 10 mg dose of psilocybin, which can be considerate a low to moderate dose, whereas the remaining three dosing visits will feature 25 mg psilocybin, a high dose that is consistent with the dosage chosen for several modern clinical trials with psilocybin. From the initial in-person screening visit to the final follow-up, participants will be in this study for approximately 6-12 weeks and visit the research site 5 times. The first visit will be an in-person screening visit, during which the investigators will assess participants' eligibility to be enrolled. There will be 4 subsequent visits to the scan center for dosing and magnetic resonance imaging (MRI) scanning, and there will be a final remote follow up. Each of the four dosing visits will include four periods of lying within the MRI scanner for scanning, each of these 'in-scanner' sessions will last for \~ 45 minutes. Actual scans, which are also called 'runs' last for \~ 12 mins. During these 'runs', the investigators will ask participants two brief questions about how positive or negative their current experience is every 100 seconds. They will be able to record their answers using a button box which they will be operating with their hand. One day after each dosing visit, the investigators will schedule a phone call with the participant to check how they are doing and perform an informal interview focused on their experience while under the effects of psilocybin.

Conditions

• Psychedelic Experiences
• Neuroimaging
• Healthy Volunteers

Interventions

DRUG

Psilocybin

Multiple dosing of healthy volunteers with up to 25 mg psilocybin separated from each other by at least one week. Participants will be scanned before and after receiving psilocybin on each dosing day. Surveys will be performed on dosing days and after dosing.

Sponsors & Collaborators

• Robin Carhart-Harris, PhD, MA

  lead OTHER

Principal Investigators

• Robin Carhart-Harris, PhD · University of California, San Francisco

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

21 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-07-31

Primary Completion

2026-01-30

Completion

2026-01-30

FDA Drug

Yes

Countries

• United States

Study Locations