Exploring Self-Other Processing in the Psychedelic State

Withdrawn

• Conditions: scientific investigation of healthy subjects; healthy

• Registration Number: NL-OMON53863
• Lead Sponsor: niversiteit Leiden

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Last Update Posted: 9 April 2024

Recruitment & Eligibility

• Status: Withdrawn
• Sex: Not specified
• Target Recruitment: 55

Inclusion Criteria

18-40 years old;

Physically and mentally healthy;

Right-handed;

Normal, or corrected-to-normal vision;

Good command of the English language;

Prior experience with a hallucinogenic drug (i.e., the subject must have taken
a serotonergic hallucinogen, such as psilocybin, LSD, DMT or ayahuasca at least
5 times) without an adverse event;

Capable of giving informed consent;

Providing informed consent prior to the study as documented by signature;

Willing to refrain from drinking alcohol up within 24 hours before each
experimental session, willing to refrain from caffeine within 3 hours before
each experimental session, and willing to refrain from nicotine during each
experimental session;

Willing to refrain from consuming psychoactive substances, except caffeine,
alcohol and nicotine, two weeks before enrolling in the study and for the
remainder of the study;

Have a family member or friend (the responsible other) with prior experience
with a hallucinogenic drug, who they can rely on for support in case they
encounter challenging experiences or after-effects during or following the
experimental session.

Agree to refrain from operating a vehicle on the evening of the experimental
session;

Agree to eat only a light snack within 4 hours before taking part in each
experimental session.

Exclusion Criteria

Have a current psychiatric diagnosis, a lifetime history of bipolar affective
disorder type 1, or a history of a primary psychotic disorder assessed via the
Mini International Neuropsychiatric Interview (MINI);

Have one or several current neurological disease(s) or long-term adverse
consequences resulting from a previous neurological disease;

Have one or more immediate family members with a current or previously
diagnosed bipolar affective disorder type 1 or primary psychotic disorder;

Any subject presenting suicide risk, as determined through the screening and
responses to C-SSRS will be excluded. Exclusion criteria include the
following:

History of a suicide attempt within the last 10 years

Suicidal ideation (a score of 1 or greater) within the past year;

Have a medically significant condition which renders them unsuitable for the
study (e.g., diabetes, severe cardiovascular disease, hepatic or renal failure
etc.);

Weigh less than 45 kg;

Significant history of head trauma, premature birth, learning disabilities,
neurological or psychiatric illness;

Are not able to give adequate informed consent;

Heart arrhythmia or hypertension;

Use of antidepressants or psychotropic medication;

Are pregnant, nursing, or can become pregnant and not willing to practice an
effective means of birth control;

Have no prior experience with a serotonergic hallucinogenic drug (e.g., LSD,
magic mushrooms or truffles, DMT, ayahuasca);

Have previously experienced an adverse response to a serotonergic
hallucinogenic drug;

Have any current moderate or severe alcohol use disorder or substance use
disorder based the results of the MINI;

Smoking more than five cigarettes a day - to avoid nicotine withdrawal effects
during the experimental session;

Use of any substance with activity on the serotonergic system, including
antidepressants, lithium, 5-HTP, and St. John*s Wort, is prohibited for 5
half-lives of the medication or active metabolite prior to the experimental
Session.

Study & Design

• Study Type: Observational non invasive
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Behavioural measures: effects of psilocybin-containing truffles on reaction<br /><br>times, recognition memory, attribution object, valence assessment (positive*,<br /><br>*negative*). </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Psychometric measures: subjective drug effects as regressors for behavioral and<br /><br>data.</p><br>