We're building a better ClinicalTrials.gov. Check it out and tell us what you think!
Working…
ClinicalTrials.gov
ClinicalTrials.gov Menu

Investigating the Mechanisms of the Effects of Psilocybin on Visual Perception and Visual Representations in the Brain

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT05265546
Recruitment Status : Not yet recruiting
First Posted : March 3, 2022
Last Update Posted : July 29, 2022
Sponsor:
Information provided by (Responsible Party):
University of California, Berkeley

Brief Summary:
The long-term objective of this project is to characterize how psilocybin affects visual perception and the brain's representation of the visual environment. We know that psilocybin alters aspects of visual perception, but the underlying brain mechanisms contributing to these effects are poorly understood. The proposed work will address these questions in a large, diverse sample of healthy human subjects by using functional magnetic resonance imaging (fMRI) to measure the brain's responses to visual stimuli. The proposed research will document which brain areas mediate the effects of psilocybin. The technique of fMRI will be employed to measure brain activity in different brain areas while subjects are performing a visual perceptual task.

Condition or disease Intervention/treatment Phase
Perception Disorders Drug: Psilocybin Phase 1

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 80 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Basic Science
Official Title: Investigating the Mechanisms of the Effects of Psilocybin on Visual Perception and Visual Representations in the Brain
Estimated Study Start Date : October 1, 2022
Estimated Primary Completion Date : December 31, 2025
Estimated Study Completion Date : December 31, 2025

Arm Intervention/treatment
Experimental: Experimental
Psilocybin 0-14 mg, before fMRI measurement
Drug: Psilocybin
The effects of different doses of psilocybin (0 - 14 mg) will be compared.

Comparator
Psilocybin 0-14 mg, before fMRI measurement
Drug: Psilocybin
The effects of different doses of psilocybin (0 - 14 mg) will be compared.




Primary Outcome Measures :
  1. Amplitude and pattern of fMRI cortical responses [ Time Frame: Functional MRI recordings will begin approximately 30 minutes after oral administration of experimental or comparator arm treatment and will continue for up to two hours. ]
    Functional magnetic resonance imaging (fMRI) responses to visual stimuli will be recorded.


Secondary Outcome Measures :
  1. Perceptual measurements [ Time Frame: Statistical tests will be performed after all data collection is complete. ]
    Within-subject inferential statistical testing will be used to assess the effects of doses of psilocybin (0-14 mg) on participants' abilities to update prior expectations based on new information. Specifically, paired t-tests will be used to contrast perceptual measures collected at MRI scan sessions.

  2. Voxelwise modeling [ Time Frame: Modeling of fMRI data will be performed after all data collection is complete. ]
    Voxelwise modeling results will be quantified by measuring the amount of variance in fMRI responses to presentation of stimuli that is accounted for by the model in each voxel. Cross-validation using held-out data will be used to assess possible overfitting and to facilitate unbiased interpretations. Model weights associated with each parameter will be contrasted between psilocybin and placebo sessions and quantified for individual brain areas using paired t-tests and appropriate corrections for multiple comparisons.

  3. Participant-reported Subjective Effects [ Time Frame: Statistical tests will be performed after all data collection is complete. ]
    Within-subject inferential statistical testing will be used to assess the effects of doses of psilocybin (0 - 14 mg) on subjective effects. Specifically, paired t-tests and between-group effect sizes with 95% confidence intervals will be used to contrast patient-reported outcomes (MEQ-30, ChEQ, 11D-ASC and POMS-SF), corrected for multiple comparisons.



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   21 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  1. Are ≥21 years of age at time of Informed Consent Form signing
  2. Are able and willing to adhere to study requirements, including attending all study visits, preparatory and follow-up sessions, and completing all study evaluations.
  3. Are able to swallow capsules.
  4. Women of childbearing potential (WOCBP) must agree to practice an effective means of birth control throughout the duration of the study.
  5. Written informed consent obtained from and ability for subject to comply with the requirements of the study.
  6. Have an identified support person and agree to be accompanied home (or to an otherwise safe destination) by the support person, or another responsible party, following dosing.
  7. Agree to inform the investigators within 48 hours of any new or changed medical conditions during the course of their study participation.

Exclusion Criteria:

  1. Breastfeeding, have a positive pregnancy test at screening or at any point during the course of the study, or unwilling to practice birth control during participation in the study.
  2. Have a current psychiatric disorder, general medical condition, or other problem or abnormality that, in the opinion of the study clinician or PI, could compromise safety, render them unsuitable for the study, or would make them unable to comply with study activities.
  3. Have MRI contraindications (e.g., metal implants, pacemakers, claustrophobia etc.) as determined by an MRI contraindications questionnaire.
  4. Uncontrolled hypertension (Systolic BP>139mmHG or Diastolic BP>89mmHG) or tachycardia (average HR>90bpm) averaged over at least two measurements.
  5. Clinically significant cardiovascular disease (e.g., history of myocardial infarction or congestive heart failure); or baseline QT/QTc>500msec; or baseline QT/QTc 451-500msec with repeat QT/QTc >500msec.
  6. Inadequate hepatic function as determined by total bilirubin or alkaline phosphatase >3x institutional upper limit of normal; or AST or ALT >6x institutional upper limit of normal. However, participants with Gilbert syndrome are allowed to enroll.
  7. Inadequate renal function as determined by eGFR < 30 mL/min/1.73 m2 (based on the MDRD equation) or CrCl < 30 mL/min (based on the C-G equation).
  8. The regular use of psychotropic medications, such as antidepressants (i.e., SSRIs, tricyclic antidepressants, and monoamine oxidase inhibitors), antipsychotics, and mood stabilizers.
  9. Concomitant dosing of psilocybin with known UGT1A10 and UGT1A9 inhibitors (e.g., diclofenac and probenecid) will be avoided. [There is no exclusion criterion based on the use of medications or substances that are inhibitors or inducers of CYP450 enzymes.]
  10. The use of Prohibited Medications:

    Serotonin Reuptake Inhibitors (SSRIs and SNRIs) Tricyclic Antidepressants (TCAs) Monoamine Oxidase Inhibitors (MAOIs) Atypical antidepressants (e.g., mirtazapine, trazodone, buspar) Antipsychotics/Neuroleptics (typical and atypical) Anti-epileptics or mood stabilizers (e.g., lithium, valproate) (does not include gabapentin used for non-epilepsy conditions) Efavirenz (Sustiva, in Atripla) Lorcaserin Over-the-counter supplements intended to affect mood or anxiety (e.g., 5HT-P, SAMe or St. John's Wort).

    Other drugs associated with the serotonin syndrome (e.g., ondansetron) used within 48 hours of study drug administration (70).

    Vasoactive drugs (e.g., sildenafil, sumatriptan, calcium channel blockers) used within 48 hours of study drug administration.

  11. Unable to agree to the following required Lifestyle Modifications: Patients will be asked to refrain from consuming alcohol, cannabinoids, prescription analgesics/stimulants/benzodiazepines, and any recreational drugs for 48 hours before, the day of, and for 48 hours after study drug administration. Participants will be advised to consume their usual amount of coffee, tea, or other caffeine-containing beverages on the morning of their Medication Visits.
  12. Have a recent history of suicidal ideation or attempted suicide that, in the opinion of the study clinician or PI, may present a risk of suicidal or self-injurious behavior.
  13. Have received an investigational drug or taken a psychedelic within 30 days of the screening visit.
  14. Have an allergy or intolerance to any of the materials contained in the investigational drug product.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05265546


Locations
Layout table for location information
United States, California
University of California, Berkeley
Berkeley, California, United States, 94720
Sponsors and Collaborators
University of California, Berkeley
Layout table for additonal information
Responsible Party: University of California, Berkeley
ClinicalTrials.gov Identifier: NCT05265546    
Other Study ID Numbers: 2021-11-14799
First Posted: March 3, 2022    Key Record Dates
Last Update Posted: July 29, 2022
Last Verified: July 2022

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
Layout table for MeSH terms
Perceptual Disorders
Neurobehavioral Manifestations
Neurologic Manifestations
Nervous System Diseases
Psilocybin
Hallucinogens
Physiological Effects of Drugs
Psychotropic Drugs