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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. Identifier: NCT05265546
Recruitment Status : Not yet recruiting
First Posted : March 3, 2022
Last Update Posted : March 3, 2022
Information provided by (Responsible Party):
University of California, Berkeley

Tracking Information
First Submitted Date  ICMJE February 22, 2022
First Posted Date  ICMJE March 3, 2022
Last Update Posted Date March 3, 2022
Estimated Study Start Date  ICMJE May 1, 2022
Estimated Primary Completion Date December 31, 2025   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: March 2, 2022)
Amplitude and pattern of fMRI cortical responses [ Time Frame: Functional MRI recordings will begin approximately 30 minutes after oral administration of psilocybin or placebo and will continue for up to two hours. ]
Functional magnetic resonance imaging (fMRI) responses to visual stimuli will be recorded.
Original Primary Outcome Measures  ICMJE Same as current
Change History No Changes Posted
Current Secondary Outcome Measures  ICMJE Not Provided
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Investigating the Mechanisms of the Effects of Psilocybin on Visual Perception and Visual Representations in the Brain
Official Title  ICMJE Investigating the Mechanisms of the Effects of Psilocybin on Visual Perception and Visual Representations in the Brain
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.
Detailed Description Not Provided
Study Type  ICMJE Interventional
Study Phase  ICMJE Phase 1
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Basic Science
Condition  ICMJE Perception Disorders
Intervention  ICMJE Drug: Psilocybin
The effects of psilocybin will be compared to placebo.
Study Arms  ICMJE
  • Experimental: Experimental
    Psilocybin (2 mg, 4 mg, 10 mg, or 14 mg), one time before fMRI measurement
    Intervention: Drug: Psilocybin
  • Placebo Comparator: Placebo Comparator
    Placebo, one time before fMRI measurement
    Intervention: Drug: Psilocybin
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Not yet recruiting
Estimated Enrollment  ICMJE
 (submitted: March 2, 2022)
Original Estimated Enrollment  ICMJE Same as current
Estimated Study Completion Date  ICMJE December 31, 2025
Estimated Primary Completion Date December 31, 2025   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

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. Have a history of a psychotic disorder (>1 month in duration), bipolar disorder (type I or II), or a dissociative disorder (determined by history).
  5. Family history (first degree relative) of primary psychotic disorder, primary bipolar disorder, or hallucinogen-induced psychotic disorder, if participant < 30 years old.
  6. History of Hallucinogen Persisting Perception Disorder (HPPD).
  7. History of a seizure disorder in adulthood, CNS metastases or current symptomatic CNS infection.
  8. History of intracerebral hemorrhage, embolic stroke, transient ischemic attack (TIA), or history of any aneurysmal vascular disease (including thoracic and abdominal aorta, intracranial and peripheral arterial vessels) or arteriovenous malformation.
  9. Uncontrolled hypertension (Systolic BP>139mmHG or Diastolic BP>89mmHG) or tachycardia (average HR>90bpm) averaged over at least two measurements.
  10. 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.
  11. Poorly controlled diabetes mellitus (e.g., history of an episode of severe hypoglycemia or hospitalization for hyperglycemia on the current diabetes regimen).
  12. 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.
  13. 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).
  14. The regular use of psychotropic medications, such as antidepressants (i.e., SSRIs, tricyclic antidepressants, and monoamine oxidase inhibitors), antipsychotics, and mood stabilizers.
  15. 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.]
  16. 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.

  17. 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.
  18. 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
  19. Have received an investigational drug or taken a psychedelic within 30 days of the screening visit
  20. Have an allergy or intolerance to any of the materials contained in the investigational drug product
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 21 Years and older   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE
Listed Location Countries  ICMJE United States
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT05265546
Other Study ID Numbers  ICMJE 2021-11-14799
Has Data Monitoring Committee Not Provided
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
IPD Sharing Statement  ICMJE Not Provided
Current Responsible Party University of California, Berkeley
Original Responsible Party Same as current
Current Study Sponsor  ICMJE University of California, Berkeley
Original Study Sponsor  ICMJE Same as current
Collaborators  ICMJE Not Provided
Investigators  ICMJE Not Provided
PRS Account University of California, Berkeley
Verification Date February 2022

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP