Imaging Cannabinoid Receptors Using Positron Emission Tomography (PET) Scanning

November 2, 2023 updated by: Deepak C. D'Souza, Yale University

Characterization of CB1 Receptors Using [11-C]OMAR

The aim of the present study is to assess the availability of cannabinoid receptors (CB1R) in the human brain. CB1R are present in everyone's brain, regardless of whether or not someone has used cannabis. The investigators will image brain cannabinoid receptors using Positron Emission Tomography (PET) imaging and the radioligand OMAR, in healthy individuals and several conditions including 1) cannabis use disorders, 2) psychotic disorders, 3) prodrome of psychotic illness and 4) individuals with a family history of alcoholism, 5) Post-Traumatic Stress Disorder 6) Opioid Use Disorder using the PET imaging agent or radiotracer, [11C]OMAR. This will allow us to characterize the number and distribution of CB1R in these conditions. It is likely that the list of conditions will be expanded after the collection of pilot data and as new data on cannabinoids receptor function and psychiatric disorders becomes available.

Those in the cannabis us disorder arm of the study will have a PET scan on at least three occasions: once while smoking as usual, once after 48-hours of abstinence from cannabis, and a final time after 4 weeks of abstinence. Additional scans may be conducted within the 4 weeks and the last scan may be conducted well beyond 4 weeks. Similarly, while most schizophrenia patients may get scanned just once, a subgroup of patients may get scanned more than once. For example to tease out the effects of medications, unmedicated patients may get scanned while unmedicated and again after treatment with antipsychotic medications. Similarly prodromes may get scanned while in the prodromal stage off medications, on medications and after conversion to schizophrenia.

Study Overview

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Connecticut
      • New Haven, Connecticut, United States, 06519
        • Recruiting
        • Connecticut Mental Health Center, Clinical Neuroscience Research Unit
        • Contact:
        • Principal Investigator:
          • Deepak C D'Souza, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

The study population is composed of schizophrenia, cannabis dependence, prodromal for psychotic illness, family history of alcoholism, healthy volunteers, Post-Traumatic Stress Disorder and Opioid Use Disorder.

Description

Inclusion Criteria:

  • Males ages 18-55
  • For cannabis users:
  • Willing to abstain from cannabis use for four weeks
  • For schizophrenia:
  • Meets DSM-IV-TR criteria for schizophrenia or schizoaffective disorder
  • For prodrome for psychotic illness:
  • Meets SIPS criteria for prodromal syndrome
  • For family history positive:
  • First degree relative with alcoholism
  • For Post-Traumatic Stress Disorder
  • Meets DSM-IV-TR criteria for PTSD
  • For OUD
  • Meets DSM-IV-TR criteria for Opioid Use Disorder

Exclusion Criteria:

  • Current neuro-psychiatric illness (including cannabis dependence) or severe systemic disease. Cannabis use disorder is permitted in the cannabis dependent group. Schizophrenia and schizoaffective disorder is permitted in the schizophrenia group. Psychotic symptoms are permitted in the prodromal group. Post-Traumatic Stress Disorder is permitted in the PTSD group and Opioid Use Disorder is permitted in the OUD group.
  • Presence of ferromagnetic metal in the body or heart pacemaker
  • Have had exposure to ionizing radiation that in combination with the study tracer would result in a cumulative exposure that exceeds recommended exposure limits
  • Are claustrophobic

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Healthy Volunteers
Healthy volunteers with no current or past major medical or psychiatric history
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
Schizophrenia
Patients diagnosed with schizophrenia both on medication and off medication
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
Cannabis dependence
Frequent users of cannabis
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
Family history of alcoholism
Healthy volunteers with a first degree relative with alcoholism
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
Prodrome for psychotic illness
Not meeting full criteria for psychotic illness but exhibiting prodromal symptoms
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
PTSD-Post Traumatic Stress Disorder
Patients diagnosed with Post Traumatic Stress Disorder
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
Opioid Use Disorder
Patients diagnosed with Opioid Use Disorder
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
PET Imaging
Time Frame: One time within 4 weeks of screening

This study will utilize the radioligand [11C]OMAR and High Resolution Research Tomography (HRRT) Positron Emission Tomography (PET) to measure brain CB1 receptor availability in all study populations.

Those in the cannabis dependent population of the study will have PET scanning on three occasions: once within four weeks of screening while smoking as usual, once 48-hours later after remaining abstinent, and once four weeks later after remaining abstinent. The change in receptor density at each time point will be evaluated.

Those in the other populations will have PET scanning done on one occasion within four weeks of screening.

One time within 4 weeks of screening

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Deepak C D'Souza, MD, Yale University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2010

Primary Completion (Estimated)

December 1, 2024

Study Completion (Estimated)

December 1, 2024

Study Registration Dates

First Submitted

June 14, 2012

First Submitted That Met QC Criteria

November 15, 2012

First Posted (Estimated)

November 21, 2012

Study Record Updates

Last Update Posted (Actual)

November 7, 2023

Last Update Submitted That Met QC Criteria

November 2, 2023

Last Verified

November 1, 2023

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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