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Imaging Cannabinoid Receptors Using Positron Emission Tomography (PET) Scanning

This study is currently recruiting participants. (see Contacts and Locations)
Verified December 2016 by Yale University
National Institute on Drug Abuse (NIDA)
National Institute of Mental Health (NIMH)
Information provided by (Responsible Party):
Deepak C. D'Souza, Yale University Identifier:
First received: June 14, 2012
Last updated: December 1, 2016
Last verified: December 2016

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, 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.

Condition Intervention Phase
Cannabis Dependence
Prodromal for Psychotic Illness
Family History of Alcoholism
Radiation: [11-C]OMAR
Phase 1

Study Type: Observational
Official Title: Characterization of CB1 Receptors Using [11-C]OMAR

Resource links provided by NLM:

Further study details as provided by Yale University:

Primary Outcome Measures:
  • 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.

Biospecimen Retention:   Samples With DNA
At the screening visit, genomic DNA will be extracted from whole blood, assigned a code, and stored for analysis of group differences in the frequency of CB1R alleles and to examine the relationship between allelic variation at the CB1R locus and [11-C] OMAR binding. In addition, other genes or markers that may be related to brain function or to behavior may be studied.

Estimated Enrollment: 100
Study Start Date: July 2010
Estimated Study Completion Date: December 2017
Estimated Primary Completion Date: December 2017 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Patients diagnosed with schizophrenia both on medication and off medication
Radiation: [11-C]OMAR
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
Radiation: [11-C]OMAR
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
Radiation: [11-C]OMAR
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
Radiation: [11-C]OMAR
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
Healthy Volunteers
Healthy volunteers with no current or past major medical or psychiatric history
Radiation: [11-C]OMAR
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.


Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   Male
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, and healthy volunteers.

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

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.
  • 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
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01730781

Contact: Gina Creatura, BA 203-974-7544

United States, Connecticut
Connecticut Mental Health Center, Clinical Neuroscience Research Unit Recruiting
New Haven, Connecticut, United States, 06519
Contact: Gina Creatura, BA    203-974-7544   
Principal Investigator: Deepak C D'Souza, MD         
Sponsors and Collaborators
Yale University
National Institute on Drug Abuse (NIDA)
National Institute of Mental Health (NIMH)
Principal Investigator: Deepak C D'Souza, MD Yale University
  More Information

Responsible Party: Deepak C. D'Souza, Associate Professor, Yale University Identifier: NCT01730781     History of Changes
Other Study ID Numbers: 1005006735
1R21DA030702-01A1 ( US NIH Grant/Contract Award Number )
1R21MH094961-01A1 ( US NIH Grant/Contract Award Number )
Study First Received: June 14, 2012
Last Updated: December 1, 2016

Keywords provided by Yale University:
Cannabis dependence
Brain Imaging

Additional relevant MeSH terms:
Marijuana Abuse
Schizophrenia Spectrum and Other Psychotic Disorders
Mental Disorders
Alcohol-Related Disorders
Substance-Related Disorders
Chemically-Induced Disorders processed this record on April 26, 2017