SchizophreniaNCT01730781
Imaging Cannabinoid Receptors Using Positron Emission Tomography (PET) Scanning
An observational study of Schizophrenia and Cannabis Dependence, run by Yale University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 55 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Schizophrenia, Cannabis Dependence, Prodromal for Psychotic Illness
- What is being tested?
- [11-C]OMAR
- Type of treatment
- Surgery or procedure
- How many people
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- Jul 2010to Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- Men only
- Healthy volunteers accepted
- Adult
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.
Who may be able to join
- 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:
Show all 13Show fewer
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Connecticut Mental Health Center, Clinical Neuroscience Research Unit
New Haven, Connecticut, 06519
Alex Selloni, BA, 203-974-7489, alexandria.selloni@yale.edu
Deepak C D'Souza, MD
About this study
Official title: 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.
- Conditions
- Schizophrenia, Cannabis Dependence, Prodromal for Psychotic Illness, Family History of Alcoholism, Healthy Control, Opioid-use Disorder
- Being tested
- [11-C]OMAR
- Keywords
- Cannabis dependence, Brain Imaging, Schizophrenia, Control, PTSD, OUD
- Medical subject headings
- Schizophrenia, Marijuana Abuse, Opioid-Related Disorders, Stress Disorders, Post-Traumatic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
[11-C]OMARRadiation
The radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan.
| Study group | Role | What they receive |
|---|---|---|
| Schizophrenia | Patients diagnosed with schizophrenia both on medication and off medication Receives: Radiation: [11-C]OMAR | |
| Cannabis dependence | Frequent users of cannabis Receives: Radiation: [11-C]OMAR | |
| Family history of alcoholism | Healthy volunteers with a first degree relative with alcoholism Receives: Radiation: [11-C]OMAR | |
| Prodrome for psychotic illness | Not meeting full criteria for psychotic illness but exhibiting prodromal symptoms Receives: Radiation: [11-C]OMAR | |
| Healthy Volunteers | Healthy volunteers with no current or past major medical or psychiatric history Receives: Radiation: [11-C]OMAR | |
| PTSD-Post Traumatic Stress Disorder | Patients diagnosed with Post Traumatic Stress Disorder Receives: Radiation: [11-C]OMAR | |
| Opioid Use Disorder | Patients diagnosed with Opioid Use Disorder Receives: Radiation: [11-C]OMAR |
What is being measured
The primary outcome is the main question the study is designed to answer.
PET Imaging
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.
Measured: One time within 4 weeks of screening
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Nov 2012 (estimated)
- Study startJul 2010
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Other
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA), National Institute of Mental Health (NIMH)
- Responsible party
- Principal investigator, Deepak C. D'Souza, Yale University
- Investigators
- Deepak C D'Souza, MD, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01730781
- Sponsor's protocol ID
- 1005006735
- Other IDs
- 1R21DA030702-01A1, 1R21MH094961-01A1
- Status last verified
- Apr 2026
- First submitted
- 14 Jun 2012
- Last updated
- 27 Apr 2026
- Results posted
- No
Publications
Ranganathan M, Cortes-Briones J, Radhakrishnan R, Thurnauer H, Planeta B, Skosnik P, Gao H, Labaree D, Neumeister A, Pittman B, Surti T, Huang Y, Carson RE, D'Souza DC. Reduced Brain Cannabinoid Receptor Availability in Schizophrenia. Biol Psychiatry. 2016 Jun 15;79(12):997-1005. doi: 10.1016/j.biopsych.2015.08.021. Epub 2015 Aug 29.
PubMed 26432420
Study at a glance
From the registry record, last updated by the sponsor on 27 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of CB1 Receptors Using [11-C]OMAR
- ClinicalTrials.gov ID
- NCT01730781
- Acronym / sponsor ID
- 1005006735
- Conditions
- Schizophrenia, Cannabis Dependence, Prodromal for Psychotic Illness, Family History of Alcoholism, Healthy Control, Opioid-use Disorder
- Keywords
- Cannabis dependence, Brain Imaging, Schizophrenia, Control, PTSD, OUD
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA), National Institute of Mental Health (NIMH)
- Study start
- Jul 2010
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 21 Nov 2012 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Observational model
- Other
- Time perspective
- Other
- Number of arms
- 7
| Arm | Type | Receives |
|---|---|---|
| Schizophrenia | – | Radiation: [11-C]OMARPatients diagnosed with schizophrenia both on medication and off medication |
| Cannabis dependence | – | Radiation: [11-C]OMARFrequent users of cannabis |
| Family history of alcoholism | – | Radiation: [11-C]OMARHealthy volunteers with a first degree relative with alcoholism |
| Prodrome for psychotic illness | – | Radiation: [11-C]OMARNot meeting full criteria for psychotic illness but exhibiting prodromal symptoms |
| Healthy Volunteers | – | Radiation: [11-C]OMARHealthy volunteers with no current or past major medical or psychiatric history |
| PTSD-Post Traumatic Stress Disorder | – | Radiation: [11-C]OMARPatients diagnosed with Post Traumatic Stress Disorder |
| Opioid Use Disorder | – | Radiation: [11-C]OMARPatients diagnosed with Opioid Use Disorder |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- 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.
Key inclusion criteria (13 listed)
- 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
Key exclusion criteria (4 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| [11-C]OMARThe radiotracer, [11-C]OMAR will be administered at no more than 10 micrograms at the beginning of each PET scan. | Radiation | Cannabis dependence, Family history of alcoholism, Healthy Volunteers, Opioid Use Disorder, PTSD-Post Traumatic Stress Disorder, Prodrome for psychotic illness, Schizophrenia |
Primary outcome
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Apr 2026.
- Derived from this study: PubMed 26432420Ranganathan M, Cortes-Briones J, Radhakrishnan R, Thurnauer H, Planeta B, Skosnik P, Gao H, Labaree D, Neumeister A, Pittman B, Surti T, Huang Y, Carson RE, D'Souza DC. Reduced Brain Cannabinoid Receptor Availability in Schizophrenia. Biol Psychiatry. 2016 Jun 15;79(12):997-1005. doi: 10.1016/j.biopsych.2015.08.021. Epub 2015 Aug 29.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Deepak C D'Souza, MD principal investigator
Yale University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Schizophrenia and Cannabis Dependence, run by Yale University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 13 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Alex Selloni, BA (203-974-7489, alexandria.selloni@yale.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
PET Imaging (time frame: One time within 4 weeks of screening). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01730781, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Apr 2026.