Opioid Use DisorderPhase 1NCT07800520
Characterization of CB1 Receptors Using [11-C]OMAR in Opioid Use Disorder
A Phase 1 study testing [11C]OMAR in people with Opioid Use Disorder and OAT, run by Yale University at 1 site in United States.
Trial summary
The goals of this sub-study is to assess CB1R availability in early abstinent individuals with OUD (following opioid agonist therapy - OAT stabilization) and in matched healthy controls. Read more about this study
- Who is it for?
- Ages 25 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Opioid Use Disorder, OAT
- What is being tested?
- [11C]OMAR
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 110 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Oct 2026to Aug 2030
- Phase
- Phase 1
- 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 25 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- All
- Normal screening bloodwork.
- Adequate arterial access for placement of an arterial line and blood sampling per study protocol.
- OUD Participants:
- Diagnosis of opioid use disorder (OUD) according to DSM-5 criteria.
- Actively seeking treatment for OUD.
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- Willingness to initiate opioid agonist therapy (OAT) with buprenorphine.
- Healthy Controls:
- Good general physical health.
- No current or past diagnosis of any psychiatric or substance use disorders.
Who cannot join
- All
- Any current major medical condition that, in the opinion of the Principal Investigator, poses a risk for PET procedures.
- Prior participation in research studies within the past year that would result in cumulative radiation exposure exceeding annual limits.
- Presence of ferromagnetic metal in the body, pacemaker, or other contraindications to MRI.
- Positive pregnancy test or current lactation.
- History of neurological conditions, including stroke or seizure disorders.
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- Hematocrit values lower than 30
- OUD Participants
- Current or past diagnosis of a serious psychiatric disorder.
- Current diagnosis of any substance use disorder other than nicotine or opioids.
- Use of any substances within the past 30 days.
- Current use of SSRIs or benzodiazepines or use within the past 30 days.
- Previous enrollment in the main study.
- Healthy Controls:
- Current or past diagnosis of any psychiatric disorder.
- Current diagnosis of any substance use disorder (excluding nicotine).
- Use of any substances within the past 30 days.
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
Abigail Dewey, 475-441-4190, abigail.dewey@yale.edu
Anahita Bassir Nia, MD
About this study
The goals of this sub-study is to assess CB1R availability in early abstinent individuals with OUD (following opioid agonist therapy - OAT stabilization) and in matched healthy controls.
Read the detailed description
Investigators will use PET imaging to investigate CB1R availability in treatment-seeking individuals with OUD during the early phase of OAT, compared to healthy controls (HCs). Using PET imaging with the CB1R-specific radioligand [¹¹C]OMAR, investigators will assess CB1R availability in predefined brain regions. Investigators will characterize group differences in CB1R availability, evaluate the relationship between CB1R alterations and negative emotional states, including mood, anxiety, and perceived stress, as well as risk of opioid relapse (defined as time to first use of non-prescribed opioids) over a 90-day follow-up period.
- Conditions
- Opioid Use Disorder, OAT
- Being tested
- [11C]OMAR
- Medical subject headings
- Opioid-Related Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
[11C]OMARDrug
Also called [11C] JHU75528
For each [11C]OMAR PET scan, up to 20 mCi of [11C]OMAR will be administered.
| Study group | Role | What they receive |
|---|---|---|
| Healthy Volunteers | Other | Healthy volunteers with no current or past major medical or psychiatric history Receives: Drug: [11C]OMAR |
| Opioid Use Disorder in Opioid Agonist Therapy (OAT) | Other | Patients diagnosed with opioid use disorder during the early phase of opioid agonist therapy Receives: Drug: [11C]OMAR |
What is being measured
The primary outcome is the main question the study is designed to answer.
CB1R Availability
To compare cortical CB1R availability (volume of distribution, mL/cm3) assessed using brain PET imaging in individuals diagnosed with opioid use disorder on chronic methadone maintenance vs. matched healthy controls.
Measured: Day 7
Mean Beck Depression Inventory (BDI) score
A 21-question self-report tool to assess depression symptoms. Total score range 0 to 63, higher scores indicating more severe symptoms.
Measured: Days 7, 28, 49, 70, 90
Mean Anxiety Inventory (BAI) score
A 21-question self-report tool to assess anxiety symptoms. Total score range 0 to 63, higher scores indicating more severe anxiety.
Measured: Days 7, 28, 49, 70, 90
Mean Perceived Stress Scale (PSS) score
The PSS is a 10-item self- report scale. PSS scores are obtained by reversing responses to the four positively stated items (items 4, 5, 7, \& 8) and then summing across all scale items. Total score range from 0-40 with higher scores indicate greater levels of stress.
Measured: Days 7, 28, 49, 70, 90
Mean Opioid Relapse days
Mean Opioid Relapse days assessed using Timeline Follow Back (TLFB)
Measured: Days 7, 14, 21, 28, 35, 42, 49, 56, 70, 77, 84, 90
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Sep 2026
- Study start1 Oct 2026
- Primary completionAug 2030 (estimated)
- Study completionAug 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Opioid Use DisorderStudies 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
- Interventional
- Phase
- Phase 1
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 110 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Responsible party
- Principal investigator, Anahita Bassir Nia, Yale University
- Investigators
- Anahita Bassir Nia, MD, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07800520
- Sponsor's protocol ID
- 2000033525_a
- Other IDs
- 1R01DA063712-01A1
- Status last verified
- Oct 2026
- First submitted
- 28 Aug 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of CB1 Receptors Using [11-C]OMAR in Opioid Use Disorder
- ClinicalTrials.gov ID
- NCT07800520
- Acronym / sponsor ID
- 2000033525_a
- Conditions
- Opioid Use Disorder, OAT
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 110 participants (estimated)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Study start
- 1 Oct 2026 (actual)
- Primary completion
- Aug 2030 (estimated)
- Study completion
- Aug 2030 (estimated)
- First posted
- 2 Sep 2026 (actual)
- 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 goals of this sub-study is to assess CB1R availability in early abstinent individuals with OUD (following opioid agonist therapy - OAT stabilization) and in matched healthy controls.
Detailed description
Investigators will use PET imaging to investigate CB1R availability in treatment-seeking individuals with OUD during the early phase of OAT, compared to healthy controls (HCs). Using PET imaging with the CB1R-specific radioligand [¹¹C]OMAR, investigators will assess CB1R availability in predefined brain regions. Investigators will characterize group differences in CB1R availability, evaluate the relationship between CB1R alterations and negative emotional states, including mood, anxiety, and perceived stress, as well as risk of opioid relapse (defined as time to first use of non-prescribed opioids) over a 90-day follow-up period.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Healthy Volunteers | Other | Drug: [11C]OMARHealthy volunteers with no current or past major medical or psychiatric history |
| Opioid Use Disorder in Opioid Agonist Therapy (OAT) | Other | Drug: [11C]OMARPatients diagnosed with opioid use disorder during the early phase of opioid agonist therapy |
Who may qualify
- Ages
- 25 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- All
- Normal screening bloodwork.
- Adequate arterial access for placement of an arterial line and blood sampling per study protocol.
- Diagnosis of opioid use disorder (OUD) according to DSM-5 criteria.
- Actively seeking treatment for OUD.
Key exclusion criteria (17 listed)
- All
- Any current major medical condition that, in the opinion of the Principal Investigator, poses a risk for PET procedures.
- Prior participation in research studies within the past year that would result in cumulative radiation exposure exceeding annual limits.
- Presence of ferromagnetic metal in the body, pacemaker, or other contraindications to MRI.
- Positive pregnancy test or current lactation.
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 |
|---|---|---|
| [11C]OMARAlso: [11C] JHU75528For each [11C]OMAR PET scan, up to 20 mCi of [11C]OMAR will be administered. | Drug | Healthy Volunteers, Opioid Use Disorder in Opioid Agonist Therapy (OAT) |
Primary outcome
CB1R Availability
Time frame: Day 7
To compare cortical CB1R availability (volume of distribution, mL/cm3) assessed using brain PET imaging in individuals diagnosed with opioid use disorder on chronic methadone maintenance vs. matched healthy controls.
Mean Beck Depression Inventory (BDI) score
Time frame: Days 7, 28, 49, 70, 90
A 21-question self-report tool to assess depression symptoms. Total score range 0 to 63, higher scores indicating more severe symptoms.
Mean Anxiety Inventory (BAI) score
Time frame: Days 7, 28, 49, 70, 90
A 21-question self-report tool to assess anxiety symptoms. Total score range 0 to 63, higher scores indicating more severe anxiety.
Mean Perceived Stress Scale (PSS) score
Time frame: Days 7, 28, 49, 70, 90
The PSS is a 10-item self- report scale. PSS scores are obtained by reversing responses to the four positively stated items (items 4, 5, 7, \& 8) and then summing across all scale items. Total score range from 0-40 with higher scores indicate greater levels of stress.
Mean Opioid Relapse days
Time frame: Days 7, 14, 21, 28, 35, 42, 49, 56, 70, 77, 84, 90
Mean Opioid Relapse days assessed using Timeline Follow Back (TLFB)
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 2 Oct 2026.
- Individual participant dataSharing planned: No
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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.
Anahita Bassir Nia, 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?
A Phase 1 study testing [11C]OMAR in people with Opioid Use Disorder and OAT, 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 10 inclusion and 17 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 2 Oct 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.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Anahita Bassir Nia, MD (203-974-7540, anahita.bassirnia@yale.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
CB1R Availability (time frame: Day 7). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 2 Oct 2026.