Characterization of CB1 Receptors Using [11-C]OMAR in Opioid Use Disorder

Inclusion Criteria:

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.
* 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.

Exclusion Criteria:

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.
* 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.