In this research study, we are trying to understand how brain chemistry—specifically the kappa opioid receptor system—changes during early recovery from opioid use disorder. These receptors are part of the brain’s stress and reward systems and may play a key role in cravings, withdrawal, and relapse. By studying these systems using advanced brain imaging (PET and MRI), we hope to better understand the biology of opioid use and early abstinence. We are also interested in how these brain changes may relate to treatment outcomes. Some participants will receive methadone during an inpatient stay, allowing us to observe the effects of medically supported detox. Our goal is to use this information to help improve treatment strategies and support long-term recovery.

You may be eligible for this study if you meet the following criteria.

Inclusion Criteria:

• Ages 21–60
• Currently using or struggling with opioids
• Able to commit to a 5–10-day inpatient stay at the Clinical Neuroscience Research Unit (CMHC/CNRU)
• Willing and able to undergo brain imaging procedures (PET and MRI scans)
• Able to attend multiple follow-up visits over 12 weeks (24 visits total)

Exclusion Criteria:

• Cannot safely undergo MRI or PET scanning (e.g., due to metal implants, claustrophobia, or pregnancy)
• Have serious or unstable medical conditions that could interfere with participation
• Have significant cognitive impairment or psychiatric conditions that would impair informed consent or study participation
• Are unable to safely detox (if applicable) or medically unsuitable for methadone treatment
• Are not available for the full inpatient stay or required follow-up visits

If you qualify and choose to participate, here’s what you can expect:

1. Phone Screening: First, we’ll talk with you over the phone to ask a few questions about your health and opioid use to see if the study might be a good fit.
2. Screening Visit (Outpatient): If you’re eligible after the phone call, you’ll come in for a 2-hour visit. During this time, you’ll:
   1. Review your medical and mental health history
   2. Have interviews and assessments
   3. Get a physical and neurological exam
3. Have lab tests, an ECG (heart test), and a drug screening. Inpatient Stay (5–10 days): If you have opioid use disorder (OUD), you’ll stay at the Clinical Neuroscience Research Unit (CNRU) in New Haven for 5–10 days.
   • You may receive methadone treatment and support for detoxification
   • During this time, you’ll also complete brain scans:
     • PET scan (about 2 hours, but may take up to 8 hours total)
     • MRI scan (about 1 hour)
4. Follow-Up Visits: After your inpatient stay, you’ll return for 24 follow-up visits over 12 weeks (2 visits per week).
   • Each visit will be under an hour
   • These visits help us track your progress and collect additional data
5. Compensation:
   You can receive up to $1200 for completing all parts of the study.
6. Support & Care:
   You’ll receive care and support from the study team, including help with opioid withdrawal, access to methadone, and referrals for ongoing outpatient treatment if needed.

As a participant, you may receive up to $1200.

There is no cost for you to participate in our research study.