Examining the Role of the Orexin System in Sleep and Stress in Persons With Opioid Use Disorder

Inclusion Criteria:

• Between the ages of 21-65, inclusive.

• Past 30-day sleep disturbance as evidenced by a Pittsburgh Sleep Quality Index TotalScore >5.

• Enrolled in either outpatient methadone-maintenance, buprenorphine-maintenance, orXR-NTX treatment for OUD.

• Willingness to be maintained on a protocolized dose starting between 60-130mgmethadone or 380mg XR-NTX for the duration of the study.

• At least two weeks of continuous abstinence from illicit opioids as evidenced byself-report and urine drug screens collected as part of routine care.

• Willing to comply with the study protocol, which will include weekly study visits,daily actigraphy and ecological momentary assessments.

• Use of birth control throughout study.

• Have no clinically significant chronic medical disorders or conditions that arejudged by the investigators to prevent participation.

Exclusion Criteria:

• Serious mental illnesses that are unstable and could affect study participation (thought disorders, hallucinations, delusions, thoughts of harm to self/others).

• Current moderate to severe substance use disorder other than OUD.

• Current illicit stimulant use, including cocaine and methamphetamine.

• Pregnant or breast feeding.

• Have a known allergy to the study medications.

• Past 30-day prescribed use of suvorexant.

• Current use of a benzodiazepine or other schedule IV medication for insomnia.

• Use of Cytochrome P450 3A inhibitors.

• Current narcolepsy, sleep paralysis, or restless leg syndrome as assessed by medicalhistory

• Apnea-hypopnea index > 30.

• Use of glucocorticoid medications and any medication that would alter thehypothalamic-pituitary-adrenal axis.

• Past 30-day suicidal behavior as assessed by the Columbia Suicide Severity RatingScale (C-SSRS).

• Have circumstances that would interfere with study participation (e.g., impendingjail; severe clinical issues).