This study is being done to determine whether suvorexant is a safe and effective treatment for insomnia in adults with opioid use disorder compared to a placebo.

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

Inclusion Criteria:

• Taking a stable dose of medication for opioid use disorder (e.g., methadone, buprenorphine)
• Experiencing sleep problems
• Able to stay overnight at a sleep lab 3 times
• Not in opioid withdrawal and have not taken opioids in last month
• Not pregnant or breastfeeding
• No major mental health disorder (e.g., schizophrenia, bipolar disorder)
• No habitual use of depressants or stimulants
• Do not use illicit substances (e.g., fentanyl, cocaine, amphetamines, phencyclidine, barbiturates)
• Ages 18-70

If you choose to participate, you may be asked to:

• Complete a phone screening to see if you qualify
• Attend in-person and virtual study visits over about 16 weeks
• Be randomly assigned to receive either suvorexant or a placebo
• Take the study medication as instructed
• Complete a short daily sleep e-diary using a phone, tablet, or handheld device
• Provide blood and urine samples and complete alcohol breath tests
• Answer questions about your sleep, health, mood, and substance use history
• Stay overnight at a sleep laboratory on three occasions for sleep studies (polysomnography)
• Receive sleep hygiene education and routine medical assessments, including physical exams and heart monitoring

Participants can receive up to $1,055 for completing study activities, including screening visits, study visits, overnight sleep studies, and daily sleep diaries. Reasonable travel expenses for study-related visits may also be provided, but are not guaranteed.

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