Targeting Orexin to Treat Nicotine Dependence

Eligibility Criteria

• * Participants will be male and female volunteers between the ages of 18-50
• * Participants must report daily smoking of at least 5 cigarettes per day over the last 6 months.
• * Participants must be nicotine dependent, having an FTND score greater than or equal to 4.
• * Participants must have an expired carbon monoxide level of 10 ppm or more on the screening day.
• * Participants must have an expired carbon monoxide level of no more than 10 ppm on the study visits.
• * Female participants must have a negative pregnancy test on all study days.
• * Participants cannot meet DSM-5 criteria for lifetime and/or current psychotic disorders such as bipolar disorder, schizophrenia, schizoaffective disorder
• * Participants cannot meet DSM-5 criteria for current substance abuse disorders other than nicotine and marihuana and cannot meet criteria for current moderate or severe alcohol use disorder (as assessed by the SCID-5)
• * Participants cannot have positive drug and alcohol screen on each study visit other than for nicotine or marijuana.
• * Participants reporting marihuana use greater than 1-2 times per week will be excluded.
• * Participants must report no marihuana use within 24 hours of the study visit.
• * Participants cannot be taking any prescription medication that could impact brain function including medications that depress CNS function
• * Participants cannot have a history of major head trauma resulting in cognitive impairment, seizure, or other neurological disorders.
• * Participants cannot be pregnant or breastfeeding.
• * Participants must be able to read screening materials including consent form and give informed consent
• * Individuals with severe hepatic impairment will be excluded.
• * Participants cannot be obese as determined by a Body Mass Index (BMI) of 30 or greater.
• * Participants cannot be using a CYP3A inhibitor/inducer (metabolism by CYP3A is the major elimination pathway for suvorexant)
• * Participants cannot have a current cardiac disorder such as palpitations, tachycardia and/or use of the cardiac medication Digoxin
• * Participants cannot have narcolepsy
• * Participants cannot self-report complex sleep behaviors such as sleep driving, preparing and eating food or making phone calls
• * Participants cannot have compromised respiratory function such severe obstructive sleep apnea or severe chronic obstructive pulmonary disease
• * Participants cannot have current major depressive disorder (within the past 6 months) and/or indorse suicidal ideation on the Beck Depression Inventory.