18 Years to 65 Years
Accepting Healthy Volunteers?
- Minimum 3 months of clinically diagnosed insomnia
- Body mass index ≤35 kg/m2
- Insomnia Severity Index (ISI) > 14 arbitrary units (i.e., moderate-to-severe insomnia)
- Pittsburgh Sleep Quality Index (PSQI) > 5 arbitrary units
- Habitual self-report and objectively-assessed (i.e., 14-day actigraphy) sleep duration
of <6.5 hours
- Pre-menopausal women must have regular menstrual cycles (~26-30 day cycles) and will
be scheduled for microneurography 2-7 days after menstruation to consistently test
during the early follicular phase (or low-hormone phase in women on contraceptives)
- Current or prior treatment of Suvorexant.
- Obstructive sleep apnea defined as an apnea-hypopnea index > 15 using an FDA approved
home sleep apnea screening devices as used in routine clinical practice.
- Participants without evidence of clinically significant obstructive sleep apnea on the
screening test will undergo an overnight in-laboratory polysomnography to confirm
absence of sleep apnea (apnea-hypopnea index of ≥ 10 episodes per hour) and to exclude
other sleep disorders (e.g. periodic limb movement arousal index of ≥ 5 episodes per
- Circadian rhythm sleep disorders
- History of meeting DSM-V criteria of major psychiatric disorder
- Have been clinically-diagnosed with diabetes, cardiovascular disease, or any other
unstable or serious medical condition.
- Current, or use within past month, of psychoactive (other than stable treatment with
antidepressant), hypnotic, stimulant or analgesic medication (except occasional
non-narcotic analgesics), beta blockers, or alpha blockers
- Shift work or other types of self-imposed irregular sleep schedules
- Habitual smoking (6 or more cigarettes per week)
- Habitual alcohol consumption (more than 2 alcoholic drinks per day)
- Breastfeeding or pregnancy