Clinical Research Directory

Inclusion Criteria: * Ability and acceptance to provide informed consent; * No perception of light; * History (within the last 3 months) of trouble sleeping at night difficulty initiating sleep or staying asleep), difficulty awakening in the morning, or daytime sleepiness as determined by answering yes to at least one question in the Sleep Complaint Questionnaire * Willing and able to comply with study requirements and restrictions including a commitment to a fixed 9-hour sleep opportunity during the study; Exclusion Criteria: * Have a probable diagnosis of a current sleep disorder other than N24HSWD that is the primary cause of the sleep disturbance based on clinical investigator medical judgment; * Current clinically significant cardiovascular, respiratory, neurologic, hepatic, hematopoietic, renal, gastrointestinal or metabolic dysfunction unless currently controlled and stable; * History (within the 12 months prior to screening) of psychiatric disorders including Major Depressive Disorder, Generalized Anxiety Disorder, Axis II Disorders, delirium or any other psychiatric disorder that in the opinion of the clinical investigator would affect participation in the study or full compliance with study procedures; * History of intolerance and/or hypersensitivity to melatonin or melatonin agonists; * Smoke more than 10 cigarettes/day * Participation in a previous tasimelteon (aka VEC-162 or BMS-214778) trial; * Use of central nervous system prescription or OTC medications, other than melatonin, that affects the sleep-wake cycle within 3 weeks or 5 half-lives (whichever was longer) of Baseline; * Use of melatonin or melatonin agonist;