Anesthesiology residency requires extended and overnight shifts, which may negatively impact the quantity and quality of sleep.

Previous studies have investigated the effect of night float shift work on anesthesiology resident sleep and performance and demonstrated that total sleep quantity and time spent in deep and rapid eye movement (REM) sleep were significantly reduced during night float and did not return to baseline after 3 nights of recovery.

Melatonin is a hormone produced by the pineal gland, which regulates the circadian rhythm that governs sleep. Exogenous melatonin may be used as a sleep aid and is available over the counter in the United States. Melatonin is effective in realigning the circadian rhythm disorder caused by night shift work and increasing sleep duration; however, melatonin's effect on improving sleep in resident trainees has not been investigated. The investigators propose a prospective double-blinded randomized control trial to investigate the effect of melatonin on sleep quantity and quality in resident physicians assigned to a night float system.

Residents in Post-Graduate Years 1-7 enrolled in residency programs with a night float system (anesthesiology, general surgery, obstetrics and gynecology, general medicine, and pediatrics) will be invited to participate in the study. A clinical study coordinator will assist in obtaining informed consent. After informed consent is obtained, participants will be randomized to receive either 3 mg melatonin or a matching placebo control. Medications will be prepared and randomization performed by the University of Virginia Pharmacy. Both participants and study coordinators will be blinded to the treatment group. Participants will be provided with a 12-day supply of medication at the start of the night float week. They will be instructed to take one capsule at least 20 minutes prior to going to bed at night or during the day after completing their night float shift. Subjects will be given a portable electroencephalography (EEG) monitor (ZMachine© Insight+ monitor (General Sleep Corporation, Euclid, OH))12 and will be shown how to apply the machine, monitor its functionality, and troubleshoot minor issues. They will be asked to wear the device for 2-3 nights of baseline sleep, 5-6 days of sleep during night float, and 3-4 nights of recovery following night float, for a total of 12 consecutive days. Baseline sleep data will serve as a control for each subject. EEG data collected will include: Light Sleep, Deep Sleep, REM, Arousals, Total Sleep Time, Sleep Efficiency, Latency to Persistent Sleep, Wake After Sleep Onset, Total Deep Sleep, Total REM Sleep, and Time Out of Bed. Data from two different night float periods separated by at least 2 weeks will be collected (one-week melatonin and one-week placebo in random order). Residents will also be asked to complete a daily questionnaire assessing daytime sleepiness (Epworth Sleepiness Scale) and the use of caffeine or other stimulants.

Inclusion Criteria:

• Post-Graduate Year 1-5
• Current enrollment in anesthesiology, general surgery, obstetrics and gynecology, general medicine, or pediatrics residency at the Unversity of Virginia

Exclusion Criteria:

• Current use of sleep aids
• Diagnosed sleep disorder
• History of a pacemaker or other medical device.
• pregnant or breast-feeding females
• Bleeding disorders
• Depression
• High blood pressure
• Seizure disorders
• History of transplant on immunosuppression therapy.

The research pharmacy will randomize the study.