Shift-Work Sleep Disorder — The Glass Is More Than Half Empty

As many as 20 percent of workers in industrialized nations are shift workers — in other words, people who work either at night or on rotating shifts.1 Shift-work sleep disorder, defined as a primary complaint of insomnia or excessive sleepiness temporally associated with a work period that occurs during the habitual sleep phase,2 has been diagnosed in as many as 10 percent of shift workers.3 Shift workers overall appear to be at increased risk for peptic ulcer disease, coronary heart disease, insulin resistance, and the metabolic syndrome,4,5 as well as for sleep deprivation, depression, sleepiness-related accidents, and curtailed family . . .