Once again your patient, an accountant and tax specialist, is complaining about his sleep. More nights than not he awakens at about 2 am. An hour goes by, sometimes 2, before he returns to sleep. You've prescribed 4 different hypnotics. Each gave the same unsatisfactory result. For 2 weeks, your patient got the 8 hours of uninterrupted sleep he—and you—seek, but then the old pattern returned. Following your instructions, he avoids caffeine, doesn't exercise after 6 pm, and confines his activities in bed to sleep, but to no avail. You refer him to a sleep laboratory, and the results there are entirely consistent with what he's been telling you. In the sleep lab he falls asleep at 11 pm, awakens at 2:30 am, returns to sleep at 4 am, and awakens for good at 7:30 am. He does not have sleep apnea, restless legs syndrome, or depression.
Your patient seems more concerned as the years go on. You've suggested to him that when he wakes up, he should get out of bed and read until he gets sleepy. But he spends his awake time worrying about why he can't sleep and how his interrupted sleep will affect his work. The length of his time awake appears to be increasing. He insists that his daytime concentration isn't as good as it once was.
At a drug company-sponsored dinner, between the veal marsala and chocolate mousse, you learn that interrupted sleep is among the most common sleep problems and that a new hypnotic promises to be better than previous ones at providing "continuous sleep-consolidated sleep," as the speaker calls it. To her credit, the drug company-sponsored speaker does not shy away from the fact that the new hypnotic works by enhancing γ-aminobutyric acid transmission, just like the older ones.
Do you subject your patient to yet another drug trial, this time with a more expensive, albeit not very different, agent? Given your patient's misery about his sleep problem and the fact that you've exhausted the available options, such a course is not unreasonable. Yet a recent discovery, not from a drug company laboratory or a university research program but from a historian, suggests that there may be another, very different, way to relieve your patient's problem.
Sleep in times past
In the course of gathering information for his book about night in preindustrial times (At Day's Close: Night in Times Past), A. Roger Ekirch, professor of history at Virginia Polytechnic Institute, uncovered the fact that before artificial illumination was widely used, people typically slept in 2 bouts, which they called first sleep and second sleep.1 In those times, sleep was more closely tied to sunset and sunrise than it is now. Within an hour or so after sunset, people retired to bed, slept for about 4 hours, and then woke up. They remained awake for a couple of hours and then returned to sleep at about 2 am for another 4 hours or so.
Written records from before the first century onward indicate that the period between first and second sleep afforded a chance for quiet contemplation, but people also got out of bed during this interval and did household chores or visited with family and friends. Although diaries, court documents, and literature of the time indicate that this sleep pattern was widely known and acknowledged, until Ekirch's work this bit of history had been lost to the current era. This pattern of sleep is no longer the norm in developed countries, where artificial light extends the day, but anthropologists have observed a similar pattern of segmented sleep in some contemporary African tribes.1 Ekirch notes that the Tiv people of central Nigeria even use the same terms—first sleep and second sleep—used by the Europeans of times past.
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