Falling asleep and staying asleep throughout the night ought to be something we do without any thought, like yawning or even scratching a mosquito bite. As teenagers most of us fought to be able to sleep longer, and have memories of dragging ourselves out of bed hours before we were ready to get up because of school and/or work.
But as we age, the ability to sink into a profound sleep and stay asleep seems sometimes as elusive as remembering an interesting dream. We, of course, make it difficult for ourselves to fall and stay asleep when we travel across time zones, rely on alarm clocks to wake us up (always too early) and insist on keeping our brains occupied with work way past our bedtime. Caffeine, alcohol, late meals, noisy neighbors or traffic, restless pet bed companions and crying children also impede our ability to fall asleep, and can be relied upon to make us wake up in what is so charmingly called “The Dead of the Night.”
Women tend to experience additional interference with a good night’s sleep. The premenstrual week of the menstrual cycle often causes restless sleep, and when women transition into menopause, hot flushes prod a woman out a sleep into a bubble of heat and sweat.
Men and women experience a decrease in the blood levels of the sleep hormone melatonin as they age. In younger individuals levels of this hormone are high enough in the blood to maintain a full night’s sleep but aging causes the melatonin levels to decline so not enough may be around by 4 or 5am to keep from an early awakening.
Tiny amounts of melatonin, enough to replace that which is missing in the older individual, usually is sufficient to allow someone over forty, the age when melatonin begins to decline, to sleep through the night. (Doses over 03-0.5 mg of melatonin may suppress the body’s own synthesis of this hormone, or cause grogginess upon awakening.)
Other equal opportunity causes of insomnia can be an overactive brain at bedtime, and an anxious emotional state when awakening at 3am. A young first-year law associate I know was frequently emailed at 11pm or later with requests to do work on an urgent legal matter, and deliver the results before the next morning. Her position at the bottom of the law firm work heap made it impossible to refuse these requests, and more impossible to fall asleep after spending several hours working on the assignment. Her eyes may have been closed, but her brain could not shut itself off from its work mode to allow her to fall asleep.
Awakening in the early morning hours invokes in many of us feelings of agitation, worry, anxiety, and even panic. Problems that seemed manageable the previous day take on gigantic proportions. The husband of a friend who had a cataract removed a few days ago told me that he would wake up and lie in bed wondering how he would manage when he became blind from the operation. (The procedure was a success.) A neighbor who looked very sleepy when I saw her on the street told me that she woke at 2:45am and could not get back to sleep because she was so worried about a speech she was giving that afternoon. “I wasn’t worried at all about the speech before I went to bed, but in the middle of the night I was sure I would make a mess of it,” she told me.