Awake All Night, or So It Seems
Here is a strange one. Some people are certain they were awake all night, yet sleep tests prove they slept for hours. This is called paradoxical insomnia, and it may affect about 5% of people with insomnia. They usually do not feel very sleepy during the day, but they still feel like they barely slept. They believe it takes them far too long to fall asleep, and they underestimate how long they stayed asleep.
For most people, though, insomnia is very real. It means trouble falling asleep or staying asleep for as long as you want. It often brings daytime sleepiness, low energy, irritability and a low mood, along with trouble focusing and learning. It can also raise the risk of accidents.
Short-term insomnia lasts days or weeks. Long-term insomnia lasts more than a month. The word itself comes from Latin and simply means without sleep.
A Brain Stuck on High Alert
Why does sleep slip away? One explanation, the cognitive model, points to rumination and hyperarousal. The mind keeps going over worries and stays too alert to switch off. Stress is a common trigger. A hard event at work can start a bout of insomnia that carries on long after the problem is solved, kept alive by the worry about not sleeping itself.
The body shows signs of this alert state too. Sleep studies found that people with disrupted sleep have higher night-time levels of the hormone cortisol. Brain scans suggest people with insomnia have higher metabolic rates both by night and by day. Nobody yet knows if these changes cause insomnia or result from it.
Other culprits include chronic pain, heartburn, asthma, shift work, jet lag and blue light from phones and computers. For some people, as little as 100 mg of caffeine a day, about one 6 oz cup of coffee, can keep disturbing their sleep.
Who Lies Awake
Insomnia is the most common sleep disorder. Between 10% and 30% of adults have it at any given moment, and up to half of people deal with it in a given year. About 6% have insomnia that lasts more than a month and is not caused by another problem.
It is not spread evenly. People over 65 get it more often than younger people. Insomnia is 40% more common in women than in men, and around half of women after menopause have sleep trouble. University students also report higher rates than the general population.
Genes play a part. Estimates of insomnia's heritability range from 38% in men to 59% in women. One large gene study found that many genes each add a small share of the risk, with one called MEIS1 standing out in both men and women. And this is no modern problem. Descriptions of insomnia go back at least as far as ancient Greece.
The Trick of Trying to Stay Awake
The first-line treatment is not a pill. It is cognitive behavioral therapy for insomnia, or CBT-I. Some evidence suggests it beats common sleeping pills not only in the long run but even over two months, and its benefits last long after therapy ends. Adding sleeping pills to it brings no extra benefit.
CBT-I has some surprising tools. In paradoxical intention, the person stops trying to fall asleep and instead makes every effort to stay awake. Removing the pressure to sleep seems to ease the anxiety that keeps people up.
With stimulus control, you go to bed only when sleepy, and if sleep does not come in about 20 minutes, you get up and do something in another place. Sleep restriction goes further. You spend only as long in bed as you actually sleep, then slowly add about 15 minutes as your sleep improves. A full course usually lasts up to three weeks.
Pills, Habits and a Hopeful Number
Sleeping pills can help, but they come with catches. Some are linked to falls, thinking problems and dependence. They are generally not recommended for more than four or five weeks, and their effect can fade as the body gets used to them. Melatonin has grown far more popular, with use among adults rising from 0.4% in 1999 and 2000 to nearly 2.1% in 2017 and 2018.
Sleep hygiene means good sleep habits: a steady bedtime, a dark and quiet room, sunlight during the day and regular exercise. Oddly, how well it works is not clearly established. One systematic review even advised doctors not to prescribe it for insomnia and to prefer CBT-I instead.
There is good news in the numbers too. A survey of 1.1 million people in the United States found the lowest mortality among those sleeping about seven hours a night. And for most people, mild to moderate insomnia was even linked to living longer.
