Most of us know that drinking coffee after dinner will probably disrupt our sleep and that regular exercise will improve it. But some ideas I see tossed out about sleep and insomnia are not quite accurate. Here are six misconceptions followed by information that is evidence based. Find sources by clicking the links in the blog.
Insomnia mainly has to do with a lack of REM sleep (when most dreaming occurs).
Overall, studies comparing people with insomnia to normal sleepers show that insomnia is associated with reductions in both deep sleep and REM sleep. Deep sleep enables the consolidation of memories for factual information and events, and persistent insomnia tends to interfere with this process. Shortened REM sleep, on the other hand, leads to alterations in the processing of emotion—another symptom of insomnia.
The fact that I don’t remember my dreams means I don’t get enough REM sleep.
No evidence shows that sufficient REM sleep is tied to the remembering of dreams. What does seem to be true is that people who remember dreams typically wake up more often during REM sleep than people who don’t remember dreams. But these awakenings are so brief that the dreamer may not be aware of them.
I need several hours of deep sleep to function well.
Young children spend about a third of the night in deep sleep. But the amount of deep sleep humans get declines dramatically during adolescence. The average middle-aged adult spends about 15 percent of the night in deep sleep, and older adults may get as little as 10 percent. As critical as deep sleep is to our ability to function, it accounts for a small percent of the total sleep we get. Our descents into deep sleep occur mostly in the first part of the night.
Rates of insomnia are highest among people in high-status, high-stress jobs.
Stress has a huge impact on sleep, and high stress reactivity may be a defining characteristic of people who develop insomnia. But all else equal, people who earn large salaries are not the ones most likely to toss and turn at night. People of low socioeconomic status with lower education levels are more vulnerable to insomnia than surgeons and CEOs.
Waking up for a stretch in the middle of the night is a sign that something is wrong with my sleep.
Not necessarily. Historical evidence suggests that until the widespread use of electric lighting, this segmented sleep pattern was not unusual. People went to bed soon after nightfall and woke up later to make love, tend to animals and crops, or simply lie awake with their minds adrift. Then they went back to sleep for the rest of the night.
Being awake in the middle of the night may be inconvenient, and with strategic use of light and sleep compression you may be able to whittle that wakefulness down. But if you’re functioning OK in the daytime, being awake at night does not signal something amiss.
If my sleep is lousy, I should make a point of going to bed earlier.
If you have insomnia, going to bed early will likely make the problem worse. The arousal system is fully engaged in the hours leading up to bedtime, early research has shown: most people have a hard time falling asleep in the evening. Here’s a better rule of thumb: If your sleep is lousy, make a point of staying up until you feel sleepy. Only then should you go to bed.
Questions or doubts about sleep or insomnia? Share them here, and I’ll do my best to respond and clarify.