Are insomniacs sleep deprived?
Letter to the Editor of the Montreal Gazette.
Every couple of weeks or so, there appears an article about sleep, most recently “A mounting sleep debt is nothing to yawn about” (Gazette 2002-12-03) Typically, the authors decry the high prevalence of insufficient sleep, the deleterious effects of sleep deprivation, the high prevalence of insomnia, and make recommendations to improve sleep quality and quality. Invariably, these articles convey the message that insomnia causes sleep deprivation.
But is this true? Consider the following: most insomniacs have what is called psychophysiologic insomnia. These individuals in general sleep as much as people without insomnia, they spend more time in bed, they are more likely to take naps, they typically underestimate their actual sleep time, and they have less daytime sleepiness than people without insomnia. The most effective treatment in the long term for this kind of insomnia is a sharp reduction of the amount of time spent in bed.
All of the above suggests that psychophysiologic insomnia may actually be caused by attempting to sleep more than one needs. Studies show that voluntarily extending one’s sleep will produce insomnia, as well as symptoms such as fatigue. This kind of fatigue, caused by too much sleep, is easily mistaken for the sleepiness that results from true sleep deprivation. Part of the problem seems to be the myth, perpetuated by the media, that every adult needs 8 hours sleep nightly. In fact, sleep requirements vary from one person to another, and appear to decrease with age. A recent large-scale study shows that there is a significant risk of dying prematurely for people who sleep longer than 7.5 hours. This is not to underestimate the importance of insomnia which is a significant risk factor for depression and other illnesses. But insomniacs who believe the hype that they are sleep deprived, and as a result attempt to sleep even more, may be doing themselves a grave disservice.