DescriptionAn in-depth report on the causes, diagnosis, treatment, and prevention of insomnia.
Studies estimate that between a quarter and one-third of American and European adults experience some insomnia each year, with between 10% and 20% of them suffering severe sleeplessness. In spite of this widespread problem, however, studies suggest that only about 30% of American adults who visit their doctor ever discuss sleep problems. Conversely, physicians seem rarely to ask patients about their sleep habits or problems.
Significant Risk Factors for Stress
A 2003 study suggested that there were seven significant factors that predicted who would be at high risk for insomnia:
Stressful events do not cause insomnia in everyone. Negative thoughts and attitudes toward events can be significant factors in insomnia. In one 2003 study, for example, the number of stressful events did not differ between good and poor sleepers. Those with insomnia, however, tended to experience these stressful events more intensively than the healthy sleepers.
In another interesting study, patients with insomnia and good sleepers were asked to record their pre-sleep images using a handheld counter. People with insomnia not only reported fewer images, but their images also tended to be more unpleasant than those of good sleepers. More of the images in people with insomnia were related to intimate relationships and to sleep itself. The images of sleepers were more likely to be random and disconnected.
Having Depression, Chronic Pain, or Both
Studies report that the strongest risk factors for insomnia are psychiatric problems, particularly depression, and physical complaints, such as headaches and chronic pain, that have no identifiable cause (called somatic symptoms). About 90% of people with depression have insomnia. In addition, insomnia and depression often coincide with somatic symptoms, particularly chronic pain. In fact, insomnia worsens chronic pain even in people who are not depressed. Headaches that occur during the night or early in the morning may actually be caused by sleep disorders. In one study, patients who had these complaints were treated for the sleep disorder only, and over 65% reported that their headaches were cured.
Overall, insomnia is more common in women than men, although men are not immune from insomnia. Sleep efficiency deteriorates equally in men and women as they get older.
Men. One major study suggested that as men go from age 16 to 50, they lose about 80% of their deep sleep. During that period, light sleep increases and REM sleep remains unchanged. (The study did not use women as subjects, and there is some evidence to suggest they are not as affected.) After age 44 REM and total sleep diminish and awakenings increase.
Women. It is not clear why young adult women suffer more from insomnia than young adult men. Some theories are as follows:
It should be noted that after menopause women are susceptible to the same environmental and biologic causes of insomnia as men. In fact, older women who are not bothered by sleeplessness tend to have longer and better sleep than noninsomniac men their own age.
Risk Factors in Elderly Adults
As people grow older, sleep changes in most older people, and about 15% of their sleeping time is in stage 1, light sleep. (In infancy, only 5% is spent in light sleep.). In a major 2003 survey, 18% of older adults (55 to 94 years old) had trouble falling asleep. A third of them woke up frequently during the night and about a quarter of them woke up too early and couldn't go back to sleep. In the same study, 33% of adults between 55 and 64 reported waking up feeling unrefreshed, which was actually greater than the percentage reported by older people (22%).
Nevertheless, age itself does not appear to be a risk factor for insomnia. A number of factors increase sleeplessness as one gets older:
Sleep loss among the elderly is not inevitable, however. While older people are more susceptible to many conditions that can cause insomnia, treatments and a healthy lifestyle, particularly regular exercises, are as useful in providing relief to the elderly as to the young. And a number of studies have found no significant increase in insomnia in older healthy adults.
Shift workers are at considerable risk for insomnia. In one major 1999 survey, 65% of shift workers reported one or more symptoms of insomnia at least a few nights a week. Workers over 50 and those whose shifts are always changing are particularly susceptible to insomnia, although night-shift workers also have a high rate of sleeplessness.
Other Risk Factors
Among the many conditions that pose a high risk for insomnia are the following: