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.
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.
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.
Younger adult women suffer from insomnia because of both cultural and biologic factors. As we’ve already examined, a number of hormonal events can disturb sleep, including premenstrual syndrome, menstruation, pregnancy, and menopause. All these conditions are natural, and in most cases the wakefulness associated with them is temporary and can be ameliorated with sleep hygiene and time.
After childbirth, most women develop a high sensitivity to the sounds of their children, which causes them to wake easily. Women who have had children sleep less efficiently than women who have not had children. It is possible that many women never unlearn this sensitivity and continue to wake easily long after the children have grown.
After menopause women are susceptible to the same environmental and biologic causes of insomnia as men are. Older women who are not bothered by sleeplessness tend to have longer and better sleep than non-insomniac men their own age.
Other groups of individuals who are likely to suffer from insomnia include those who travel frequently – especially when crossing time lines, those with post-traumatic stress syndrome, and individuals with brain injuries.
Most people sleep around 7 hours a night. Doctors suggest that we get a full 8 hours of rest. The reason is because we are much more mentally alert when we do get a good night’s sleep. Without that sleep, the risks can be huge.