Risk Factors

Studies estimate that 25 - 33% of adults experience some insomnia each year. In spite of this widespread problem, however, studies suggest that only about 30% of American adults who visit their doctor ever discuss sleep problems. And, doctors seem rarely to ask patients about their sleep habits or problems.

Psychosocial Problems

Stressful events do not cause insomnia in everyone. However, negative thoughts and attitudes toward events can be significant factors in insomnia. Those with insomnia, however, tend to experience stressful events more intensively than the healthy sleepers.

Gender Factors

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 age from 16 - 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 women suffer more from insomnia than men. Some theories include:

• In women, a number of hormonal events can disturb sleep, including premenstrual syndrome, menstruation, pregnancy, and menopause. All these conditions are short-term, however, and in most cases the wakefulness associated with them is temporary and can be eliminated 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.
• Women are at higher risk than men are for depression and anxiety, which are known risk factors for insomnia. In fact, some researchers believe that this is a main reason for the gender differences in insomnia.

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 patterns change. Elderly adults tend to wake up frequently during the night, wake up earlier, and report waking up feeling unrefreshed. There is no gold standard for the normal number of hours of sleep an elderly person needs.

Although age itself does not appear to be a risk factor for insomnia, a number of factors may interfere with sleep as one gets older: