Sleep problems send psychiatric signals.

Sleep problems send psychiatric signals

Persistent sleep disturbances such as insomnia and excessive sleepiness have long served as cardinal symptoms of severe depression. But these sleep problems may also provide an early warning that a full-blown depression or an anxiety disorder is brewing, according to a new epidemiologic study.

Primary care physicians who quickly recognize and treat sleep disturbances may help prevent the development of depression and other psychiatric problems, say Daniel E. Ford of Johns Hopkins Hospital in Baltimore and Douglas B. Kamerow of the Public Health Service in Washington, D.C.

Interviewers asked a total of 10,534 people, representing part of a random national sample gathered by the National Institute of Mental Health for a study of psychiatric disorders, whether they had trouble falling asleep or had slept too much over a period of at least two weeks during the prior six months. Interviewers also inquired about symptoms of psychiatric disturbances. They conducted follow-up sessions one year later with 7,954 study participants.

Overall, one in 10 persons reported insomnia and about one in 35 reported excessive sleepiness (hypersomnia) at the first interview. Women, the unemployed, low-income individuals and those widowed or separated from a spouse reported the most insomnia. Subjects who were unemployed, younger than 24 or never married had higher rates of hypersomnia.

About half of those initially reporting insomnia and two-thirds of those with hypersomnia had a psychiatric disorder at that time or one year later, compared with approximately one-quarter of those without a sleep complaint, Ford and Kamerow report in the Sept. 15 JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION.

The most important finding, the researchers maintain, is that subjects reporting insomnia or hypersomnia at both interviews had significantly higher rates of new cases of both severe depression and anxiety disorders at the follow-up, compared with people whose sleep problems cleared up after one year and those with no sleep complaints.

The relationship of sleep problems to anxiety disorders, which include panic disorder, obsessive compulsive disorder and phobias, is not clear, the investigators note. The official manual of psychiatric diagnoses does not cite sleep disturbance as a symptom of those particular anxiety disorders.

Sleep disturbance may link most strongly to anxiety disorders among young adults, whereas a link to depression and bereavement appears more likely among older individuals, writes psychiatrist Charles F. Reynolds III of the University of Pittsburgh School of Medicine in an accompanying editorial. Further epidemiologic work is needed to address this question, he says.

Nevertheless, routine inquiry about sleep disturbances would probably lead to greater recognition of depression and anxiety disorders by primary care physicians, Ford and Kamerow conclude.

Insomnia can result from numerous factors other than a psychiatric disturbance, Reynolds adds. Behavior changes, such as setting a regular wakeup time and limiting time in bed to six or seven hours nightly, show promise as early treatments for insomnia, he says.