Sleep disturbances and mood disorders: An epidemiologic perspective

Epidemiologic studies of sleep disturbances and mood disorders that may pro vide more valid estimates of associations between these two conditons than clinical samples due to differential use of health care services. Increasin g uniformity of questionnaires to assess sleep disturbances has decreased t he variance in estimates of insomnia and hypersomnia within community sampl es. Women are more likely to report insomnia than men in every age group. T here appear to be no clear racial or ethnic differences in rates of insomni a or hypersomnia. Several community-based studies have found that sleep dis turbances are powerful risk factors for the development of new episodes of major depression in the following year. Individuals who report insomnia or poor quality sleep may be at higher risk for depression throughout their li fetime. Epidemiologic studies will be used for developing the long-term per spective on the natural history of sleep disturbances and mood disorders an d the consequences of treatment. (C) 2001 Wiley-Liss, Inc.