Clinical and Socioeconomic Correlates of Insomnia

Insomnia is characterized by difficulty falling asleep (sleep onset disturbance), difficulty stayingasleep (sleep maintenance disturbance), or poor quality (nonrestorative) sleep, leading to impairmentof next-day functioning, including psychological distress. Published prevalence estimates of insomniavary considerably, very likely due to differences in definitions, study setting, and data collectionmethods. However, estimates based on large population-based surveys provide a rather constant prevalencerate for chronic insomnia in the United States of about 10% (approximately 25 million people).Chronic insomnia is associated with numerous physical and psychiatric conditions and is more commonin women and the elderly. Although it is often perceived as a symptom of depression, insomnia isalso a precursor of depression and is associated with a substantial increase in the relative risk of majordepression. Chronic insomnia is correlated with impaired mood, subjective functioning, and quality oflife and, in some cases, with increased daytime sleepiness and accident risk. Those reporting insomniahave higher rates of absenteeism and health care utilization. Direct costs of insomnia have been estimatedto be $13.9 billion annually, with a large majority of costs attributable to nursing home care.Chronic insomnia is a common problem, often associated with negative waking mood or function. Assuch, heightened clinical attention and clinical research appear warranted.