Chapter 3 - What Is Insomnia?

Summary

Insomnia is common, affecting approximately 10% of the population. In addition to night-time sleep difficulties, insomnia disorder requires the presence of concomitant daytime impacts, making it a 24-hour problem. It is not surprising, therefore, that insomnia disorder is associated with significant impacts to quality of life and economic costs. Many patients with insomnia also have comorbid physical and/or mental health disorders, and sometimes also other sleep disorders. This chapter reviews the key features, prevalence, and consequences of insomnia disorder, and provides background information to aid clinicians as they begin to think about formulating treatment approaches.