Insomnias

This chapter reviews contemporary understanding of insomnia disorder. Specifically, it examines insomnia prevalence and associated morbidity, clinical approaches to the evaluation of insomnia, and models of insomnia development and maintenance. Recent evolution of insomnia classification is emphasized, together with novel perspectives on the role of insomnia in conferring risk for mental and physical disease. It is concluded that the development of theoretical models that integrate both psychological and neurobiological levels of analysis will provide a fuller understanding of insomnia pathophysiology and subsequently guide treatment innovation.