ABSTRACT
Insomnia is a common and impairing sleep disorder that has strong psychobiological determinants. This chapter reviews the core features of insomnia, outlines key psychobiological mechanisms, and summarises models of insomnia development and maintenance. Contemporary models emphasise altered cognitive-behavioural and neurobiological processes that give rise to – and reinforce – key features of insomnia disorder. Insomnia can be considered a quintessential psychobiological disorder because psychological processes serve to dysregulate sleep biology. Contemporary perspectives on the expression of insomnia emphasise excessive arousal across cognitive, neurophysiological and autonomic parameters. Neuroimaging techniques are increasingly used to investigate brain function in patients with insomnia. With respect to heart rate variability parameters, there are several studies suggesting that insomnia patients are characterised by a pattern of findings indicating increased sympathetic activity and/or decreased parasympathetic activity. Cognitive-behavioural therapy has been shown to improve sleep in those with chronic insomnia several months after active administration.
