Chapter 5 - Sleep Dysregulation and Related Regulatory Models

Abstract

This chapter focuses on sleep in Major Depressive Disorder (MDD) and dysthymia, which are the so-called unipolar depressions. Consolidated and restorative sleep is a critical component of mental health. Sleep disruption affects mood regulation in healthy individuals, and people with more longstanding sleep difficulties are at increased risk to develop clinical forms of depression. Insomnia, hypersomnia, and fatigue are frequently reported by depressed patients, and objective indices of sleep disruption and of neurobiological alterations during sleep are consistently observed in depressed patients. Sleep disturbance often precedes relapse or recurrence of depression. The sleep disturbances associated with depression can persist despite otherwise successful antidepressant therapies, and such residual symptoms can increase the risk for depression recurrence. Adjunctive pharmacological and non-pharmacological treatments specifically target sleep disturbances in depressed patients. The physiology, neurobiological, and architecture of normal sleep are described. The nature of sleep disturbances in depression, and the physiological and neurobiologcal alterations that characterize depression during sleep are reviewed.