Circadian rhythm sleep disorders

Bhanu P Kolla,^1,2 R Robert Auger,^1,2 Timothy I Morgenthaler<sup>1

1</sup>Mayo Center for Sleep Medicine, ²Department of Psychiatry and Psychology, Mayo Clinic College of Medicine, Rochester, MN, USA

Abstract: Misalignment between endogenous circadian rhythms and the light/dark cycle can result in pathological disturbances in the form of erratic sleep timing (irregular sleep–wake rhythm), complete dissociation from the light/dark cycle (circadian rhythm sleep disorder, free-running type), delayed sleep timing (delayed sleep phase disorder), or advanced sleep timing (advanced sleep phase disorder). Whereas these four conditions are thought to involve predominantly intrinsic mechanisms, circadian dysrhythmias can also be induced by exogenous challenges, such as those imposed by extreme work schedules or rapid transmeridian travel, which overwhelm the ability of the master clock to entrain with commensurate rapidity, and in turn impair approximation to a desired sleep schedule, as evidenced by the shift work and jet lag sleep disorders. This review will focus on etiological underpinnings, clinical assessments, and evidence-based treatment options for circadian rhythm sleep disorders. Topics are subcategorized when applicable, and if sufficient data exist. The length of text associated with each disorder reflects the abundance of associated literature, complexity of management, overlap of methods for assessment and treatment, and the expected prevalence of each condition within general medical practice.

Keywords: circadian rhythm sleep disorders, assessment, treatment