Thorpy MJ (2012). Classification of Sleep Disorders. Neurotherapeutics. https://doi.org/10.1007/s13311-012-0145-6.

Abstract

The classification of sleep disorders is neces- sary to discriminate between disorders and to facilitate an understanding of symptoms, etiology, and pathophysiol- ogy that allows for appropriate treatment. The earliest classification systems, largely organized according to major symptoms (insomnia, excessive sleepiness, and abnormal events that occur during sleep), were unable to be based on pathophysiology because the cause of most sleep disorders was unknown. These 3 symptom- based categories are easily understood by physicians and are therefore useful for developing a differential diagno- sis. The International Classification of Sleep Disorders, version 2, published in 2005 and currently undergoing revision, combines a symptomatic presentation (e.g., in- somnia) with 1 organized in part on pathophysiology (e.g., circadian rhythms) and in part on body systems (e.g., breathing disorders). This organization of sleep disorders is necessary because of the varied nature and because the pathophysiology for many of the disorders is still unknown. The International Classification of Sleep Disorders, version 2 provides relevant diagnostic and epidemiological information on sleep disorders to more easily differentiate between the disorders.