Circadian Rhythm Sleep Wake Disorder

About Circadian Rhythm Sleep Wake Disorder

Circadian rhythm sleep wake disorders are a group of conditions caused by an alteration of the internal body clock, or a mismatch between that clock and the sleep schedule demanded by their environment, school or work. The result is persistent or recurrent sleep disruption leading to insomnia, excessive sleepiness or both. DSM-5 describes several types, including delayed sleep phase type, common in adolescents and young adults, in which people fall asleep and wake much later than desired; advanced sleep phase type, more common in older adults; irregular sleep wake type, seen in some neurodegenerative conditions; non 24 hour type, which particularly affects some blind people; and shift work type. Sleep is often normal in quality when people are able to follow their natural timing. Assessment usually relies on sleep diaries and activity monitoring. Management focuses on carefully timed light exposure, consistent schedules, and in some cases timed medication such as melatonin, ideally with specialist guidance.