Delayed sleep-wake phase disorder

Definition

Delayed sleep-wake phase disorder is a recurrent pattern of disturbance of the sleep-wake schedule characterised by persistent delay in the major sleep period compared to conventional or desired sleep times. The disorder results in difficulty falling asleep and difficulty awakening at desired or required times. When sleep is allowed to occur on the delayed schedule, it is essentially normal in quality and duration. The symptoms should have persisted for at least several months and result in significant distress or mental, physical, social, occupational or academic impairment.

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