Advanced Sleep-Wake Phase Disorder

Advanced sleep-wake phase disorder (ASP) is one of several circadian rhythm sleep-wake disorders. These disorders occur in people who sleep at times that seem to be out of order with “normal” sleep times. People with ASP have an “early bird” circadian clock. They fall asleep several hours before a normal bedtime. As a result, they also wake up hours earlier than most people wake in the morning.

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