What is delayed sleep-wake phase disorder (DSWPD)?

What is delayed sleep-wake phase disorder (DSWPD)?

Delayed sleep-wake phase disorder (DSWPD) is a disorder in which a person's sleep is delayed by two or more hours beyond the socially acceptable or conventional bedtime. This delay in falling asleep causes difficulty in waking up at the desired time. As an example, rather than falling asleep at 10:00 pm and waking at 6:30 am, an adolescent with DSWPD will fall asleep well after midnight and have great difficulty getting up in time for school.

Most children and adolescents with DSWPD describe themselves as "night owls" and say they function best or are most alert during the evening or night hours. If they were to keep a sleep log it would show short sleep periods during the school/work week (with few or no awakenings during the night) and lengthy sleep-ins (late morning to mid afternoon wake up times) on the weekend.