What are the signs and symptoms of delayed sleep-wake phase disorder (DSWPD)?

What are the signs and symptoms of delayed sleep-wake phase disorder (DSWPD)?

Symptoms of DSWPD include:

• Inability to fall asleep at the desired time. This usually presents as insomnia complaints. It may be heightened by the social pressures teenagers feel to stay up late (homework, internet or cell phone use).
• Inability to wake up at the desired time and excessive daytime sleepiness. Usually this is the most common complaint because it is more readily evident than the nighttime insomnia. Because of the delay in falling asleep and yet still needing to get up at the required time for work or school, children or adolescents with DSWPD often experience excessive daytime sleepiness as a result of not getting enough sleep, at least on weekdays.
• Generally no sleep problems if allowed to maintain their desired sleep/wake schedule. If uncomplicated by other sleep disorders, children and adolescents with DSWPD sleep well through the night with few or no awakenings once they fall asleep. They simply suffer from a shift in their internal clock or sleep-wake cycle. Children and adolescents with DSWPD often sleep well during vacations or school breaks when there is no pressure to wake at a certain time. Sleep maintenance is not an issue.
• Depression and behavior problems. Children and adolescents with DSWPD may experience depression and other psychiatric problems including behavioral problems as a result of daytime drowsiness and missing school. Daytime drowsiness can also lead to lowered academic performance from missed school days or tardiness and inattention. Dependency on caffeine, sedatives or alcohol may also be seen.