What is delayed sleep phase syndrome?
Delayed sleep phase syndrome (DSPS) is a disorder in which a
person’s sleep is delayed by 2 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 DSPS will fall asleep well after
midnight and have great difficulty getting up in time for school.
Most children and adolescents with DSPS 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.
What causes DSPS?
The exact cause of this disorder is not completely known.
However, approximately 7 to 16 percent of adolescents have DSPS. Thus, it is a
common disorder. Scientists think DSPS may be an exaggerated reaction to the
normal shift in the internal clocks that is seen in adolescents after puberty.
It is important to understand that this is not deliberate behavior. DSPS most
commonly occurs during adolescence, but cases have been reported during
childhood; it is rare for it to begin after early adulthood.
What are the signs and symptoms of DSPS?
Symptoms of DSPS 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 DSPS often experience excessive daytime
drowsiness as a result of not getting enough sleep at least on weekdays.
- Generally no other sleep problems. If uncomplicated by other sleep
disorders, children and adolescents with DSPS 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 – pushing it later by 2 or
more hours. Sleep maintenance is not an issue.