Delayed sleep phase syndrome (DSPS) is a circadian rhythm disorder. People with delayed sleep phase syndrome go to bed considerably later than what is considered normal and have an extremely difficult time waking up early in the morning.
While nearly everyone experiences some variation in sleeping hours, DSPS prevents people from synchronizing sleep with their external environment. Although their ability to sleep is normal, DSPS sufferers have difficulty sleeping during traditional sleeping hours.
Causes of Delayed Sleep Phase Syndrome
Daytime sleepiness associated with DSPS isn’t related to jet lag, working night shifts or other external factors. Instead, DSPS results from an abnormality in body rhythms, causing the internal clock to be out of sync with normal sleep-wake cycles.
Most people with DSPS have trouble going to bed before 2 a.m., and even more difficulty waking up early in the morning. Daytime sleepiness and difficulty functioning during normal waking hours results if the person is unable to get a full night’s sleep.
Delayed Sleep Phase Syndrome in Children
Symptoms usually appear in adolescence. Symptoms of delayed sleep phase syndrome include daytime sleepiness, depression, insomnia and irritability.
Delayed sleep phase syndrome in children and adults can negatively affect performance at school, work and personal relationships. Delayed sleep phase syndrome in children often leads people to assume that the child is a “night owl” or not a “morning person.”
Diagnosing Delayed Sleep Phase Syndrome in Children
Sleep logs and sleep monitoring devices that chart sleep and wake patterns are key to diagnosing DSPS. However, because symptoms such as daytime sleepiness are vague, doctors often misdiagnose DSPS as insomnia or another sleep disorder. Symptoms may also be confused with those of conditions such as depression or attention deficit disorder.
Treatment for DSPS may not always be necessary. If a person’s lifestyle accommodates his sleep schedule and the individual has no complaints, treatment may not be necessary.
If DSPS treatment is necessary, however, it typically focuses on synchronizing the internal body rhythms with the demands of work, school and social activities. Treatment helps people with DSPS wake up at normal times without experiencing daytime sleepiness.
Mild cases of DSPS respond to gradually moving bedtime to earlier hours, resulting in more sleep during traditional sleep times. Lifestyle changes, such as maintaining regular schedules and avoiding caffeine and other stimulants in the evening can also help alleviate symptoms.
For severe cases of DSPS, doctors recommend light therapy, a treatment that relies on using a bright light timed to turn on in the morning at a patient’s bedside. In conjunction with bright light in the morning, this treatment limits bright light in the evening to ease the body into a more restful state.
Chronotherapy resets the body’s natural sleep/wake rhythm. The person goes to sleep later each night over a period of time until the desired bedtime is reached, gradually adjusting the internal clock.
Some doctors may prescribe vitamin B12 and melatonin to DSPS patients. However, researchers have yet to determine the effectiveness and potential side effects of such supplements.
Health Communities (2007). DSPS overview, incidence and prevalence. Retrieved August 10, 2010, from http://www.sleepdisorderchannel.com/dsps/.
Kidzzzsleep. (2009). Delayed sleep phase syndrome. Retrieved August 23, 2010, from http://www.kidzzzsleep.org/handouts/delayedsleep.htm.
Stanford University. (1999). Delayed sleep phase syndrome. Retrieved August 23, 2010, from http://www.stanford.edu/~dement/delayed.html.