Delayed Sleep Phase Syndrome:    A disorder of sleep timing that results in an inability to sleep until two or more hours later than the socially acceptable time for sleep. Teenagers, who have a natural inclination to sleep later, tend to develop this condition.


     The timing of sleep is shifted later by two or more hours in those with Delayed Sleep Phase. People Syndrome with DSPS cannot fall asleep earlier. They are able to fall asleep when their internal clock allows them to do so. Sleepiness generally develops two to three hours past the desired bedtime, usually midnight to 3:00 a.m. When the propensity for sleep arises, it will continue for a normal amount of time--usually  eight hours. Unfortunately, the majority of society operates on an earlier schedule. Attempting to force the body awake for school, a job, or social needs may lead to daytime sleepiness, altered eating habits, and fatigue. When a person with DSPS is left to his or her schedule, the quality and amount of sleep is normal, unless an additional sleep disorder is present.


        A physical exam is recommended to rule out the possibility of another sleep disorder or health problem. Since the symptoms of DSPS are similar to insomnia , a sleep specialist can identify the exact reason for the delayed sleep pattern. A diary of sleep habits is an integral part of diagnosing DSPS. The sleep log will demonstrate a regular pattern of delayed sleep that is otherwise normal. Sleep studies are not normally needed to confirm a diagnoses of this condition, unless sleep problems are severe. If needed, a polysomnogram will not only pinpoint sleep times,  but measure brainwaves, heart rate, breathing, and muscular activity during sleep.


      Delayed Sleep Phase Syndrome responds well to behavioral therapies.
Chronotherapy aims to reset the internal biological clock. Patients delay bedtime by three hours per day over the course of five or six consecutive days, until the desired bedtime is reached. Yes, it involves sleep deprivation, but in a well-directed manner! A modified version of this therapy involves staying awake for a full night and day, followed by going to bed 90 minutes earlier than usual for a week. This process is repeated weekly until the new bedtime is reached.
Light Therapy resets the internal clock by using a full spectrum lamp or portable visor set to 10000 lux for 30 to 90 minutes immediately upon awakening, or just before getting up. Exposure to sunlight at this time may also help. Bright light should be avoided in the late afternoon and evening, when the body needs to prepare for sleep. Lastly, healthy sleep hygiene such as avoiding caffeine after noon and alchol within four hours of bedtime will allow other therapies to work better.

DSPS Mechanics

      Although the exact cause of Delayed Sleep Phase Syndrome is not known, it is related to circadian rhythms, which regulate the internal biological clock. A desynchronization develops between the desired sleep time and an individual's biological clock.  This desynchronization is not affected by travel or a change in the environment. Rather, the natural inclination to sleep is delayed because the 'internal clock' is set to a later time. DSPS is sometimes mistaken for insomnia because the later bedtime leads people to believe they cannot sleep at all. In reality, they have no problem falling asleep, when the time is right for them.

Suggested Downlaods

Out of Sync
Delayed Sleep Phase Syndrome