Advanced Sleep Phase Syndrome:    A disorder of sleep timing that results in a propensity to sleep at least two or more hours earlier than the socially acceptable time for sleep. Older persons, who have a natural inclination to fall asleep earlier, tend to develop this condition.


     The timing of sleep is shifted earlier by two or more hours in those with Advanced Sleep Phase Syndrome. Sometimes known as "morning people" or "larks", people with ASPS have difficulty staying awake in the evening but otherwise sleep normally.
      Sleepiness develops pretty early in the evening but lasts for a normal duration (eight hours). Typical sleep onset times are between 6:00 and 8:00 p.m. (no later than 9:00 p.m.) and wake times between 1:00 and 3:00 a.m. (no later than 5:00 a.m.). Daytime activities such as work or school are not affected by this schedule, which provides for wakefulness in the earlier part of the day. However, evening activities are often missed or cut short by the need to retire early. When a person with an advanced sleep phase 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 Advanced Sleep Phase are similar to hypersomnia, a sleep specialist can identify the exact reason for the advanced sleep pattern.A Sleep Log or diary of sleep habits is an integral part of diagnosing ASP. The sleep log will demonstrate a regular pattern of advanced sleep-that is otherwise normal. Sleep studies are not normally needed.


      Some people--especially those who are retired or who have careers that allow them to work early in the day- A few options for treating ASPS are available. As with a delayed sleep phase, an advanced sleep phase responds well to behavioral therapies.

Chronotherapy aims to reset the internal biological clock. Patients systematiclly advance (or delay) bedtime over the course of five or six consecutive days, until the desired 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 early in the evening.

        Lastly, healthy sleep hygiene such as avoiding caffeine after noon and alcohol within four hours of bedtime will allow other therapies to work better.

ASPS Mechanics

      Although the exact cause of Advanced Sleep Phase Syndrome is not known, it is related to circadian rhythms which regulate the internal biological clock. A desynchronization develops between the environment (desired sleep time) and an individual's biological clock.  The natural inclination to sleep is delayed because the 'internal clock' is set to a later time. ASPS is sometimes mistaken for a hypersomnia 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
Advanced Sleep Phase Syndrome