Circadian Rhythm Sleep Disorder Information

What is Delayed Sleep-Wake Phase Disorder?

Delayed Sleep-Wake Phase Disorder (DSP) is a circadian rhythm disorder. It consists of a typical sleep pattern that is "delayed" by two or more hours. This delay occurs when one’s internal sleep clock (circadian rhythm) is shifted later at night and later in the morning. Once sleep occurs, the sleep is generally normal. But the delay leads to a pattern of sleep that is later than what is desired or what is considered socially acceptable. This pattern can be a problem when it interferes with work or social demands.

A person with DSP is likely to prefer late bedtimes and late wake-up times. When left to his or her own schedule, a person with DSP is likely to have a normal amount and quality of sleep. It simply occurs at a delayed time. One sign of this disorder is difficulty falling asleep until late at night. Another sign is having a hard time getting out of bed in the morning for work or school. These signs can make DSP look like insomnia. Daytime functioning can be severely impaired by DSP. It can lead to excessive sleepiness and fatigue. When able to sleep on their own schedules, people with DSP often stay up until they get tired and then sleep until they awaken late in the morning. In this case, they tend to have no complaint of difficulty falling to sleep or feeling poorly during the day.

Someone with DSP may:

  • Have a delay in their sleep pattern in relation to their desired sleep and wake times
  • Have trouble falling asleep at the desired time of night
  • Be unable to awaken at the desired or socially acceptable time
  • Have a normal duration and quality of sleep when left to their own sleep schedule, but this sleep occurs in a stable, but delayed time period in relation to what is desired or socially acceptable
  • Have this kind of stable but delayed sleep time for at least seven days

*It is also important to know if there is something else that is causing your sleep problems. They may be a result of one of the following:


  • Another sleep disorder 
  • A medical condition
  • Medication use
  • A mental health disorder
  • Substance abuse

What is Advanced Sleep-Wake Phase Disorder?

Advanced Sleep-Wake Phase Disorder (ASP) is one of several circadian rhythm sleep disorders. These disorders occur in people who sleep at times that seem to be out of order with “normal” sleep times. People with ASP have an “early bird” circadian clock. They fall asleep several hours before a normal bedtime. As a result, they also wake up hours earlier than most people wake in the morning.

People with ASP feel sleepy in the late afternoon. Bedtime tends to occur between 6 p.m. and 9 p.m. Since bedtime is early, they also wake up early. They tend to wake up between 2 a.m. and 5 a.m. While the timing of sleep is early, sleep itself is normal.

All of the circadian rhythms related to sleep also occur at early times. This includes an earlier release of melatonin and other hormones. The body temperature curve is also moved earlier. This has been used as a marker to detect this disorder.

Some people with ASP are able to follow this early schedule. But problems often occur when social plans take place during the late afternoon or evening. This makes them struggle to stay awake. They may appear very sleepy to others during these evening hours. Missing a few hours of evening sleep over time can cause chronic sleep deprivation. This results in true sleepiness. Even when deprived of sleep, people with ASP still tend to wake up early.

People with ASP may mistake their problem for something else. They may think that waking up too early is a sign of either insomnia or depression. They may worry about being awake so early. It is hard for them to be awake at a time when others are asleep. They may develop a secondary form of insomnia as a result of their worries.

People with ASP may adjust their lifestyles or jobs around their natural “early bird” clock. For example, an “early bird” clock would be ideal for working the early shift. This includes jobs such as a baker or surgeon. Other people with ASP do things to worsen their condition. They try to realign their early clock to match the schedules of others. For example, they may drink too much coffee or take stimulants to stay awake at night. They may also try to stay asleep during the morning hours. To do this, they may drink alcohol or take sleeping pills. These choices will only make their sleep worse.


Do You Work Odd Hours And Have Trouble Sleeping in Anchorage?

If you have difficulty sleeping at night, and think you might be suffering from a circadian rhythm disorder, contact the sleep specialists at Stellar Sleep in Anchorage today. We'll help improve the quality of your sleep!