Circadian Rhythm Sleep Disorder

A person’s circadian rhythm is an internal biological clock that regulates a variety of biological processes according to an approximate 24-hour period. The malfunctioning of a person’s circadian system, or biological clock, causes circadian rhythm disorders. The circadian rhythm disorder related to the sleep-wake cycle can be categorized into the following 2 main groups: transient or chronic disorders.

A circadian rhythm sleep disorder that would be considered transient is when jet lag or an altered sleep schedule due to work hours affects a person’s sleep. Illness can do this to a person as well.

Circadian rhythm sleep disorders that are considered chronic include disorders that show a mismatch between the body’s internal clock and the world’s 24 hour clock. These disorders affect the timing of sleep. A person will want to fall asleep too early or maybe too late.



A common disorder is Delayed Sleep-Phase syndrome (DSPS). This is characterized by a persistent (that is, lasting longer than 6 months) inability to fall asleep and awaken at socially acceptable times. Individuals with DSPS fall asleep late (for example, in the early morning hours) and wake up late (for example, in the late morning hours or in the early afternoon hours). Once asleep, however, persons with DSPS are able to maintain their sleep and have normal total sleep times.

Another disorder is Advanced Sleep-Phase Syndrome (ASPS). ASPS is characterized by a persistent early evening sleep onset time (between 6:00 pm and 9:00 pm) and an early morning wake-up time (between 3:00 am and 5:00 am).

What are the signs and symptoms of Circadian Rhythm Disorders?

Common signs and symptoms for DSPS is:

• Difficulty falling and staying asleep, and or late night insomnia.
• A general lack of energy in the morning.
• An increase of energy in the evening or late at night.
• Difficulty concentrating, being alert, or accomplishing tasks
• Some DSPS sufferers oversleep and have trouble getting up

Commons signs and symptoms for ASPS is:

• Early morning awakening and/or early morning Insomnia
• Inconsistent sleep with one or more awake periods during the night
• Lack of energy during the day, feeling tired in the early afternoon and/or evening
• Alertness and ability to function may also be diminished
• Some ASPS sufferers may not notice a sleep problem but lose energy and feel tired or down in the afternoon or evening time.

Who does Circadian Rhythm Disorders affect?

What are the treatments of Circadian Rhythm Disorders?