Circadian Rhythm Sleep Disorder

Circadian rhythm sleep disorder occurs in people who experience a persistent disruption of their “internal body clock,” which regulates the approximate 24-hour cycle of biological processes.  The internal body clock, or circadian rhythm, is vital in determining sleep and wake-related patterns. When the rhythm is disrupted, symptoms of insomnia, excessive sleepiness during the day and impaired functioning may be experienced. 

Causes of Circadian Rhythm Sleep Disorder

Many factors contribute to the development of a circadian rhythm sleep disorder.  Two of the most common causes are an altered sleep-wake schedule and an inequality between a person’s sleep-related demands and natural sleep-wake cycle.  Common circumstances that may lead to circadian rhythm sleep disorder include:

• Pregnancy
• Shift work
• Medications
• Time zone changes
• Changes in routine

Circadian Rhythm Sleep Disorder Symptoms and Types

There are various types (or subtypes) of circadian rhythm sleep disorder, and circadian rhythm sleep disorder symptoms vary depending on type.  These different types include:

• Delayed Sleep Phase Syndrome (DSPS) – A disorder of sleep timing, DSPS refers to people who fall asleep very late at night and have difficulty waking on time for school, work or social engagements.  Symptoms of this type of circadian rhythm sleep disorder include:
  • Sleepiness during desired wake periods
  • Insomnia or excessive sleepiness
  • Difficulty functioning in the morning
• Advanced Sleep Phase Syndrome (ASPS) – Also a disorder of sleep timing, ASPS refers to people who fall asleep and wake much earlier than the desired time.  Common symptoms of ASPS include:
  • Evening sleepiness
  • Decreased daytime alertness
  • Tendency to awaken spontaneously earlier than desired
• Shift Work Sleep Disorder – A circadian rhythm sleep disorder that affects people who work frequent rotating shifts or night shifts.  Shift work sleep disorder can lead to:
  • Insomnia
  • Excessive sleepiness
  • Increased stress levels
  • Trouble concentrating
  • Headaches
  • Lack of energy
  • Irritability and other mood-related problems
• Jet Lag – This circadian rhythm sleep disorder affects people who travel across time zones.  Symptoms of jetlag generally intensify based on the number of time zones crossed, and include:
  • Feelings of disorientation
  • Fatigue and general tiredness
  • Inability to sleep at night
  • Loss of concentration and drive
  • Headaches
  • General malaise

Treatment for Circadian Rhythm Sleep Disorder

Treatment for circadian rhythm sleep disorder varies depending on type, but essentially aims to help the patient equate their sleep-wake cycle with the demands of their desired lifestyle.  Treatment methods include behavioral therapy such as Chronotherapy, where the patient will adjust bedtime gradually and systematically until a goal is reached, and Bright Light Therapy designed to reset the circadian rhythm.  Combined with proper sleep hygiene, most people with circadian rhythm sleep disorder can successfully manage their symptoms.

If you are concerned that you may have circadian rhythm sleep disorder, consult with your doctor or visit a sleep center for professional diagnosis and treatment.

Disclaimer: These statements and products are not intended to diagnose, treat and cure or prevent disease. Always consult your physician regarding any sleeping disorders.