Basic Facts

  • Circadian rhythm sleep disorders are a group of sleep disorders that all share the common feature of a disruption in the timing of sleep. 

Symptoms of circadian rhythm sleep disorders include:

  • Insomnia (difficulty falling asleep or staying asleep).
  • Excessive daytime sleepiness.
  • Difficulty waking up in the morning.
  • Sleep loss.
  • Depression.
  • Stress in relationships.
  • Poor work/school performance.
  • Inability to meet social obligations.



Situations that can trigger a circadian rhythm sleep disorder include:

  • Frequent changes in work shift.
  • Jet lag.
  • Frequent changes in time to go to bed and time to wake up.
  • Brain damage resulting from such medical conditions as stroke, dementia, head injury intellectual disabilities.
  • Blindness or lack of exposure to sunlight for long periods of time.
  • Certain drugs.
  • Poor sleep hygiene (lack of practices, habits and other factors that promote good quality sleep).
  • Older age.




Your healthcare specialist will gather information about your sleep and work schedule history and ask you to keep a sleep diary for one to two weeks. Your healthcare provider will also exclude other sleep and medical disorders, including narcolepsy, which often mimics delayed sleep phase disorder.

Sleep diaries are often used together with a wrist watch-like device (called an actigraph) that records sleep and wake activity over the course of days to weeks. Sometimes overnight and daytime sleep studies may be required.


Lifestyle and behavior therapy: This approach encourages changes to improve sleep and to develop good sleep habits. Good sleep habits include maintaining regular sleep-wake times (even on weekends and vacations); avoiding naps (exception: shift workers); developing a regular routine of exercise (avoid high-intensity exercise within one hour of bedtime); and avoiding alcohol, caffeine, nicotine, and stimulating activities within several hours of bedtime.

Bright light therapy: Bright light therapy is used to advance or delay sleep. The timing of this treatment is critical and requires guidance from a sleep specialist. Bright light therapy works by resetting the circadian clock to be more in sync with the earth’s cycle of light and dark. A high intensity light (2,000 to 9,500 lux) is required and the duration and timing of exposure varies from one to two hours.

Exposure to bright light in the morning may help you if you have a delayed sleep disorder. You should also decrease your exposure to light in the evening and during the night by reducing indoor lighting and avoiding bright TV and computer screens. Exposure to bright light in the evening may help if you have advanced sleep disorder.

Medications: Medications and short-term sleep aids may be used to adjust and maintain the sleep-wake cycle to the desired schedule.

Chronotherapy: This therapy approach uses progressive advancement or delay (three hours every two days) of sleep time depending on the type and the severity of the disorder. This type of therapy requires a firm commitment by you and your partner, as it can take weeks to successfully shift the sleep-wake cycle. Once the desired schedule is achieved, you have to keep this regular sleep-wake schedule.