Children's Hospital Colorado

Circadian Rhythm Sleep Disorders

What are circadian rhythm sleep disorders?

Circadian rhythm sleep disorders are conditions in which a person does not follow the traditional sleep times at night. Circadian rhythm refers to the natural, biological patterns people experience in a day. It controls the timing of body rhythms such as temperature, hormone levels and the sleep-wake cycle. There are several different types of circadian rhythm sleep disorders, which include:

  • Delayed sleep phase disorder
  • Advanced sleep phase disorder
  • Irregular sleep rhythm disorder
  • Non-24-hour sleep rhythm disorder
  • Jet lag disorder
  • Shift work disorder

Which is the most common circadian rhythm sleep disorder among teenagers?

Delayed sleep phase disorder is the most common circadian rhythm sleep disorder among teenagers. It is a disorder in which a teenager’s internal body clock causes them to sleep at late times. Teenagers are often described as "night owls" or are late to bed and late to rise. Occasionally, teenagers can develop a sleep disorder, in which they are unable to fall asleep until very late, have difficulty waking for school, and are severely sleepy in the daytime. In severe cases, youth may experience school failure or truancy.

What causes circadian rhythm sleep disorders?

Delayed sleep phase disorder can be caused by genes passed down from parents, which is why being a "night owl" tends to run in families.

Normally, the daily rhythm of temperature, hormone levels, light levels, meals and exercise tell your child when it’s time to sleep at night and be awake during the day. Sometimes this daily rhythm can get off course. For example, many people have experienced fatigue after traveling to a new time zone, which is known as jet lag. People get jet lag when their circadian rhythm does not match up with the normal wake and sleep times of the new environment.

As children get older and become teenagers, they experience a natural delay in their circadian rhythms and begin to go to bed later and prefer to sleep in later. If allowed, teens with delayed sleep phase disorder would go to bed very late or in the early hours of the morning, sleep soundly, and wake up refreshed in the early afternoon. Teens with delayed sleep phase disorder have extreme difficulty falling asleep at a normal time or waking up in the morning to get to school on time.

What are the signs and symptoms of delayed sleep phase disorders?

  • Extreme difficulty waking up in the morning
  • Sleeping very late
  • Difficulty falling asleep at a typical bedtime
  • Daytime symptoms such as sleepiness, moodiness or irritability
  • Trouble thinking or focusing during the day

What tests are used to diagnose delayed sleep phase disorder?

A thorough review of medical and sleep history can help us diagnose this disorder. Keeping a sleep log or diary for several weeks to document sleep habits (bedtime, wake time, how long it takes to fall asleep) and if your child feels rested in the morning is also helpful. Sleep logs often show that teenagers sleep in or try to catch up on the weekends when their circadian rhythm does not interfere with school.

An actigraphy study is another way to analyze a teen's sleeping patterns. An actigraphy watch is a device that looks like a wristwatch. It records movements to estimate sleep duration, timing of sleep, how long it takes to fall asleep, how much time is spent awake through the night, and the amount of light in the room. Results from this study can show if your teen has a delayed sleep phase disorder, and the results can help guide treatment.

How are circadian rhythm sleep disorders treated?

First, we find out what your child's natural sleep patterns are. Then we use strategies to shift the timing of sleep along with timed light exposure to help reset sleep patterns that are closer to desired wake and sleep times.

Since light is the body's biological "time-keeper," light therapy can be a helpful approach to correct a teen’s circadian rhythm. Light therapy may include avoiding bright light and planning exposure to bright light at specific times of day. Bright light options include natural sunlight or a light box, a device that emits very bright light. Light therapy treatment plans are individualized for each teen, based on their current sleep habits and unique situation.

Once your teen reaches the desired sleep schedule, it is important to maintain consistent bedtime and wake times. Even on weekends or holidays, teens should wake up within one hour of their weekday schedule. Naps should be avoided. Your provider can help solve any problems your teen may have with following the schedule so they can be successful.

Before starting treatment for delayed sleep phase disorder, parents should consult a provider at the Children's Hospital Colorado Sleep Program because certain conditions may get worse if not properly treated. Using bright light therapy inappropriately can make a delayed sleep phase disorder worse.

It is important that we also address other causes of daytime sleepiness or sleep disruptions, such as snoring and obstructive sleep apnea, movement disorders, narcolepsy and many others.

Why choose us for treatment of delayed sleep phase disorders?

Our care team has specialized expertise in diagnosing and treating a variety of sleep disorders, including circadian rhythm sleep disorders. The team includes physicians who specialize in sleep medicine, pediatric neurology, pediatric pulmonology and pediatric ear, nose and throat (ENT), sleep psychologists, nurse practitioners, physician assistants, respiratory therapists and dedicated sleep nurses.

We see children who have been referred to us from all over the Rocky Mountain region for evaluation of any and all sleep concerns. Our providers are also actively involved in pediatric sleep research. We collaborate with patients and families to develop an individualized treatment plan for a variety of sleep issues.

  • The National Sleep Foundation offers a lot of information about sleep disorders, including this article about circadian rhythms.
  • American Academy of Sleep Medicine has more information about sleep research and how sleep disorders are treated.
  • Healthy Children provides parents with health information on a variety of health issues and is from the American Academy of Pediatrics.
  • Medline Plus provides easy-to-understand information based on the latest medical research with links to pictures, related topics, and other trusted sources.

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