Circadian Rhythm Disorders: Understanding Delayed Sleep-Wake Disorder

Sleep is regulated by the body’s internal clock, known as the circadian rhythm, which aligns with the 24-hour day-night cycle. Circadian Rhythm Sleep Disorder or commonly known as Sleep-Wake Cycle Disorders are sleep problems where patients have a disruption in the timing of their sleep cycle. The common types of Circadian Rhythm Sleep Disorder or Sleep-Wake Cycle Disorders are delayed sleep wake disorders, advanced sleep wake disorders and irregular sleep wake disorders. The most common type of circadian rhythm disorder is Delayed Sleep-Wake Disorder (DSWD).

This section deals with the causes, investigations, and treatment options for DSWD, particularly in children and adolescents.

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Symptoms of Circadian Rhythm Sleep Disorders?

The symptoms of Circadian Rhythm Sleep Disorder or Sleep-Wake Cycle Disorders in children depends on the type of disorder the child is having. The most common type of Sleep-Wake Cycle Disorder is the delayed sleep wake disorder.

What is Delayed Sleep-Wake Disorder?

Delayed Sleep-Wake Disorder is a condition in which an individual's sleep pattern is delayed by two or more hours compared to conventional sleep times. People with this disorder struggle to fall asleep at a typical bedtime, this is usually interpreted as insomnia or difficulty in going to sleep.

Children with delayed sleep wake disorder if they have to get up at normal times (need to go to school by work), they find it difficult to wake up as they do not get adequate sleep. They hence are excessively sleepy in the day also called, as excessive daytime somnolence. Classically, if these children wake up at their usual routine (say 12 noon or 1 am) they get the adequate duration of sleep and are not sleepy during the day. This is usually seen during weekends when they do not need to go to school or work. This disturbance in the sleep-wake cycle can lead to problems such as depression, stress in the relationships and a poor work/school performance. Some children can also have an advanced sleep wake disorder. In this situation, the child goes to sleep very early at 6:00 AM or 7:00 AM and wakes up at night. Say 2:00 AM or 3:00 AM.

Causes of Delayed Sleep-Wake Disorder

Humans have an “internal clock” which controls our body’s sleep-wake cycle. The “internal clock” tells us when it is time to sleep or wake up. Our “internal clock” tries to align sleep and wake with environmental cues, such as day/night, physical activity etc. Circadian Rhythm Disorders or Sleep-Wake Cycle Disorders happen when the body’s 24-hour “internal clock” gets out of sync with the environment. When this happens patients find it difficult to sleep and be awake at socially appropriate times. Several factors contribute to the development of DSWD, including:

Biological Predisposition:

Adolescents are naturally inclined toward later sleep and wake times due to hormonal changes during puberty.
Genetic factors may also play a role, as DSWD often runs in families.

Behavioral and Lifestyle Factors:

Irregular sleep schedules, such as staying up late on weekends.
Excessive use of screens (phones, tablets, or computers) emitting blue light that suppresses melatonin production.

Environmental Factors:

Exposure to artificial light at night
Lack of natural light during the day, disrupting the body’s internal clock.

Psychological Factors:

Anxiety, stress, or depression can worsen delayed sleep patterns.
Conditions like ADHD may also be associated with circadian rhythm disruptions.

Investigations for Delayed Sleep-Wake Disorder

Accurate diagnosis of DSWD is essential for effective management. Common investigations include:

Sleep History and Diary:

Diagnosis of Circadian Rhythm Sleep Disorder requires a detailed case history.
A detailed record of sleep and wake times over 1-2 weeks helps identify patterns of delayed sleep onset.

Actigraphy:

A wearable device (like a smart watch) tracks activity and rest cycles with the time of the day to provide objective data about sleep timing and helps to understand the sleep-wake schedule.

Polysomnography (if needed):

In cases where other sleep disorders like obstructive sleep apnea (OSA) and restless legs syndrome are suspected, a detailed sleep study may be conducted.

Questionnaires and Psychological Assessment:

Tools like the Morningness-Eveningness Questionnaire (MEQ) may be used to assess chronotype preferences.

Treatment for Delayed Sleep-Wake Disorder

Treatments for Circadian Rhythm Sleep Disorder aims to reset a child's sleep-wake rhythm to align the child’s environment. Common approaches include:

Behavioral Interventions:

Sleep Hygiene Education: Encourage regular sleep and wake times, limit screen use before bed, and create a quiet, dark sleep environment.
Gradual Adjustment of Sleep Times: Gradually advancing the bedtime by 15-30 minutes each day to align with a desired schedule.

Light Therapy:

Exposure to bright light in the morning helps shift the circadian rhythm earlier.
Devices such as light boxes may be used under professional guidance.

Melatonin Supplementation:

Low-dose melatonin taken in the evening can help advance sleep timing. This should always be used under medical supervision.

Cognitive Behavioral Therapy (CBT):

CBT can address any psychological issues, such as anxiety or stress, contributing to sleep disturbances.

Chronotherapy:

In cases where gradual adjustments fail, chronotherapy involves delaying sleep time by several hours each day until the sleep pattern aligns with the desired schedule.

Parental and School Support:

For children, collaboration with schools to adjust schedules temporarily may be necessary during treatment.

Delayed Sleep-Wake Disorder is a manageable condition when identified and treated appropriately. Addressing lifestyle, behavioural, and environmental factors is key to restoring healthy sleep patterns. If your child is struggling with irregular sleep schedules, consult a pediatric sleep specialist to develop a personalized treatment plan.
Conclusion

Circadian Rhythm Disorders