Non-24-Hour Sleep-Wake Disorder: Causes, Symptoms, & Treatment

Last Updated On November 15th, 2023
Non-24-Hour Sleep-Wake Disorder: Causes, Symptoms, & Treatment

Key Takeaways

  • Disorder Overview: Non-24-Hour Sleep-Wake Disorder, also known as Non-24, is a circadian rhythm sleep disorder that disrupts the internal body clock’s ability to regulate the sleep-wake cycle. It leads to irregular sleep patterns, difficulties falling asleep or waking up, and a misalignment between natural sleep tendencies and societal norms. It is particularly prevalent in individuals who are blind, but it can also affect sighted individuals.
  • Causes and Symptoms: The disorder is primarily caused by disruptions in the internal circadian clock, which results in a sleep-wake cycle that gradually shifts later each day. This leads to symptoms such as insomnia, excessive daytime sleepiness, and difficulties in daily functioning. Complete blindness can contribute to Non-24, as individuals lack the light cues necessary to reset their internal clock. However, even sighted individuals can experience Non-24.
  • Diagnosis and Treatment: Diagnosing Non-24 involves analyzing sleep logs, medical records, melatonin assessment, and response to treatment. Melatonin and light therapy are commonly used treatments to realign the sleep-wake cycle. Lifestyle adjustments, maintaining a regular sleep schedule, and managing external time cues like meal timing and physical activity also contribute to managing the disorder.

An estimated 1 in 2000 people wrestle with a unique sleep disorder called Non-24-Hour Sleep-Wake Disorder, a type of circadian rhythm sleep disorder. This condition disrupts the sleep-wake cycle, causing individuals to experience a perpetual lag, similar to an extreme form of Delayed Sleep Phase Syndrome. Over time, it can severely mess up someone’s daily schedule.

In this blog post, we’ll navigate the complex terrain of circadian rhythm disorders using insights from the Circadian Sleep Disorders Network.

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What Is Non-24-Hour Sleep-Wake Disorder?

Non-24-Hour Sleep-Wake Disorder, commonly referred Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source to as Non-24, is a rare but impactful Circadian Rhythm Sleep Disorder. A circadian rhythm disorder Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source is a condition in which an individual’s internal body clock, responsible for regulating the sleep-wake cycle and other physiological processes, becomes disrupted. This disruption can lead to irregular sleep patterns, difficulties falling asleep or waking up, and a mismatch between the person’s natural sleep tendencies and societal norms. There are many types Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source of such disorders.

Unlike other sleep disorders, Non-24 leads to a gradual delay in the timing of sleep, causing a person’s sleep-wake cycle to “drift” later each day away from their desired sleep time. Over time, this drift can result in sleep periods that occur at inappropriate times, further disrupting the circadian rhythm.

Often misunderstood, Non-24 primarily affects Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source people who are completely blind, as they lack the light cues necessary to reset the body’s internal clock.

However, sighted individuals can also be affected, albeit less commonly. This disorder adds another layer to the complex mosaic of Circadian Rhythm Sleep Disorders that the Circadian Sleep Disorders Network continues to study and address.

What Causes Non-24-Hour Sleep-Wake Disorder?

The origins of Non-24-Hour Sleep-Wake Disorder can be traced back to disruptions in our internal circadian clock. This complex biological mechanism is programmed to regulate our sleep-wake cycle over a roughly 24-hour period, aligning our patterns of wakefulness and sleep with the natural cycle of day and night.

However, certain factors can disrupt this intricate alignment. In individuals with Non-24, the circadian clock runs on a cycle slightly longer than 24 hours and fails to adjust correctly to the light-dark cycles of the environment. As a result, the timing of their sleep gradually shifts later each day, causing their sleep-wake cycle to rotate around the clock.

Complete blindness is a primary cause Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source of Non-24. In these cases, Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source the inability to perceive light prevents the environmental light cues from resetting the human circadian clock daily. In blind patients, this often leads to a free-running sleep pattern that does not adhere to a 24-hour cycle.

However, it’s important to note that a minority of sighted individuals can also experience Non-24, not just blind people. Research is ongoing to understand why this happens.

While understanding of the precise risk factors for Non-24 continues to evolve, the role of treatments such as light therapy and melatonin administration has become clear. These treatments work by helping to match a person’s body clock to a regular 24-hour day. This makes it easier for them to fall asleep at the right time and reduces feelings of being overly sleepy during the day.

What Are the Other Normal Time Cues for Sleep?

Aside from light, there are several other normal time cues that can influence our sleep-wake cycle, also known as the circadian rhythm. These cues help regulate our body’s internal clock and signal to healthy adults when it’s time to be awake or sleep.

  • Meal Timing: Regular meal times, especially larger meals, can affect our sleep. Eating heavy or rich meals close to bedtime may disrupt sleep due to increased metabolism and discomfort, which is why it’s smart to be cautious about what and when you eat before bed.
  • Physical Activity: Engaging in regular physical activity can promote better sleep. Regular exercise can improve sleep quality, but intense exercise too close to bedtime might have a stimulating effect and interfere with sleep.
  • Internal Temperature: Our body temperature naturally fluctuates throughout the day, and a decrease in body temperature signals the body that it’s time to sleep. Cooler bedroom temperatures can facilitate falling asleep and staying asleep, so consider ways to cool down your bedroom without over-relying on air conditioning.
  • External Noise: The absence or presence of background noise in our environment can impact sleep quality. A quiet environment is generally more conducive to restful sleep.
  • Social Cues: Social interactions and daily routines can influence our sleep patterns. For example, the typical work or school schedule and regular social activities, along with included meal times and such, can help regulate when we feel alert and when we start to feel sleepy.

Each person also has an internal biological clock that influences their preferred sleep-wake times, a chronotype. Some individuals are “night owls,” while others are “morning larks.” Respect your body’s natural tendencies when planning your sleep schedule.

How Is Non-24-Hour Sleep-Wake Disorder Diagnosed?

Diagnosing Non-24-Hour Sleep-Wake Disorder involves multiple steps, each crucial to accurately identifying this complex condition:

  • Sleep Logs and Questionnaires: These tools are often the first step in diagnosis. They help document an individual’s sleep patterns, sleep-wake schedule, and any delay in sleep onset time.
  • Checking Medical and Sleep Records: A deep look into a person’s past health and sleep patterns can reveal their sleep issues, problems with falling asleep, and any health conditions that might be causing these sleep troubles.
  • Melatonin Assessment: Tests to assess the timing of the body’s production of the hormone melatonin, such as measuring dim light melatonin onset (DLMO), can indicate Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source the timing of the body’s internal “clock.” This information can be crucial in confirming a diagnosis of Non-24.
  • Response to Treatment: The use of Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source bright light therapy and melatonin treatment can serve as both a diagnostic tool and a form of treatment. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source These interventions can shift sleep patterns and alter sleep onset time, offering relief to those with a delayed sleep-wake pattern.

Common Symptoms of Non-24-Hour Sleep-Wake Disorder

Non-24-Hour Sleep-Wake Disorder presents a unique array of both daytime and nighttime symptoms due to disruptions in the human circadian timing system.

  • Symptoms at Night: As a person’s sleep schedule shifts out of sync with the normal day-night cycle, they may experience problems like insomnia. This can make it hard for them to fall asleep or stay asleep throughout the night. This misalignment may also lead to frequent awakenings or disturbances such as periodic limb movement disorder.
  • Daytime Troubles: Messed-up sleep schedules can cause you to feel super tired during the day. You may find it hard to stay awake, concentrate, or be alert. Over time, this excessive daytime sleepiness can really impact your daily life, work, social time, and how you feel overall.

What’s more, if Non-24 isn’t managed, the resulting sleep deprivation could lead to Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source serious health problems like heart disease, metabolism issues, and mood swings.

In order to accurately identify and track these symptoms, tools like a sleep diary can be helpful. Through regular entries, patients can document their sleep and wake times, sleep quality, and any daytime sleepiness or disturbances.

This information can be crucial in diagnosing Non-24, as well as ruling out other potential sleep disorders such as obstructive sleep apnea.

The ultradian constant routine study, which measures Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source various aspects of circadian rhythms, may also be used to detect shifts in circadian melatonin production, further aiding in the diagnosis and understanding of this complex disorder.

Treatment and Lifestyle Modifications for Non-24-Hour Sleep-Wake Disorder

When it comes to treating Non-24-Hour Sleep-Wake Disorder, a holistic approach is often the most effective. This includes a combination of medical treatment options and lifestyle adaptations:

  • Medication and Therapy: Research indicates that medications, including melatonin and melatonin agonists, can be critical in realigning disrupted sleep-wake cycles and aiding in melatonin secretion. Light therapy, recommended by a clinical practice guideline, can also prove beneficial, especially for sighted patients, as it can help reset the body’s internal clock based on the phase response curve.
  • Importance of Routine and Hygiene: Keeping a regular sleep-wake schedule and adhering to healthy sleep habits are paramount. A quiet sleep environment and avoidance of electronics before bedtime can improve sleep quality and alleviate difficulty falling asleep. Other sleeping tips for the blind and visually impaired, such as establishing non-visual cues for bedtime, can help.
  • Lifestyle Adjustments: Lifestyle changes play significant roles in managing Non-24. Dietary changes and regular exercise can help manage free-running circadian rhythms. Moreover, strategies for stress management and mental health support can greatly improve overall well-being.

Despite the strides made in understanding and treating Non-24, it’s crucial to acknowledge existing limitations. Managing this disorder can be a process of trial and error, given the intrinsic circadian period unique to each individual.

However, ongoing research into circadian rhythms and sleep disorders offers hope for new treatment methods. The future of managing Non-24 lies in personalized treatment plans that cater to the unique lifestyle, symptoms, and therapy responses of each patient.

Treating Non-24 isn’t a one-size-fits-all deal. It comes with diagnostic and treatment challenges. It’s a mix of medical help, shaking up your lifestyle, and tailoring a plan that fits just right for you and your unique situation.

By employing these strategies, including morning-light exposure for those who are sighted, individuals with Non-24 can enhance their sleep quality and overall well-being.

FAQs

Is non-24-hour sleep-wake disorder a disability?

While it is not a disability in itself, the irregular sleep patterns associated with Non-24 can significantly impact a person’s daily functioning, leading to challenges in maintaining a regular schedule, attending work or school, and engaging in social activities. Strategies for managing this often include open communication with employers or educators about the condition, flexibility in work or study schedules, and managing sleep deprivation effectively.

In some cases, individuals with severe Non-24 may qualify for disability benefits if it significantly impairs their ability to work or perform daily activities. It’s essential for individuals experiencing symptoms of Non-24 to seek medical evaluation and support to manage the condition effectively. Regular consultation with a sleep specialist can also provide personalized advice and treatment options.

What is the difference between non-24 and DSPS?

Non-24-hour sleep-wake disorder (Non-24) and Delayed Sleep Phase Syndrome (DSPS) are both circadian rhythm sleep disorders, but they have distinct differences in their patterns. In Non-24, a person’s sleep-wake cycle follows a longer-than-24-hour pattern, causing their sleep schedule to shift gradually each day. This results in the individual going to bed and waking up progressively later, leading to a disrupted sleep-wake pattern.

Delayed Sleep Phase Syndrome, on the other hand, involves a consistent and persistent delay in a person’s sleep-wake schedule. People with DSPS have a natural tendency to fall asleep and wake up significantly later than what is considered socially acceptable. For example, they might have difficulty falling asleep until the early hours of the morning and struggle to wake up at a typical morning time.

Is a sleep-wake rhythm disorder a mental illness?

No, sleep-wake rhythm disorders, including Non-24-hour sleep-wake disorder, are not mental illnesses. They are classified as circadian rhythm sleep disorders, which are conditions related to the body’s internal clock and the natural sleep-wake cycle. While these disorders can have a significant impact on an individual’s daily life and emotional well-being, they are not considered mental illnesses in themselves.

However, the disruptions in sleep patterns can exacerbate or contribute to mental health issues like anxiety and depression, making it essential for affected individuals to seek proper evaluation and management from healthcare professionals who specialize in sleep medicine.

Can you have non-24 without blindness?

Yes, Non-24-hour sleep-wake disorder can occur without blindness. Non-24 is often associated with blindness because the condition is more prevalent among individuals who are completely blind or have very little light perception. The absence of light perception can disrupt the entrainment of the circadian rhythm to the 24-hour day-night cycle, leading to Non-24.

However, it’s important to note that Non-24 can also occur in individuals who are not blind but may have other underlying causes or disruptions to their circadian rhythm. The whys and hows of this disorder are still being studied.

What medication is there for Non-24?

Many patients use common melatonin supplements to help manage Non-24. In individuals with Non-24, melatonin administration can be crucial in helping to synchronize the sleep-wake cycle with the 24-hour day. It is typically taken in the evening or at night to simulate the body’s natural melatonin secretion and promote sleep.

Tasimelteon Verified Source Medline Plus Online resource offered by the National Library of Medicine and part of the National Institutes of Health. View source is another medication prescribed to treat non-24. The medication falls under the class of melatonin receptor agonists and works similarly to melatonin, a natural substance in the brain that plays a vital role in regulating sleep. For adults with non-24, tasimelteon is typically taken once a day, without food, about 1 hour before bedtime.

Conclusion

Non-24-Hour Sleep-Wake Disorder disrupts the sleep-wake cycle, causing individuals to experience a perpetual lag, leading to a mismatch between their natural sleep tendencies and societal norms. While it is more commonly observed in individuals who are completely blind, it can also affect sighted individuals, albeit less frequently. Maintaining a stable job or academic life with Non-24-Hour Sleep-Wake Disorder can be challenging.


About the author

Mitchell Tollsen is a graduate student and a freelance writer who’s contributed to the Early Bird blog for three years. Mitchell’s always been fascinated by the science of sleep and the restorative processes our bodies undergo when at rest. The self-titled “Sleep Expert” is always looking for ways to improve his shut-eye, and throughout the years has implemented numerous lifestyle changes and tried dozens of sleep-promoting gadgets to determine the best ways to truly get better rest.

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