Night Terrors


The irregular sleep-wake rhythm is a circadian rhythm disorder that leads to anomalies in sleeping times with no main sleep episode at night. People with the disorder have undefined sleep-wake patterns and take frequent naps during the day. Excessive daytime fatigue and drowsiness with little to no sleep at night are the main symptoms of this disorder. It can be damaging to one’s health with studies showing that it is linked to other chronic degenerative diseases such as obesity. Fortunately, it is treatable either medically or through personal initiatives such as lifestyle changes.


The irregular sleep-wake rhythm occurs due to spontaneous changes in the circadian rhythm. This rhythm gives the body a routine for sleeping and waking up. The following are some of the causes of the disorder.

1. Lack of a regular schedule

The lack of a set schedule in a person’s daily life increases the risk of developing this disorder. People with undefined daily schedules will commonly have poor sleep habits that can develop into an irregular sleep-wake rhythm. This is common for people who experience frequent changes in work shifts or often travel across different time zones.

2. Lack of exposure to sunlight

A prolonged lack of sunlight exposure has a significant effect on the sleep-wake rhythm.

Light from the sun sends signals to the sleep-wake centers in the brain to determine the natural timing that the body should follow. Thus, sunlight sets the body internal clock correctly and gives us a natural sleep-wake routine.  The internal biological clock enables a person to stay alert during the day while performing tasks and fall asleep at night to rest. When one does not receive the normal 24-hour solar cycle for a prolonged period, the biological clock tries to re-adjust to the unanticipated changes in light exposure. This reset is useful in situations such as moving from one time zone to another, where the body needs to adjust to the solar-cycle in the new geographical location. A reset in the biological clock becomes harmful when it is too frequent and inconsistent since it causes irregularities in the circadian rhythm.

3. Age

Other than sunlight, age-related factors have also been found to increase the risk of irregular sleep-wake rhythm disorder. This is because medical, neurological, and mental disorders increase with age, thus disrupting normal bodily functions. These conditions increase the possibility of irregularities occurring in a person’s sleep-wake pattern. Studies show a high prevalence of irregular sleep-wake rhythm in the elderly, especially those who are institutionalized, and patients who have dementia.

4. Exposure to artificial light at night

Artificial light suppresses the production of melatonin in the body, thus causing wakefulness. With the increased use of gadgets such as smartphones at night, small amounts of melatonin are produced in the body. Melatonin is a hormone that is produced by the pineal gland when there is darkness. It causes mental, physical, and behavioral changes that prepare an individual for sleep. Low levels of melatonin may reduce the sleep periods of an individual and can cause insomnia. Recurring lack of sleep due to low levels of melatonin leads to irregular sleep-wake rhythm disorder.

Symptoms of irregular sleep-wake rhythm disorder

When the circadian rhythm is interrupted, the normal body processes and routines are altered. Hence, the following symptoms may be felt or seen:

  1. Irregular sleeping and waking patterns.
  2. Lack of a defined sleeping period.
  3. Irresistible urges to take short naps of about two hours frequently throughout the day.
  4. Lack of sleep at night
  5. Falling asleep only for short periods, even at night, instead of having concentrated sleep episodes of up to 8 hours like healthy people.
  6. Experiencing fatigue, drowsiness, and excessive sleepiness during the day.
  7. Inattentiveness, poor performance, and reduced alertness when performing tasks during the day.


To diagnose the disorder, doctors will assess one’s sleep-wake patterns. Physicians will ask about the history of the symptoms exhibited by a patient. They may also probe pre-existing health issues, which may disqualify the disorder. Doctors may also measure melatonin levels to determine whether the hormone is produced in sufficient quantities at night. Furthermore, they may have to confirm at least 3 irregular sleep-wake cycles to make a positive diagnosis of the disorder. Devices such as smartwatches and actigraphs, which can collect data about one’s daily activity levels and sleep-wake patterns. Normally, doctors will track sleep-wake cycles for 7 days to get sufficient data to confirm whether one has the disorder. In most cases, a patient with this sleep disorder will have multiple fragmented and short naps during the day and night.



The disorder is treatable using any means that can correct the circadian rhythm. Hence, the treatment options that are currently prescribed aim to ensure wakefulness during the day and induce sleep during the night. The following are the most common treatment methods.

1. Light therapy

Most clinical treatment methods of the irregular sleep-wake rhythm disorder involve the use of light to reset the circadian rhythm. Doctors may use artificial light while retuning the circadian rhythm.  Naturally, sunlight sets the body’s internal clock by helping the biological clock determine the appropriate times for staying awake and sleeping. Artificial light is used in hospitals to create the same effect for a given duration. Blue light of a 460nm wavelength is commonly used because eyes have retinal ganglion cells that are highly sensitive to it. The light activates the ocular photoreceptors in the eyes that make the signals that are used to modify the circadian rhythm.  Light exposure is controlled to ensure that it aligns with the natural 24-hour solar cycle of day and night. The variation between bright light and darkness is registered in the hypothalamus and is used to develop a regular sleep-wake routine. This resets the body’s internal clock and corrects the circadian rhythm, which treats the irregular sleep-wake rhythm disorder.

2. Melatonin supplements

Melatonin supplements are administered clinically or over-the-counter as a treatment option for this disorder to improve a patient’s quality of sleep at night. It is useful to people who have frequent changes in work shifts and those who travel across different time zones. These changes tend to affect the sleep patterns, thus melatonin is administered to help one fall asleep at night. Melatonin supplements are, however, not safe for use by elderly people, especially those who have dementia.

3. Self-medication

Over-the-counter drugs and stimulants can be used to try and restore normal bodily function during the day if one suffers from the disorder. Stimulants such as caffeine, amphetamines, cocaine, nicotine, and khat are commonly used to increase alertness and make an individual more energetic during the day. In small doses, they cause feelings of wellbeing, euphoria, and increased alertness. They temporarily increase the activity of the brain, thus enabling one to stay awake and avoid taking naps during the day. Stimulants such as methylphenidate and dextroamphetamine are commonly used to control irregular sleep-wake rhythm disorder. They are contained in drugs such as Adderall, Dexedrine, Concerta, and Ritalin. Individuals who experience compulsive naps during the day that affect their normal function can get these over-the-counter drugs to help them stay alert.

It is, however, important to take the drugs only when necessary and in the right doses. This is because misuse leads to problems such as anxiety, seizures, headaches, paranoia, nausea, and addiction. Many of the common over-the-counter drugs that are used as stimulants, such as Adderall and Ritalin, can be addictive, leading to dependence when taken frequently and in large doses. Pharmacists give strict directions of use for such drugs which should be followed to avoid negatively affecting one’s health and worsening the condition.

There are several alternatives to these stimulants that pose a lower risk of side effects, such as addiction. These include atomoxetine, which is commonly sold over-the counter as Strattera, and modafinil, which is a widely accepted amphetamine alternative. Atomoxetine works by boosting the norepinephrine levels in the brain but, unlike the common stimulants, it does not boost the dopamine levels. Thus, it increases the alertness of the individual without causing dependence. Modafinil is commonly sold as Provigil, which is the generic form. One can consider using these alternatives although they have different availability over-the-counter depending on the country. They are, however, useful in enabling full wakefulness.

4. Lifestyle changes

People suffering from the irregular sleep-wake rhythm can benefit from several lifestyle changes such as follows.

a) Sunlight exposure

Getting sufficient sunlight exposure can help alleviate the symptoms or to slowly treat the disorder. The circadian rhythm is normally synchronized with the 24-hour solar day to ensure that a person stays awake and alert during the daytime when the sun is shining and then gets enough sleep in the night hours. This creates a daily routine that the body can get used to and follow. The lack of exposure to sunlight, therefore, alters the normal sleep-wake rhythm. Hence, to counter the disorder, one can ensure that they get sunlight for a lengthy duration during the day. This can be achieved by sitting in places with adequate natural light or going outside to bask in the sun. Daily sunlight exposure for several hours will lead to consistent production of signals in the neurons that will be registered in the hypothalamus, thus causing an adjustment in the sleep-wake rhythm.

b)  A fixed daily schedule

One should establish a fixed daily schedule that they can follow. This will make the body develop a regular rhythm around the schedule. Many people who have the irregular sleep-wake disorder lack a fixed schedule of activities. In the absence of a specific routine to follow, it becomes quite easy to end up sleeping at irregular times of the day. The circadian rhythm is affected by this inconsistency leading to an irregular sleep-wake rhythm. Therefore, one should create a fixed schedule for waking up, carrying out activities, eating, and sleeping because the body will adjust to the consistent routine, and this can resolve the disorder.

c) Modifications to one’s environment

The spaces in which one spends time should also be purposed to aid in setting a correct circadian rhythm. The bedroom should be kept dark and quiet at night to ensure that one gets sufficient, uninterrupted sleep. On the other hand, living and working spaces should be brightly lit during the day to prevent the production of melatonin. The changes to these environments will aid the body’s internal clock in setting the correct wakefulness and sleeping times.

d) Reduced exposure to artificial light-emitting devices

Lastly, the use of devices such as computers and smartphones should be reduced several hours before bedtime. These gadgets emit artificial light that can affect the production of melatonin and interfere with the sleep-wake cycle. However, some devices have inbuilt mechanisms to filter blue light at certain times, while others offer a dark mode, which is less intrusive to the sleep cycle as it does not suppress the production of melatonin, the sleep hormone. Thus, one should either use light settings that do not interfere with the body’s sleeping cycle or reduce their exposure to artificial lights late into the night.


The irregular sleep-wake rhythm disorder occurs when there are changes in the circadian rhythm that lead to irregular sleeping times.  The disorder is caused by irregular activity schedules, lack of sunlight exposure, aging, and exposure to artificial light.

The symptoms associated with it include irregular sleep-wake patterns, reduced sleeping duration, urges to take short naps during the day, lack of sleep at night, and fatigue and drowsiness during the day.

The disorder can be diagnosed in the hospital through the assessment of the sleep-wake cycle and analysis of the exhibited symptoms. Individuals who show signs and symptoms of irregular sleep-wake rhythm should consult a doctor immediately to avoid further complications. This is because the disorder affects the other body functions as well as an individual’s work or school activities.

The disorder is curable through treatment procedures that can correct the circadian rhythm. Light therapy is used in hospitals to reset the body’s internal clock and realign it to the normal day and night cycles whereby one remains alert during the day and falls asleep at night. Melatonin supplements can be administered to instigate the body’s sleeping mechanisms.

Self-treatment through over the counter drugs and stimulants can also be used, but remember to follow the instructions on the bottle to avoid further complicating the disorder. Lastly, lifestyle changes can help treat the disorder. Such changes include getting exposed to sunlight during the day, reducing exposure to artificial light during the night, following a fixed daily schedule, and modifying living and sleeping spaces to ensure light during the day and darkness during the night.


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