Most people go to bed at night and sleep until morning. People with irregular sleep-wake syndrome experience disrupted sleep that is often unstructured and broken. According to the National Institutes of Health (NIH), this syndrome is very uncommon (NIH, 2010).
People with irregular sleep-wake syndrome usually sleep one to four hours at a time. They have several sleep sessions in a 24-hour period. The longest period of continuous sleep is typically between the hours of 2 a.m. and 6 a.m. (Zee & Vitiello, 2009).
People with irregular sleep-wake syndrome are not considered sleep-deprived. They get an adequate amount of sleep. However, it is spread over a 24-hour period rather than concentrated into seven or eight hours. People with this condition have problems with both insomnia and excessive sleepiness during the day.
It is helpful to know a little about circadian rhythms and their relation to sleep to better understand irregular sleep-wake syndrome. Circadian rhythms are physical, mental, and behavioral changes in response to light and dark. Your body essentially has a 24-hour internal clock. This clock controls a number of processes, including sleep-wake cycles.
Melatonin is a hormone produced by the brain that makes you feel tired. This hormone is secreted in higher amounts at night, when it is dark. It is vital to the regulation of normal sleep-wake cycles.
The root cause of irregular sleep-wake syndrome is a near absence of the circadian rhythm responsible for regulating periods of wakefulness and rest.
It appears that those who do not have a daily routine or set schedule are at an increased risk of developing irregular sleep-wake syndrome.
The prevalence of irregular sleep-wake syndrome increases with age. However, age itself is not a risk factor. Age-related increases in medical, neurological, and psychiatric disorders contribute to the development of this condition.
Some factors unrelated to irregular sleep-wake syndrome can temporarily disrupt the sleep-wake circadian cycle. These include working irregular shifts (switching between day shifts and overnight shifts) and frequently traveling among different time zones.
Sleeping and waking at irregular times and sleeping for short periods is not a medical emergency. It is normal to occasionally have difficulty sleeping. However, you may want to see a doctor if you are exhibiting signs of irregular sleep-wake syndrome on a regular basis and have not yet been diagnosed with the disorder. This is especially important if you can’t think of any factors that could be accounting for the disturbance.
Your doctor will ask you about recent sleeping habits. He or she will also ask about ongoing issues with insomnia and/or excessive sleepiness during the day.
A doctor may use a sleep diary and an actigraph to help diagnose irregular sleep-wake syndrome. A sleep diary involves keeping a record of how long and when you slept over a period. An actigraph is a device that resembles a watch. It tracks your sleep/wake patterns.
These tools will likely be used to track your sleep for at least seven days. A physician will look for a minimum of three cycles of sleeping and waking within a period of 24 hours to make a diagnosis.
There is no simple cure for irregular sleep-wake syndrome. However, several therapies and lifestyle changes may help. These include:
- controlling exposure to light: the patient should be exposed to blue light (e.g. from computer screens and television) during the day. The period of exposure should also be increased. Exposure to blue light should be minimized at night
- melatonin supplementation
- adding more structure to the patient’s day: this could include scheduling social interaction, exercise, and other activities.
- making the sleep environment as inviting and comfortable as possible
- minimizing the amount of noise in the sleep environment
The ultimate goal of treatment is to help the person sleep longer at night and maximize wakefulness during the day.