For the majority of individuals the cycle of day and night is taken for granted; when it’s light outside your body acknowledges it’s daytime, and when the sun sets the body goes into bedtime mode. Even people on alternate schedules, such as those who work third shift, manage to train their body’s to respond to an appropriate sleep-wake cycle. But what if your body didn’t recognize day-night transitions? You may have non-24-hour sleep-wake disorder.
Known as a circadian rhythm disorder, non-24-hour sleep-wake disorder (non-24, for short) is commonly associated with blind individuals who have never known what the terms “night” and “day” represent. Anyone can have non-24, however, and the Circadian Sleep Disorders Network indicates non-24 in sighted individuals, though rare, is generally linked to students or other individuals who find themselves in situations promoting irregular sleep patterns.
What exactly is non-24-hour sleep-wake disorder?
Non-24 is a neurological disorder where an individual is unable to adjust his or her sleep schedule to the actual length of day/night. In other words, a regular sleep pattern in a 24-hour period is never achieved; the person with non-24 may sleep 12 hours in one session and then two hours in the next with no set amount of awake time in between.
“The person is unable to adjust his sleep/wake cycle to the length of the day, and his sleep time progresses around the clock,” states the Circadian Sleep Disorders Network. “For example, if he goes to sleep at midnight and sleeps until 8 am one day, he may not be able to fall asleep until 1 or 2 am the next night, and will need to sleep correspondingly later the following morning. The delay does not stop at 1 or 2am but continues to get worse every day until he is going to sleep at 4am, then 6am, 8am, 10am, noon, 2pm etc. Eventually he comes around the clock again to his starting point and the process continues on. For some people the length of their cycle varies from day to day, and they cannot predict their sleep/wake schedule in advance.”
In a healthy individual, there is a natural sleep/wake pattern maintained by the body. This is known as the circadian rhythm. Non-24, a website dedicated to spreading information regarding this disorder, indicates a healthy person’s master body clock runs slightly longer than 24 hours. What this means is that rather than cycle on a 24-hour day, most people’s natural rhythms actually cycle a bit longer, sometimes by two minutes, sometimes by 30 minutes–all depending on the individual. People with non-24 have these minutes add up day after day, a few one day adding to a few more the next, eventually causing a noticeable change in the times during the day when the body expects to sleep and expects to be awake.
If you answer “yes” to some of the following questions, you may be suffering from non-24:
- Do you have a hard time sleeping through the night?
- Do you find you have a strong urge to nap during the day?
- Is it hard for you to concentrate?
- Are you feeling restless, overtired, or frustrated?
- Do you feel your sleep patterns are different from those around you?
- Does it seem like you’re the only person who’s experiencing these things?
What can be done for non-24-hour sleep-wake disorder?
Non-24 is not only difficult to diagnose because of the lack of patterns associated with it, but it can also cause serious health issues that can impact day-to-day life. Not only do people with non-24 suffer from sleep deprivation and the health conditions that result form it (depression, lowered immune response, anxiety disorders, weight gain, fibromyalgia, diabetes, and cancer), they suffer from other health conditions that result from an unregulated internal clock.
Individuals with non-24 may also find their digestive systems are out-of-sync, as circadian rhythm is also linked to when the body feels it needs to replenish energy.
Unfortunately, the treatments for non-24 can vary as much as the individuals affected. Most sufferers must wait until their sleep cycle hits the “norm” and then, during that time, they must practice light and dark stimulus therapy as well as take a variety of medications, such as melatonin. If this doesn’t work, sometimes individuals must be taught how to adapt to their situation, embracing their irregular schedule rather than fighting it.
There is some hope a drug approved by the FDA this January will offer relief for non-24 patients. The medication, Hetlioz, is a melatonin receptor agonist and showed significant success in research trials.
“Non-24- hour sleep-wake disorder can prevent blind individuals from following the normal daily schedule that we all take for granted,” said Eric Bastings, M.D, deputy director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, in a statement. “Hetlioz can improve the ability to sleep at night and to be active during the day.”