5 Myths About Circadian Rhythm Sleep-Wake Disorder

Regular disturbances in your sleep-wake cycle can lead to sleep-wake disorders. Here are five myths about these disorders and the facts to set them straight.

Circadian rhythm sleep-wake disorder involves disturbances in the sleep-wake cycle that deviate from a normal day-night sleeping schedule. It is usually identified by trouble falling asleep and staying asleep, waking up too early or being unable to wake up. Sleep-wake disorders are diagnosed when a person’s circadian rhythm issues negatively affect their ability to function in everyday life.

There are five common circadian rhythm sleep-wake disorder myths that people think are true. However, the scientific facts about sleep-wake disorders prove that these myths shouldn’t be believed.

Myth #1: Sleep-wake disorders always manifest the same way.

Fact: There are six different types of sleep-wake disorders.

As defined by the Diagnostic and Statistical Manual of Mental Disorders, there are six different types of sleep-wake disorders that can be grouped into two categories: intrinsic and extrinsic.

Intrinsic disorders are caused by a person’s natural circadian rhythm varying from the normal 24-hour light-dark cycle that most people run on. The individual disorders are defined based on where the sleep-wake cycle is disrupted:

• Advanced sleep phase type happens when people fall asleep earlier than others do. This causes them to go to bed earlier in the evening and get up earlier in the morning than most people since they still require the same amount of sleep. People with this phase-type disorder tend to complain about being tired during the day and not being able to sleep in.
• Delayed sleep phase type is the opposite of advanced sleep phase, meaning that people with this disorder tend to fall asleep later than most. Since they also require the same amount of sleep, they also tend to wake up later in the morning. They often have a hard time getting out of bed in the morning and also complain of tiredness during the day.
• Non-24-hour sleep-wake type, also known as a free-running disorder, occurs when a person’s circadian rhythm is out of sync with the typical 24-hour cycle. It is usually longer than 24 hours, making them go to bed later and get up later every day. Eventually, this will throw them completely off from a normal sleep cycle and cause them to sleep during the day.
• Irregular sleep-wake type occurs when a person has no clear circadian rhythm. As a result, their sleep is fragmented into different stages during a 24-hour period without any constant periods of sleep. These individuals experience insomnia at night and tend to nap during the day.

Extrinsic disorders are circumstantial and occur when something affects the natural circadian rhythm cycle:

• Shift-work type occurs when a person’s work schedule does not align with their intrinsic circadian rhythm. This is common among people who work at night and sleep during the day or people who have to be at work very early in the morning.
• Jet lag occurs when someone travels to a different time zone, where the daylight hours are different from their circadian rhythm. Until their rhythm adjusts to the new time zone, they will be tired at the wrong time of day.

Myth #2: Naps are helpful for people with circadian rhythm sleep-wake disorder.

Fact: Naps can shift circadian rhythm phases, but it depends on how and when the nap is taken.

Our daily exposure to light and dark is a major contributor to our circadian rhythm and its ability to stay aligned with a 24-hour clock. This varies with the length of the day, which will depend on the season. Melatonin, a chemical that makes us tired, is created through our exposure to light and dark. Melatonin production is decreased in response to light, allowing us to be awake during daylight hours.

In general, naps are not suggested as a treatment for sleep-wake disorders. However, a study in the American Journal of Physiology showed that naps can impact the circadian rhythm by changing levels of melatonin. In particular, they found that napping in the dark can shift the circadian rhythm, depending on when the napping occurs.

In the morning, napping in the dark resulted in melatonin being released later in the day. Dark naps in the evening resulted in an earlier release of melatonin, shifting it to earlier in the day. Naps in the dark during the afternoon had no effect on the timing of melatonin release. Therefore, the timing of darkness and sleep exposure affected circadian rhythm. This timed napping system could be considered as a way to help realign circadian rhythms in sleep-wake disorders.

Myth #3: Drinking coffee can help alleviate symptoms.

Fact: Evening caffeine consumption delays the circadian rhythm.

People affected by sleep-wake disorders often find themselves fighting to stay awake during the day. Since naps may not always be feasible, some people turn to caffeinated beverages in an attempt to stay up. However, due to the caffeine in drinks like soda and coffee, the circadian rhythm can be thrown off its normal cycle.

A study from Science Translational Medicine found that when people consumed caffeine in the evening, it delayed their circadian rhythm by 40 minutes. This is similar to what is observed in delayed sleep phase type disorders. They also observed that melatonin levels were significantly shifted with caffeine consumption, rising later in the evening than normal.

This same study also found that prolonged caffeine exposure lengthened the circadian rhythm of cells in a dish, suggesting that our cells might respond similarly. This implies that people who chronically drink caffeine may induce a non-24-hour sleep-wake type disorder by making their circadian rhythm longer than 24 hours.

Myth #4: Shift workers can easily adapt to a new sleep schedule.

Fact: 30% of shift workers complain of sleeplessness and insomnia related to their work schedule.

Night shift sleep disorder results from working at night and trying to sleep during the day, which is the opposite of the biological circadian rhythm. While some people with this schedule say they can easily adjust, 30% of the population working in shifts have sleeplessness and insomnia related to their work schedule.

Management of shift-work disorder involves trying to align a person’s circadian rhythm with their work schedule and improve their sleep quality. The following are sleep strategies for shift workers:

• Avoiding disturbances during sleep time, such as family or friends
• Maintaining a regular sleep schedule
• Taking planned naps, usually right before your shift
• Using appropriately timed light exposure therapy
• Taking melatonin supplements
• Using caffeine to stay awake during your shift but avoiding it in the hours prior to going to sleep

Myth #5: Circadian rhythms stay the same over time.

Fact: Circadian rhythms slowly dwindle as we age.

Sleep cycles by age are different from one another. Older people don’t achieve the same levels of deep sleep as when they were younger and tend to wake up more during the night. In fact, diagnoses of sleep-wake disorders are more common in older adults. This results in less sleep as we age.

It’s thought that our circadian rhythm becomes less consistent with age. As we get older, the circadian rhythm tends to move forward and melatonin is released earlier in the day. The urge to go to bed begins to happen earlier in the evening. As a result, advanced sleep phase type disorders are more common in older adults versus younger adults.

Older adults also have an impaired ability to adjust their circadian rhythm in response to extrinsic factors, such as jet lag. Older adults may also experience a prolonged decrease in sleep efficiency in response to jet lag. This may be the result of their aged circadian rhythms having a decreased sensitivity to light, which would normally help the body adjust its circadian rhythm to the new time zone.

If you or a loved one are struggling with a sleep-wake disorder and a co-occurring substance use disorder, The Recovery Village can help. To learn more about our comprehensive treatment plans, call today to speak with a representative.

Editor – Jonathan Strum

Jonathan Strum graduated from the University of Nebraska Omaha with a Bachelor's in Communication in 2017 and has been writing professionally ever since. Read more

Medically Reviewed By – Dr. Trisha Sippel, PhD

Dr. Sippel is a diversely trained scientist with expertise in cancer biology and immunology. Read more