What is it?

This disorder does not clearly fit into any other categories for circadian rhythm sleep disorders (CRSDs). People with this disorder have sleep times that seem to be out of alignment. Their sleep patterns do not follow the “normal” sleep times at night.

If you sleep or are awake at the wrong time, there is usually a specific pattern that fits the other circadian rhythm disorders. Or there is a cause such as jet lag or shift work. The problem may also result from using a drug or substance. A medical condition may also be the cause of the problem. Circadian rhythm sleep disorder, other, describes a problem that has no clear pattern or cause for sleeping or being awake at the wrong time.

This may be a temporary diagnosis while your doctor does tests or makes observations. The specific diagnosis will then be used if a pattern or cause is found.

The category of “other” is used for a problem that does not follow the patterns or causes seen with any of these CRSDs:

Delayed sleep phase disorder
You fall asleep late (for example, between 4 a.m. and 6 a.m.) every night. As a result you awaken at noon or in the afternoon every day.

Advanced sleep phase disorder
You fall asleep early (for example at 6 p.m.) every night. As a result you awaken early every day (for example at 2 a.m.).

Irregular sleep-wake rhythm
Your sleep pattern is broken up into short pieces. You sleep off and on in a series of naps over a 24-hour period.

Free-running (nonentrained) type
Your sleep time happens later and later every day.

Jet lag

Shift work

Circadian rhythm sleep disorder due to medical condition

Circadian rhythm sleep disorder due to drug or substance

If you have any of these CRSDs, then you do not have circadian rhythm sleep disorder, other.

Who gets it?

The rate at which this disorder occurs is not known. It may be a temporary diagnosis while the doctor does tests or makes other observations. It would be the final diagnosis if no cause or pattern can be detected.

How do I know if I have it?

1. Do you sleep at the wrong time, and your doctor can find no other circadian rhythm disorder pattern?
2. Does your sleep problem keep you from sleeping well or cause you to be very sleepy during the day?
3. Does your sleep problem have a negative effect on your social life or work performance?
4. Does your problem have none of these causes?

• Jet lag
• Shift work
• Medical condition
• Drug or substance use

If your answer to these questions is yes, then you might have circadian rhythm sleep disorder, other.

Do I need to see a sleep specialist?

Yes. You should seek a doctor’s advice. This disorder can cause problems with work and family. You are asleep or are awake at times that are different from family and friends. You would have trouble maintaining relationships and responsibilities.

Having this disorder may make you home bound and isolated. Being home bound can make this condition worse. Because sleep time is out of line with others, some people try behaviors or medicines that might worsen this condition. They may get into trouble if they try to fix this problem on their own by taking more pills or alcohol. Some of these drugs and medications are habit forming. Addiction and tolerance to the substance is possible.

What will the doctor need to know?

The doctor should ask you about your medical, neurologic, and sleep symptoms. The doctor also should ask you about your medications, alcohol, and your family history. Be sure to inform him or her of any past or present drug, alcohol, and medication use. Also tell the doctor if you have ever had any other sleep or neurological disorders.

The doctor should do a thorough medical and neurological exam.

You will be asked to complete a sleep diary to record your natural sleep and wake up times over several weeks. You may be asked to record the timing of any mediations or substances. You may need to take drug tests. You may be asked to rate your sleep with the Epworth Sleepiness Scale.

Will I need to take any tests?

The diagnosis of circadian rhythm sleep disorder, other, is made clinically and with the use of the sleep diary. You may be asked to wear an actigraph. This is a device that records inactive and active episodes over a period of one to two weeks. An actigraph looks like a funny wrist watch and you wear it day and night.

Other testing methods to measure body temperature or melatonin levels may be used. Most often these methods are used for research.

Your doctor may suspect that a neurological condition or another medical problem is involved. In this case, you may be asked to have blood testing performed. You may also need a CT scan or an MRI.

Some medications and substances can affect your breathing while you sleep. This can increase sleep apnea. They can also increase other sleep disorders such as periodic limb movement disorder.

An overnight sleep study is usually not needed to detect a CRSD. You may need to do a sleep study if you are at risk for other sleep disorders. The sleep study is called a polysomnogram. It charts your brain waves, heart beat, muscle activity, and breathing as you sleep. It also records how your arms and legs move. This shows if there are other sleep disorders that are causing or increasing your sleep problems. Examples include sleep apnea and periodic limb movement disorder.

How is it treated?

Treatment for this disorder is aimed at helping you to have one long sleep time at night and one long awake time during the day.

The doctor likely will also recommend good sleep behaviors for you to follow. These will improve your circadian rhythm. Good sleep hygiene is important to keeping one main sleep time. Light, exercise, and other scheduled activities increase stimulation to reset the sleep clock in the brain. Education and behavioral counseling can be helpful. Your progress may be monitored by having you complete sleep logs during treatment. The doctor also may want to change medications for your medical problem. The doctor may choose medications that also help you sleep better at night and stay awake during the day. As research studies continue, more information will become available about the causes and other future treatments of this sleep disorder.

By Sharon L. Schutte-Rodin, MD
Updated March 27, 2006