Circadian Rhythm – What is it?

Circadian rhythms are physical, mental, and behavioral changes that follow a roughly 24-hour daily cycle, affected by environmental cues, like sunlight and temperature. This category of disorders includes conditions in which the sleep times are out of alignment. A patient with one of these disorders does not follow normal sleep times at night.

Delayed Sleep-Wake Phase Disorder

What is it?

Delayed sleep-wake phase disorder (DSP) is a circadian rhythm disorder where one’s sleep pattern is off by two or more hours. They tend to go to sleep two or more hours later than what is considered normal. Consequently, they will also want to wake up at a later time than most consider appropriate. They will sleep the appropriate amount of time for their age but will start their sleep cycle later in the night than most people do.

This sleep disorder becomes problematic when the cycle interferes with work. Most occupations begin a few hours before someone with delayed sleep-wake phase disorder would naturally want to wake up. A person with DSP may be confused with someone who has insomnia because they stay up later, but must force themselves to wake earlier than they would if left alone so they can attend school or work. This lack of sleep leads to severe sleepiness and fatigue during the day.

What causes it?

For most people with DSP, this is their natural sleep cycle and more than likely runs in the family. However, it could be caused by environmental factors, such as poor exposure to bright light in the morning, and too much bright light exposure in the evening hours. There could also be other underlying problems to cause DSP, such as:

• Another sleep disorder
• Certain medication use
• A mental health disorder
• Substance abuse

Possible solutions

One solution that has been proven to help people with DSP fall asleep at a normal time and stay asleep is the supplementary hormone Melatonin. This supplement boosts your body’s natural ability to regulate your sleeping pattern.

Another possible solution is bright light therapy. This therapy helps reset one’s sleep-wake cycle and regulate their internal circadian rhythm by reminding them when it is time to wake up and time to go to bed based on the amount of light around them. Bright light indicates it’s time to wake up and do wakeful things and the gradual deterioration and eventual absence of light indicates it is time to go to sleep and stay asleep.

Why get treatment?

It is important to get treatment for DSP because most jobs require work to be done based on the assumption that their workers have a more typical sleeping pattern and are able to work from the morning through the afternoon. Those with DSP will have an extremely difficult time complying with these hours and complications at work or school will arise.

Advanced Sleep-Wake Phase Disorder

What is it?

Advanced sleep-wake phase disorder (ASP) is another circadian rhythm disorder similar to DSP except that a person with ASP will naturally want to fall asleep a few hours before what most consider a normal bedtime. These people will want to go to bed between 6 P.M. and 9 P.M. and wake up very early, usually, between 2 A.M. and 5 A.M. Just like DSP, the sleep time and quality of someone aligns with what is considered normal and sufficient for their age. The only abnormality is they need to go to sleep a few hours earlier than most people.

What causes it?

ASP is quite rare and only affects 1% of middle-aged adults, but is a little more common in older adults and seniors. A genetic link has been found between most individuals impacted by ASP. Environmental factors may also play a role in ASP.

Possible solutions

Bright light therapy is also a possible solution to ASP. Bright light will help encourage sleep at the desired times and also help to re-establish a more typical circadian rhythm.

Why get treatment?

The biggest reason to seek treatment is because of the strain ASP can cause in a person’s social life. Most social engagements occur in the late afternoon and evening, revolving around most people’s work life. If followed, the “early bird” sleep schedule lends itself to more job opportunity but makes it almost impossible to experience a healthy and more typical social life.

Irregular Sleep-Wake Rhythm Disorder

What is it?

Irregular sleep-wake rhythm is a sleep disorder where people do not follow a sleep pattern resembling anything normal. Unlike the previously mentioned disorders, people suffering from irregular sleep-wake rhythm do not sleep for a normal amount of time or experience a smooth, uninterrupted sleep. Instead, they alternate times of being asleep and awake over a 24-hour period so often that it appears they take a lot of naps instead of actually going to sleep. The total amount of time that they are asleep during this 24-hour period will match up with the appropriate amount for their age, but this sleeping cycle is more consistent with infants than children, teens, adults, or seniors.

What causes it?

Irregular sleep-wake rhythm is so rare it is not known how many people have it. Sleep experts believe those who suffer from it have a very weak body clock and may occur in people who have a neurological problem. Individuals who practice poor sleep habits may suffer from irregular sleep-wake rhythm as they develop a weak internal clock. This is especially the case for those who have limited exposure to light and do not get enough bright light during the day.

Possible solutions

Light treatment may help reset and adjust a weakened body clock. In addition, the timely use of melatonin can help induce sleep at appropriate times. These treatments work best alongside good sleeping habits like consistent wake and sleep times and avoidance of stimulants like caffeine and nicotine at times of day associated with “normal” sleep.

Why get treatment?

It is extremely difficult to maintain relationships and responsibilities with this sleeping disorder. Due to the inconsistency and periodic sleep times throughout the day, one may decide to stay at home all the time and isolate themselves. This can have a negative affect and make it all the worse because at home you would have 24-hour access to a place to sleep. This usually ends up encouraging this irregular sleep schedule and hinders treatment.

Non-24-Hour Sleep-Wake Rhythm

What is it?

If you have Non-24-Hour Sleep-Wake Rhythm, then your sleep times and wake times shift later and later every day, and therefore you are sleeping at a different time every night, later and later, until you are sleeping at very odd times during the day.

What causes it?

The number one cause of Non-24-Hour Sleep-Wake Rhythm is blindness. The majority of people do have a circadian rhythm that lasts longer than 24 hours, so if left alone, they would fall asleep later and later every night on their own. However, other factors like morning light and the need to go to work or school in the morning keep us from doing that. Blind people do not recognize this light exposure in the same way and therefore have difficulty resetting their circadian rhythm each day like the rest of us. Light is the most important factor in resetting our internal clock.

Possible solutions

Using Melatonin at the correct time of night can help establish a nightly routine that your body can pick up on. Also having things scheduled in your day to make sure you need to wake up can help while practicing overall healthy sleep hygiene. For example, waking up at the same time every morning to go to work or for a certain activity. Your body will adjust as it catches onto consistent bedtimes and wake times. Bright light therapy is helpful for the rare cases of individuals who are not blind and have Non-24-Hour Sleep-Wake Rhythm.

Why get treatment?

Treatment is necessary to maintain a job and normal day to day responsibilities. Even shift work jobs do not align with this kind of sleep disorder. One will eventually be awake at all times of day varying from week to week, but even alternating shift work runs according to a regular schedule.

Shift Work Disorder

What is it?

Shift work disorder occurs when you have difficulties adjusting to a work schedule that takes place during a time which most people sleep. When you have shift work disorder, there is a conflict between your body’s circadian rhythms and your work schedule. You may have to be at work when your body wants to sleep. Consequently, when you have to sleep, your body expects to be awake.

What causes it?

People with shift work disorder may sleep up to four hours less than the average worker. Shift work disorder causes you to have trouble sleeping or to be severely tired. The quality of sleep may be poor, and you may wake up feeling unrefreshed. You may feel fatigued or exhausted. This can hurt your performance at work and can put you at risk for making a costly mistake or getting injured on the job.
Not everyone who does shift work has shift work disorder. Many people have difficulty initially adjusting to a new shift. If after several weeks you have difficulty falling asleep or staying asleep or you feel tired even after sleeping 7-8 hours, you may have shift work disorder.

Possible solutions

The symptoms of shift work disorder usually last as long as you keep the shift work schedule. The sleep problems tend to go away once you begin sleeping at a normal time again. Some people may have sleep problems even after the shift work schedule ends.

Why get treatment?

It is important to get treated so that you can adjust to your work schedule. If not then you will become extremely tired and fatigued during working hours. Most likely experience sleep attacks and endanger yourself and your fellow workers.

Jet Lag

What is it?

If you travel across multiple time zones you may have difficulty adjusting; this difficulty is called jet lag. When you experience jet lag your body’s circadian rhythms are aligned to the previous time zone you were in. Therefore, your body may want to sleep or be awake at the wrong times according to the new time zone you are in. For instance, your body may want to sleep in the middle of the day according to your regular internal clock. You can be very sleepy during the day and wide awake at night in the new time zone. According to estimates, it takes around one day per time zone you have crossed for your body to adjust fully.

What causes it?

Jet lag is caused by the dramatic change in time of day without giving your body ample time to adjust its circadian rhythm naturally. Your mind comprehends that you are in a new time zone, but your body is not able to adjust in such a limited amount of time.

Possible solutions

The best solution to jet lag is not treatment but certain behavioral adjustments, such as:

• Planning ahead— in the weeks leading up to your trip slowly adjusting your wake and sleep times as much as your current schedule allows will help your body be prepared for the new time zone.
• Sunlight— after arriving in a new time zone exposure to direct sunlight can help reset your body’s internal clock.
• Melatonin— Melatonin is a natural way to help your body adjust to a new bedtime in a new time zone.
• Exercise— According to recent studies, moderate exercise is a great way to adjust to a new time zone (particularly outdoor exercise where you can enjoy direct sunlight as well).

Why get treatment?

It is important to be prepared for jet lag, so you are better able to function normally in whatever time zone you travel too. Otherwise, your internal clock will be under extreme duress while trying to adjust and you may experience extreme tiredness, difficulty concentrating, fatigue, and difficulty remembering. Whether you are on a trip for business or pleasure taking the proper steps to prepare for and treat jet lag is crucial to your ability to function properly and get the most out of the time you spend in that new time zone.