The circadian rhythm is what is commonly referred to as our internal body clock. It is what wakes us up and makes us feel sleepy at more or less the same time every day. The circadian rhythm is a little over 24 hours and is governed by the dawning and fading of daylight. Upsetting the circadian rhythm causes sleep-wake disorders. There is no identified clear cut cause for Circadian rhythm disorders. It could be a disruption of the sleep-wake pattern because of an internal, physiological issue. Or it may be caused by a clash between the body clock and external environmental factors. One such example is routinely staying up late socializing and then waking up early to reach college/work.  Sometimes an existing family history of circadian sleep disorders may bring down the age of onset or may lead to a more severe form of the disorder. People living with Circadian rhythm sleep-wake disorders tend to experience insomnia and excessive day time sleepiness, sleep loss, and depression. They may have disrupted social, and work schedules, and often, their personal relationships are negatively affected. They tend to have poor productivity, drop-in creativity, loss of concentration, and focus.

Types of Circadian Rhythm Disorders

Jet Lag

One of the most well-known sleep disorders is jet lag. Travel between international time zones throws the circadian rhythm out of sync. Frequent air travel can lead to severe jet lag and slow the turnaround time. Depending on the direction of travel (east-west etc.) and the time difference between start and endpoints of travel, a person may take a couple of days to a week to stabilize. Traveling to the East (you gain time) is harder because it’s easier to delay sleep than to go to sleep before your normal bedtime.

Shift Work Disorder

Working night shifts is very hard to get used to, and initially, most people struggle with sleep loss and exhaustion. However, rotating shifts means a person’s circadian rhythm is being constantly upset, and the circadian rhythm is constantly disrupted. This results in insomnia and or excessive sleepiness during the day.

Delayed Sleep Phase Disorder

This sleep disorder is most common to teenagers and young adults. The ‘night owls’ who are alert and productive late at night and typically do not sleep before 2 a.m. Typically, these people are perfectly fine if they can sleep till 3 pm without being disturbed. But if forced to wake up and be part of morning activities study classes, work, etc. they are unfocused and sluggish and usually seen as underperformers.

Advanced Sleep Phase Disorder

Usually, this is a problem associated with elderly people. People with this disorder rise with the birds and go to sleep with the birds! It becomes a problem when the person starts to feel sleepy early in the evening (5 pm onwards) and wakes up pre-dawn, even as early as 2 am!

Irregular Sleep-Wake Disorder

This circadian rhythm sleep disorder is mostly seen in people suffering from neurodegenerative disorders like Parkinson’s disease, Alzheimer’s disease, and Huntingdon’s disease. Typically, the person suffers from insomnia and as a result, sleeps in intervals during the day.

The Non-24-Hour Sleep-Wake Disorder

This disorder is most common in visually impaired people with impaired ability to perceive light.  In this case, the person’s natural body clock does not align with the 24-hour day. So, the person feels sleepy according to their body clock, which may or may not be in sync with the daylight-nighttime time table. This imbalance causes the person to be awake at night and sleepy in the day. There are times when their internal body clock matches the 24-hour day, but these periods, unfortunately, do not last.

Treatment Options for Circadian Rhythm Disorders

For a circadian rhythm, sleep-wake disorders, treatment is more or less specific to the disorder and the nature and severity of it. Jet lag usually sorts itself out within a few days. Behavior therapy to effect lifestyle changes also helps treat DSP. Avoiding taking stimulants close to bedtime, establishing a sleep-wake routine, strategically planning nap time, etc. will help to reverse DSP. Sleep hygiene is important for ensuring good sleep. For people dealing with advanced sleep phase disorder increasing exposure to light in the evenings will help to correct the circadian rhythm. Bright Light Therapy monitored by sleep specialists will also help to correct disturbances in the sleep-wake cycle. Drugs that induce sleep can be used in the short term, closely monitored by a physician to get the person to sleep at a fixed time. Melatonin hormone has a major impact on the perception of tiredness and the need to sleep. Hormone supplements may also be prescribed to correct the disruption of the rhythm.