Circadian Rhythm Disorders describe the types of insomnia caused by disruptions in your internal biological clock.
Did you know you have an internal clock? Brain researchers have actually pinpointed it in the brain. It doesn’t tick or anything (sorry) but it does have an interesting name: “suprachiasmatic nucleus.” For obvious reasons, it’s often shortened to “SCN.”
The SCN consists of two tiny clusters of about 20,000 neurons each, both situated in the hypothalamus, a part of the brain that’s very close to the optic nerves that relay signals from your retina – the photosensitive tissue behind your eyes that allow you to see.
This is a strategic location for the SCN, because guess what it uses to run the “clock” properly? Mostly sunlight and darkness… which is perceived through the eyes.
Light forms the “cues” that tell the SCN what the general time of day is. Then the internal clock then sends signals to other parts of the brain, which produce various hormones, such as melatonin, that cause you to feel sleepy after dark… or shuts it off to make you feel wide awake in daylight.
Cues for Sleep
Sunlight is the most important cue, but it’s not the only one. Other factors help, too, such as sounds, smells, artificial lights… plus your hunger and energy levels at various times of the day.
All the cues help the internal clock set itself for a 24-hour day. This helps us to fall sleep at roughly the same time at night and wake up on time in the morning.
It’s easy to ignore the internal clock, but it does have consequences. And that’s when circadian rhythm disorders come in as one of the main causes of insomnia, especially in nightworkers and people with irregular work schedules.
Interesting note: almost all sleep deprivation studies involve deliberating disrupting the sleep cycle to measure this particular effect of insomnia on the participants.
Circadian rhythm disorder also includes jet lag, which is caused by crossing time zones and causing all kinds of confusion to your hapless SCN.
Jet lag-related insomnia is usually resolved after a few days, but sometimes it serves as a trigger to a longer-lasting period of insomnia, and that’s when trouble begins.
Symptoms of Circadian Rhythm Disorders and Sleep Cycle Disruptions
The main symptoms include feeling sleepy when you’re supposed to be wide awake and alert… and then having insomnia when it’s time to sleep.
Although outside factors can certainly cause circadian rhythm disorders – such as jet lag, working nights and having your work-schedule change – I have found that having insomnia itself can cause your internal clock to get out of whack.
It’s another paradox (or effect) of insomnia. First, you might get insomnia from disruptions in the sleep cycle and your circadian rhythms. Or you might get it from any number of other insomnia causes, whether physical, emotional, or environmental.
But then, as your insomnia turns from acute to chronic, your circadian rhythms get even more out of whack.
Since you’re trying very hard to get enough sleep so you can feel rested, you start sleeping late to make up for hours lost, or take naps during the day when you’re exhausted. This seems like the right thing to do, and it could be if all you’re dealing with is one night of lost sleep. But as we know, insomnia is way more complicated than that.
When your circadian rhythm is out of whack, so is your life, really. It can seem that you’re always fighting your body’s natural tendencies, which always come out at the wrong time. This is not a fun way to live.
So how do you treat circadian rhythm disorders?
The sleep schedule is the most important – setting a consistent bedtime and wake-up time and sticking to it. This is the solution for chronic insomnia triggered by circadian rhythm disorder – when your work schedule is consistent.
If you’re on night shift, but it’s consistent, you can still set your sleep schedule, but it’s important to use bright light and darkness to set the cues for your internal clock. This can be done using bright light therapy, light-blocking drapes for day sleeping, and following a good sleep hygiene program.
If you’re on an irregular schedule, it gets a bit more difficult. If your symptoms are severe, and your job requires alertness, you might consider a change. If that’s not in the picture at all for you at this time, you can try bright light therapy for wakefulness and light-blocking drapes for sleeping.
Don’t forget, stress relaxation techniques can help in any situation.
Sometimes you just need to feel more in control of your life in order to sleep better.
Delayed Sleep Phase Syndrome
There’s another circadian rhythm disorder known as delayed sleep phase syndrome (DSPS) in which your internal clock is set for a 25-hour day rather than the 24-hour day.
If you have this problem, you may find yourself going to bed later and later at night and having a lot of trouble waking up on time in the morning.
Resolving this type of insomnia requires patience – because it will take a while to adjust to a new earlier, more consistent schedule – and a certain amount of will power because you won’t want to go to bed when you need to. This often affects young people, a major cause of teenage insomnia at a vulnerable time of life.
With determination, a few powerful environmental cues, such as bright light therapy and a darkened room, plus good sleep hygiene, you can get the rest you need.
If you try your best and your circadian rhythm disorders persist, seeking medical treatment for insomnia may be the next step.