Internal Clock & Sleep Health | Circadian Rhythm Uncovered

Circadian rhythm disruptions or upsetting of your sleep-wake cycle can interfere with daily life and make you feel sleepy, tired, and depressed. Most such interruptions in your sleep are short-lived and caused by travel (jet lag) and job timings (night shift).

Humanity remains rooted in nature, even as artificial intelligence takes giant leaps toward the singularity.

Singularity is a point in time when robots take over the control of technological growth from humans. We continue to rely on Earth’s freshwater and rich soil, as well as its daily rotation around the Sun. That last one can dramatically impact the way we feel and function in our daily lives.

The mind and body are complex and dynamic systems. One of its unusual phenomena is the syncing of numerous brain regions and nerve cells with the brightness and darkness of the day. Due to this, our brains evolved an internal clock that closely aligns with dawn and dusk.

Called Circadian rhythm, our body’s internal clock syncs to the Earth’s rotation and regulates our daily sleep-wake cycle. The word “circadian” comes from Latin circa, meaning “around or approximately or nearly,” and diem, meaning “a day.”


The circadian system runs in the background as we go about our day, typically resetting in 24-hour increments, mimicking the length of the Earth’s rotation. It can make us feel happier at certain times of the day.

Our circadian rhythm spans well beyond single days. It is also fine-tuned to detect seasonal changes in the duration of light. Seasonal Affective Disorder (SAD) is a condition that causes one to feel depressed during the winter months when there is less sunlight. SAD can be helped by light-boxes.

Let’s take a closer look at the circadian rhythm and see the various ways its disruption might harm our mental health.

Defining Circadian Rhythm In A Digital World

Circadian rhythm is the natural cycle of physical, mental, and behavioral changes that the body undergoes in a 24-hour cycle. It is controlled by a group of 2,000 neurons inside the hypothalamus of the brain, which composes the suprachiasmatic nucleus (SCN).

For much of history, humans relied on the Sun to know when to sleep, when to wake up, and when to migrate to warmer climes. But modern life, full of artificial light and life’s other challenges, has made a mess of our internal clocks. Light and darkness are no longer what they once were.

This ambiguity disrupted our natural circadian rhythms, affecting our sleep and health in the long run. Now, with our internal clock gone out of sync, many of us suffer from symptoms like difficulty in sleeping, irritability, and poor mental sharpness.

“For every day you are in a different timezone, your suprachiasmatic nucleus can only readjust by about one hour.” ― Matthew Walker

Circadian Rhythm Disruption, Sleep Disturbance, And Wellbeing

Sleep links directly to happiness and mental well-being. A study on final-year university students found there is a strong association between sleep quality and psychological well-being. The researchers discovered that each 10% increase in poor sleep quality resulted in a 26% rise in mental health problems.

On the flip side, having a full night’s sleep on a regular basis has been linked to a slew of health benefits. Good sleep habits can boost our happiness, mental resilience, and physical health while also lowering our overall stress levels.

Generally speaking, circadian rhythms are natural processes that respond to light levels, affecting most forms of life on Earth. In the natural world, circadian rhythms can be seen when birds “fly South” for the winter, and among animals that hibernate, including bears.

For humans, the 24-hour circadian rhythm cycle depends on the amount of light present at any given time. It controls various bodily functions and processes, from eating habits to body temperature, metabolism, and sleep patterns.

Along with light and darkness, several other external factors may influence your natural circadian rhythm. People of different ages often experience circadian rhythm patterns in different ways, and your lifestyle habits can also play a role.

For instance, if you work a job during atypical hours, like a graveyard or late-night shift, your sleep-and-wake cycles will differ from those of a 9-to-5 employee. Those who are physically healthy and get plenty of exercise sleep better than those who have a sedentary lifestyle.

Physical pain, whether from an injury or chronic condition, is another factor that can affect your sleep patterns and circadian rhythm.

Circadian Rhythm: Disruptions & Disorders

“We have made clocks that are perfectly in sync with the industrial machinery and the Information Age and perfectly out of sync with nature and our circadian rhythm.” ― Khang Kijarro Nguyen

When your circadian rhythm gets disrupted, even the best sleep hacks from scientists will only get you so far. It can be difficult to take a nap and reset your internal clock, if you have poor daily sleep habits, or drink copious amounts of caffeine, for instance. Medical professionals recommend that you abstain from caffeinated beverages and other stimulants at least 4 hours before your preferred bedtime.

In recent years, scientists have identified many “circadian rhythm disorders,” and these can impact your mental health if not properly addressed.

But if you have worked hard to fix the irregularities in your circadian rhythm, yet still feel depressed and tired, there may be other factors at play. Please consult your mental health counselor.

Some circadian rhythm disorders are even genetic in origin, altering your hormones in a way that directly impacts periods of sleep and wakefulness. One such disorder, Smith-Magenis syndrome affects 1 in about 25,000 people worldwide, and disrupted sleep patterns are its primary symptom. For those living with Smith-Magenis syndrome, the body has trouble regulating the hormone melatonin, which helps control the body’s sleep-wake cycle.

Melatonin is produced in the pineal gland, and some people with sleep disorders have found success with melatonin supplements, which are widely available over the counter. Yet an over-reliance on sleep aids, even natural-based ones like melatonin, can further alter your circadian rhythm. And you may find yourself unable to fall asleep without some outside help.

Unfortunately, sleep aids are common throughout the digitized world, where artificial light keeps our internal clocks guessing throughout the year.

Mental Health and Your Internal Clock

But artificial lights and sleep aids are just the beginning when it comes to circadian rhythm cycle disruptions. In the modern world, our internal clock is often thrown out of whack.

When we fly for business or vacation, for example, we end up in another time zone altogether and typically need time to adjust upon arrival. And for some travelers, crossing the international dateline can be a surreal experience, akin to time travel in some respects.

One prime example of how our natural, internal rhythm can be disturbed is the practice of daylight saving. First practiced in Germany during World War I, daylight saving time involves the adjustment of clocks twice per year to achieve longer evening daylight during the summer months.

Clocks are set forward during the spring, and back to normal sometime during the fall. Interestingly, among the countries that do have daylight saving time, there is no international standard on specific beginning and end dates, which can vary significantly by location.

Daylight Saving Time And Circadian Rhythm Disruption

Today, daylight saving time is practiced in 70 countries around the world. Yet, many countries resist the practice. Many Eurasian nations, including India, Belarus, China, Russia, and Japan, do not adjust their national clocks at all during the year.

Nations that sit close to the equator have little need for daylight saving time, as there is little variation in the length of day throughout the year.

There are also potential downsides to daylight saving time, and many government leaders around the world aren’t willing to take the risk. The transition immediately following the time change, whether forward or back, is particularly taxing on both one’s physical and mental health. Residents of nations that practice daylight savings often report mood and sleep disruptions following a time change.

Anxiety, depression, and suicidal thoughts are also unfortunately common during the daylight saving adjustment phase. For some, the experience is particularly jarring, and it can take several weeks for one’s internal clock to get back to normal. Additionally, the potential sleep disruptions associated with the transition in and out of daylight saving can have lasting effects, even after one has fully adjusted.

Quitting Bad Habits To Improve Circadian Rhythm & Wellbeing

While many of us can’t escape from potentially rough experiences like daylight saving time, you can make changes to improve personal sleep habits and overall well-being.

Start by taking an honest look at your daily habits, and identify any problem areas that can be easily addressed. If you have trouble falling asleep, you may need to alter your eating habits or reduce screen time during the nighttime hours.

And make no mistake: The screens in question, especially cell phones, can directly contribute to poor sleep quality, and the continued disruption of circadian rhythm cycles.

Researchers have found a direct link between mobile phone use before bed and poor sleep habits. Young people, in particular, are at a high risk of developing long-term insomnia due to excessive cell phone use and can even become addicted to their devices.

Other bad habits that can affect our sleep-wake cycle include smoking, binge drinking, and a lack of physical exercise. We’ve long known that exercise can help boost your mood, offering a natural alternative to antidepressants and similar pharmaceuticals. Regular exercise, at least five times a week, has proven mental health benefits for trauma victims and those living with various mental health disorders, including ADHD and depression.

For people from all walks of life, moving the body has the benefit of addressing the core issue of a disrupted circadian rhythm. Moving the body tells it that it is awake time. It gets your circadian rhythm back on track.

Final Words

When we’re feeling depressed or anxious, every small setback may feel akin to an insurmountable challenge. Extreme tiredness can compound these negative feelings, and an off-kilter circadian rhythm may be at the heart of the problem. By listening to your body’s natural cycles and getting the proper amount of sleep every night, you may experience a clearer mind and a better outlook on life.

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Author Bio: Adrian Johansen is a freelance writer who writes to both teach and learn. She draws from her experiences in business, health, and education to offer others insight and points to consider. You can find more of her writing on Contently.

Edited and rewritten by Sandip Roy.

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When it comes to mental well-being, you don't have to do it alone. Going to therapy to feel better is a positive choice. Therapists can help you work through your trauma triggers and emotional patterns.