The Circadian Rhythm and Its Connection to Mental Health - Sleep and Mood Disorders.
By Ana Brown, B.A. Psychology, Mental Health Content Writer & Reviewed by Dr. Pascale Piron, Psy.D., M.A., LCPC
July 4, 2025
How a disrupted sleep-wake cycle can affect your mood. What is the circadian rhythm and why it matters for our mental health.
I often felt invincible as a teenager. My body was like a brand-new car ready to drive for hours and hours with no breaks. That also meant sleepless nights. Staying up late and waking up late was part of my routine, and I felt fine. As I grew older, my sleeping patterns changed for the worse and I realized it also changed my mental wellness. The less I slept the moodier I became. I was trapped in an unhealthy sleep-wake cycle for years that was costing my ability to function at full capacity during the day. My circadian rhythm became off with inconsistent sleep schedules and work pressures leaving me constantly fatigued and mentally drained. My internal clock was no longer working properly.
In simple words our circadian rhythm is the internal clock in our brain that regulates cycles of being awake and falling asleep over a period of 24 hours and it's mostly affected by light exposure but can also be impacted by other factors such as stress. It influences several important bodily functions. The National Library of Medicine lists the following organ systems that may be affected by any disruptions in our circadian rhythm:
Immune
Reproductive
Gastrointestinal
skeletal
Endocrine
Renal
Cardiovascular
In addition, Harvard Health adds mood disorders such as anxiety, depression, bipolar disorder, and seasonal disorder as possible side effects of an irregular circadian rhythm.
HOW A DISRUPTED SLEEP-WAKE CYCLE CAN AFFECT YOUR MOOD
An article by The Lancet Psychiatry Medical Journal confirms that "Circadian disruption is reliably associated with various adverse mental health and well-being outcomes, including major depressive disorder and bipolar disorder. Lower relative amplitude might be linked to increased susceptibility to mood disorders."
A disrupted sleep-wake cycle can create a myriad of symptoms and signs that your body has been affected by sleep disturbances:
Irritability
Memory Fog
Anxiety
Depression
Difficulty concentrating
Difficulty making decisions
Insomnia
Impulsive behaviors
HOW SLEEP DEPRIVATION, JET LAG, AND SHIFT WORK AFFECT YOUR CIRCADIAN RHYTHM?
Let's look at how these different situations can affect our sleeping patterns:
Sleep deprivation: It often results in less restorative sleep which makes it harder for our body to feel rested in the morning. Waking up feeling tired will affect the rest of your day. It also affects the production of hormones such as melatonin, the hormone that makes you feel sleepy, which in turn, confuses our internal clock leading to more changes in our sleeping patterns. It can cause sensitivity to light, more alertness when you should be falling asleep, it increases fatigue and lack of concentration and a heightened risk for injuries.
Jet Lag: Traveling across different time zones can create this temporary sleeping disorder until your body adjusts. Some of the symptoms include fatigue, trouble staying alert, digestive issues and insomnia, mood changes and a general feeling of not being well.
Shift Work: Certain jobs demand you work night shifts, split shifts or rotating shifts. It often disturbs your body's ability to discern day and night. Some work environments limit people to light exposure confusing our internal clock and causing significant disruptions in our circadian rhythm. This also affects the production of melatonin. UCLA Health studies show that "even if you do get enough sleep, the reversal of light and dark that shift workers experience can affect your production of melatonin, the hormone that helps you fall asleep more deeply. When cells don't get repaired during deep sleep, DNA damage accumulates."
As we can see through scientific research, our internal clock is fundamental for our overall not only physical but also mental health. What are the steps we can take to improve our wake-sleep patterns? Healthy habits, happier life.
BEST MORNING AND EVENING ROUTINES TO SUPPORT MENTAL HEALTH
I'm a firm believer in the power of routine if you want to achieve success and live a healthier lifestyle. I like to have some predictability and control of how I spend my precious time in this very unpredictable world we live in. It decreases anxiety and it creates space for an organized schedule. Below are some routines to establish that can support your circadian rhythm and improve your mental health.
Morning routines:
Wake up early and meditate. The news and social media can wait. Start your day with positive affirmations which can empower and prepare you for whatever your day brings.
Welcome sunlight: Fundamental for the circadian rhythm is our exposure to sunlight in the morning. It keeps our internal clock differentiating day and night and setting our bodily functions to activate and function in harmony.
Eat balanced meals at a regular schedule: It regulates our appetite and digestive patterns. It helps create a more predictable rhythm. Digestive issues can prevent us from getting to bed at reasonable time and stay asleep.
Exercise: There is an indisputable truth that exercise does improve sleeping patterns. Whether you prefer your working out routine to be done in the morning or nights (night work outs may interfere with your sleeping patterns due to the boost of energy in the evening), consistency is key to shift your circadian rhythm to a healthier pattern.
Evening routines:
Below are a set of activities you can do one to two hours prior to bedtime.
Put away your electronic devices: Even better if you can store them outside your bedroom to resist the temptation to check social media at 3:00am. The blue light coming from the screen impacts the production of melatonin disrupting your sleep-wake cycle.
Set your alarm: Setting your alarm to wake up at the same time every day creates consistency for your circadian rhythm and helps you have a better night of sleep.
Install light dimmer switches: It gives you control of how much light is in the bedroom at night. The darker the room the better the quality of your sleep.
Stop consuming alcohol and caffeine 3 hours before bedtime. This will avoid digestive issues and an unwanted rush of energy.
Take a warm bath: According to Healthline a research at The University of Texas at Austin concluded that "bathing one to two hours before bed in water at 104 to 109F (40 to 43C) did the trick to help people get the best quality sleep, and researches also concluded that this routine helps people fall asleep an average of 10 minutes quicker than normal."
Read a book or watch a light tv show: Social media and the news bombard our brain with unnecessary and overwhelming amount of information which can create a shift from relaxation to agitation before bedtime. Enjoy falling asleep naturally and allowing your body to get a more restorative sleep.
If you are experiencing a mental health crisis, always seek professional help immediately. Please call 911 or the suicide prevention lifeline at 988 or go to your local emergency room for immediate medical attention.
TRACK YOUR SLEEP FOR A CALMER MIND
Although I miss my teenage years when my body didn't seem to need much rest, I now embrace the importance of rest and relaxation. I guess wisdom does come with age. Nature is perfect and it's no accident that the night falls after a hard day at work facing a world full of challenges. This break gives us a chance to reset our brain, and close any mental files left open during the day. Restful nights establish a harmonious circadian rhythm by replenishing energy, sharpening our focus and improving our mood and mental health. We renew our strength and resilience to continue braving through life.
It's ok to disconnect to reconnect. Nite Nite!
Be kind. Be brave. Be well.
Always with love,
HELPFUL LINKS
American Psychological Association
Anxiety and Depression Association
National Suicide Prevention Lifeline - Call or text 988
Crisis Text Line - text HOME to 741741
DISCLAIMER
The content of these webpages and blogs and information provided is for general informational and educational purposes only and is not intended as a substitute for professional medical or mental health advice, diagnosis, or treatment. Always seek the advice of your qualified health provider with any questions you may have regarding a medical or mental health condition. Seek professional help immediately if you are experiencing a mental health crisis or any other medical condition.