Do you often find yourself working late at night for your exams or work? Although you find yourself working more efficiently late at nights, if taken to extreme, this can have negative impact on your health leaving you feeling exhausted, confused and possibly ill. This is because most living individuals have a biological clock that keeps your body in sync with the cycles of day and night. That is your circadian rhythm. By understanding your circadian rhythm, you can you improve your sleep and possibly better mental health.

What is Circadian Rhythm?

Many of the body’s systems are adjusted to the appearance and disappearance of natural light. Anyone living has a circadian rhythm. If your circadian rhythm gets disturbed, it will impact your eating and sleeping pattern. The main regulator of circadian rhythm can be found in the hypothalamus. The hypothalamus is responsible for connecting your nervous system to your endocrine system. Nerve cells in hypothalamus are connected to the optic nerve that allows the nerve cells to react to light and dark.

How does light impact your body?

When the nerve cells detect light from the optic nerve in the morning, they send signal to several cardiovascular systems in your body.

It increases your:

  • Body temperature
  • Heart rate
  • Blood pressure

It decreases:

  • The release of hormones especially melatonin.

How does the dark impact your circadian rhythm?

When the light disappears, the nerve cells in the hypothalamus send signals to the other systems in your body.

It decreases your:

  • Body temperature
  • Heart rate

It increases your:

  • Sleep inducing hormones such as melatonin

The different stages of sleep and how it impacts your mental health

There are four stages of sleep; your sleep becomes increasingly deeper.

Stage 2 and stage 3 of sleep:

During stage 2 and 3 of sleep, your body temperature will drop, muscles will relax, and heart rate and breath will decrease. The deepest stage also promotes physiological changes that are beneficial for your immune system.

REM Sleep:

Dreams occur during REM or rapid eye movement sleep. Moreover, your heart rate, blood pressure and body temperature begin to rise and are reported to be at the same levels when you are awake. Additionally, REM improves learning and memory in complicated ways, which contributes in better mental health.

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How sleep impacts your mental health

Your sleeping pattern and your mental health are closely associated. Importantly, you are more likely to suffer from mental health problems when you are sleep deprived. The brain and its relationship tosleepand mental health are still not fully understood by researchers and other professionals. Nevertheless, neuroscience suggests that a good night of sleep promotes better mental health and emotional strength, while poor sleep results to negative thinking and emotional vulnerability.


Research indicates that our circadian rhythm has a crucial role in regulating our mood. The circadian gene in the hypothalamus is responsible for reacting to light and dark. It isalso expressed in other area of the brain. Notably, the amygdala is a region of the brain that is associated with emotion regulation. Evidence for this comes from a study with depressed patients that showed altered circadian rhythms and sleep disturbances. Interestingly, chronotherapy is a potential way to reset your circadian rhythm. This form of therapy includes bright light exposure, sleep deprivation and social rhythm therapies, that might be helpful in seasonal and non-seasonal depression.

Cognitive functions

Research shows that a decline in attention is observed in participants suffering from sleep deprivation. As the circadian gene is expressed in various regions of the brain, the disruption of the circadian rhythm may also have an impact on the function of frontal lobe. The frontal lobe is notably involved in the brain’s cognitive performance such as memory, alertness and concentration. In fact, total sleep deprivation impairs attention and working memory, in addition to decision-making and long-term memory, whilst part sleep deprivation impacts attention.

What can you do to improve sleep?

  • Limit caffeine and alcohol – Both alcohol and caffeine can inhibit sleep as it increases your heart rate and makes you alert.
  • Control the light and temperature of the room – There is a greater chance of you falling asleep in a darker and cooler environment.
  • Limit screen time – The light from your phone, computer and TV radiate light that keeps your brain alert and awake. Try to reduce your screen time at least an hour before bed. Put on an alarm that will remind you to the reduce screen time.

How can we support you?

Our experienced team of therapists will explore your sleep pattern, and understand how your depression may be linked to your sleep quality and duration. They will guide you through interventions that can help you improve your sleep.