Have you ever noticed that some people are very sleepy in the morning and can only “function” better in the afternoon or evening and that others are much more productive when they wake up early? These patterns are part of the so-called biological clock, also known as the circadian rhythm, and vary from person to person.
What research published in 2021 in Nature revealed is that going against this individual mechanism can lead to depression or anxiety. This may have to do with genetic factors as well as environmental, sociocultural factors and habits.
The study mapped the gene of more than 80,000 people and found that those who were more misaligned with their natural body rhythm were more likely to report lower well-being and more symptoms of depression and anxiety.
Furthermore, they found evidence that if a person’s genes programmed them to wake up early, it could help protect them from depression, possibly because they would be more in line with society’s expectations — which would lead to less stress —, as well as your natural circadian rhythm.
A 2018 study published in the journal never Psychiatry, showed that poor quality sleep can cause an increase in the connection between brain regions linked to short-term memory and negative emotions with an area related to “I” awareness. This would be behind the relationship between sleep and depression.
“We tend to fight with our cycle (for various reasons) and that’s when we can have problems that seem to have no apparent causes, such as changes in sleep, weight, anxiety, stress, depression”, explains psychiatrist Fabiana. Arruda, from the Âme Institute of Psychology and Health, in Goiânia.
What is the biological clock or circadian rhythm
It’s an internal clock that we all have and that keeps track of time. It directs our body’s daily rhythm, controlling physiological, psychological processes such as body temperature, hunger and sleep-wake patterns. This clock reflects changes in mental and physical states that undergo regular changes within a 24-hour period.
The circadian rhythm is controlled by an area of the brain that is influenced by light, which enters the eye and stimulates cells at the back of the eye (retina). It, in turn, sends nerve impulses that stimulate the production of melatonin, a hormone that promotes sleep, throughout the day. But in addition to light, noise, odors, social life also play a role in the functioning of the body’s clock.
Also, people have what is known as a chronotype. Early risers, or morning-type chronotypes, have an internal clock that prompts them to go to sleep and wake up earlier, while night-time type usually have trouble going to bed early and prefer to sleep and wake up later. But there are also intermediaries, in the middle of this path.
According to psychiatrist Marcel Fulvio Padula Lamas, coordinator of psychiatry at Hospital Albert Sabin in SP, people who sleep earlier and wake up earlier are less likely to have depressive symptoms, mental health diagnoses and need medication.
But that doesn’t mean that those who are more afternoon (tend to sleep later and wake up later) necessarily need to change this behavior. Inducing sleep in these cases, for example, even if properly, can lead to waking up a lot at night and increase irritability, impulsivity, give a feeling of weakness, concentration, worsen cognitive, among other consequences.
How to change the biological clock
First of all is to understand what your circadian cycle is. That’s because knowing this “helps you make the most of the potential you have”, according to Arruda. “If you are daytime and manage to maintain this cycle regularly, you will be able to better organize your day and optimize your activities according to your functioning”, points out the doctor.
You can evaluate your behaviors to try to find out what your cycle is or you can take the test that evaluates the chronotype, available on the Sleep Institute website. From there, it is possible to know yourself and work according to your biological clock. Seeing a specialist to help with this process, such as a psychiatrist, can be helpful.
Remembering that chronotypes can be adapted according to routine and also tend to change according to age, but genetics largely determines them — and behavior reinforces them. Hence the importance of the person being more concerned with getting enough sleep to meet their individual needs.
This means, for example, giving cues to signal your body that it’s time to sleep or wake up. Below are some tips:
- Waking up at the same time every day;
- Exposing yourself to light right after waking up;
- Avoid being in the dark during the day;
- Use more yellow lights at night;
- Have a balanced diet;
- Avoid large meals at night;
- Exercise regularly;
- Limit naps, especially later in the day;
- Avoid caffeine, alcohol and tobacco, especially at night;
- Turn off screens at least 1 hour before bed.
Sources: Fabiana Arrudapsychiatrist at the Âme Institute of Psychology and Health, in Goiânia; Marcel Fulvio Padula Lamaspsychiatrist coordinator of psychiatry at Hospital Albert Sabin in SP; Slanowa Cruzpsychiatrist at Itagara Memorial Clínica da Dor, in Salvador.