4 min readJun 15, 2024 08:00 AM IST
First published on: Jun 14, 2024 at 01:49 PM IST
If you go to sleep after 1 am, you could be at a higher risk of developing mental health issues, regardless of your lifestyle and whether you are a morning person or a night owl. So says a new study by Imperial College, London, reinforcing that sleep is not a luxury but a necessity for our brain to function optimally.
The study finds that people who went to bed before 1 am had healthy mental profiles. But surprisingly, people who keep late hours and are comfortable staying awake till 1 am and beyond, experienced the poorest mental health. The research analysed data of 73,888 people from the UK Biobank, who slept seven hours daily. “Most of my patients have trouble sleeping beyond six hours,” says Dr Shaunak Ajinkya, consultant psychiatrist, Kokilaben Dhirubhai Ambani Hospital, Mumbai, So let’s understand what really happens.
How do irregular habits disrupt circadian rhythms?
Our bodies operate on a natural 24-hour cycle known as the circadian rhythm, which is regulated by the brain in sync with the natural environment. However, consistently going to bed after midnight leads to a mismatch between our body’s internal clock and the external world. This mismatch not only makes it difficult to fall asleep, stay asleep, or have a refreshing sleep but also causes chronic sleep deprivation. This triggers mental disorders like anxiety and depression.
How late hours impact sleep quality?
Late bedtimes shorten sleep periods if you need to wake up early for work. They also suppress the production of the sleep hormone melatonin, which is released by the brain’s pineal gland that regulates sleep-wake cycles. Sleep is a complex process with various stages, each playing a crucial role in our mental and emotional well-being. Deep sleep, for instance, repairs and rebuilds the body, while REM (rapid eye movement phase when dreams occur) sleep strengthens our memories and helps regulate our emotions. However, a late bedtime significantly curtails the time spent in these vital healing stages.
What’s the science of sleep vs mental health?
The brain clears toxins and metabolic waste products during sleep, particularly deep sleep, and prepares for the demands of the following day. However, lack of adequate sleep means these substances cannot be filtered out. As they keep piling up, they lead to cognitive impairment, such as attention, concentration and decision-making difficulties. It can also hinder learning and memory as the brain becomes less efficient at processing and retaining new information. Sleep is essential for neuroplasticity, which is the brain’s ability to reorganise itself by forming new neural connections. Insufficient sleep can hinder this process, affecting learning and adaptation. Poor sleep weakens the immune system, making the brain susceptible to inflammation and infections which can further impair cognitive functions.
Insufficient sleep triggers the release of stress hormones and makes the person more prone to anxiety. Over time, this can contribute to the development of generalised anxiety disorder, panic disorder and other anxiety-related conditions. All of this leads to increased irritability, mood swings and a lower threshold for coping with stress and challenges.
Gradually, a bidirectional relationship sets in. Poor sleep contributes to the onset and persistence of depression, while depression further disrupts sleep, creating a vicious cycle.
How is sleep related to brain chemicals?
1) Adenosine builds up in the brain during wakefulness and promotes sleepiness. It is then cleared away during sleep.
2) GABA (Gamma-Aminobutyric Acid): It reduces neuronal activity in the brain and promotes relaxation and sleep.
3) Orexin (Hypocretin): It regulates arousal and wakefulness. Low levels of orexin are characterised by excessive daytime sleepiness.
4) Acetylcholine is prominent during REM sleep and contributes to REM-sleep-related functions.
Sleep is a complex process with various stages, each playing a crucial role in our mental and emotional well-being. (Pexels) 
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