Going to bed after 1am could increase your risk of developing mental health problems, regardless of your lifestyle or whether you’re a morning or night owl. This is according to a new study from Imperial College London, confirming that sleep is not a luxury, but a necessity for the brain to function optimally.
A study found that people who went to bed before 1 am had healthier mental health. But surprisingly, those who stayed up late and were okay with staying up past 1 am had the worst mental health. The study analysed data from 73,888 people from UK Biobank. They slept seven hours daily. “Most of my patients struggle to sleep more than six hours,” says Dr Shaunak Ajinkha, consultant psychiatrist at Kokilaben Dhirubhai Ambani Hospital, Mumbai. So let’s understand what’s actually going on.
How do irregular habits disrupt circadian rhythms?
Our bodies operate on a natural 24-hour cycle called the circadian rhythm, which is regulated by the brain in sync with the natural environment. However, regularly going to bed after midnight creates a mismatch between your body clock and the outside world. This mismatch not only makes it harder to fall asleep, sleep less deeply and refreshed, but also leads to chronic sleep deprivation, which can trigger mental disorders such as anxiety and depression.
How much does staying up late affect the quality of your sleep?
If you have to get up early for work, a later bedtime shortens your sleep time. It also suppresses the production of melatonin, the sleep hormone secreted by the pineal gland in the brain that regulates your sleep-wake cycle. Sleep is a complex process with different stages, each of which plays an important role in your mental and emotional health. For example, deep sleep repairs and rebuilds your body, while REM sleep (the rapid eye movement stage in which you dream) strengthens your memory and helps regulate your emotions. But a later bedtime drastically reduces the time you spend in these important healing stages.
What’s the science behind sleep and mental health?
During sleep, especially deep sleep, the brain clears out toxins and metabolic waste products to prepare for the demands of the next day. However, when we don’t get enough sleep, these substances cannot be filtered out. If they continue to build up, they lead to cognitive impairments such as difficulties with attention, concentration and decision-making. They can also impede learning and memory as the brain processes and retains new information less efficiently. Sleep is essential for neuroplasticity, the brain’s ability to reorganize itself by forming new neural connections. Lack of sleep impedes this process, affecting learning and adaptation. Lack of sleep weakens the immune system and makes the brain more susceptible to inflammation and infection, which can further impair cognitive function.
Lack of sleep increases the production of stress hormones and makes you more anxious. Over time, this can lead to the development of generalized anxiety disorder, panic disorder, and other anxiety-related disorders, all of which lead to increased irritability, mood swings, and a decreased ability to cope with stress and challenges.
Gradually, a two-way relationship develops: poor sleep contributes to the onset and maintenance of depression, and depression further disrupts sleep, creating a vicious cycle.
How does sleep relate to brain chemistry?
1) Adenosine accumulates in the brain during wakefulness, promotes sleepiness, and is then removed during sleep.
2) GABA (Gamma Aminobutyric Acid): Inhibits neural activity in the brain, promoting relaxation and sleep.
3) Orexin (Hypocretin): Regulates wakefulness and alertness. Low levels of orexin lead to increased daytime sleepiness.
4) Acetylcholine is prominent during REM sleep and contributes to REM sleep-related functions.
