Mind Matters Chapter 8: Sleep

4 min read

This series of articles has been adapted from [Mind Matters in Children] by Dr Kenneth Lyen. It delves into both the normal as well as the abnormal functioning of a child’s mind, and gives practical advice on how to manage children’s mental health and problems like ADHD, dyslexia, autism and depression.


There is a debate being discussed in the news and on social media concerning how much sleep children need. In many Asian countries, children wake up at 6 am in order to reach school by 7:30 am. They are half-asleep during lessons, unable to imbibe much information. This is compounded by the fact that many schools pile on a ton of homework, so children stay up late to complete their assignments. How much sleep do we need? What happens when we are robbed of our beauty sleep? 

The Sleep Cycle

There is a sleep clock embedded in the brain behind the eyes, known as suprachiasmatic nucleus located in the anterior hypothalamus right next to the branch point of the optic nerves. This clock is also known as the circadian pacemaker or the biological master clock. 

The suprachiasmatic nucleus regulates the secretion of the hormone melatonin from the pineal gland, and this hormone helps one sleep. The precise neurological mechanism is still not established. However, the suprachiasmatic nucleus is also sensitive to light, which can block melatonin production and can affect our sleep cycle. 

Melatonin is available as a tablet for those who are jetlagged, people who have daily work schedule changes (shift-workers), and people who have difficulty establishing a day and night cycle. It also helps children who have problems with sleeping, and it enables them to sleep longer. The current recommendation is that melatonin should not be for extended use, because there may be potential long-term side effects.

How Many Hours of Sleep Does One Need?

Babies need 14 to 17 hours of sleep each day, but this gradually decreases as one gets older. For infants and preschoolers, they may divide their total daily sleep into smaller nap times. Toddlers need 11-14 hours sleep each day, and many parents try to get their 3 years and older children to go to bed around 6pm to 7:30pm.

School Hours

A 2021 survey showed that during the Covid-19 pandemic, Singapore school children only sleep 6.8 hours per day, which is less than 7 hours of sleep in 2020. This is far short of the 8 to 10 hours recommended for secondary school children. During the Covid-19 pandemic they may even stay up later watching TV, playing computer games or become addicted to social media, and many do not go to bed until past midnight.

During the more severe lockdown phase of the Covid-19 pandemic, there have been other effects on school children, including remaining at home for longer periods, watching some classroom teaching online, deprived of face-to-face social interaction with their peers, and cutting down on sports. The deleterious effects of Covid-19 include the marked rise in depression and suicide rates (22). All these psychological consequences can affect the duration and quality of sleep.

How to Get a Good Night’s Sleep?

No doubt, parents have different policies for their child and for themselves to optimise their sleep. For young children, we advise setting a regular bedtime routine for them to follow. After dinner, perhaps families can engage in some activities that their child enjoys. Limit watching TV or playing handphone or computer games. Avoid excessively strenuous exercises before sleep. When it is time for sleep, darken the bedroom and keep it cool with minimum of distracting noises. Just before going to bed, it may be a good idea for the child to visit the bathroom.


We spend one third of our lives sleeping. We are slowly beginning to understand its value. Sleep is one of the most impactful undertaking we can accomplish every day to reset the health of our brain and body. It can help improve our memory, our creativity, reduce obesity, hypertension, diabetes and other medical problems. Ultimately, it will help us live longer and more healthily.

Written by Dr Kenneth Lyen
Illustrated by Jasreel Tan


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