Sleep is one of the most - maybe even the most - important factors contributing to human health, maybe even more so than diet and exercise, and this is particularly true during childhood and adolescence.
Sleep plays a pivotal role in cognitive functioning, including learning, problem-solving, and the consolidation of memories. Insufficient sleep actually impairs the brain’s ability to form new memories, and can make it difficult for children to retain the information they’ve learned during the day in school. Inadequate sleep also impairs a child’s ability to focus and concentrate, and they may be sleepy and inattentive. Unsurprisingly, this has an impact on academic achievement, and numerous studies have shown that students who get sufficient sleep generally outperform those children that do not.
Sleep also has a significant impact on regulating emotions and behaviour, especially in children and teenagers. If children do not get enough sleep, they are more likely to be irritable, quick to anger, and susceptible to mood disorders such as depression and anxiety. They are also prone to impulsive and risky behaviour and poor decision-making. Puberty is a difficult enough time anyway - for everyone involved! Lack of sleep makes the situation even worse.
This may be a little surprising, but sleep deprivation actually has a huge impact on physical health. Inadequate sleep can weaken the immune system, making children more susceptible to illness. There is also evidence that sleep deprivation disrupts the regulation of glucose and also a person’s metabolism, leading to weight gain and an increased risk of developing type 2 diabetes. In later life, it appears there is a link between sleep deprivation and Alzheimer’s - a stark reminder that everyone, not just young people, requires adequate sleep (8 hours a night is optimal).
Teenagers are not ‘lazy’ for sleeping in, nor ‘difficult’ for refusing to go to bed. A teenager needs more sleep than an adult, and their circadian rhythm starts and ends naturally later, which means their natural sleep pattern is likely 12 midnight til 10am. If you try to send them to bed at 10pm there’s a good chance they will be physically unable to fall asleep! It also shows that a school start time of 8:30am is hardly ideal.
We are unlikely to be able to push back school start times, but there are simple things that we can all do to improve our sleep:
First, download a blue light filter on your devices for evening use. Blue light affects our circadian rhythm, impairing melatonin production and making it harder to fall asleep. If possible, have an hour technology-free before bed (although I know this won’t be popular). Use dim, warm yellow light in the evenings. Read before bed, and have a relaxing bath (which will bring your body temperature down; our core temperature needs to drop in order for us to fall asleep). Make sure your bedroom isn’t warmer than 18 degrees. Avoid coffee after 12pm - in fact, children and teenagers should try to avoid caffeine altogether.
In conclusion, there is compelling evidence that sleep deprivation has a serious and long-lasting effect on children and teenagers. Inadequate sleep impairs cognitive function and the regulation of emotions, and it affects physical and mental health and academic performance. It is therefore crucial that parents, educators and young people themselves prioritise and promote good sleep hygiene.