«Lack of sleep during puberty can make you ill»
Mrs Tarokh, how does sleep change with the onset of puberty?
In the adolescent phase between the ages of around 11 and 25, the biological day-night rhythm shifts. As a result, teenagers fall asleep later and later in the evening.
What order of magnitude are we talking about here?
The natural bedtime shifts by around two hours between the onset of puberty and the age of 17. Around the 20th birthday, this trend towards later bedtimes gradually reverses, but is not fully completed until a few years later.
Why is that?
The shift in the internal clock and the associated later bedtime during puberty is a typical biological phenomenon that we also observe in animals such as adolescent monkeys or mice. So it's not the teenagers' fault.
What happens in the body?
Science is still unable to explain exactly what happens at cellular level. However, we assume that the increased release of male and female sex hormones plays a role in this phase.
We also assume that a greater tolerance for sleep pressure develops. With the duration of wakefulness, tiredness builds up comparatively slowly in adolescents. This means that, compared to younger children, adolescents can easily stay awake late in the evening. Those who stay awake longer in the evening are also more exposed to artificial light sources. Light, in turn, slows down the production of melatonin. In fact, a delayed release of the sleep hormone can be measured during adolescence. This is another reason why teenagers become tired later.
Are the remodelling processes in the brain also involved?
This is our assumption. During brain maturation in puberty, those contact points between nerve cells, i.e. synapses that are not used very often, are broken down, while other, frequently used connections between neurons and between different brain regions are strengthened. Overall, many synapses are lost during adolescence, which greatly increases the plasticity and efficiency of the brain. This is a completely natural and healthy process that makes new connections in the brain possible in the first place, but also has an effect on sleep.
Using electronic media in bed at night is certainly not favourable.
Can you explain this in more detail?
Based on current knowledge, synapses need a lot of deep sleep to recover from the day's activities. Because the number of synapses decreases significantly during puberty, the proportion of deep sleep phases also decreases. When we measure brain waves during sleep using an EEG, we can observe a reduction in deep sleep of around 40 per cent in adolescents. This in turn reduces sleep pressure, which means that teenagers stay awake longer in the evening.
Parents primarily blame the increased use of mobile phones and tablets for the later bedtime of teenagers.
The use of electronic media in bed at night is certainly not favourable. However, there are other typical processes that coincide with adolescence and actively promote the tendency to fall asleep late. School usually lasts longer, homework and study time increase. As a result, hobbies and leisure activities take place increasingly later. In addition, the desire for autonomy and a willingness to take risks increases, which means that young people are reluctant to be told what to do by adults.
The school does not take the changed sleep rhythm into account. What are the consequences?
Many teenagers get far too little sleep during the week due to the consistently early start to school. The natural need for sleep during this sensitive development phase is significantly higher than for adults and averages 9.1 hours. However, with a bedtime of 11 pm, teenagers usually only sleep for eight hours or even less.
How dangerous is sleep deprivation during puberty?
Research findings indicate that a constant sleep deficit in adolescence can have negative effects. For example, there are indications that the risk of mental illnesses such as depression or anxiety disorders is increased with a permanent lack of sleep. In addition, too little sleep is associated with a reduced ability to concentrate, resulting in poorer school performance and an increased risk of accidents, for example in road traffic.
Parents should consistently adhere to the sleep hygiene tips and ensure consistent bedtimes.
Insufficient sleep slows down body growth, while weight gain is favoured because a lack of sleep stimulates the appetite. The immune system is also weakened, which increases susceptibility to illness. In addition, the brain's maturation processes suffer, which makes it more difficult for cognitive abilities to develop optimally.
What can parents do?
Admittedly, the influence of parents is limited during puberty and the framework conditions for sleep time are largely set by biological processes. However, there are certainly ways to improve adolescents' sleep and counteract the shift of bedtimes into the late evening hours to a certain extent.
What do you suggest?
I recommend consistently adhering to the sleep hygiene tips and ensuring consistent bedtimes. Drinks and food containing caffeine should not be consumed after lunch. Electronic media should be switched off completely outside the room before going to bed. Constant availability and responding to incoming messages via smartphone often mean that young people unintentionally fall asleep even later.
That is easier said than done.
On the one hand, parents should set a good example. On the other hand, I recommend giving young people comprehensive information about the risks of sleep deprivation and asking them to act accordingly in their own interest. Parents can now also get support from popular influencers on social media. The pronounced health awareness of Generation Z plays into our hands here. They have rediscovered sleep as a true miracle source for fitness, performance and mental health.
And if that doesn't convince you either?
Then perhaps an appeal to vanity will help. After all, a lack of sleep not only promotes weight gain, but also has a negative effect on the appearance of the skin and favours acne. If you want to have beautiful skin and be slim, you should therefore make sure you get enough sleep.
