Tired teenagers - lazy teenagers?
The most important information
Teenagers who almost fall asleep at school - sound familiar? No wonder, because many adolescents feel the same way. They can barely keep their eyes open in class and are considered lazy and overtired. But what's behind it all? The sleep-wake rhythm changes during puberty. It's not the teenagers' fault. As a result, they fall asleep later and later. But there are more than just biological explanations: The consumption of electronic devices shortly before falling asleep is also a hindrance to healthy sleep. In short: young people who look at their mobile phone display or PC screen before going to sleep have a harder time falling asleep.
Read the full article to find out how many hours of sleep teenagers need and what consequences a chronic lack of sleep can have.
15-year-old Leon hangs apathetically in his chair. His eyelids are heavy and he struggles to keep his eyes open. The teacher's voice reaches his ears as if through a fog. «Leon! Wake up! You can sleep at home!» But Leon is still dog-tired, can barely concentrate and feels tired.
Many teenagers are like Leon - parents and teachers can tell you a thing or two about it. Because with the onset of puberty, primary school children who used to be lively early in the morning suddenly become sleepy, bad-tempered teenagers who don't get out of bed voluntarily before 10 o'clock in the morning. However, it would be unfair to young people to blame this solely on changes in leisure activities or even growing laziness. In fact, it has been proven that it is primarily biological factors that cause teenagers to fall asleep later. Sometimes even illnesses that start at this age can be behind daytime sleepiness.
The internal clock ticks differently
The main cause of increased daytime sleepiness in adolescents is an altered sleep-wake rhythm. The sleep-wake rhythm, also known as the internal clock, determines when we are awake and when we sleep. In addition to external factors such as daylight, darkness, physical activity and rest, it is primarily controlled by the body's own release of the sleep hormone melatonin. Only when the melatonin level in the blood has reached a certain concentration does the so-called sleep pressure rise to a level that allows us to fall asleep without any problems.
«During puberty, however, the release of melatonin shifts continuously and significantly backwards in time for reasons that have not yet been explained,» explains Prof. Johannes Mathis, neurologist and head sleep physician at the University Sleep-Wake Centre at Inselspital in Bern. As a result, adolescents from around ten years of age to adulthood fall asleep around a quarter of an hour later every year. «In an American study, a shift in bedtime of almost an hour from 11.00 p.m. to 11.54 p.m. was measured in children from the fifth to the eleventh grade,» explains the sleep physician. «By the age of 18, bedtime can even be up to two hours later.»
The mobile phone as a sleep robber?
This mechanism is reinforced by a number of social factors that play an important role during this time, such as increased leisure activities in the evening and at night, consumption of coffee, energy drinks and alcohol, as well as the generally poor image of going to bed early during this phase.
«But the increased use of electronic media such as PCs, mobile phones and tablets, which also keep us awake with bright light in the blue spectrum, can also cause us to fall asleep later,» adds Mathis.
Falling asleep later is particularly problematic because waking up at the same time with a constant school start time of 8 a.m. or even 7.30 a.m. inevitably leads to a chronic lack of sleep.
Sleeping in at the weekend also disrupts the sleep-wake cycle.
Prof. Johannes Mathis, neurologist and head sleep physician at the University Sleep-Wake Centre at the Inselspital in Bern.
«Teenagers need around nine hours of sleep to feel fresh and rested,» explains Mathis. On average, however, they sleep less than seven hours during the week, as scientists from the University of Marburg and the Dilleburg Institute for Health Promotion and Research found out in 2012 in a large-scale study of over 8,000 young people.
«Adolescents tend to make up for the sleep they miss during the week at the weekend by sleeping in late into the afternoon,» says the sleep physician from Bern. «However, these unusual sleeping times also disrupt the sleep-wake rhythm, making it even harder to get to bed early on Sunday evenings.»
The ideal solution would therefore be to move the start of school back by one hour from middle school onwards. However, this solution has not yet been practised in Switzerland. The chronic lack of sleep among young people has far-reaching consequences. «Many young people complain of concentration and memory problems, listlessness, headaches and poor school performance,» explains Mathis. «In pre-pubertal children, it can also lead to hyperactivity and signs of ADHD.»
Daytime sleepiness also increases the risk of accidents, especially in road traffic. Mental disorders, including depression, can also occur or worsen. «A persistent lack of sleep also has a negative effect on the metabolism, which can indirectly lead to weight gain and an increase in obesity,» explains the sleep expert.
How do teenagers get more sleep?
You can't fight your body clock. So it makes no sense to simply send your son or daughter to bed earlier. But it is possible, to a certain extent, to use external factors to influence the internal clock so that young people can fall asleep a little earlier in the evening and feel more rested and fit during the day.
The main cause of increased daytime sleepiness in adolescents is an altered sleep-wake rhythm.
«Regularity and rituals around going to bed and getting up have a particularly favourable effect,» explains Mathis. «Ideally, bedtimes should be as consistent as possible and the last one to two hours before going to sleep should be calm and consistent.» Admittedly: It's a little difficult to convince teenagers of this - but still try to encourage your son or daughter to avoid exciting films, video games, homework or intense conversations just before falling asleep and to put their mobile phone, tablet & co. out of their bedroom late at night or at least switch them off.
«Strong physical exertion such as late-night sport also tends to stimulate rather than make you tired,» emphasises the sleep physician. «Calm activities such as reading or meditating are more favourable.» If your teenager can't get out of bed in the morning, bright daylight helps to better adjust the internal clock. «In winter, when it's still dark early in the morning, special daylight lamps can be used for this purpose,» Mathis advises.
Eating in the morning and physical exercise in the fresh air help to synchronise your internal clock.
Prof Johannes Mathis, neurologist and sleep physician.
«Eating in the morning and physical exercise in the fresh air also counteract daytime sleepiness and help to synchronise the internal clock.» Teenagers should therefore not be taken to school by car after their morning meal if possible, but should cycle or walk to school on their own.
Last but not least, you should let your teenager sleep in at the weekend - even if their sleep-wake cycle suffers as a result. This way, at least some of the hours of sleep missed during the week can be made up for.
Don't be afraid that the adolescent late-sleeper status will be inoculated forever: it will gradually reverse itself. By the end of puberty, at around 19 to 20 years of age, the spook is usually over again.
Practical test: How much sleep your child needs
Because there are almost always differences of opinion between parents and teenagers when it comes to sleep requirements, sleep physician Johannes Mathis advises carrying out a simple practical test: During the holidays, teenagers should sleep in for at least three nights in a row and record the number of hours slept from the time they fall asleep
to the first time they wake up for at least 15 minutes. The average number of hours from these three nights is the actual sleep requirement. You can also see at what time the sleep pressure is high enough to fall asleep without any problems.
Daytime sleepiness as a symptom of illness
If daytime sleepiness persists despite getting enough sleep at night, it may be due to a genuine sleep-wake disorder. «With sleep apnoea, for example, breathing stops can occur up to once a minute during sleep, which leads to a short-term lack of oxygen and repeated waking reactions,» explains sleep expert Johannes Mathis.
«Even prolonged sleep is then no longer restorative.» Daytime sleepiness is also a typical symptom of narcolepsy, which often begins in adolescence: "Narcolepsy is a disease of the brain, which causes regular sleep attacks during the day - despite undisturbed sleep at night - in which those affected sometimes suddenly fall asleep at the most impossible moments," emphasises Mathis. «There is often a great deal of unrecognised suffering because those affected are often ridiculed and considered lazy.» In the event of unexplained daytime sleepiness, parents should therefore take their adolescent to their family doctor or paediatrician as soon as possible, who will then refer them to a sleep-wake centre for further clarification. Sleep disorders such as sleep apnoea or narcolepsy can be treated well there.
