Sleep research indicates that teenagers – long labelled as lazy – are living in a state akin to permanent jet lag. Physiological changes during adolescence mean that body clock timing actually shifts, so that teenagers find it easier to stay awake at night and more difficult to wake up in the morning.
And in the same way you wouldn’t expect to spring out of bed the day following a flight from London, we can’t expect teenagers to cope with these physiological changes alone, says UniSA sleep expert Dr Michelle Short.
“While primary school-aged children find it hard to stay up late, don’t have a lot of trouble falling asleep, and then wake up spontaneously in the morning raring to go, with teenagers we find the opposite,” she says.
“They find it easier to stay awake at night, harder to fall asleep – particularly earlier on – and then it’s really hard for them to wake up in the morning.
“Often that’s because the timing of their body clock has shifted, and suddenly that 7am start is, for them, like waking up at 5am would be for adults. The absolute low point of their day is when they are trying to wake up.
“This happens across the teenage years and then slowly wanes in the early twenties.
“Changes to the biological systems that regulate sleep and wake-times are responsible for this phase, but lifestyle can also play a huge part. Parents have an important role in helping to keep the body clock in check to make it more manageable for teenagers.
“When there are no controls in place teenagers tend to stay up late, they have trouble waking up in the morning and they aren’t getting enough sleep. If they’re getting to school they might be late because they are sleeping in, and if they are actually getting there on time their learning is probably compromised because of sleep restriction and the circadian low-point.”
A study by Professor Mary Carskadon, Director of the University’s Centre for Sleep Research, allowed teenagers to take advantage of a long sleep opportunity in a laboratory environment, to determine their sleep needs.
The results indicated that the average teenager needed nine-and-a-quarter hours’ sleep each night, significantly more than the eight hours recommended for adults.
Furthermore, the effects of insufficient sleep are likely to be worse for adolescents as their brains are still developing, particularly the frontal areas, which are especially affected by sleep deprivation, and are important for emotional regulation and learning.
Parents and teachers report sleep-deprived teenagers are often grumpier, can be more depressed, lack energy and enthusiasm, and find it difficult to sustain attention, making school more challenging.
Another recent study of almost 400 teenagers carried out by Dr Short found that only about 15 per cent of them had any parental regulation for bedtimes on school-nights, and none did at weekends. Those who did have a parent-set bedtime performed better at school, functioned better during the day, and were less fatigued and more alert.
“Setting a bedtime and wake-time for teenagers is vital, as many teenagers restrict their sleep during the school week and then sleep in on the weekend,” Dr Short says.
“All that achieves is to shift their body clock even more. It’s like having a system where your body clock is pushing later, and then the brakes are off at the weekend and it’s allowed to drift even further, and then they have to get up on Monday morning.
“Although the sleep-debt may be reduced, the underlying problem is exacerbated. We suggest keeping a regular bedtime and wake-time across school nights and weekends.”
While parents and teens can try to create the best sleep routine to allow for the changes to body-clock timing, in some parts of the world – where school start times are very early – they are working against education structures at odds with teenagers’ physiology.
Prof Carskadon, who joined UniSA part-time last year while also serving as Director of the United States-based Chronobiology and Sleep Research Centre at Brown University, says early start times at US schools (often before 8am) have become an issue for communities across the country.
“In the US, schools are community-based and organised, with decision-makers sitting on school committees in every town,” Prof Carskadon says.
“Communities have made the decision to move the start time later on the basis of findings that show adolescent mood and performance improves with later rising times and hence more sleep. The systems in each town, however, have a significant amount of resistance to change and no legislative initiative at a state or federal level has mandated a change.
“The evidence to date is that students do benefit from starting school later. By sleeping more, they are less moody, more likely to perform better in school, and two or three studies now show that car crash rates go down for teen drivers when the school schedule is changed.
“Some parents and teachers find issues with such things as older teens not being home to look after younger siblings or teens not being able to have after-school jobs. On the whole, however, the issues are few.”
Back in Australia, several schools in Victoria are also planning to change school starting times to accommodate teenagers’ sleep requirements.
The technology that infiltrates homes also contributes to whether teenagers get a good night’s rest, but Dr Short says that can be hard for parents to monitor.
“Often parents assume that if their children are in their rooms and their lights are off they’re asleep, but what we actually found is that they have their phones, TVs and game consoles,” she says.
“If they’re not texting, they’re making phone-calls or they’re on Facebook, which interferes with their sleep.”
Dr Short suggests banning all technology, as well as homework, an hour before bedtime, and substituting a relaxing activity such as reading a book for surfing the net.
Current analysis of a UniSA study which looked at the activity that teenagers performed in the hour before bed and their subsequent sleep patterns indicates that the worst sleep patterns are associated with active technology-use such as gaming, surfing the internet and using social media, followed by passive technology such as watching TV or listening to the radio. Early results indicate that reading a book is the best activity to relax and prepare for a good night’s sleep.
But it’s not just our teenagers who need to follow this advice, according to Dr Short. She says it’s important for parents to model the behaviour they want their children to emulate.
“Parents can model good behaviour,” Dr Short says. “If we are up all night encouraging a culture of ‘work hard’ and ‘sleep is for the weak’ and we are in bed using our laptops, it’s probably not setting the best example.
“At a basic level, we can all benefit from good sleep hygiene which refers to having a sleep environment which is safe, a cool temperature, is dark and quiet, and without too many distractions, while also keeping regular bedtimes.”
So the next time you reach for your smartphone before bed, maybe grab a book instead – it’s not just your own sleep you could be saving.
Connect with Prof Carskadon: @sleepyteens