Why Are Teenagers Sleeping Less Than Before?

A teenager can be exhausted at 7am, struggle through school, and still not feel ready to sleep at 9pm.

That is one reason the usual explanation for teenage sleep loss, too much screen time, is starting to look incomplete.

Phones, gaming and social media can certainly interfere with sleep. But recent research suggests the more useful question is not simply “How many hours did they spend on a screen?” It is also when they used it, what they were doing, and what else was competing with sleep.

Puberty shifts the biological clock later. School still starts in the morning. Homework, sport, friendships, worries, caffeine, commuting and late-night conversations can squeeze the available sleep window from both ends.

Why are teenagers sleeping less? The short answer

Teenage sleep loss appears to be a multifactorial problem rather than the result of one bad habit.

For many teenagers, several things happen at once: their body naturally becomes ready for sleep later, but their required wake-up time does not move later with it. Add school pressures, activities, stress, caffeine and sometimes screens after getting into bed, and an eight-to-ten-hour night can quickly become six or seven.

The important distinction: screens may be part of the problem, particularly when they delay an attempt to sleep, but current evidence does not support treating total daily screen time as the single explanation for the wider decline in teenage sleep.

How much sleep do teenagers actually need?

For teenagers aged 13 to 18, the widely used recommendation is 8 to 10 hours of sleep per 24 hours. Children aged 6 to 12 generally need 9 to 12 hours.

That means a 12-year-old who has just started secondary school may need more sleep than an older teenager even though their school routines may look similar.

These are population guidelines, not a diagnosis. One unusually short night is different from repeatedly having too little opportunity to sleep.

NHS Healthier Together sleep guidance also recommends 8 to 10 hours for teenagers aged 13 to 18.

What did the major 2026 JAMA study find?

The figures that brought renewed attention to teenage sleep came from a large US study published in JAMA in 2026.

Researchers analysed 120,950 high-school students who took part in the national Youth Risk Behavior Survey between 2007 and 2023.

The students reported how much sleep they usually got on an average school night.

The change was substantial:

• Students reporting 7 hours or less rose from 68.9% in 2007 to 76.8% in 2023.
• Students reporting 5 hours or less rose from 15.8% to 23.0%.
• The percentage reporting 6 to 7 hours did not show the same increase.

In other words, the most worrying shift was towards very short school-night sleep.

There was another intriguing finding. The increase was seen across demographic groups and across many behavioural-risk groups. It was not concentrated only among teenagers with heavy electronic-media use or other behaviours commonly blamed for poor sleep.

That does not prove screens are harmless.

It means the population-wide trend cannot be confidently explained by screens alone.

The researchers themselves did not establish the cause of the decline. The study was observational and relied on self-reported sleep, so it can show us a trend but cannot tell us which individual factor caused it.

Original study: Bommersbach TJ, Olfson M, Rhee TG. Insufficient Sleep Among US Adolescents Across Behavioral Risk Groups. JAMA. 2026;335:1173–1176. DOI: 10.1001/jama.2026.1417.

So, are phones causing teenagers to lose sleep?

Sometimes. But “screen time” is too broad a label to tell us much on its own.

Think about two teenagers who both use a screen for an hour.

One finishes homework on a laptop at 7pm.

The other gets into bed at 11pm, opens a group chat, switches to a game, checks a video, replies to another message and keeps going when they had intended to sleep.

Those are not equivalent exposures.

What happened when researchers measured screen use objectively?

A 2024 JAMA Pediatrics study followed 79 young people aged 11 to 14 over 323 nights. Instead of asking them to remember how much screen time they had used, researchers measured their screen behaviour and sleep more directly.

Screen use during the two hours before bed was not associated with most sleep measures that night.

But the picture changed once the young people were actually in bed.

Screen use after getting into bed was associated with shorter sleep, especially when the activity was interactive. Gaming, messaging and multitasking were more strongly associated with sleep loss than simply looking at a daily screen-time total.

For every additional 10 minutes of interactive screen use while in bed, the study estimated about 9 minutes less total sleep. That figure is an association, not proof that the screen directly caused every minute of lost sleep.

Still, it gives families a much more practical target:

Protect the time after getting into bed.

That may be more realistic than turning every laptop, television and phone off two hours before bedtime regardless of what it is being used for.

Study: Brosnan B, Haszard JJ, Meredith-Jones KA, et al. Screen Use at Bedtime and Sleep Duration and Quality Among Youths. JAMA Pediatrics. 2024;178(11):1147–1154. DOI: 10.1001/jamapediatrics.2024.2914.

Newer research makes the screen-time story even more interesting

A systematic review and meta-analysis published in JAMA Pediatrics in 2026 looked specifically at day-to-day changes within the same young people.

When a young person used screens more than usual on a particular day, researchers found a small association with going to sleep later.

However, higher daily screen use was not significantly associated with total sleep time, sleep efficiency, time taken to fall asleep, waking after sleep onset or subjective sleep quality across the included studies.

This does not mean screens cannot interfere with sleep.

It suggests something more precise:

The timing, context and activity may matter more than a single daily screen-time number.

Study: Bourke M, Maddren CI, Sippel F, Thomas G. Within-Person Association Between Daily Screen Use and Sleep in Youth: A Systematic Review and Meta-analysis. JAMA Pediatrics. 2026;180(5):500–509. DOI: 10.1001/jamapediatrics.2025.6490.

Teenagers are also working with a different biological clock

Parents sometimes describe the same puzzling pattern: their child used to fall asleep easily at 9pm, but a few years later they seem wide awake at 10.30pm and impossible to wake in the morning.

Part of that change is biological.

During adolescence, circadian timing tends to shift later. Teenagers become more inclined to feel alert later in the evening and sleepy later in the morning.

Sleep pressure also changes during adolescence, helping some teenagers remain awake later than they could when they were younger.

This is why simply telling a teenager to “go to bed earlier” may not immediately result in sleep. Being physically in bed and being biologically ready to sleep are not always the same thing.

Regular wake times, morning daylight, activity during the day and calmer evenings can help support a stable rhythm, but they do not completely remove the developmental shift that occurs during puberty.

Background research: Crowley SJ, Acebo C, Carskadon MA. Sleep, Circadian Rhythms, and Delayed Phase in Adolescence. Sleep Medicine. 2007;8(6):602–612. DOI: 10.1016/j.sleep.2006.12.002.

Early school mornings can squeeze the sleep window

Now put that later biological clock beside a fixed school-morning alarm.

A teenager may not feel sleepy until late in the evening, yet still need to get up at 6.30 or 7am.

The maths becomes difficult.

A 2024 systematic review and meta-analysis found that later school start times were associated with longer weekday sleep and lower social jet lag, although the size of the effect varied between studies.

This does not mean changing every school timetable would solve teenage sleep deprivation. Transport, family routines, sport and after-school activities all matter.

But it supports the wider point: teenage sleep is partly a scheduling problem, not simply a discipline problem.

Research: Rodríguez Ferrante G, Lee F, Leone MJ. Effects of school start time and its interaction with the solar clock on adolescents' chronotype and sleep: A systematic review and meta-analysis. Sleep Medicine Reviews. 2024;78:101988. PubMed record.

Stress can steal sleep without appearing on a screen-time report

Not every teenager who stays awake late is entertained.

Some are worrying.

Exam pressure, friendships, family problems, academic expectations, part-time work, sport and uncertainty about the future can all follow a teenager into the bedroom.

Stress can make it harder to switch off. Poor sleep can then make the following day harder to cope with, creating an unhelpful cycle.

That is why a conversation about sleep should not begin with an accusation.

Instead of:

“You are always on that phone.”

it may be more useful to ask:

“What usually keeps you awake when you want to sleep?”

The answer might be TikTok. But it might also be chemistry homework, a friendship problem, a late football session or simply not feeling sleepy yet.

Caffeine can quietly push bedtime later

Caffeine does not only come from coffee.

Tea, cola, iced coffee, energy drinks, chocolate, some pre-workout products and other drinks can contain it.

Caffeine can delay sleep and reduce sleep quality, although sensitivity varies considerably from person to person.

The practical issue is timing. A caffeinated drink after school may still be relevant at bedtime for someone who metabolises caffeine slowly.

For a teenager struggling to fall asleep, reducing or avoiding caffeine later in the day is a simple variable worth testing before reaching for more complicated solutions.

Review: Clark I, Landolt HP. Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials. Sleep Medicine Reviews. 2017;31:70–78. PubMed record.

What about sleeping until lunchtime at the weekend?

A weekend lie-in can feel wonderful when a teenager has spent five school days getting up too early.

Extra weekend sleep may provide some short-term recovery from sleep debt. But it is not the same as getting enough sleep consistently.

Large changes between weekday and weekend sleep timing can also produce what researchers call social jet lag: the body's preferred schedule and the schedule demanded by school keep moving apart and back together.

So the aim does not need to be an identical bedtime seven days a week.

A more realistic goal is to avoid turning every weekend into a complete reversal of the school-week schedule.

The UK picture deserves attention too

The headline JAMA statistics are from the United States, so they should not be presented as UK prevalence figures.

However, England has its own concerning data.

The Health Behaviour in School-aged Children England study surveyed 5,377 young people aged 11, 13 and 15 in 2021–22.

Only 42% reported at least 8.5 hours of sleep on school nights. That had fallen from 63% in 2018 and 71% in 2014.

The same survey reported that 55% experienced difficulty sleeping at least once a week, while 34% said they did not get enough sleep to feel awake and concentrate on schoolwork during the day.

The definitions and age groups are different from the US JAMA study, so the percentages should not be directly compared. But both datasets point towards the same practical concern: insufficient and difficult sleep is affecting a substantial number of young people.

UK source: Health Behaviour in School-aged Children England. Adolescents' Experiences of Sleep factsheet.

What can parents actually do?

The research does not point towards one magic rule. A better approach is to find the pressure that is taking the biggest bite out of that particular teenager's sleep.

• Start with the morning. Work backwards from the required wake-up time and ask whether there is genuinely enough opportunity for 8 to 10 hours of sleep.
• Protect the bed from highly interactive screen use. Gaming, messaging and multitasking after getting into bed are useful behaviours to target.
• Look at caffeine timing. Afternoon and evening caffeine may be worth reducing if falling asleep is difficult.
• Keep some rhythm across the week. Weekend recovery is understandable, but very large shifts can make Monday morning harder.
• Get daylight and movement during the day. Both can support healthy sleep-wake timing.
• Ask about pressure. Homework, worry and social problems cannot be fixed by confiscating a phone.
• Make the bedroom easy to sleep in. Aim for a dark, reasonably quiet, comfortable room that is not excessively warm.

Where does the bedroom environment fit?

A comfortable bedroom will not fix an overloaded timetable, anxiety, a sleep disorder or an early school start.

But it can remove avoidable sources of discomfort.

If someone is already short of sleep, spending part of the night fighting a hot room, clammy bedding, noise or bright light is not helpful.

This is where bedding belongs in the conversation: as part of the sleep environment, not as a treatment for sleep deprivation.

Azenue bamboo bedding is made from 100% bamboo viscose with a 300-thread-count sateen weave and is designed to provide a soft, breathable feel. Azenue bedding is also OEKO-TEX® certified.

It cannot treat insomnia, anxiety or circadian-rhythm problems, and changing sheets cannot create an extra two hours in a teenager's schedule.

But when warmth or bedding comfort is one of the things disturbing the sleep environment, it is a practical factor families can change.

Explore Azenue bamboo bedding →

If you want to understand the fabric itself before buying, read how bamboo bedding can support a more comfortable sleep environment.

When is poor teenage sleep worth discussing with a GP?

Occasional short sleep around exams, travel, illness or an unusual week is common.

Professional advice becomes more important when sleep problems are persistent, distressing or affecting everyday functioning.

Speak to a GP or appropriate NHS service if a young person has severe daytime sleepiness, regularly struggles to fall or stay asleep despite having enough opportunity to sleep, snores loudly, appears to choke or stop breathing during sleep, has uncomfortable sensations in their legs at night, or has significant changes in mood or anxiety.

If there are concerns about self-harm, suicide or immediate safety, seek urgent professional help rather than treating it as simply a sleep-hygiene problem.

Frequently asked questions about teenage sleep

How much sleep should a teenager get?

Most teenagers aged 13 to 18 should aim for around 8 to 10 hours of sleep per 24 hours. Individual needs vary, but routinely sleeping far below that range deserves attention.

Why do teenagers naturally stay awake later?

During adolescence, circadian timing shifts later. Teenagers often become biologically ready to fall asleep later than younger children while still having to wake early for school.

Are phones the main reason teenagers are sleeping less?

Current evidence does not establish phones as the single cause. Screen use can contribute, particularly when interactive activities continue after a teenager gets into bed, but biology, school timing, stress, caffeine and competing demands also matter.

Is five hours of sleep enough for a teenager?

For most teenagers, no. Five hours is substantially below the usual recommendation of 8 to 10 hours. One short night can happen, but regularly sleeping around five hours should not be treated as normal.

Can teenagers catch up on sleep at weekends?

Extra weekend sleep may help with some immediate tiredness, but it should not be considered a complete replacement for sufficient sleep during the week. Large changes in sleep timing may also contribute to social jet lag.

What is the most useful screen rule for sleep?

There is unlikely to be one rule that suits every family. Recent research suggests that limiting highly interactive screen use once a teenager is already in bed may be a particularly useful place to start.

Can better bedding make a teenager sleep longer?

No bedding can guarantee longer sleep. Bedding can improve physical comfort and help create a more pleasant sleep environment, but it cannot replace enough time for sleep or treat an underlying sleep or mental-health problem.

Final thought

It is easy to look at a tired teenager holding a phone and believe we have found the explanation.

The science suggests we should look a little wider.

A teenager may be fighting a biological clock that has moved later, a school day that has not, an evening full of demands and a phone that becomes especially difficult to put down once they finally reach bed.

That changes the conversation from:

“Why won't teenagers just go to sleep?”

to a better question:

“What is preventing this teenager from getting enough opportunity to sleep?”

That is a much better place to start.

Sources and further reading

Bommersbach TJ, Olfson M, Rhee TG. Insufficient Sleep Among US Adolescents Across Behavioral Risk Groups. JAMA. 2026;335(13):1173–1176. DOI: 10.1001/jama.2026.1417.

Brosnan B, Haszard JJ, Meredith-Jones KA, et al. Screen Use at Bedtime and Sleep Duration and Quality Among Youths. JAMA Pediatrics. 2024;178(11):1147–1154. DOI: 10.1001/jamapediatrics.2024.2914.

Bourke M, Maddren CI, Sippel F, Thomas G. Within-Person Association Between Daily Screen Use and Sleep in Youth: A Systematic Review and Meta-analysis. JAMA Pediatrics. 2026;180(5):500–509. DOI: 10.1001/jamapediatrics.2025.6490.

Crowley SJ, Acebo C, Carskadon MA. Sleep, Circadian Rhythms, and Delayed Phase in Adolescence. Sleep Medicine. 2007;8(6):602–612. DOI: 10.1016/j.sleep.2006.12.002.

Rodríguez Ferrante G, Lee F, Leone MJ. Effects of school start time and its interaction with the solar clock on adolescents' chronotype and sleep: A systematic review and meta-analysis. Sleep Medicine Reviews. 2024;78:101988.

Clark I, Landolt HP. Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials. Sleep Medicine Reviews. 2017;31:70–78.

Health Behaviour in School-aged Children England. Adolescents' Experiences of Sleep: HBSC England National Report 2021–2022.

Health information note: This article is for general information and education and is not a substitute for individual medical advice, diagnosis or treatment.