Teens need at least eight hours’ rest a night to develop properly and regulate emotion

This represented a downward shift from 2018, when half of this age cohort got the right amount of sleep. But with 50% “not sleeping OK” at that point, Planet Youth coordinator Emmet Major says: “We could see sleep was an issue.”

Planet Youth’s 2024 survey concluded just before Christmas, results have not been fully analysed yet but Major reports a glimmer of hope — 45% are now getting eight hours plus sleep per night compared to 44% in 2022. But it doesn’t take from the fact that the teen sleep picture, as Major puts it, “is not good”.

And yet adequate, quality sleep is vital for adolescents because it underpins a lot of the physical, cognitive and emotional growth that needs to happen in this phase, says Dr Aoife Dáibhis, senior clinical psychologist with the VHI.

“Adolescents have unique sleep needs, different to younger children and adults — because this is one of the most critical periods of development across the lifespan.”

On the brain maturation front, Dáibhis points out that the pre-frontal cortex is now undergoing a rapid stage of development. “The pre-frontal cortex governs decision-making and impulse control. And, of course, teens are faced with lots of decision-making tasks and a lot of moments when they need to be able to rely on controlling their impulses.

“Normal brain maturation is supported by adequate sleep. Sleep consolidates memory and it supports good attention,” she adds.

In physical terms, growth hormones are released during sleep, while health, immune function, and energy regulation are also moderated by good sleep. “It helps regulate metabolism. Adolescents not getting adequate sleep have a higher risk of obesity and cardiovascular ill-health in later life,” says Dáibhis, who also highlights sleep’s role in emotional regulation.

“We know that deep sleep supports regulation of stress hormones like cortisol. Adolescents who sleep the recommended amount report lower levels of anxiety and depression. And it promotes healthier behaviour — and fewer riskier ones.”

The link between inadequate sleep and higher stress levels

Major has seen a correlation between inadequate teen sleep and higher stress levels

through the Planet Youth surveys. Just 19% of students who had less than six hours of sleep nightly had low-stress scores compared to 60% of those who slept over eight hours. And just under one-quarter of the ‘less than six hours nightly’ group had high wellbeing scores — contrasting with 65% of those who slept eight hours or more.

“I believe the biggest preventable health problem in our teen population is lack of sleep,” Major says.

Yet the odds can be stacked against teens when it comes to getting good sleep — even at the level of biology.

“There’s a natural shift, biologically, in the adolescent circadian rhythm. They release the sleep hormone melatonin one to two hours later than adults. They might only start getting sleepy at 11pm. Which clashes with the school schedule that has kids starting at 8.30am,” says Dáibhis, who cites other obstacles to optimum teen sleep.

“A lot of adolescents have really exhausting schedules — academic, with homework and study when they get home, social pressures, sports routines and extracurricular activities, not to mention any commuting time that has to be built in. It’s a very demanding schedule.”

“They’re getting up early, going to bed later, and they’re taking a while to fall asleep. They’re not getting enough hours, or good enough quality sleep. Their routine is skewed away from what they need.”

With study and homework often extending long after the evening meal, McKitterick says this poses challenges for switching off. “They have limited time to wind down. And their social lives often come alive late into the evening. The most important thing, especially for those in early adolescence, is their friends and social lives — a lot of which is lived on phones.”

In its 2022 questionnaire, Planet Youth asked some extra questions, including ‘Do you have a phone in your bedroom at night?’ A staggering 83% of mid-teens said they did — the just-completed 2024 survey reported a marginal improvement on this, with 80% saying they had their phone overnight.

“Phones in bedrooms is a huge problem. Young people say they need the phone for homework or as an alarm, and it creeps in,” says Major, adding that “phones really don’t belong in a bedroom after lights out”.

“And phones are really addictive. They keep teens engaged — the pre-frontal cortex is developing through adolescence and they don’t yet have the impulse control to step away as an adult would. So it all competes for the time they should be sleeping — they’re scrolling instead of sleeping.”

Then, there are disturbances in the form of notifications, for example, that come from the phone. “Kids worry about their friends’ mental health, about being available for them. I’ve met very conscientious kids who are up during the night supporting friends,” says Dáibhis.

How to turn a poor sleep routine around

So, what are the signs your teen is not getting enough sleep? “There are lots,” says Dáibhis, citing low energy, mood swings and irritability, as well as tell-tale signs in their appearance. “Dark circles under the eyes, however, they look when they’re tired — perhaps pale. And if it’s hard to wake them and get them up in the morning.”

To turn a teen’s poor sleep routine around, Dáibhis recommends:

• Exposure to daylight. “Earlier in the day is particularly helpful, for example, walking to school.”
• Regular exercise but preferably not before bedtime.
• Consistent meal schedule. “If they’re not eating enough, they won’t sleep well either.”
• Avoiding heavy meals before going to bed — as well as avoiding caffeine, nicotine and energy drinks.
• Protecting a wind-down period for an hour before bed. “Ideally, there should be no devices in that time. Your teen should be relaxing, slowing down, organising themselves for the next day, having a shower, reading for leisure.”
• Paying attention to the sleep environment. “The bedroom should be cool, dark, quiet and comfortable.”
• No devices in the bedroom. “Parents need to enforce this. Teens might fight you on it but it’s a responsibility for the parent to implement this boundary.”

Sleeping well can be part of a behavioural trajectory that starts in adolescence, says Dáibhis. “At this time, young people are at a crossroads where they can develop healthy habits.”

• Vhi Verified, an expert-led blog, offers insights on various health and wellbeing topics: www1.vhi.ie/blog