More than a quarter of young people aren’t getting enough sleep, a World Health Organisation study has suggested.
The research found one in four 11 to 15-year-olds in England are failing to get enough shut eye, which is leaving them feeling sleepy and unable to concentrate on their schoolwork.
The Health Behaviour in School-aged Children (HBSC) in England report also indicates that increasing numbers of teenagers are experiencing periods of feeling low.
Researchers quizzed 3,398 11, 13 and 15-year-olds every four years on everything from their physical health to life satisfaction.
They found that 27% of young people report not having enough sleep to feel awake and concentrate on their lessons, with teenagers more likely to struggle with the issue as they get older.
While 17% of 11-year-olds said they battle with sleep, this rose to 28% of 13-year-olds and again to 42% of 15-year-olds.
Typically, girls are having more of a sleep struggle than their male classmates with around a third (32%) of girls not getting enough sleep, compared to 23% of boys.
The research also analysed mental wellbeing and found there has been an increase in the number of 15-year-olds reporting feeling low once a week - rising to 50% from 40% in 2014.
Worryingly, a quarter of poll participants had self-harmed, with the figures showing a steeper rise in boys admitting to doing so than girls.
It’s possible that the lack of sleep could be linked to a reduction in physical activity with the report revealing just one in six of the youngsters are physically active for at least one hour a day.
And seven in 10 take part in intense physical activity at least twice or three times a week, with girls less likely to do so than boys.
Interestingly, however, the WHO study also suggested that children are becoming less likely to take part in risky behaviours such as smoking, drinking, trying cannabis, and having sex.
Dr Ellen Klemera, senior research fellow at the University of Hertfordshire, which hosted the study, said: “Research on adolescent health has highlighted how important the second decade of life is for health and wellbeing, which is why this continued decline of emotional wellbeing is really worrying.
“Although there are far less reported incidences of risk behaviours, young people are facing a multitude of different challenges that other generations have not really experienced, such as the prominence of smartphones and social media.
“These can have a negative impact on wellbeing, particularly if they are exposed to cyber-bullying or if it affects their sleep.”
Martin Weber, a WHO programme manager for child and adolescent health and development, said: “The mental health of young people is as important as their physical health.
“The new HBSC report gives us a good insight into the problems young adolescents face and the effect it has on their health.
“Increase in sleep difficulties, feeling low and self-harm are just some of the issues that need to be addressed.”
This isn’t the first time concerns have been raised about the amount of sleep youngsters are getting.
Last year MPs considered calls for the school day to start at 10am to help tired teenagers.
The debate came after a petition urging the Government to consider the plea gained more than 183,000 signatures – a petition that gains more than 100,000 signatures is considered for debate in parliament.
“School should start at 10am as teenagers are too tired,” the petition reads.
“Teenagers are so tired due to having to wake up very early to get to school. The Government should require secondary schools to start later, which will lead to increased productivity at school.”
How much sleep do teenagers need?
The NHS says that a minimum of 8 to 9 hours’ good sleep on school nights is recommended for teens.
The Sleep Foundation explains that humans’ circadian rhythms – the body clock that manages the cycle of sleep and wakefulness – change in adolescence, when most teens experience a sleep phase delay.
“This shift in teens’ circadian rhythm causes them to naturally feel alert later at night, making it difficult for them to fall asleep before 11:00 pm,” the site explains.
“Since most teens have early school start times along with other commitments, this sleep phase delay can make it difficult to get the sleep teens need.”