The change in schedules dictated by school, work or free-time may have a similar effect to jet lag, according to researchers.

The findings, published in the journal Sleep Medicine Reviews, highlight the importance of regular bedtimes, even at weekends, experts said.

Researchers at the University of Southampton aimed to explore the relationship between so-called “social jet lag” and anxiety in youngsters aged 12 to 18.

The team analysed 12 studies, involving more than 235,000 people, and a further six in a narrative review.

They found a small link between teenagers experiencing greater levels of social jet lag and higher levels of anxiety.

Researchers said that although this “appears as a potentially small effect, it is unlikely to be due to chance and it is evident across studies”.

Dr Sarah Chellappa, of the University of Southampton, said: “During puberty, the body’s internal clock usually shifts back by a few hours, meaning teenagers naturally don’t start feeling sleepy until later and would ideally wake up later too.

“But teenagers also face demands on their time, from early school starts to socialising online, which can rob them of sleep, especially during the week.”

“Many teenagers ‘lie in’ on the weekends to catch up on missed sleep, but this mismatch between weekday and weekend sleep schedules can worsen social jet lag.”

A report published by Children’s Commissioner Dame Rachel de Souza in June found more than a million children in England were referred for, or are awaiting treatment, from mental health services – the equivalent of one in 10.

Data obtained by her office suggested the top reason for referrals was anxiety.

Dr Hannah Ravenhall, lead author of the paper, who undertook the research as part of her doctorate at the University of Southampton, said: “The findings highlight the importance of maintaining regular bedtimes and wake times throughout the week, even at weekends.

“It’s important to look beyond what individuals can do alone and recognise how broader societal systems can influence sleep.

“This starts with acknowledging the biological sleep changes that occur in adolescence, advocating for their sleep needs, and reconsidering secondary school start times to support young people’s wellbeing.”