“This is a huge issue for society,” Kelley said. “We are generally a sleep-deprived society but the 14-24 age group is more sleep-deprived than any other sector of society. This causes serious threats to health, mood performance and mental health.”
If schools across the UK adopted the new start times, he said, GCSE attainment would rise by about 10%.
The problem goes beyond merely feeling tired, Kelley said. If a child gets less than six hours sleep a night, over the course of a week this can lead to more than 700 changes in the way their genes behave.
Similar changes are not seen in children who get eight-and-a-half hours sleep a night. He said illnesses as serious as schizophrenia often developed at an age associated with the beginnings of sleep deprivation problems.