When it comes to the importance of sleep, it’s all about the biology, say pediatric experts. And in a new report, the American Academy of Pediatrics supports pushing back start times for older kids, particularly teens, because it’s better for their mental and physical health.
"The evidence is clearly mounting both in terms of understanding the repercussions that chronic sleep loss has on the health, safety and performance of adolescents, and there is also really solid compelling data supporting the fact that delaying school start times is a very important intervention that can mitigate some of the impact of sleep loss," says Dr. Judith Owens, director of sleep medicine at Children’s National Medical Center and lead author of the report.
In a statement published in the journal Pediatrics, the Academy’s Adolescent Sleep Working Group reviewed the studies to date involving how inadequate sleep among teens—which means anything less than 8.5 hours to nine hours a night on school days—can contribute to health issues such as obesity, diabetes, mood changes and behavior problems. They even analyzed studies linking poor sleep to increased reliance of substances like caffeine, tobacco and alcohol and the effect of sleep deprivation on academic performance. The evidence, they concluded, supports giving teens more time in bed by pushing back the time they have to be at school to at least 8:30am. Even a half-hour delay, some studies showed, can have dramatic effects on improving children’s health and academic performance.
The AAP committee studied the issue of adolescent sleep for nearly four years to come up with this policy statement, says Owens, and that data show that puberty may biologically wire teens to stay up late and wake up late—which means that forcing them to bed earlier won’t do much good. Something about the hormonal changes occurring during that period of development shifts their body clocks, which regulate the balance between sleeping and waking, later, like daylight savings in reverse. Puberty also pressures kids to stay up later because the normal sense of tiredness that builds up during the day is slower to develop among teens, so they can’t fall asleep earlier even if they wanted to.
Some 70 school districts involving more than 1,000 schools have adopted later start times for high school students are seeing substantial benefits. In one district that pushed back start times by one hour, half of the students reported getting eight or more hours of sleep, compared to 37% who had prior to the shift.