Middle and high school should start no earlier than 8:30 a.m., says the American Academy of Sleep Medicine (AASM) in a position statement. Doctors say that starting school earlier in the morning prevents children and teenagers from getting a full night’s sleep, which can affect their health, safety and academic performance.
The argument for a later school day isn’t new, but this was the first time the AASM—a group of scientists and health experts with more than 10,000 members—has taken an official position on the subject. For years, studies have suggested that later school starts can benefit adolescents and teens, who scientists say are wired to stay up late and sleep in.
The statement, published in the Journal of Clinical Sleep Medicine, follows similar recommendations from the American Academy of Pediatrics and the Centers for Disease Control and Prevention (CDC). It asserts that if middle- and high-school students are allowed to wake up later in the morning, they’ll be more focused during the day, more alert behind the wheel and less likely to be late to (or absent from) school.
The AASM recommends that teenagers should sleep 8 to 10 hours a night. But according to the CDC, almost 70% of high-school students report sleeping 7 hours or less on a regular basis.
That’s partially because as children approach and go through puberty, their brains begin producing the sleep-inducing hormone melatonin on a delayed schedule, making it difficult for them to feel tired before 11 p.m. Because it’s normal to spend some time in bed before falling asleep, the authors write, “a teenager who goes to bed at 11 p.m. would need to sleep until 7:30 a.m. or later in order to obtain sufficient sleep.”
But because many schools start before 8 a.m., those students are falling short of those sleep targets. That can have serious consequences. Chronic sleep loss among teenagers has been associated with poor school performance and a higher risk for depressive symptoms, obesity, cardiovascular problems, risk-taking behaviors and athletic injuries, to name a few.
Research also suggests that delaying the start of the school day can reduce automobile accidents caused by sleepy teen drivers. In one 2008 study in the Journal of Clinical Sleep Medicine, crash rates fell by 16.5% in the two years after a school district shifted its start times an hour later, compared to the two years before.
School districts have begun to take note, and some have delayed their start times. (Seattle Public Schools started a new delayed-start schedule in September.) It’s not always an easy switch, however; schools must sometimes rejigger bus schedules, after-school activities and sports programs.
Dr. Nathaniel Watson, lead author of the AASM statement and associate professor of neurology at the University of Washington, says that so far, successful changes have been the result of parents, physician groups and concerned citizens raising the issue at school board meetings. “I think if it’s done in a thoughtful manner with all of the stakeholders involved, many of the issues that people are concerned about can be addressed,” says Watson. “We all want the same thing: healthy, vibrant, educated children who have every opportunity possible to succeed in this world.”
The AASM statement also acknowledges that shifting school start times won’t solve all of teenagers’ sleep problems. Parents should also encourage a regular sleep-wake schedule, and children should avoid sleep-disrupting electronic devices before bed or during the night.
Instituting a school-wide schedule change would be a good start, says Watson, and it may even motivate kids and parents to prioritize sleep and develop better sleep habits overall.
“This change provides an opportunity for healthy sleep for teenage students, but it’s up to the student and their families to take advantage of it,” he says. “If the system can make these accommodations and set a good example, maybe it will stimulate an internal dialogue for these students about the importance of sleep, and really help them make these other changes as well.”