Is school depriving your teen of much-needed sleep?

Teenagers fighting to sleep in on school mornings have some doctors on their side. The American Academy of Pediatrics (AAP) issued a policy statement on Monday urging middle and high schools to start later in the day because students aren’t getting enough sleep. During the 2011-12 school year, about 43 percent of public high schools in America began before 8 a.m., according to the National Center for Education Statistics. The AAP statement says these early hours can contribute to chronic sleep loss in teenagers and lead to poor academics, health, behavior, and safety.

High school seniors average less than 7 hours of sleep on school nights when they should be getting between 8.5 and 9.5 hours, according to the AAP. But setting an earlier bedtime might not solve sleepiness because research has shown puberty shifts “sleep-wake cycles” two hours later in the day. “On a practical level, this research indicates that the average teenager in today’s society has difficulty falling asleep before 11 p.m. and is best suited to wake at 8 a.m. or later,” according to the AAP.

The National Sleep Foundation also suggests delaying school start times. “Adolescent sleep deprivation is largely driven by a conflict between teens’ internal biological clocks and the schedules and demands of society,” its website says. It cites a study from the University of Minnesota in which suburban high school students reported gaining about an hour of sleep per night when schools changed their start times from before 7:30 a.m. to 8:30 a.m. or later. The ability to sleep late did not cause students to stay up later on school nights.

One effect of sufficient sleep is improved alertness. The National Sleep Foundation’s 2006 poll focused on sleep habits in adolescents and found 28 percent of high school students fell asleep at least once a week in school while 22 percent fell asleep at least once a week doing homework or studying.

Though multiple studies have shown that a later school start leads to more sleep for teens, the AAP statement acknowledges academic improvements aren’t proven. But some studies suggest a later start does lead to higher grades. Kyla Wahlstrom from the University of Minnesota led a three-year research study including more than 9,000 students and concluded that math, English, science, and social studies grades improved in schools “with the later start times of 8:35 a.m. or later.”

Chronic sleep loss among adolescents also affects other areas of life. Obesity, anxiety, depression, suicidal ideation, poor impulse control, and deficits in abstract thinking and verbal creativity are among the many harmful impacts listed in the AAP statement. Drowsy driving can also create a safety risk. Wahlstrom reports that when the Teton County School District in Wyoming changed its high school start time from 7:35 a.m. to 8:55 a.m., the number of car crashes for drivers between 16 and 18 years old fell from 23 to 7, a 70 percent decrease.

But changing school schedules causes complications. School districts often stagger start times so buses can transport more than one round of students. Starting older students later might mean forcing younger children to catch early buses and arrive home sooner than older siblings, leaving them unsupervised. Some are also concerned later school days will sacrifice after-school athletics and jobs.

And starting the school day later won’t alone fix teen sleep deprivation, the AAP acknowledges. It outlines other factors, including use of digital devices, and suggests parents enforce a “media curfew.” Though the AAP recommends schools accommodate student sleep patterns, its conclusion emphasizes “the personal responsibility that families and students themselves have in modifying their sleep habits.”