Many high school teachers are familiar with the sight of a dozing teenager slumped over his or her desk.
But a study by the National Sleep Foundation in Washington suggests just how severe the problem is.
Only 20 percent of the 11- to 17-year-olds surveyed for the study receive the recommended nine hours of sleep on school nights. Nearly half—45 percent—said they receive less than eight hours of sleep.
More than 1,600 adolescents and their parents were questioned about sleep habits during a survey conducted last September and October. The results were released late last month.
The sleep deficit, the researchers say, has consequences in the classroom: Adolescents who don’t get enough sleep tend to have lower grades than their peers who report getting sufficient sleep.
That’s no surprise, given the study’s findings that 28 percent of adolescents surveyed reported falling asleep in class at least once a week, that 22 percent reported falling asleep at least once in a week while doing homework, and that 14 percent said they had either missed or were late to school because they overslept.
Students don’t need to eliminate our-of-school activities entirely to get more sleep, Jodi A. Mindell, the co-chairwoman of the survey task force and a vice chair of the National Sleep Foundation, said in an interview last week. Ms. Mindell, who is also the associate director of the Sleep Center at the Children’s Hospital of Philadelphia, said some adolescents report spending two to three hours an evening communicating online with friends by instant messaging.
“But they can [instant message] for an hour instead,” she said, to allow time for their studies. “It’s all about balance.”
Schools and teachers, she said, also play a huge role in addressing the problem of sleep-deprived students. Sleeping in school is often ignored, when it should be reported to parents, she said.
“In a classroom, where you have to sit down and be still for half an hour, an hour, two hours,” Ms. Mindell said, “you’re going to see that sleepiness surface.”