Virtually all U.S. high school students are sleep-deprived, a new study finds.
It might come as no surprise to parents, but what is surprising is just how many kids fall short of the recommended nine to 10 hours of sleep a night — and just how little sleep they really are getting.
More than 90 percent of 9th through 12th graders fell short of this goal, and 95 percent of high school seniors missed out.
The consequences can be bigger than just nodding off in class. Youngsters who miss out on sleep are more likely to be obese, to get diabetes and to do poorly in school. And older high-schoolers are often driving. Sleepy drivers are far more likely to be involved in crashes.
One study found that teens who slept the least were 21 percent more likely to have been involved in a crash than those who got more sleep. Those who got six hours or less sleep on the weekend were 55 percent more likely to be in a crash than those who slept more.
Drowsy driving plays a role in as many as 7,500 fatal crashes a year — 25 percent of all crashes — the Centers for Disease Control and Prevention has found.
"Sleep is essential for the health of the human brain," Charles Basch and colleagues at Columbia University in New York wrote in their report, published in the journal Preventing Chronic Disease.
"The data show a need for universal interventions — those directed toward all students," they added.
"For example, the American Academy of Pediatrics has encouraged school districts to establish start times that optimize students' sleep. Unfortunately, intervention research directed toward high school populations has received little attention."
For the study, Basch's team looked at in-depth interviews done with teenagers from 2007 to 2013. They were asked detailed questions about sleep. Only 6 to 7 percent of girls and 8 to 9 percent of boys said they got nine or more hours of sleep a night.
A different study done at Columbia earlier this year found that one-fifth of 16-year-olds reported getting less than six hours of sleep a night. They were 20 percent more likely to be obese by age 21, compared to their peers who got more than eight hours of sleep.
The National Sleep Foundation says adolescents are biologically wired to stay up later at night, so they need a chance to sleep longer in the morning, or need help getting to bed earlier at night. The group recommends that teenagers, especially, limit the use of video screens late at night, establish a nightly routine much like parents are advised to do for young children, and, if all else fails, take naps.