Teenagers can make do with less sleep: Study finds

By Dr. Ananya Mandal, MDFeb 21 2012

According to guidelines teenagers need nine hours of sleep a night, but a new study suggests more sleep can actually hurt a teen's grades.

According to the Brigham Young University study by economists Eric Eide and Mark Showalter, for older teens, six to seven hours a night was adequate. The optimal amount of sleep for 12-year-olds was higher, about eight hours, while 10-year-olds did best with about nine hours.

“If your kid’s not getting nine hours of sleep, maybe you don’t have to worry so much,” Showalter says, unless they’re regularly getting significantly less. “Certainly there is good scientific evidence that extreme sleep deprivation or oversleeping has serious health consequences,” he says.

Showalter believes the current recommendations are based on surveys of adolescents in the 1970s. The teens were brought into a lab a few days a year for three years and told to sleep as long as they wanted to. Any parent of a teen knows that how much they want to sleep could be way more than how much they need to sleep.

“We couldn’t find much scientific empirical backing for the common recommendations,” Showalter says, echoing a paper that came out last week in the journal Pediatrics. That report, by Australian researchers, concluded that “no matter how much sleep children are getting, it has always been assumed that they need more.”

“So when (parents) read our study and find out that seven hours is really fine, then that makes them feel better about their teenagers sleep patterns,” said Eric Eide, a Brigham Young University economist. This study is the first to analyze the school performance of teens, and it looked at a nationally representative sample of 1,724 students. The report appears in the current issue of the Eastern Economics Journal.