Children who stay up past their bedtimes may face more problems than just frustrated parents.

A new study shows that elementary and middle school-aged children who stay up late have more problems at school.

Researchers found teachers rated students who got eight hours or less of sleep as having the most trouble remembering older material, learning new lessons, and completing high-quality work.

"Just staying up late can cause increased academic difficulty and attention problems for otherwise healthy, well-functioning kids," says researcher Gahan Fallone, PhD, associate professor at the Forest Institute of Professional Psychology in Springfield, Mo., in a news release. "So the results provide professionals and parents with a clear message: When a child is having learning and attention problems, the issue of sleep has to be on the radar screen."

Fallone presented the results of the study today at the American Medical Association's 24th annual Science Reporters Conference in Washington. The study also appears in the journal Sleep.

What Kind of Sleeper Are You?

Poor Sleep, Poor Performance

Researchers say it’s the first study to use teachers to assess the effects of poor sleep in elementary and middle school students.

In the study, teachers were asked to complete weekly performance reports on 74 school children aged 6 to 12 without knowing how much sleep the students received.

Over the course of the three-week study, researchers varied the amount of sleep the children received. For example, one week they went to bed and woke up at their usual times. Another week, they stayed up much later than normal, and in the last week the children got no less then 10 hours in bed a night.

The results showed that teachers reported many more academic problems during the week that the children stayed up late and got less sleep compared with the weeks that they followed their normal sleep schedule or got more sleep than normal.

The teachers also reported that the students had more difficulty paying attention when they stayed up late.

However, the study did not show that sleep restriction or staying up late caused hyperactivity. In fact, teachers reported that students were slightly less active after staying up late.

"My advice for parents is to maintain a consistent emphasis on the importance of sleep and not to back off from enforcing bedtimes with kids, whether it's on school nights or weekend nights,” says Fallone. “Know when your kids are going to sleep and how they're sleeping during the night. If your child is having persistent difficulty with sleep, then talk to your doctor and get help."

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By Jennifer Warner, reviewed by Louise Chang, MD

SOURCES: Fallone, G.Sleep, December 2005; vol 28: pp 1561-1567. News release, Brown University. News release, American Medical Association.