March 3, 2003 -- Kids beg, they whine: "Can we stay up just a little longer?" Well, there's evidence now that sleep deprivation brought about by even one less hour of sleepdoes make a difference in a how well a child learns the next day.
"Even minor changes in sleep ... can impair a school kid's learning, memory, attention, concentration," researcher Avi Sadeh, DSc, director of the Laboratory for Children's Sleep and Arousal Disorders at Tel Aviv University, tells WebMD. His study appears in the current issue of Child Development.
It points to the need for establishing a "sleep ritual" for young children, says Glenn Isaacson, MD, chief of the pediatric ear, nose and throat service at Temple Children's Hospital in Philadelphia. He commented on Sadeh's study for WebMD.
All too often, kids are too wired to sleep -- they've been drinking sodas, watching TV, playing video games right up to bedtime. "There's so much excitement in the house, that they want to be part of it," Isaacson tells WebMD. "It's important to establish a pattern or ritual in the evening that will help them quiet down and go to sleep. Have an established bedtime and stick to it, including during weekends."
Previous studies of adults have found that sleep deprivation significantly impairs the brain's executive control system, which helps people organize, prioritize, and focus on tasks. But few studies have focused on children. Those few have tended to examine extreme rather than modest sleep deprivation, says Sadeh.
In his study, Sadeh looked at the effects of adding or subtracting just one hour of sleep. The 77 children in his study were in fourth and sixth grades.
Each wore an actigraph, a device on the wrist that detects movement. Information gleaned from the actigraph was used to determine the children's sleep schedule -- the time they fell asleep and the duration of sleep. The device also gives researchers an indication of sleep quality -- how many times they wake during the night and how long they were awake.
For the first two nights of the five-night study period, each child kept his or her normal sleep hours. For the last three nights, the parents were randomly asked either to extend or reduce their child's sleep time by one hour.
He also gave the children a series of tests at both the beginning and end of the study, to see how changes in sleep patterns affected their performance.
Which children functioned best? Those who got an extra hour of sleep did best on the tests -- even though they woke up more during the night, reports Sadeh. For those children whose sleep was decreased by one hour, just the opposite was true -- they did worse on the tests, but woke up less during the night, indicating it's the amount of sleep time that counts.
Much the same is true of adults, says Isaacson. "When you sleep late on the weekends, you find yourself repeatedly waking up a little in the morning -- which I find quite delicious, myself. When I get up, I feel fresher and better able to perform."
Almost all studies have shown that when people are deprived of sleep, their mood and ability to perform tests is a bit worse, Isaacson says.
"Having a ritualistic bedtime pattern, especially for younger kids, will help them slow down, get ready to sleep. Also, avoid caffeine and sugar before bedtime because it gives the body the wrong signals and won't let them feel sleepy," he advises.
With teenage kids, a later bedtime may be more acceptable -- since studies have shown that a teen's natural pattern of sleep is to go to bed later and wake up later, says Isaacson.