TEL AVIV, Israel -- An extra hour of sleep could mean the difference between an alert child and a more sluggish one, research reveals.
"In real life, the daily struggles between parents and children are around these narrow margins of an extra hour, extra TV show, et cetera," said Avi Sadeh, psychology professor at Tel Aviv University.
Too little sleep could lead to lower performance in school and more accidents, he said.
To investigate the effects on children of adding or subtracting an hour of sleep, Sadeh tweaked the number of hours slept by 77 fourth and sixth graders for five days during a week when the children were healthy and there were no special social events or school activities.
Sadeh and his colleagues found an extra hour of sleep can make a big difference. The children who slept longer, although they woke up more frequently during the night, scored higher on reaction tests, Sadeh reported in the March/April issue of the journal Child Development.
"When the children slept longer their sleep quality was somewhat impaired -- it was more fragmented and they woke up more often -- but in spite of this their performance improved because the extra sleep was more significant then the reduction in sleep quality," Sadeh said.
Previous sleep deprivation studies have focused on extreme, short-term periods of inadequate sleep and largely on adults, he said, adding the new findings are important because other studies have shown children get less sleep than they did a couple of decades ago. What this and past research cannot say with certainty is whether sleep deprivation as a child affects development into adulthood, although some possible influences have been hypothesized, he said.
"Some studies suggested that sleep-disturbed infants are more likely to develop attention deficit hyperactivity disorder when they grow older," Sadeh said.
In earlier studies, Sadeh's team found that fourth graders slept an average of 8.2 hours and sixth graders slept an average of 7.7 hours.
Previous research has shown children in elementary school need at least nine hours of sleep a night on a regular basis, said Carl Hunt, director of the National Center on Sleep Disorders Research in Bethesda, Md. Middle- and high-school-age children need somewhat less, he said, adding the consequences of insufficient sleep could be serious.
"A tired child is an accident waiting to happen," Hunt said. "And as kids get older, toys get bigger and the risks higher."
Hunt also noted too little sleep could result in learning and memory problems and long-term effects on school performance.
"This is an important extension of what we already know," Hunt said of Sadeh's research, adding sleep is as important as nutrition and exercise to good health.
To translate this into application, Hunt said, parents should make sure they know when their children actually are going to sleep and their rooms are conducive to sleeping instead of playing.
Consistent bedtimes and limiting children's caffeine intake starting in the late afternoon until they go to sleep also can help improve the quality of sleep a child gets, Hunt said.