Once upon a time, not very long ago, experts and lay people alike tended to see post-toddlers and preteens as excellent sleepers. Children in that age group exhibited neither the night wakings of the diaper set nor the night-owl tendencies of those for whom the peer group rules.
Over about the past 15 years, though, research has suggested that the untroubled sleep of elementary-school-age children is something of a fairy tale. They appear to suffer from some of the same sleep problems as younger and older children, and many sleep researchers suspect that, like Americans in general, they tend not to get enough sleep.
Understanding more about sleep in the 5-to-11 age group has taken on new urgency, too, because of the steep increase in the number of children diagnosed with attention deficit hyperactivity disorder. ADHD manifests itself in many of the same ways that inadequate sleep does.
“Elementary-school-age children are probably the least studied in terms of sleep,” said Jodi A. Mindell, a professor of psychology at St. Joseph’s University near Philadelphia and the associate director of the sleep-disorders center at the Children’s Hospital of Philadelphia. “There is more that we know today than 15 years ago, when we knew nothing, but there is dramatically more that we don’t know.”
Campaign Under Way
One sign of the increased attention to the issue among policymakers is the $4 million earmarked by the National Institutes of Health to underwrite research into children’s sleep disorders. The new grants will build on earlier NIH-financed work that looked at a pediatric condition called obstructive sleep apnea.
One of the first sleep problems to be studied extensively in children of school age, obstructive sleep apnea refers to trouble children have breathing during sleep because of enlarged tonsils or adenoids.
The National Heart, Lung, and Blood Institute at the NIH has also taken a lead in bringing the sleep needs of young children to public attention.
In a five-year campaign launched last summer, an array of organizations, including the National Association of Elementary School Principals, endorses the idea that at least nine hours of good sleep a night is critical for children to do their best in school and other activities, to stay healthy, and to avoid accidents.
The campaign features Garfield, the popular cartoon cat, as its “star sleeper.”
“There’s been accumulating evidence about the importance of sleep to good overall health for all ages,” said Dr. Carl E. Hunt, the director of the NIH’s National Center on Sleep Disorders Research.
“And there’s been increasing awareness on the part of sleep researchers that information about sleep is not known or appreciated by the public,” he added.
Marsha C. Egan, a school psychologist in the Liverpool, N.Y., district, couldn’t agree more. In a survey of students, parents, and teachers she conducted in two Liverpool elementary schools last year, more than 20 percent of the 120 parents who responded said they did not believe the amount of sleep their children got affected their school performance the next day.
“That tells me there’s an educational piece that should come into play,” she said.
Research suggests that elementary-school- age children who get enough sleep, which ranges down from about 11 hours a night, do better in school, are more contented, suffer fewer accidents, and are less likely to become obese than children who don’t get the sleep they need, Dr. Hunt said.
Researchers point to a multitude of sleep-deficit effects on children’s moods, their ability to focus and think, and their self-control.
“The primary thing the studies show got affected is mood,” said Dr. Judith A. Owens, who heads the pediatric-sleep-disorders clinic at Hasbro Children’s Hospital in Providence, R.I.
“Children more easily became frustrated, intolerant, irritable, and oppositional [when they were short of sleep]. And there seems to be a pretty consistent finding that attention span, reaction time, and vigilance all suffer,” she said.
Some school-age children simply aren’t getting the sack time they need. But others have trouble sleeping, problems often similar to those that affect adults, though children were once thought to be exempt from such woes.
Dr. Owens found that among almost 500 children attending kindergarten through 4th grade in the Portsmouth, R.I., school district, 37 percent had at least one sleep- related problem. The prevalence of the problems in the study ranged from close to 4 percent for disordered breathing to 15 percent for bedtime resistance.
And teachers reported a full 10 percent as being significantly sleepy during the school day—almost certainly lower than the total number of children affected, because youngsters often react to a lack of sleep by becoming more active, rather than slowing down.
The picture may be even more worrisome for children at the older end of the elementary span. Recent research by the psychologist Avi Sadeh and others at Tel Aviv University in Israel suggests that 6th graders are adopting the sleep patterns of teenagers, which are influenced both by puberty and an increased number of late-night activities.
Teenagers naturally go to bed later and get up later, but they are often unable to rise as late as they want, leading to sleep deprivation.
In its study of 140 children in 2nd, 4th, and 6th grades, the Israeli team also found a negative relationship between family stress and sleep quality.
One of the most striking discoveries made by pediatric-sleep researchers is that children diagnosed with attention deficit hyperactivity disorder are more likely to have sleep problems than children without that diagnosis.
While the phenomenon is not well understood, it raises the possibility that some children will be diagnosed with ADHD when they are short of sleep.
But Dr. Owens, who along with her work on sleep disorders runs a program on learning, attention, and behavior at Rhode Island Hospital, cautions that some sleep problems may be an intrinsic part of ADHD or related to medications used to treat the disorder.
Many sleep specialists advise screening to detect sleep disorders for children with behavior problems as well as for those who are outright drowsy.
“Some children get labeled as ADHD who actually have sleep problems, like apnea,” Dr. Owens said, “and some have both sleep problems and ADHD.”
Coverage of research is underwritten in part by a grant from the Spencer Foundation.
A version of this article appeared in the November 28, 2001 edition of Education Week as Sleep Troubles of Young Children Studied