An Hour of Sleep Counts for Kids

Children with insufficient sleep have trouble behaving but extra sleep helps behavior

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) It's an awards night on TV, and your child wants to stay up until the end. Will losing just a half hour or hour of sleep make that much of a difference? Maybe.

A recent study has found that nearly a half hour of extra sleep can help children's behavior at school. And losing an hour of sleep means less control over their school behavior.

"Kids need enough sleep."

The study, led by Reut Gruber, PhD, of the Attention, Behavior and Sleep Laboratory at the Douglas Mental Health University Institute in Quebec, Canada, aimed to find out how extending or shortening children's sleep affected their behavior at school.

The study was small, involving 33 children who were on track developmentally and did not have any reported sleep, behavioral, medical or academic problems.

The children were between the ages of 7 and 11 and were randomly split into two groups for the experiment.

Seventeen kids were assigned to a group that would be given an extra hour to sleep for five school days.

The other group, with 16 kids, would have an hour of sleep taken away from them for five school days.

Both groups were assessed for five nights at home without any sleep intervention before the experiment began.

The hour added or taken away came from whatever the child's initial typical sleeping time was.

The children's sleep was assessed by an actigraph watch and by a daily log kept by the parents.

The behavior of the kids was assessed by their teachers, who were not told which sleep group each child was assigned to. The teachers used a standard behavioral assessment tool from the researchers.

The teachers assessed the children on the first and last days of both the week with normal sleep and the week of the experimental sleep conditions.

In addition, the parents were asked to rate the daytime sleepiness of their children following the sleep experiment.

The group of children who received an extra hour to sleep actually ended up getting an average of 27 minutes of additional sleep.

The children restricted from an hour of sleep lost an average of 54 minutes sleep.

The researchers found that getting an additional 27 minutes of sleep was linked to an improvement in the children's restless-impulsive behavior and the child's evenness of moods.

The additional 27 minutes of sleep was also associated with a significant decrease in daytime sleepiness reported by the children.

Meanwhile, taking away 54 minutes of sleep from the children resulted in a decrease in children's ability to manage their moods and their impulsive behavior.

"A modest extension in sleep duration was associated with significant improvement in alertness and emotional regulation, whereas a modest sleep restriction had opposite effects," the researchers wrote.

They noted that these findings match up with past research showing that too little sleep can lead to irritability, frustration and difficulty managing emotions.

Their findings made one thing clear: "Sleep must be prioritized, and sleep problems must be eliminated."

Experts agree.

"This article supports previous research about the debilitating potential of insufficient sleep in terms of cognition and behavior," said William Kohler, MD, director of the Florida Sleep Institute and director of Pediatric Sleep Services at Florida Hospital Tampa. "

"The comment that the authors made at the end that sleep must be prioritized is very important," Dr. Kohler added. "We keep gathering all these studies that show the important of sleep and the negative aspects of insufficient and poor quality sleep."

He said the study's small size was a weakness, as was the use of subjective measurements of behavior, but the assessments were standardized in a way that may help minimize the bias, and the use of actigraphs provides more accuracy than sleep logs.

The study was published October 15 in the journal Pediatrics. The research was funded by the Natural Sciences and Engineering Research Council of Canada and the Canadian Institutes of Health Research. The authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
October 9, 2012
Last Updated:
October 14, 2012