Small changes in child’s sleep can have big impact at school

Small increases in the amount of sleep a child gets can improve behavior at school by a significant amount, while slight decreases in sleep can make them more likely to act out, according to a new study.

The authors say that the study, published Monday in the journal Pediatrics, is the first controlled investigation of the effect of sleep extension or reduction on the behavior of healthy children at school.

The researchers split 34 children ages 7 to 11 into two groups of 17, extending the sleep of one group by up to an hour and reducing the sleep of the other group by about the same amount. They measured the amount of sleep each child got during a baseline period and then during the experimental period using a special wristwatch called an actiwatch that keeps track of how much each child moved during the night. To test changes in a child’s behavior, the researchers gave a questionnaire to the child’s teacher with questions about mood and behavior. Importantly, the teachers did not know which group each child was in.

The team had more luck reducing sleep than extending it: The extension group slept an average of 27 minutes longer than normal, while the reduction group slept 54 minutes less.

Both groups, however, showed significant changes in behavior. Based on the teachers’ responses, children who slept more acted out less and were less moody, and parents reported they were less sleepy as well. Meanwhile, children who slept less received worse scores from their teachers, and their parents thought they were much sleepier during the day.

The results may not seem surprising -- everyone knows that we all get grumpy after a bad night’s sleep. But the changes are noteworthy given the small differences in total sleep time and the relatively short period of the study: The researchers changed the kids’ sleep only for a week.

The researchers write that their findings confirm a widely held view among researchers and clinicians that a lack of sleep “is associated with difficulty in the modulation of impulse and emotion.” As a result, “sleep must be prioritized, and sleep problems must be eliminated,” they write, if our kids are to be given the best chance to succeed at school.

You can read a summary of the study here.

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