Less Sleep in Early Childhood May Impact Learning
Fewer than 10 hours a night associated with hyperactivity, lower intelligence scores
FRIDAY, Sept. 7 (HealthDay News) -- Children who slept fewer than 10 hours a night as infants are more likely to be described as hyperactive-impulsive and to score lower on cognitive performance tests than children who consistently slept 10 hours or more, according to a report published in the Sept. 1 issue of Sleep.
Jacques Y. Montplaisir, M.D., Ph.D., of the Sacre-Coeur Hospital in Montreal, Canada, and colleagues studied six-year-olds from 1,492 families who participated in the Quebec Longitudinal Study of Child Development. Parents answered questionnaires regarding sleep patterns, hyperactivity-impulsivity, inattention and daytime sleepiness. Subsets of the total group were given receptive vocabulary tests (948 children) and non-verbal intellectual tests (1,124 children) at age 5 and 6 years, respectively.
Children who slept less than 10 hours a night were more likely to have low scores on the vocabulary and non-verbal intellectual tests than children who slept 10 hours a night (41 percent versus 16.6 percent). Children whose sleeping hours changed from shorter to longer duration at 41 months were more than three times as likely as 11-hour sleepers to be described as hyperactive-impulsive. No significant association was found between sleep duration patterns and inattention or daytime sleepiness.
"Our results support the notion that 6-year-old children are more likely to exhibit externalizing behaviors such as hyperactivity-impulsivity instead of the classic signs of sleepiness when they do not get sufficient nocturnal sleep," the authors conclude.