BETHESDA, MD. -- American children aren't getting enough sleep.
Children in every age group "don't even meet the low end of the range recommended by experts" for sleep in a 24-hour period, according to a national survey, Mary A. Carskadon, Ph.D., said at a conference on sleep disorders sponsored by the National Institutes of Health.
Dr. Carskadon was referring to the results of the National Sleep Foundation's annual Sleep in America poll, which included data on children's sleep for the first time this year. The NSF found that televisions and computers in children's bedrooms are the main contributors to sleep loss. In the phone survey of a random sample of 1,473 parents and caregivers, respondents reported that nearly half (43%) of schoolaged children, one-third of preschool children, and "an astounding 20% of infants and toddlers" had TVs in their bedrooms, Dr. Carskadon said.
These children go to sleep an average of 20 minutes later and sleep 40 minutes less per night than children with no TV in their rooms, for a loss of more than 2 hours of sleep every week. Many never "catch up" on their sleep on the weekends, as approximately one-fourth of children 3-10 years old actually sleep less on weekends than on weekdays, said Dr. Carskadon, professor of psychiatry and human behavior at Brown University, Providence, R.I.
For these children, bedtimes are delayed, overall sleep time is decreased, and daytime sleepiness is common. "A paper coming out soon in the Archives of Pediatrics and Adolescent Medicine shows that among young adolescents, watching TV in the bedroom at night predicts major sleep disturbances such as insomnia in young adulthood," she added.
Most of the parents polled reported that their children get "the right amount" of sleep, apparently unaware that the actual number of hours they say their children sleep falls far short of the experts' recommendations.
The other major culprit in children's sleep loss is caffeine consumption. The NSF poll showed that 26% of children 3-10 years old drink at least one caffeinated beverage every day. Those who have caffeinated drinks sleep less than children who don't ingest caffeine (an average of 9.1 versus 9.7 hours per night), for a loss of about 3.5 hours every week.
Dr. Carskadon noted that myriad caffeinated drinks are specifically targeted to children and adolescents, and coffee snops offer chocolate drinks, teas, and coffee concoctions with flavors calculated to appeal to children and teenagers.
Early school start times are another contributor to children's sleep loss.
With the delay in circadian phase and the delay in the melatonin secretory phase that accompany puberty, preadolescents and adolescents in particular "are under enormous physiological pressure to delay their sleep cycle"--to stay awake until late at night and to rise late in the morning.
"These kids' circadian cycles are already hammered by their biology. …