Is lack of sleep a problem in your home?

If sleep deprivation happens frequently, the important brain development that needs to take place during childhood (or at least some portion of it) simply can't happen. But sleep scientists say that they haven't studied sleep deprivation in children long enough to have definite answers about such long-term effects.

"The bottom line is that we don't really know," says Owens. "What we do know is that even modest amounts of chronic sleep deprivation in adults clearly have a cumulative effect." Owens is referring to the research on adult sleep deprivation that shows the huge cost of this deficit to society (in terms of accidents and health care).

"From a neurophysiological standpoint, I don't think there's any reason to suspect that it's significantly different in children and it may be even worse," she adds.

Sleep deprivation among children is a ubiquitous and largely unrecognized barrier to learning, reports Edward Gibson, an epidemiologist at McMaster University in Hamilton, in a paper he presented earlier this year. The former president of Sleep/Wake Disorders Canada recently surveyed 3,200 Canadian high school students and found that 70 per cent feel "very sleepy" between 8 and 10 a.m. Today's teens are thought to be the most sleep deprived among children because their sleep need is approximately nine hours, but they rarely get that much. Gibson's study also found that 75 per cent slept fewer than 8.5 hours each night.

If sleep-deprived adults can make mistakes that may lead to serious accidents, what about children? Research is only beginning in this area. A 2001 Italian study of emergency-room visits by young boys showed a connection between risk of injury and less than 10 hours' sleep. The study also noted a direct association between injuries occurring between 4 p.m. and midnight, when the children had been awake at least eight hours.

Sleep scientists are also finding connections between inadequate sleep and hyperactivity. How children behave when they're tired is different from how adults behave when they're sleepy. "People say, ÔI'd know if my child were sleep deprived because he'd be dopey,'" says Stanley Coren, a psychologist at the University of British Columbia in Vancouver. "But that's not the way it works."

In kids, loss of sleep often shows up as symptoms of hyperactivity because they are trying hard to stimulate themselves and stay awake. "The child unconsciously notices that if he speeds up his activities and bounces off the walls, that gets the activity hormones going," says Coren. "This makes him more alert, so you have what appears to be a hyperactive child. It's like an adult self-medicating for a sleep problem by drinking massive amounts of coffee." Doctors who deal with hyperactivity often prescribe more sleep as a first step because it frequently solves the problem. If your kids constantly seem wound up, maybe it's sleep that their bodies crave, not more physical activity.

Sleep deprivation is also linked to attention deficit hyperactivity disorder (ADHD). "Some studies show that infants with sleep problems in early childhood are more likely to be diagnosed with ADHD and hyperactivity later," says Sadeh. "Even if the sleep issue isn't the original cause of ADHD, it can exacerbate it because it leads to additional pressure on the same systems."