MONDAY, April 5, 2004 (HealthDayNews) -- Experts know too much TV is bad for older kids, but it may also harm the attention spans of children as young as 1 year old, a new study suggests.
"We found that watching television before the age of 3 increases the chances that children will develop attentional problems at age 7," said study author Dr. Dimitri Christakis, of the University of Washington, Seattle.
The study appears in the April issue of Pediatrics.
Experts estimate that between 4 percent and 12 percent of U.S. children may be affected by Attention Deficit Hyperactivity Disorder (ADHD). Many parents may believe their children are just "born that way," but the home environment can also play a key role in the development of the disorder, Christakis said.
"Nurture profoundly influences nature -- you're born with genetic predispositions, and then your environment really shapes them," he pointed out. "There's every reason to believe that early experiences can profoundly affect the brain."
In most American homes, part of that "early experience" involves television viewing. A recent Kaiser Family Foundation survey found an estimated 30 percent of U.S. kids under 2 years of age had a TV in their bedroom. And more than a third of families -- 36 percent -- said they had their televisions switched on "all the time."
In their study, Christakis and his team examined data on nearly 1,300 children from a major government survey of children and youth. They compared rates of TV watching during the first three years of life to the later development of attention problems at age 7.
The researchers found that "for each additional daily hour of television that young children watched on average, the risk of subsequently having attentional problems [by age 7] was increased by almost 10," Christakis said. This means that 1- to 3-year-olds who watched eight hours of television a day "would have an 80 percent higher risk or attentional problems compared to a child who watched zero hours," he explained.
According to the study, the average 1-year-old is exposed to about two hours of TV a day, and that number rises to about 3.6 hours a day by 3 years of age.
Christakis stressed the study could not conclude that children who watch TV in infancy or as toddlers were at increased risk for ADHD because teacher reports -- a key part of an ADHD diagnosis -- were not part of the government data available. However, the results of tests used in the study to diagnose attention problems tend to mirror those used to diagnose ADHD, he said.
The study was also unable to dismiss the possibility that "even at age 1, children who are predisposed to developing attentional problems are drawn to television," Christakis said. But he believes that hypothesis is "unlikely, because we don't think of 1-year-olds as having attentional problems, certainly not a clinically detectable one," he added.
The question remains how television influences the developing mind. "Our hypothesis is that it's the rapidity of image-change that's potentially damaging to children's brains," Christakis said. "They are experiencing events unfolding in a surreal fashion -- this is not how life unfolds."
And the trouble may extend beyond what parents think of as just "bad" TV.
"Even children's programming is not immune, because it exploits rapid image-change to keep children engaged with the screen; it is part of what makes it interesting," Christakis said. "The question is -- is it good for them? Our study suggests that it very well may not be."
Christakis, a pediatrician at Seattle's Children's Hospital and Regional Medical Center, tells all of the parents he works with that "they should not let their child watch television during the first two years of life, and subsequently they should exert extreme caution both with respect to the amount and content." That advice coincides with current guidelines issued by the American Academy of Pediatrics.
There are plenty of other reasons to keep kids away from the TV, Christakis said. "We know that for older kids, watching TV is associated with aggression, with obesity, with inactivity," he said. "And now we know that for very young children, it may predispose them to attentional problems."
Every year, the American Academy of Pediatrics tries to get children and their parents off their living room sofas and away from the TV by launching "TV-Turnoff" week, which this year is scheduled for April 19-25.