TUESDAY, Sept. 4, 2007 (HealthDay News) -- Watching more than two hours of television daily during childhood increases the likelihood of attention problems in adolescence, according to a new study.
Yet far from settling the debate, the findings add more confusion to the debate on whether television viewing might contribute to attention problems. The new research largely agrees with one previous study but disagrees with two others.
"I wouldn't advocate that watching TV is a good thing," said Tara Stevens, assistant professor of educational psychology at Texas Tech University in Lubbock, who in 2006 published a study finding no link between television viewing and hyperactivity disorder. "I'm just not sure there's a direct relationship between having a disorder and watching TV. I don't think that's definitive. This is one important piece to the argument, but it is still not the end," she said.
The current study is published in the September issue of Pediatrics and led by Robert John Hancox of the University of Otago in Dunedin, New Zealand. His team monitored the television-viewing habits of more than 1,000 children born in Dunedin in 1972 and 1973 between the ages of 5 and 15, as well as reports of attention problems at ages 13 and 15.
The authors determined that watching more than two hours of television per day between the ages of 5 and 11 increased the likelihood of attention problems in adolescence, with each hour of television viewing increasing the risk of "high adolescent attention problems" -- that is, the top 10 percent of attention difficulties -- by about 40 percent. This association held even after accounting for gender, socioeconomic status, early attention problems, and early cognitive ability.
"We found the amount of television did predict the amount of problems at age 13 and 15," Hancox said. "And these effects were not explained by early attention problems."
The team further found that TV watching during childhood and adolescence were independently associated with attention problems, suggesting that time in front of the television leads to both short- and long-term effects.
"Childhood TV viewing was associated with attention difficulties regardless of what you watch as an adolescent," he explained. "The amount of TV watched between 5 and 11 predicted problems between ages 13 and 15 regardless of what you watch between 13 and 15."
That doesn't mean it would be pointless to curtail your child's viewing habits now, he said. But it might only relieve short-term damage and not any longer-term effects.
"You may not be able to reverse what happened in childhood, but you can stop compounding the problem," he said.
The take-home message, Hancox concluded, is that parents should heed the American Academy of Pediatrics' recommendations, which say that children under two should watch no television at all, and that children over the age of two should watch no more than two hours per day -- recommendations that are in line with his findings
"This increase in risk kicked in with people who watched two hours of television per day," Hancox said. "For those who watched less, there was no increase in risk."
Hancox's findings are in general agreement with a 2004 study led by Dr. Dimitri Christakis of the Seattle's Children's Hospital and Regional Medical Center, which found a relationship between television watching at age 3 and attention problems at age 7. Yet they contradicted both Stevens' 2006 study, which found no link between TV viewing at age 5 and attention deficit-hyperactivity disorder at age 6, and an additional study out of Denmark.
Stevens lauded Hancox's effort. Yet she noted that, as a correlational study, it says nothing at all about causation. In that sense, it cannot answer a key question: Does TV viewing cause kids' attention problems, or do the parents of children with attention problems drop them in front of the TV more often to keep them occupied?
Additionally, the study makes no distinctions about what the children are watching, how much they are paying attention, and so on. Finally, Stevens questioned the lack of several key statistical variables.
"I would say there is some ambiguity in the results, because some statistical values were omitted," she said. "I wouldn't necessarily have come to the same conclusion with just the information they reported. I would be more confident in my conclusion if I knew they had looked at these other values."
Hancox's findings are published in the same issue of Pediatrics as another study, which found that the vast majority of TV food ads directed at children and adolescents promote foods that are high in fat, sugar, and sodium, and low in nutritional content.
Read the American Academy of Pediatrics' Committee on Public Education position paper, "Children, adolescents, and television," here.