By Amy Norton
NEW YORK (Reuters Health) - Children with ADHD are more likely than their peers to cross the street when cars are dangerously close, according to a study published Monday.
The findings, researchers say, may help explain why children with the disorder have a higher-than-average risk of being hit by a car.
Past studies have found that children with ADHD (attention-deficit hyperactivity disorder) have raised rates of various injuries, including roadway accidents, but the reasons have not been clear.
Since children with the disorder have difficulty staying focused and controlling their behavior, the researchers on the new study thought these kids might tend to act impulsively "curbside" -- not taking the time to look left and right before darting into the street.
But that was not the case, they found. In a virtual-reality test that simulated street-crossing, children with ADHD did typically check traffic like they should.
"They were actually like other kids in looking right and left before crossing," said lead researcher Despina Stavrinos, of the University of Alabama at Birmingham.
Instead, things went awry somewhere in the children's decision process about whether it was safe to cross.
Compared with their peers, Stavrinos told Reuters Health, "children with ADHD chose to cross when there were smaller gaps between cars, which is risky."
On average, by the time kids with ADHD reached the other side of the virtual road, they had less time to spare before traffic would have closed in on them.
That all suggests problems with "executive function" could be at work, according to Stavrinos and her colleagues.
The term, Stavrinos explained, refers to the control center of the brain, and such critical functions as judgment and planning. "So in the example of crossing the street," she said, "that would mean questions like, 'How far away is that car?' and 'How long will it take me to cross?'"
The findings, reported in the journal Pediatrics, are based on 78 children ages 7 to 10, half of whom had been diagnosed with ADHD. The other half had no known developmental disorders.
Each child made 15 simulated street-crossings in a virtual reality environment. They also took standard tests of attention and executive function, while parents reported on their kids' tendency to follow, or not follow, rules.
Overall, the study found, children with ADHD picked less-safe times to cross the street. And their scores on the measure of executive function correlated with the safety of their street-crossings.
In fact, "executive dysfunction" seemed to fully account for the link between ADHD and the safety of a child's crossings.
But while executive function sounds complex, Stavrinos said the findings do offer parents practical tips for making sure a child with ADHD knows how to cross the street safely.
"It's important for parents to be aware that maybe teaching kids to look right and left is not enough," she said.
Stavrinos suggested that parents also talk to their children about how to judge when it is safe to cross and practice safe crossings with them. "I think practice really is the key," she said.
One limitation of the current study is that all of the children with ADHD had been off of their medication for 24 hours before the tests.
So it's not clear, Stavrinos said, if children on medication would fare better. That's a question for future studies, she said.
She noted, though, that kids usually take ADHD medications in the morning. So by after-school time, when many would be making their solo street-crossings, the medication would be wearing off.
SOURCE: http://bit.ly/nTAzoL Pediatrics, online July 25, 2011.