Injury kills more 11-year-olds in the United States than all other causes combined, and a new study from University of Alabama at Birmingham reveals ADHD almost doubles the risk of serious injury among this age group.

"We found that children with more ADHD symptoms, those in the 90th percentile, are nearly twice as likely to get hurt as those with symptoms in the 10th percentile," says David Schwebel, Ph.D., director of the UAB Youth Safety Laboratory and lead author. Boys, he said, are nearly twice as likely to be injured as girls.

The research, published in the September/October Academic Pediatrics, studied 4,745 fifth-graders from Houston, Los Angeles and Birmingham. Serious injury is defined as one that requires medical attention; more than half of the injuries included broken bones.

"These are children that no longer have adults or parents or teachers watching over them all the time, which means they have to make decisions on their own," Schwebel said. "Children with ADHD are impulsive, inattentive; they may not notice things because their mind is wandering, and they're hyperactive so they're always moving and getting into things."

The Center for Disease Control and Prevention says 9.4 percent, or 5.4 million, kids ages 4-17 in the United States have been diagnosed with ADHD. Schwebel, professor in the UAB Department of Psychology, says this study will improve injury-prevention strategies for millions of mental health practitioners, pediatricians, parents and children.

"Medication, seeing a psychologist and getting treatment for ADHD will reduce the risk and the symptoms," Schwebel said. "In some cases you can make the child aware and get them to think about what they're doing so they will slow down and be more careful. It won't work for everyone, but it certainly can't hurt to try."

This study is part of UAB's Healthy Passages research, a decade-long program funded by the CDC, designed to help families, health-care providers, schools and communities develop effective policies and programs to keep children and adolescents healthy. The participants' gender was 52 percent male. The mean age was 11.12 years. The racial/ethnic breakdown for the youth was: 30 percent African-American, 42 percent Hispanic, 23 percent white non-Hispanic, 5 percent multiracial or of other ethnicities.

Schwebel also analyzed the affect of Conduct Disorder. CD is a disorder marked by chronic behavioral problems like breaking rules without reason, physically or psychologically abusing people or animals and destruction of property, symptoms that go beyond simple mischievousness. Researchers wanted to know if the combination of CD and ADHD had a multiplier effect on a child's chances of injury.

"What we found in the past, with younger children, is that ADHD and oppositional behaviors mattered equally. But in this study with fifth-graders, we found that ADHD is more relevant," says Schwebel. "When you put ADHD and CD together statistically, we did not see multiplication at all. ADHD is the primary issue."