Nine Percent Of US Children Age 8 To 15 Meet Criteria For Having ADHD, Study Suggests

"Despite widespread concern that the rate of attention-deficit/hyperactivity disorder (ADHD) is on the rise, the national population-based prevalence of ADHD in U.S. children has not [previously] been firmly established," the authors write as background information in the article. ADHD is characterized by hyperactivity, impulsive behavior and an inability to pay attention to tasks; the condition affects social behaviors and achievement at school and work.

Tanya E. Froehlich, M.D., of Cincinnati Children's Hospital Medical Center, and colleagues studied a group of 3,082 children designed to represent the entire population of 8- to 15-year-olds in the United States. Between 2001 and 2004, children's parents or other caregivers were interviewed by phone and provided information about each child's ADHD symptoms, including when they first appeared and any impairment they caused during the previous year. They also reported whether their child had ever been diagnosed with ADHD or taken medicine to treat it, in addition to providing sociodemographic details.

Based on standard diagnostic criteria, 8.7 percent of the children (equivalent to 2.4 million children nationwide) fulfilled criteria for ADHD in the year prior to the survey. Hispanics were less likely than whites to have ADHD and boys were more likely than girls to meet criteria, although girls who did have ADHD were less likely to have their condition recognized. A total of 47.9 percent of the children who met ADHD criteria had previously been diagnosed with the condition.

The poorest one-fifth of children were more likely than the wealthiest one-fifth of children to have ADHD. "Reasons for the increased likelihood of ADHD in poorer children may include the elevated prevalence of ADHD risk factors (i.e., premature birth and in utero or childhood exposures to toxic substances) in this group," the authors write. "In addition, given the high heritability of ADHD and its negative impact on social, academic and career outcomes, it is plausible that families with ADHD may cluster within the lower socioeconomic strata."

Among children meeting criteria for ADHD, 39 percent had received some medication treatment and 32 percent were treated consistently with ADHD medications during the previous year. Despite the prevalence of ADHD in poorer children, they were least likely to receive medications consistently. This finding "warrants further investigation and possible intervention to ensure that all children with ADHD have equitable access to treatment when appropriate," the authors conclude.

Reference: Arch Pediatr Adolesc Med. 2007;161(9):857-864.

This study was supported by the Ambulatory Pediatrics Association Young Investigator Grant, a National Research Service Award grant, a grant from the National Institutes of Health and a Robert Wood Johnson Generalist Physician Faculty Scholars Award.