Minority children are less likely to be diagnosed with attention-deficit/hyperactivity disorder (ADHD) according to a new study published online today in the journal Pediatrics.

Researchers looked at the records of over 17000 children from the kindergarten class of 1998 to 1999 who were enrolled in the Early Childhood Longitudinal Study. The disparity in diagnoses between minority and white children continued through the eighth grade.

Lead author Paul Morgan, an associate professor of education at Pennsylvania State University, and his team found that by eighth grade, the parents of seven percent of white children reported an ADHD diagnosis. In comparison, only three percent of black children and four percent of Hispanic children had been diagnosed.

“It’s a consistent pattern of what we’re interpreting as comparative underdiagnosis.” Morgan told Reuters.

“If you’ve got certain groups of kids with a disorder that is not being picked up…they might not be accessing treatments that can help in terms of their school-based functioning,” he said. Without treatment, children may act out or have poor self-esteem.

The researchers caution that more study is needed to determine if minority children have been underdiagnosed or white children have been over diagnosed. Still, they said “Medical and school-based professionals should ensure their efforts to reduce ethnic/racial disparities in ADHD diagnosis and treatment also extend to groups other than African Americans.”

Boys are more likely to be diagnosed than girls. Being raised by an older mother and growing up in an English speaking home raised the likelihood of a diagnosis as did certain types of problem behaviors.

The study also found that minority children were less likely than white children to receive medication to treat ADHD.

The study authors says ADHD is the mostly commonly diagnosed mental health disorder for children in the United States. According to the CDC, ADHD is characterized by regularly having difficulty in focusing and paying attention. Children with the disorder may have trouble sitting still. Other symptoms may include forgetting things, frequent daydreaming, speaking without taking turns or acting without thinking.

There is no single test to diagnose ADHD and many of the symptoms may be associated with other causes. Hearing and visions test may be used to rule out other problems. Doctors may talk with parents, teachers and sometimes the child himself to make a diagnosis.

Once diagnosed, the treatments may include taking medication and behavioral therapy. The CDC says an early diagnosis can help a child reach his or her full potential.