Attention deficit hyperactivity disorder is one the rise among U.S. children, according to a new study from the Centers for Disease Control and Prevention, which found that nearly 10 percent of minors are now diagnosed with the condition.

Commonly known as ADHD, the disorder is usually diagnosed in childhood and is marked by impulsivity, as well as problems paying attention, sitting still and concentrating. Children who are afflicted but left untreated often experience difficulties interacting in school and at home.

Between 1998 and 2009, the percentage of children diagnosed with ADHD rose from 7 to 9 percent, with researchers finding even larger increases among kids living in the South and Midwest regions of the nation. However, researchers were quick to point out that the new findings don't necessarily mean more children are developing the condition.  

It probably indicates that children have a better opportunity to get diagnosed now, rather than a huge change in the numbers of children with ADHD, Dr. Lara Akinbami, the study's lead author and a medical officer at the CDC's National Center for Health Statistics, told MSNBC.

Using data from a survey conducted by the National Center for Health Statistics, Akinbami and her colleagues discovered that ADHD diagnoses rose almost equally in boys and girls, with cases among females climbing from 3.6 percent to 5.5 percent, compared to 9.9 percent to 12.3 percent among males. However, Akinbami said researchers were surprised to see that diagnoses in minority and poor children -with the exception of those of Mexican descent - have increased enough to catch up with the rest of the population.

Western states continue to have the lowest rates of ADHD, with diagnosis have ranged from 5.4 percent to 5.8 percent over the last decade.

It does match trends for several other chronic conditions which have lower prevalence in the west, Akinbami told the source, adding that the greater proportion of Mexican children in that region may account for the lower rate.

While the exact cause of ADHD is unknown, scientists may be closer to identifying a cause. Researchers at the National Institute on Drug Abuse recently published a study in the journal Molecular Psychiatry that signaled out a specific dopamine receptor in the brain that may increase a person's risk of developing the condition.