Attention Deficit Hyperactivity Disorder (ADHD) cases among American children have soared in the past decade, according to a new study. Researchers also found that the rates of ADHD diagnosis amongst white children and black girls have increased dramatically.

ADHD or Attention-Deficit / Hyperactivity Disorder is characterized with the inability in paying attention, controlling behavior and being overtly active, according to Centers for Disease Control and Prevention (CDC). The condition is rapidly increasing in the U.S., with one out of every ten children showing symptoms of ADHD. The condition can't be cured but, can be successfully controlled.

The study included 850,000 children aged between 5 and 11 years from various races and ethnicities.  All the study participants were cared at care at Kaiser Permanente Southern California between 2001 and 2010. More than 39,000 or 4.2 percent children were diagnosed with ADHD within 11 years.

Researchers found that children belonging to white or black communities were more likely to be diagnosed with ADHD than Asians or Pacific Islanders.

 New ADHD cases increased from 2.5 percent in 2001 to 3.1 percent in 2010, an increase of about 24 percent, the study says. During the same period, ADHD diagnosis for black girls rose by 90 percent.

 "Our study findings suggest that there may be a large number of factors that affect ADHD diagnosis rates, including cultural factors that may influence the treatment-seeking behavior of some groups,"  said Darios Getahun, MD, from Kaiser Permanente Southern California's Department of Research & Evaluation and study lead author of the study.

In the present study, boys were about three times more likely to be diagnosed with ADHD than girls. Also, children belonging to higher socio-economic class had more likelihood of being diagnosed with ADHD than kids from families earning $30,000 or less.

"While the reasons for increasing ADHD rates are not well understood, contributing factors may include heightened awareness of ADHD among parents and physicians, which could have led to increased screening and treatment. This variability may indicate the need for different allocation of resources for ADHD prevention programs, and may point to new risk factors or inequalities in care," said Dr. Getahun in a press release from Kaiser Permanente.

The study is published in the journal JAMA Pediatrics