08/18/2011 02:39 pm ET Updated Dec 06, 2017

1 In 10 Kids Diagnosed With ADHD: Study

About one in 10 kids is diagnosed with attention deficit hyperactivity disorder (ADHD), according to a new government report, which is an increase from more than 10 years ago.

However, that doesn't necessarily mean there are more kids who have ADHD -- rather, it could just mean better detection or an increase in diagnoses of the disorder, researchers said.

"We don't have the data to say for certain what explains these patterns, but I would caution against concluding that what we have here is a real increase in the occurrence of this condition," Akinbami told HealthDay.

The mental health disorder includes symptoms if inattentiveness, impulsivity and hyperactivity, which usually begin in childhood.

The new Centers for Disease Control and Prevention report shows that children's diagnoses of ADHD rose from 7 percent between 1998 and 2000 to 9 percent between 2007 and 2009, though diagnosis of the disorder in Mexican children was lower than other ethnic groups.

More boys than girls have ADHD, but the increase in ADHD diagnoses rose about equally for both sexes, according to the report. ADHD diagnoses for boys ages 5 to 17 rose from 9.9 percent to 12.3 percent from 1998-2000 to 2007-2009, while for girls, diagnoses rose from 3.6 percent to 5.5 percent.

There was also a rise in diagnoses for poor children -- over the last 10 years, ADHD diagnoses increased to 10 percent for kids whose families have an income that is less than 100 percent of the poverty level, and 11 percent for kids whose families have an income that is 100 to 199 percent less than the poverty level.

About half of kids with ADHD also continue on to have it in adulthood. Here, Health.com explains 15 signs for knowing if you have adult ADHD: