Attention deficit hyperactivity disorder (ADHD) rates rise among children.New research from the Centers for Disease Control and Prevention (CDC) reveals an additional two million kids have attention attention-deficit/hyperactivity disorder compared to stats collected nearly a decade earlier.

Susanna Visser, an epidemiologist with the CDC’s National Center on Birth Defects and Developmental Disabilities, said in a press release. «When children diagnosed with ADHD receive proper treatment, they have the best chance of thriving at home, doing well at school, and making and keeping friends».

ADHD is characterized by problems paying attention and controlling impulses, daydreaming, being overly active with squirming or fidgeting, and having difficulty getting along with others, CBS reports.

About half of the children were diagnosed by age 6, but about half of those with severe cases of ADHD received a diagnosis around 4 years old.