Primer text from The College of William & Mary

ADHD is one of the most commonly diagnosed conditions of children (Centers for Disease
Control and Prevention, 2015). 

In a 2016 Centers for Disease Control and Prevention study, scientists found that 6.1 million children aged 2-17 years living in the U.S. had been diagnosed with attention-deficit/hyperactivity disorder (ADHD), which is similar to previous estimates.

• Ages 2-5: Approximately 388,000 children
• Ages 6-11: Approximately 2.4 million children
• Ages 12-17: Approximately 3.3 million children

The diagnostic term attention deficit/hyperactivity disorder (ADHD) refers to individuals who display patterns of inattention, impulsivity, and overactive behavior that interfere with daily functioning (American Psychiatric Association [APA], 2013).

The Diagnostic and Statistical Manual (DSM) V (APA, 2013) criteria for diagnosing ADHD list
three types of ADHD and the accompanying characteristics.