What is ADHD?
Attention deficit hyperactivity disorder (ADHD) is a disorder that affects behavior. It manifests around the age of 5 or 6, although symptoms can appear in younger children. Three main symptoms define ADHD including inattention, hyperactivity, and impulsivity. The symptoms are severe enough to affect the child's behavior in social situations and at school. The criteria for ADHD diagnosis were established in the Diagnostic and Statistical Manual of Mental Health (DSM-IV; American Psychiatric Association) in 1994. To be diagnosed with ADHD, a child must exhibit the symptoms outlined in this slideshow for at least six months.