 Attention-Deficit Hyperactivity Disorder ADHD is a chronic developmental disorder characterized by symptoms of inattention, impulsivity and hyperactivity that do not correspond to the childs developmental level American Psychiatric Association, 2013. For a diagnosis to be confirmed, symptoms must be present before age 12 and must be observed in at least to two domains of functioning, such as school, work, social interactions and family life American Psychiatric Association, 2013. 