Attention-Deficit/Hyperactivity Disorder (ADHD) is an inability to use skills of attention effectively. Many who have this disorder are "inattentive" and "impulsive." ADHD seems to be caused by a weakness in how the brain uses chemicals, or neurotransmitters. Medications, such as the class of stimulants, are used most often to treat ADHD because of the deficiency in brain chemicals.
