Buy ADHD Medications , Other names: ADD; Attention Deficit Disorder; Attention-Deficit Hyperactivity Disorder (ADHD); Childhood Hyperkinesis, Attention deficit hyperactivity disorder (ADHD) is a common behavioral disorder diagnosed in roughly 10 percent of school-aged children and adolescents. There are three main subgroups of ADHD: Predominantly inattentive ADHD: inattention is the main characteristic, daydreaming is common, Predominantly hyperactive/impulsive ADHD: hyperactivity and impulsiveness predominate. Combined ADHD: all three behaviors (inattention, hyperactivity and impulsiveness) are present.