Attention deficit disorder, which is also known as ADD or ADHD, is one of the most common psychiatric disorders affecting children. The three main types are: the predominantly inattentive type, the predominantly hyperactive-impulsive type, and the combined type. Warning signs include talking too much, fidgeting the hands and feet, and problems with organization. Symptoms usually become evident in the preschool or early elementary years, and can continue into adolescence and even adulthood. In many cases, the most effective treatments include medications and behavioral therapies.