Attention deficit hyperactivity disorder -- also referred to as ADD or ADHD -- is a biological, brain based condition that is characterized by poor attention and distractibility and/or hyperactive and impulsive behaviors. It is one of the most common mental disorders that develop in children. It is estimated that between 3 and 5 percent of preschool and school age children have ADHD or approximately two million children in the United States. Symptoms may continue into adolescence and adulthood. If left untreated, ADHD can lead to poor school/work performance, poor social relationships and a general feeling of low self esteem.

Those with the predominantly inattentive type often:

Those with the predominantly hyperactive/impulsive type often: