Attention-deficit/hyperactivity disorder (ADHD) is a neurobiological disorder characterized by developmentally inappropriate impulsivity, inattention, and in some cases, hyperactivity.
Everyone has occasional difficulty sitting still, paying attention, or controlling impulsive behavior. For some children and adults, however, the problem is so pervasive and persistent that it interferes with their daily lives at home, at school, at work, and in social settings.
Until recently it was believed that children outgrew ADHD in adolescence. This is because hyperactivity often diminishes during the teen years. However, we now know that many symptoms continue into adulthood. If the disorder goes undiagnosed or untreated, adults with the disorder may experience trouble at work and in relationships, as well as emotional difficulties such as anxiety and depression.