Attention deficit hyperactivity disorder (ADHD) is a developmental condition of inattention and distractibility, with or without accompanying hyperactivity. In the past, various terms were used to describe this condition, including hyperactive syndrome and, from the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III), "minimal brain dysfunction." In the revised DSM-III, this condition was renamed ADHD. In the DSM-IV-TR, adults or children must have had an onset of symptoms before age 7 years that caused significant social or academic impairment. More recently, attention has focused on adult forms of ADHD, which probably have been underdiagnosed. From the app MedScape.