ADHD, or Attention Deficit Hyperactivity Disorder, used to be divided into two separate diagnoses, ADD and ADHD depending on whether a person exhibited inattention without hyperactivty, or exhibited inattention and hyperactivity. Currently, only the diagnosis of ADHD exists, with various subtypes.
All people are restless and inattentive occasionally. These qualities are more severe, persistent, and impairing in children with Attention-Deficit/Hyperactivity Disorder (ADHD). A diagnosis of ADHD, requires that trouble with restlessness and inattention must cause difficulty in multiple areas such as at home, in school, or with friends. (more)