Attention Deficit Disorder And Impassivity And Overactivity ADHD is attention deficit disorder accompanied by impassivity and over activity. Medical scientists think ADHD is caused by a chemical problem in the brain. The front part of the brain helps you pay attention, concentrate, organize things, and put breaks on impulsive or unacceptable behavior. People’s brains with ADHD may not be able to use the brain’s main signal senders, neurotransmitters, the way it is suppose to. The front part of the brain has very little to do with intelligence, so it is possible to be very smart and still have ADHD. “ 3-5% of