• We studied 32 boys with attention deficit disorder (ADD)—21 with hyperactivity, and 11 without hyperactivity. The ADD group with hyperactivity had significantly more neurological and cognitive abnormalities and a higher frequency of prenatal and neonatal abnormalities. It seems that hyperactivity is an important determinant of the degree of neurological and cognitive involvement in children with ADD. It also seems that a cause of "early" brain insult is more likely when hyperactivity is present.
(AJDC 1988;142:153-155)