Boys identified as hard-to-manage at age 4 and age-matched controls
were assessed on
laboratory measures of inattention, impulsivity, and hyperactivity at ages
4, 6, and 9.
Hard-to-manage boys still exhibited some behavioral difficulties at age
9, but were not more
inattentive or impulsive than controls. Boys with Attention Deficit Disorder
(ADD) at age
9 showed performance deficits in each symptom-related domain relative to
problem boys
without ADD and controls. However, hard-to-manage problem boys with and
without
ADD did not differ on most earlier measures of inattention, impulsivity,
and hyperactivity,
suggesting that symptoms specific to ADD emerged more clearly between ages
6 and 9.