Direct assessment of the cognitive correlates of attention deficit disorders with and without hyperactivity

Abstract

The cognitive functioning of children identified as attention deficit disorder with hyperactivity (ADD/H) was compared to that of children identified as attention deficit disorder without hyperactivity (ADD/WO). Based on information on symptoms supplied by teachers, 20 ADD/H and 15 ADD/ WO children were selected according to DSM-III criteria from a large elementaryschool learning disabilities and behavior disorders population. For comparison purposes, 16 normal children from regular classrooms were also selected. Children from all three groups were evaluated with a battery of cognitive tests. Intelligence test scores differentiated the two ADD groups, with the ADD/H children obtaining significantly lower Full Scale IQ scores than both ADD/WO and control children. In addition, ADD/H children obtained significantly lower Verbal IQ scores than ADD/WO children. Both ADD groups performed more poorly than controls on Spelling and Reading Achievement, and the ADD/WO group performed more poorly on Math Achievement. The two ADD groups took longer to complete six Stroop and rapid naming tasks than the control groups but did not differ among themselves. The ADD/WO group made more errors on a visual matching task than the controls, but neither ADD group differed from controls on the accuracy of the Stroop tasks, rapid naming tasks, measures of receptive and expressive language, visual-motor integration, or sustained visual attention. The differences between the two ADD groups were fewer than expected on the basis of previous research and are more global than specific.