Executive Functioning Deficits in Attention‐Deficit/Hyperactivity Disorder Are Independent of Oppositional Defiant or Reading Disorder

ABSTRACT

Objective

To evaluate deficits of executive functions in children with attention-deficit/hyperactivity disorder (ADHD) classified by type (combined [CT] or predominantly inattentive [IT]) and comorbidity with oppositional defiant disorder (ODD) and reading disorder (RD).

Method

The Wisconsin Card Sorting Test (WCST) and Tower of Hanoi (TOH) were administered to 28 community volunteers and 359 children (7.5–13.5 years old) divided into ADHD types, RD, and ODD.

Results

ADHD/CT children solved fewer puzzles and violated more rules on the TOH than ADHD/IT or non-ADHD subjects. On the WCST there were no differences between diagnostic samples in perseverativeness, but ADHD/CT patients made more nonperseverative errors than ADHD/IT children. ODD was associated with moderately better TOH performance and RD with excessive rule breaks.

Conclusions

Executive functioning deficits were found for only ADHD/CT children and were independent of comorbidity with RD or ODD. J. Am. Acad. Child Adolesc. Psychiatry, 1999, 38(9):1148–1155.