Objective: The current study investigated the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) cluster profiles of children with ADHD to examine the association between IQ profiles and diagnostic frequency, symptomatology, and outcome in this population.
Method: Hierarchical cluster analysis was conducted on 189 children with a diagnosis of ADHD-inattentive (ADHD-I) and ADHD-combined (ADHD-C) subtypes. Clusters were then compared across symptom rating scale factor scores, behavioral rating scales, and achievement scores.
Results: A five-cluster solution was extracted. One cluster was identified to have reduced processing speed relative to other WISC-IV indexes and significantly higher ratings of inattention and incidence of ADHD-I diagnosis. A second cluster had impairments in processing speed and working memory and was associated with impaired behavioral functioning.
Conclusion: Findings support a relationship between reduced processing speed and inattention and provide evidence that WISC-IV profiles may be helpful in predicting symptomatology and outcome in children with ADHD.