Executive function impairments in high IQ children and adolescents with ADHD

Abstract

Objective: To demonstrate that high IQ children and adolescents diagnosed with ADHD tend to suffer from executive function (EF) impairments that: a) can be identified with a combination of standardized measures and normed self-report data; and b) occur more frequently in this group than in the general population. Method: From charts of 117 children and adolescents aged 6 to 17 years with high IQ (≥ 120) who fully met DSM-IV diagnostic criteria for ADHD, data on 8 normed measures of executive function (EF) were extracted: IQ index scores for working memory and processing speed, a standardized measure of au-ditory verbal memory, and 5 clusters of the Brown ADD Scale, a normed, age-graded rating scale for ADHD-related executive function impairments in daily life. Significant impairment was computed for each individual relative to age-appropriate norms for each measure and comparisons were made to base-line rates in the general population. Results: Sixty-two percent of participants were significantly impaired on at least 5 of these 8 markers of EF. Chi-square com-parisons of scores from these high IQ participants were significantly different (p < 0.001) from standar-dization norms for each of the eight EF measures. Conclusions: High IQ children and adolescents with ADHD, despite their cognitive strengths, tend to suf-fer from significant impairments of executive functions that can be assessed with these measures; incidence of these impairments is significantly greater than in the general population. These results are fully consistent with data on high IQ adults diagnosed with ADHD.