Comparing Intelligence Test Profiles to Assess Tourette's Disorder with Attention-Deficit Hyperactivity Disorder

OBJECTIVES: The study compared the intelligence test profiles of Tourette's Disorder (TD), attention-deficit hyperactivity disorder (ADHD), and TD with ADHD (TD+ADHD) groups. METHODS: The Korean Wechsler Intelligence Scale for Children-third edition (K-WISC-III) and Korean Wechsler Intelligence Scale for Children-fourth edition (K-WISC-IV) were administered to 13 children and adolescents with TD, 17 children and adolescents with ADHD, and 15 children and adolescents with TD+ADHD. Each parameter was compared among the groups using the Kruskal-Wallis test. RESULTS: The mean scores of the freedom from distractibility/working memory index (FD/WMI) and the digit span and arithmetic subtests of the TD+ADHD group were significantly lower than those of the TD group. CONCLUSION: According to the intelligence test results, the comorbid ADHD+TD group showed a significant decrease in working memory compared to the TD group. These findings are similar to those of previous research on cognitive functions and suggest that the TD+ADHD comorbid and TD alone groups exhibit different endophenotypes. The results also imply that WISC-III and WISC-IV, the most commonly used intelligence tests clinically, are effective in evaluating cognitive functions such as attention. Further research is required to confirm these results.

Korean Wechsler Intelligence Scale for Children-Fourth Edition Profiles in Child and Adolescent with Attention-Deficit Hyperactivity Disorder : Retrospective Study

OBJECTIVES: The aim of this study was to investigate Korean Wechsler Intelligence profiles and specific abilities related to attention problem of children with attention-deficit hyperactivity disorder (ADHD). METHODS: The Korean Wechsler Intelligence Scale for Children-fourth edition (K-WISC-IV) and Advanced Test of Attention (ATA) were administered to 91 children and adolescents (age 8.5+/-2.6 years, 73 boys) with ADHD. Pearson correlation and independent t-tests were used. RESULTS: The means of Working Memory Index (WMI) and Processing Speed Index (PSI) showed a score of low average in K-WISC-IV. WMI scores for the K-WISC-IV showed clinically significant correlations with omission errors, commission errors, and response time variability on auditory ATA. PSI scores also showed significant correlations with response time and variability on visual ATA. In addition, significantly lower digit span backward scores were observed in hyperactive-impulsive/combined subtypes compared to inattentive subtype (t=3.60, p<.001). CONCLUSION: Children with ADHD showed significantly lower scores in WMI and PSI which were clinically correlated with ATA scores, and hyperactive-impulsive/combined subtypes showed poorer working memory functions in WMI. Follow-up studies are proposed.