Objective: The aim of this study was to examine the differences between ADHD subtypes in executive function tasks compared to themselves and normal controls.
Method: In this study, 45 school aged children with Attention Deficit Hyperactivity Disorder (ADHD) and 30 normal children who were matched based on age and IQ score in Wechsler Intelligence Scale for Children-Revised (WISC-R) were compared in terms of executive function. We used Wisconsin Sorting Card Test to assess executive function in both groups. We also used children's scores in Children Symptom Inventory-4 (CSI-4) for diagnosing ADHD and specifying ADHD subtypes. Data were entered in SPSS-17 and analyzed by T-test and ANOVA static tests to clarify the differences between ADHD and controls and between ADHD subtypes. Scheffe's test was also used to identify which groups were different from one another. The mean and standard divisions (SD) were used for descriptive analysis.
Results: ADHD subtypes are significantly different in terms of perseverative responses (p≤ 0/01) and perseverative errors (p≤ 0/001). Based on Scheffe's test, Attention Deficit Hyperactivity Disorders-Hyperactive type (ADHD-H) is not that different from Attention Deficit Hyperactivity Disorders-Inattention type (ADHD-I) and Attention Deficit Hyperactivity Disorders-Combined type (ADHD-C), but there are significant responses and perseverative differences between ADHD-I and ADHD-C in terms of perseverative errors. ADHD-C shows more perseverative responses and perseverative errors than ADHD-I.
Conclusion: The findings of this study revealed that executive function patterns are different in children with ADHD compared to normal children. In this study it was also found that ADHD subtypes are also different in terms of perseveration and response inhibition domains; ADHD-C has more deficits in these domains.
Keywords: ADHD; Executive Function; Subtypes; Wechsler Intelligence Scale for Children-Revised (WISC-R).