This study aimed to investigate the presence of specific cognitive impairments and the diagnostic utility of the WISC-III in children with ADHD. Ninety-eight children with ADHD and 81 children without ADHD matched by age and gender (control group), between the ages of 6 and 12 years, participated in the study. Children with ADHD revealed the most pronounced deficits in the subtests tapping working memory and processing speed. Freedom from Distractibility was the cognitive profile most impaired and that showed the highest diagnostic accuracy to discriminate children with ADHD. The optimal cutoff scores of the most common WISC-III cognitive profiles revealed greater diagnostic accuracy than the traditional approach of full or partial profiles. Taken together, these results suggested that in the context of a comprehensive psychological assessment, the WISC may provide knowledge about the specific cognitive strengths and weaknesses that characterize this disorder and may be useful in the decision-making process relative to ADHD diagnosis.
Keywords: Attention-Deficit/Hyperactivity Disorder (ADHD); WISC; cognitive profiles; processing speed; working memory.