The potential clinical relevance of the WISC-V in ADHD assessment: an analysis of structural models and within-subject cognitive discrepancies

The current study examined the clinical utility of the Wechsler Intelligence Scale for Children – Fifth Edition (WISC-V) as a valid tool for the evaluation of Attention-Deficit/Hyperactivity Disorder (ADHD) in children and adolescents. The primary objectives were to explore the construct validity of the WISC-V based on its original factor structure and alternative structural models, including hierarchical and bifactor models. Additionally, the study aimed to investigate whether significant differences between primary and complementary indices could reveal a cognitive pattern associated with ADHD. A total of 241 participants, aged 6 to 17 years and recently diagnosed with ADHD, were included in the study. Confirmatory factor analyses were conducted to evaluate the fit of different models. Results indicated that the four-factor higher-order model showed the best fit among admissible models, whereas bifactor parameterizations yielded improper solutions. The original hierarchical five-factor model proposed by Wechsler also showed good, though significantly poorer, fit than the four-factor model. Moreover, scores on the Working Memory and Processing Speed indices were significantly lower, with medium to large effect sizes, than those on Verbal Comprehension, Visual-Spatial Reasoning, and Fluid Reasoning indices. Additionally, the Cognitive Proficiency Index was significantly lower than the General Ability Index. These findings suggest that, although the discrepancies are more frequent in ADHD than in the general population, they are neither sensitive nor specific enough to serve as diagnostic markers. They may complement, but not replace, other sources of information in ADHD assessment. The study highlights the need for further research to validate the WISC-V’s clinical utility as a supplementary tool in ADHD assessment.