WISC-V cognitive profiles in ADHD, SLD, and ADHD-SLD comorbidity: Overlap, dimensional associations, and limited discriminative utility.

Attention-deficit/hyperactivity disorder (ADHD), specific learning disorder (SLD), and their comorbidity are associated with weaknesses in cognitive efficiency; however, the diagnostic utility of WISC-V index patterns remains unclear. This study examined WISC-V cognitive profiles in children with newly diagnosed ADHD, SLD, ADHD-SLD comorbidity, and typically developing controls (N = 133; 6-16 years), with emphasis on Working Memory and Processing Speed. Age-controlled ANCOVAs evaluated group differences across primary and composite indices, including the General Ability Index (GAI), the Cognitive Proficiency Index (CPI), and their discrepancy. Dimensional associations were analyzed using partial correlations and multiple regressions across informants, and multinomial logistic regression with leave-one-out cross-validation assessed classification performance. Clinical groups showed lower Processing Speed and Cognitive Proficiency relative to controls; however, neither the GAI-CPI discrepancy nor intraindividual profile configuration differentiated diagnostic categories. Inattention emerged as the most robust cognitive correlate, particularly for Processing Speed. Cross-validated accuracy was modest (accuracy =.32), only slightly exceeding chance. Findings support a shared-vulnerability framework and caution against interpreting WISC-V index patterns as disorder-specific markers.