Cognitive Profiling of Children and Adolescents with ADHD Using the WISC-IV.

Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder characterised by cognitive and behavioural impairments. This study aimed to identify cognitive patterns associated with ADHD in a sample of 719 children and adolescents (363 with ADHD and 356 controls) assessed using the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). Compared to controls, the clinical group exhibited significantly lower scores in the Working Memory Index (WMI), Processing Speed Index (PSI), and Cognitive Proficiency Index (CPI). No significant group differences were found in Verbal Comprehension (VCI) or Perceptual Reasoning (PRI) after controlling for age and sex. Factorial MANOVA results revealed that WMI, PSI, and CPI deficits remained stable across age groups and were more pronounced in males. Females with ADHD outperformed males in PSI. A binary logistic regression model including WISC-IV core indices classified VCI, PRI, WMI, and PSI with a Nagelkerke R2 of 0.44 as significant predictors of group membership, indicating that lower scores in WMI and PSI, and higher scores in VCI and PRI, increased the likelihood of ADHD classification. These findings reinforce the use of the WISC-IV as a complementary tool in the cognitive characterisation and clinical assessment of ADHD in youth.