Cognitive profiles of children with attention deficit hyperactivity disorder: differences between those with and without comorbid psychiatric diagnoses

Abstract

Objective: The Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) is widely used to measure cognitive abilities of children with attention-deficit/hyperactivity disorder (ADHD). In this study, we aimed to investigate whether the cognitive profiles of children with ADHD and comorbid psychiatric disorders differ from those of children with a diagnosis of ADHD only. Specifically, the study aimed to examine whether the processing speed index (PSI) scores differed between the two groups.. Method: The participants were 245 children aged between 6 and 17 years old, who had been diagnosed with ADHD and completed the WISC-IV test. The participants were divided into two groups, one with a psychiatric comorbidity (n=52) and one without (n=193). The two groups were compared regarding age, sex, WISC-IV full scale IQ, and subtest scores which were retrospectively collected from medical records. Results: The results showed that the mean age of the comorbidity group (11.56 + 3.25) was higher than the group without comorbidities (10.08 + 2,78, p=0.004). Furthermore, the group with comorbidities had lower PSI scores (81.69 + 21.518) compared to the group without comorbidities (89.88 + 19.105, p=0.008). Discussion: The results support the hypothesis that the cognitive profiles of children with ADHD and comorbid psychiatric disorders differ from those of children with ADHD only. These findings provide important insights for the assessment and diagnosis of ADHD, as well as the role of cognitive assessments in identifying potential comorbidities in children with ADHD.