Sex differences in neuropsychological functioning among children with attention-deficit/hyperactivity disorder

Cognitive impairments are often reported in research on children with attention-deficit/hyperactivity disorder (ADHD). However, studies analyzing sex differences in this context are still sparse. This study aimed to compare the neuropsychological performance of boys and girls with ADHD across several cognitive domains. Verbal comprehension, perceptual reasoning, working memory, processing speed, and general cognitive performance were assessed in 240 children aged 6-17 years: 120 children (65 boys) with a clinical diagnosis of ADHD and 120 typically developing children (60 boys). Underperformance of children with ADHD compared to controls was observed in all the evaluated cognitive domains, except for verbal comprehension. Significantly lower scores in perceptual reasoning, with a medium effect size, were found in girls with ADHD relative to boys, although the sexes did not significantly differ in terms of the remaining variables. Children's ADHD subtypes did not correlate significantly with any performance measure, and no significant interaction effects between children's age and sex were noted in the results. The performance commonalities found between boys and girls with ADHD outweighed the differences, which highlights the importance of further research on cognitive dysfunction in girls with ADHD, regardless of sex differences in the prevalence of the disorder.