Objective: Psychopathological, neuropsychological and genetic findings indicate an association between ASD Spectrum Disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). The goal of this study was to compare the neuropsychological profiles of attention functions in children with ADHD and with ASD and without comorbid ADHD. The hypothesis was that either ADHD and autistic children with comorbid ADHD symptoms were more impaired in inhibition and sustained attention performance and that all individuals with ASD show more deficits in divided attention.
Method: Children aged 6 to 18 years old with ADHD (n = 30) or ASD with (n = 21) and without comorbid ADHD (n = 20) and 30 healthy children were included consecutively. Psychopathology was evaluated using the KIDDIE-SADS and symptom checklists for ADHD and ASD according to DSM-IV. Assessed neuropsychological functioning included inhibition, sustained as well as divided attention and alertness tasks.
Results: Age and IQ-corrected z-scores were used. Statistically significant group effects were found for the variables sustained attention median (F = 3.2, = .02), hits (F = 3.3, p = .02) and false alarms (F = 3.9, p = .01), divided attention hits (F = 3.3, p = .02), errors (F = 3.1, p = .03) and false alarms (F = 3.3, p = .03) and alertness false alarms (F = 2.9, p = .04). Pearson Correlations revealed associations between ADHD symptoms and sustained attention in the ADHD group and between ADHD symptoms and inhibition in the ASD+ group.
Conclusion: Our hypothesis was partly confirmed as ADHD children showed more deficits in sustained attention and ASD children in divided attention tasks. However there was no evidence that children with ASD and comorbid ADHD symptoms have a specific profile in comparison to pure ASD children.