Autism and ADHD: an investigation of executive function and symptom presentation

This study is an investigation of executive functioning and symptom presentation in autism and ADHD. It is argued that the distinction between these disorders is not always clearly apparent, particularly when more marginal cases are considered. This study particularly included for examination a group of children who appeared to meet the diagnostic criteria for both autism and ADHD, notwithstanding that the present diagnostic criteria (DSM-IV-TR, APA, 2000) preclude such comorbidity. The children in the three diagnostic groups were examined with a battery of executive function measures - since both autism and ADHD have been explained in terms of executive function impairment - to determine whether the disorders presented with an executive function fingerprint that might differentiate them. In addition, the current and previous symptom presentation of children in the clinical groups was examined. Principal findings were that the clinical groups were not differentiated on the executive function measures. However, the autism and ADHD groups were clearly differentiated on symptoms. The comorbid group had a combination of symptoms that were diagnostic of autism as well as those symptoms that were diagnostic of ADHD. This is taken to support the possible comorbidity of autism and ADHD.