Impaired sustained attention, focused attention, and vigilance in youths with autistic disorder and Asperger's disorder

• More ADHD-related symptoms and attention deficits were noted in ASD than typically-developing youths.
• Youths with Asperger's disorder (AD) had more oppositional symptoms than those with autism.
• Youths with AD had more sustained attention deficits than youths with autism.
• Youths with autism had more focused attention deficit than those with AD.
• There were low correlations between CCPT indexes and ADHD symptoms in ASD youths.

The study compared the attention-deficit/hyperactivity disorder (ADHD) related clinical symptoms and a wide-ranging attention performance in 216 youths with autistic disorder (autism), 138 youths with Asperger's disorder (AD) and 255 typically-developing youths. The diagnosis of autism and AD were made based on the clinical assessments according to the DSM-IV criteria and confirmed by the Autism Diagnostic Interview-Revised. All the participants were assessed with the Conners’ Continuous Performance Test (CCPT) and the questionnaires about ADHD, oppositional, and autistic symptoms. All indices of the CCPT were analyzed based on a recently developed factor structure, including focused attention, cognitive impulsivity, sustained attention, and vigilance. We found that compared with typically-developing youths, youths with autism and AD showed more inattentive, hyperactive/impulsive, and oppositional symptoms, and performed worse in focused attention and sustained attention as assessed by the CCPT. Youths with AD also showed more oppositional symptoms than youths with autism. Moreover, youths with autism had poorer focused attention than youths with AD; but, youths with AD had more impaired sustained attention. Our results validate different manifestations of ADHD-related symptoms and attention performance between youths with autism and youths with AD and suggest intervention for youths with autism spectrum disorders should consider these specific measures.