A B S T R A C T
Children with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) share
many common symptoms, including attention deficit, behavioral problems, and difficulties with social
skills. The aim of this study was to distinguish between ASD and ADHD by identifying the characteristic
features of both the disorders, by using multidimensional assessments, including screening behavioral
checklists, cognitive assessments, and comprehensive neurological battery. After screening for comorbid
disorders, we carefully selected age-, sex-, IQ-, and socio-economic status-matched children with typical
development (TD). In the Wechsler Intelligence Scale for children, a lower score was observed for the
ASD group than for the TD group in Picture concept, which is a subscale of perceptual reasoning. A lower
score was shown by the ADHD group than by the TD group in the spatial working memory test in the
Cambridge Neuropsychological Test Automated Battery (CANTAB1). Although ASD and ADHD have
many similar symptoms, they can be differentiated by focusing on the behavioral and cognitive
characteristics of executive function.