Score of inattention subscale of ADHD rating scale-IV is significantly higher for AD/HD than PDD.

Attention-deficit/hyperactivity disorder (AD/HD) and pervasive developmental disorder (PDD) must be differentiated because the respective treatments are different. However, they are difficult to distinguish because they often show similar symptoms. At our hospital, we have the rearer of a patient answer both the ADHD Rating Scale-IV (ADHD-RS) and the Autism Spectrum Screening Questionnaire (ASSQ), and use the results as an aid for the diagnosis of AD/HD or PDD. These results were compared with reference to PDD and AD/HD for an examination of the features of the two disorders. The subjects of our study were 45 children with AD/HD and 77 children with PDD. ADHD-RS score was significantly higher for AD/HD than PDD, but the total ASSQ score was significantly higher for PDD than AD/HD. Furthermore, for the inattention subscale of ADHD-RS, both total score and number of high-score items were significantly higher for AD/HD than PDD. As for the ASSQ score for PDD, it was significantly higher than for AD/HD in the domains of repetitive behavior, social interaction, and communication problems. In addition, PDD features many high-score items in the social interaction domain. We thought that these results about both ADHD-RS and ASSQ were useful for the differentiation of AD/HD or PDD.