Cognitive profiles for school-age children with Attention-Deficit/Hyperactivity Disorder or with Mathematics Disorder on the Differential Ability Scales-Second Edition (DAS-II)

The purpose of this study was to examine differences in cognitive functioning between children with Attention-Deficit/Hyperactivity Disorder (ADHD) and children with Mathematics Disorder. More specifically, this study examined whether differences in various areas of cognitive functioning existed between the two groups and if so, were the differences reflected in discrepancies in the proportion of children who exhibited weaknesses in certain domains. Cognitive functioning was assessed using the Differential Ability Scales-Second Edition (DAS-II; Elliott, 2007). Eighty-six (ADHD n = 47 and Mathematics Disorder n = 39) primarily English-speaking school-age children of at least Low Average intelligence were evaluated by trained and supervised graduate students. An analysis of covariance (ANCOVA) was conducted for each of the relevant DAS-II cluster and subtest scores. Children with ADHD earned significantly higher scores than children with Mathematics Disorder on measures of nonverbal reasoning ability, spatial ability, working memory, processing speed, and long-term storage and retrieval. In addition, the proportion of children with Mathematics Disorder who had weaknesses in certain cognitive domains was significantly higher than the proportion of children with ADHD who had weaknesses in these areas. Implications of these findings, including the possibility that having Mathematics Disorder affects a myriad of the broad cognitive abilities, in addition to mathematics achievement, are discussed.