Reading comprehension, word decoding and spelling in girls with autism spectrum disorders (ASD) or attention‐deficit/hyperactivity disorder (AD/HD): performance and predictors

Abstract

Difficulties with aspects of literacy are often seen in children with autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (AD/HD). The bases of the connections between these disorders and literacy difficulties are poorly understood. Furthermore, it is not clear if existing research is representative for girls. There were three aims: (1) to compare performance in reading comprehension, word decoding, and spelling in girls with ASD (n = 20), AD/ HD (n = 36), and community girls with typical developing (girls; n = 54); (2) to assess rates of reading and writing disorders within groups; and (3) to examine the predictive value of measures of autistic and AD/HD symptomatology to reading comprehension in the whole girl sample. Participants were aged between 8 and 17 years, and had a full scale IQ>70. Standardized tests of literacy, oral vocabulary, and non-verbal ability were administered. Parent ratings of degree of autistic symptomatology and both parent and teacher ratings of AD/HD symptomatology were collected for all girls. Girls with diagnosed ASD could not be separated significantly from typically developing girls or girls with AD/HD on average performance on any literacy test. However, among girls with ASD, 40% had at least one reading and writing disorder. Girls with AD/HD performed lower than typically developing girls in reading comprehension, word decoding, and spelling, and 56% had at least one reading and writing disorder. In regression analysis, using the total sample, both degrees of autistic and AD/HD symptomatology negatively contributed to the variance in reading comprehension after controlling for oral vocabulary, word decoding, and non-verbal ability. Whereas AD/HD contributed to the variance in reading comprehension once autistic symptomatology was controlled for, the opposite was not true. However, a large bivariate correlation between autistic and AD/HD symptomatology somewhat complicates the interpretation of that result. The findings highlight the importance of monitoring and supporting the literacy development in girls with ASD or AD/HD. Results from regression analyses suggested that word decoding and/or oral vocabulary training may not be sufficient for the girls fully to overcome difficulties in the important skill of reading comprehension.