Reading and math achievement in children with dyslexia, developmental language disorder, or typical development: Achievement gaps persist from second through fourth grades

We examined how children (n=448) who met research criteria for separate vs. co-occurring DLD and dyslexia performed on school-based measures of academic functioning in reading and math between second and fourth grades. Growth curve models were used to examine the overall form of growth and differences between groups. Children with DLD and/or dyslexia in second grade showed early and persistent deficits on school-administered measures of reading and math. In second grade, children with typical development (TD) scored significantly higher than all other groups, children with DLD+dyslexia scored significantly lower than all other groups, and children with dyslexia-only and DLD-only did not differ from each other. Only small differences in growth rates were observed, and gaps in second grade did not close. Few children (20-27%) meeting research criteria for dyslexia and/or DLD had received specialized support services. Children with DLD only received services at less than half the rate of the dyslexia groups, despite similar levels of academic performance. Evidence of significant and persistent functional impacts on academic achievement support the validity of standard research criteria for dyslexia and DLD. Low rates of reported support services in these children —especially those with DLD-only— highlight the need to raise awareness of these disorders.