Kristina Moll|Karin Landerl|Margaret J. Snowling|Gerd Schulte?Körne
Understanding comorbidity of learning disorders: task?dependent estimates of prevalence
Ludwig-Maximilians-Universität München|University of Graz|University of Oxford|Ludwig-Maximilians-Universität München
background reading disorder rd mathematics disorder md frequently cooccur however exact comorbidity rates differ largely studies given md characterised high heterogeneity symptom level differences comorbidity rates may result different mathematical subskills used define md comorbidity rates rd likely higher md measured mathematical subskills build number processing also require language ie arithmetic fluency measured magnitude processing skills methods association literacy arithmetic fluency magnitude processing well overlap deficits domains assessed representative sample 1454 third graders results associations significantly higher literacy arithmetic literacy magnitude processing also reflected comorbidity rates comorbidity rates literacy arithmetic deficits four times higher expected chance whereas comorbidity rates literacy magnitude processing deficits exceed chance rate deficits two mathematical subskills showed overlap also revealed dissociations corroborating high heterogeneity md results interpreted within multipledeficit framework implications diagnosis intervention discussed conclusions overlap rd md depends subskills used define md due shared domaingeneral factors mathematical subskills draw language skills strongly associated literacy require language findings indicate symptom deficits arithmetic associated different cognitive deficits deficit language skills deficit number processing