Understanding comorbidity of learning disorders: task‐dependent estimates of prevalence

Abstract

The overlap between RD and MD depends on the subskills used to define MD. Due to shared domain-general factors mathematical subskills that draw on language skills are more strongly associated with literacy than those that do not require language. The findings further indicate that the same symptom, such as deficits in arithmetic, can be associated with different cognitive deficits, a deficit in language skills or a deficit in number processing.

Longitudinal Effects of the Home Learning Environment and Parental Difficulties on Reading and Math Development Across Grades 1–9

“…The findings support those of earlier studies indicating that mathematical difficulties more often co-occur with reading difficulties than the other way around ( Landerl and Moll, 2010 ; Carvalho and Haase, 2019 ). The findings do not, however, explain the comorbidity of reading and mathematical difficulties that is often found using fluency-based assessments ( Moll et al, 2019 ). The processes underlying the specific link between children’s reading comprehension and parental mathematical difficulties need to be examined further.…”

“…Literacy and numeracy development are strongly interrelated, and the comorbidity of reading and mathematical difficulties is frequent (e.g., Purpura et al, 2011 ; Davidse et al, 2014 ; Purpura and Ganley, 2014 ; Korpipää, 2020 ). Of the people with either reading or mathematical difficulties, up to 70% also perform worse than average in the other domain ( Landerl and Moll, 2010 ; Moll et al, 2019 ; Joyner and Wagner, 2020 ). Research has identified multiple shared and unique risk factors for reading and mathematical difficulties at the level of cognitive skills ( Geary, 2011 ; Moll et al, 2016 ; Child et al, 2019 ) and brain processes ( Raschle et al, 2011 ; Evans et al, 2015 ; Norton et al, 2015 ).…”

“…The multiple deficit model (e.g., Pennington, 2006 ) explains the emergence of learning difficulties and their comorbidity by the complex interactions between multiple risk factors at different levels (genes, brain, cognition, and environment), which can be either domain-specific (i.e., associated only with difficulties in one domain—either reading or mathematics) or domain-general (i.e., associated with difficulties in multiple domains). It has been established that, for example, a deficit in phonological awareness is specific to reading difficulties ( Melby-Lervåg et al, 2012 ) and a deficit in numerosity processing is specific to mathematical difficulties ( Hannula et al, 2010 ; Anobile et al, 2016 ), whereas difficulties in working memory, processing speed, and oral language are likely to affect more than one learning domain ( Koponen et al, 2007 ; Moll et al, 2019 ; Daucourt et al, 2020 ).…”

Predicting individual differences in reading, spelling and maths in a sample of typically developing children: A study in the perspective of comorbidity

“…while proximal processes generally indicate domain-specific processes (e.g. [17]). However, the proximal-distal dichotomy refers more explicitly to a formal architecture of the reading (spelling, maths) not only to the breadth of the processes considered.…”

Introduction to the Special Issue “Comorbidities between Reading Disorders and Other Developmental Disorders”

“…For example, poor performance on mathematical word problems or fact retrieval (i.e. multiplication facts) can be caused by poor number processing skills, or a consequence of poor language or reading skills (De Smedt & Boets, 2010;Donlan, Cowan, Newton, & Lloyd, 2007;Goebel & Snowling, 2010;Koponen, Mononen, Rasanen, & Ahonen, 2006;Moll et al, 2015;Moll, Landerl, Snowling, & Schulte-Körne, 2019;Simmons & Singleton, 2006).…”