The comorbid RD+MD group is more impaired than groups with RD only or MD only on seven of ten neuropsychological composites¶

Claim · All claims
Evidence · 1 study · associational r2 · q3
Currency · newest study 2013 · not yet checked against its sources · not reviewed by a person · overdue for a recheck since 2018: baselines and conditions change

Subclaims¶

q3 i? Children with comorbid RD+MD show greater neuropsychological impairment than children with either disorder alone on seven of the ten constructs measured. → Willcutt 2013

Evidence¶

Willcutt 2013¶

Willcutt, E. G., Petrill, S. A., Wu, S., Boada, R., DeFries, J. C., Olson, R. K., & Pennington, B. F. (2013). Comorbidity between reading disability and math disability: Concurrent psychopathology, functional impairment, and neuropsychological functioning. Journal of Learning Disabilities, 46(6), 500-516. https://doi.org/10.1177/0022219413477476

q3 · i? · associational · r2

Group comparisons (ANOVA/chi-square) in the CLDRC twin sample of 241 RD-only, 183 MD-only, 188 RD+MD, and 411 controls found the comorbid group "more impaired than the groups with either disorder alone on seven of the ten neuropsychological composites."

"Comparisons among the groups with RD or MD indicated that the comorbid group was more impaired than the groups with either disorder alone on seven of the ten neuropsychological composites."

Discussion¶

Related Claims¶

• Groups with RD, MD, and RD+MD show elevated depression regardless of ADHD status, and the comorbid group has the highest rates of internalizing disorders — related
• Children with MD only receive extra math assistance far less often than children with comorbid RD+MD — related
• Comorbidity with ODD and CD in RD and MD is restricted to individuals who also meet criteria for ADHD — related
• Groups with reading difficulties perform significantly better than controls on the Stroop interference measure, and only math groups show set-shifting weakness — related
• Working memory, processing speed, and verbal comprehension weaknesses are shared across reading and math deficits — related
• Reading deficits are uniquely associated with phoneme awareness and naming speed, whereas math deficits are uniquely associated with set shifting — related
• Executive function deficits in comorbid RDMD show some evidence of under-additivity, especially in inhibition, shifting, and updating — related
• The math deficit profile of children with comorbid RDMD is additive: it equals the sum of the deficits of isolated RD and MD groups — related
• Children with comorbid RDMD are significantly more impaired than children with isolated RD or MD in math, reading, and executive function outcomes — related
• Math difficulties are more strongly associated with social isolation than reading difficulties, and peer dislike of readers with RD is explained by ADHD symptoms — related
• Group differences in math skills between LD and comorbid groups are more pronounced in symbolic than non-symbolic math tasks — related