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Updated: Jun 18, 2026

Assessing Dyslexia at Six Year of Age
Published on: May 1, 2020
Reading Disabilities With and Without Co-Occurring ADHD: No Evidence for Additive Impact on Reading Skills
Rebecca A Marks1,2, Hanna Thesken2, Rachel T Norton3
1Department of Human Development and Family Science, Purdue University, West Lafayette, Indiana, USA.
Purpose:
Reading disabilities (RD) and attention deficit/hyperactivity disorder (ADHD) frequently co-occur. We investigated whether RD+ADHD co-occurrence is associated with differences in reading outcomes, or in the brain basis of word reading, compared to RD alone.
Method:
In Study 1, 175 children (ages 7-13) completed literacy-related assessments and a reading task during fMRI. Groups included 50 RD, 53 RD+ADHD, and 72 students without disabilities (SWOD). Study 2 replicated analyses in an independent sample of over 2,100 children.
Results:
In Study 1, SWOD differed from the groups with RD on all reading measures. We found no evidence of significant differences behaviorally, or in functional brain activation, between the RD and RD+ADHD. Study 2 replicated the behavioral findings of Study 1; a fourth group of children with ADHD only had mean reading scores in the typical range.
Conclusion:
Together, these studies suggest that co-occurring RD+ADHD is not associated with meaningfully greater reading impairment than RD alone.
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