Schedule of Events | Symposia

Sketchpad Series

Differentiating ADHD Diagnosis and Executive Function Contributions to White Matter Microstructure in Dyslexia

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

A. Takahesu Tabori¹ (atakahesutabori@mghihp.edu), A. Azor¹, R. Marks², A. Cardinaux³, A. Kaminsky¹, K. Wade³, R. Norton¹, A. Doyle^4,5, E. Braaten^4,5, J. D. E. Gabrieli³, J. A. Christodoulou¹; ¹MGH Institute of Health Professions, ²Purdue University, ³Massachusetts Institute of Technology, ⁴Harvard Medical School, ⁵Massachusetts General Hospital

Executive Function (EF) challenges are often identified in children with Dyslexia (DD) and ADHD, disorders that frequently co-occur. Our prior work found that EF weaknesses, rather than ADHD diagnosis, predict reading ability and related brain function among children with DD (Al Dahhan et al., 2022), pointing to EF as a shared mechanism for ADHD and DD. Here, we test the hypothesis that EF ability rather than ADHD diagnosis predicts differences in the brain’s white matter (WM) microstructure in children with DD. Diffusion data and standardized test scores were analyzed for 59 3rd-6th graders with DD (28 ADHD). Diffusion MRI data were preprocessed using QSIPrep (V.0.18.1). The auto-track feature of DSI Studio was employed to streamline the reconstruction of WM tracts, and quantitative scalar measures were computed at each voxel. We examined if there were group differences in WM tracts related to reading and EF as a function of diagnostic group (DD only vs DD +ADHD) and by EF ability (EF-low vs EF-high). ‘EF low’ was operationalized as 1.5 SD below the mean of controls of the same age group on the behavioral EF measures. Linear regressions were fitted predicting microstructure values in WM tracts of interest. There were no differences in WM microstructure as a function of ADHD diagnosis, but there were differences in some EF-related WM tracts as a function of EF. Results suggest (1) low EF scores serve as a risk factor for co-occurring ADHD and DD, and (2) ADHD and EF have little overlap in WM microstructure.

Topic Area: EXECUTIVE PROCESSES: Other