Investigating the white matter tract pattern in ADHD compared to healthy controls

Objective: Previous Diffusion Tensor imaging (DTI) studies have revealed microstructural alterations in white matter (WM) tracts among children with attention deficit hyperactivity disorder (ADHD). Although ADHD can persist into adulthood in more than half of the diagnosed children, few studies have investigated the WM tracts in adults with ADHD. In this study, the emphasis is placed on the adult population with regard to WM abnormalities. Method : Using the UCLA Consortium for Neuropsychiatric Phenomics (CNP) dataset, we compared the microstructural indices of tracts of interest between ADHD subjects and healthy controls. Results: In the ADHD group, both fractional anisotropy (FA) and generalized fractional anisotropy (GFA) were lower than the control group in Right Cingulum Rarolfactory, Corpus Callosum (CC) Forceps Major, and Right Superior Longitudinal Fasciculus1 (SLF1). Diffusivity indices, including mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD), were increased in widespread WM tracts. However, only RD and FA in CC Forceps Major remained significantly different between two groups after correction for multiple analysis. Interestingly, our analysis found increased NQA in all tracts of interest, except for the left fornix. Conclusion : This study revealed several WM abnormalities in certain tracts of the limbic system, SLF1 and, most noticeably, CC in adults with ADHD. These findings, along with the finding of altered NQA, suggest the need for further study to determine the neurophysiological basis of the disease.