Better characterization of attention and hyperactivity/impulsivity in children with ADHD: The key to understanding the underlying white matter microstructure

Anthony Gagnon, Maxime Descoteaux, Christian Bocti, Larissa Takser

Psychiatry Research: Neuroimaging

https://doi.org/10.1016/j.pscychresns.2022.111568

Highlights

• High variability in ADHD diagnosis across clinicians, cultures and settings.
• The assessment method of symptom severity influences the results.
• The use of RDoC criteria to evaluate cognitive functions outside and across diagnoses is mandatory.
• Novel multimodal MRI and artificial intelligence approaches are required to obtain a more biologically sustained model.

Abstract

The apparent increase in the prevalence of the attention deficit hyperactivity disorder (ADHD) diagnosis raises many questions regarding the variability of the subjective diagnostic method. This comprehensive review reports findings in studies assessing white matter (WM) bundles in diffusion MRI and symptom severity in children with ADHD. These studies suggested the involvement of the connections between the frontal, parietal, and basal ganglia regions. This review discusses the limitations surrounding diffusion tensor imaging (DTI) and suggests novel imaging techniques allowing for a more reliable representation of the underlying biology. We propose a more inclusive approach to studying ADHD that includes known endophenotypes within the ADHD diagnosis. Aligned with the Research Domain Criteria Initiative, we also propose to investigate attentional capabilities and impulsive behaviours outside of the borders of the diagnosis. We support the existing hypothesis that ADHD originates from a developmental error and propose that it could lead to an accumulation in time of abnormalities in WM microstructure and pathways. Finally, state-of-the-art diffusion processing and novel artificial intelligence approaches would be beneficial to fully understand the pathophysiology of ADHD.