Altered brain white matter microstructural asymmetry in children with ADHD

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Child Psychiatry

Background:

• Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder.
• Alterations in brain white matter integrity are increasingly implicated in ADHD pathophysiology.
• Understanding white matter development and its relation to ADHD symptoms is crucial.

Purpose of the Study:

• To investigate brain white matter integrity differences in children diagnosed with ADHD compared to healthy controls.
• To explore the relationship between white matter lateralization and ADHD symptom severity.
• To examine correlations between white matter asymmetry and cognitive functions.

Main Methods:

• Diffusion Tensor Imaging (DTI) was employed to assess white matter microstructure.
• Tract-based spatial statistics were used to analyze fractional anisotropy (FA) in 40 regions of interest.
• Lateralization Index (LI) was calculated, and group differences and correlations with clinical/cognitive measures were examined.

Main Results:

• Children with ADHD showed significantly greater leftward asymmetry (LI) in the posterior thalamic radiation (PTR) compared to controls.
• External capsule (EC) LI was significantly negatively correlated with inattention symptoms in both ADHD and control groups.
• PTR LI correlated with inhibitory function in healthy controls, but not in the ADHD group.

Conclusions:

• Increased leftward white matter asymmetry in the PTR is a potential neuroimaging marker in pediatric ADHD.
• External capsule white matter lateralization is associated with ADHD symptom severity across groups.
• These findings highlight the role of white matter asymmetry in ADHD and its relationship with core symptoms.