Global and regional gray matter reductions in ADHD: a voxel-based morphometric study

Area of Science:

• Neuroscience
• Developmental Psychology
• Pediatrics

Background:

• Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder marked by inattention, hyperactivity, and impulsivity.
• Neuroimaging studies suggest fronto-striatal circuits and the cerebellum are implicated in ADHD, though findings vary.
• Discrepancies in previous research may stem from diverse neuroimaging techniques used.

Purpose of the Study:

• To investigate cerebral gray matter (GM) and white matter (WM) abnormalities in children with ADHD.
• To compare brain structure in children diagnosed with ADHD against healthy controls using voxel-based morphometry.

Main Methods:

• Voxel-based morphometry (VBM) protocol applied to 25 medicated children/adolescents with ADHD (aged 6-16) and 25 healthy controls.
• Analysis focused on identifying regional differences in GM and WM volumes between the two groups.

Main Results:

• ADHD brains exhibited a global GM volume decrease of 5.4% compared to controls.
• Significant regional GM reductions were observed in the left fronto-parietal cortex, left cingulate cortex, bilateral precuneus, right middle temporal gyrus, left parahippocampal gyrus, and bilateral posterior cerebellum.
• No significant differences in WM volume were found between ADHD children and controls.

Conclusions:

• The findings support the hypothesis of widespread GM abnormalities in ADHD, particularly in fronto-parietal and cerebellar regions.
• These structural differences may underlie the motor and attentional deficits characteristic of ADHD.
• The results align with previous neuroimaging studies, reinforcing the identified neural correlates of ADHD.