Grey matter volumes in treatment naïve vs. chronically treated children with attention deficit/hyperactivity
Thomas Villemonteix1, Stéphane A De Brito2, Martin Kavec3
1INSERM, U894, 2 ter rue d'Alésia, 75014 Paris, France.
Insights
Methylphenidate treatment may normalize grey matter (GM) volume in children with ADHD, with longer treatment associated with increased GM volume in the nucleus accumbens.
Area of Science:
- Neuroscience
- Developmental Psychology
- Radiology
Background:
- Attention deficit/hyperactivity disorder (ADHD) is commonly treated with psychostimulants.
- The impact of psychostimulant treatment on brain development in children with ADHD is not fully understood.
- Previous studies focused on limited brain regions, necessitating a comprehensive analysis.
Purpose of the Study:
- To investigate medication-related differences in grey matter (GM) volume across the entire brain in children with ADHD.
- To compare GM volumes between never-medicated children with ADHD, medicated children with ADHD, and typically developing children.
- To explore the association between methylphenidate treatment duration and GM volume in specific brain regions.
Main Methods:
- Utilized optimized voxel-based morphometry (VBM) to analyze structural MRI scans from 77 children (aged 7-13).
- Compared three groups: never-medicated ADHD (n=33), medicated (methylphenidate) ADHD (n=20), and typically developing (TD) children (n=24).
- Employed automated tracing for caudate nucleus, amygdala, and nucleus accumbens volumes, controlling for age and gender.
Main Results:
- Never-medicated ADHD children showed reduced GM volume in the insula and middle temporal gyrus compared to both medicated ADHD and TD groups.
- Medicated ADHD children exhibited decreased GM volume in the middle frontal and precentral gyri relative to TD children.
- A positive association was found between methylphenidate treatment duration and GM volume in the left nucleus accumbens.
Conclusions:
- Methylphenidate treatment may be associated with normalization of GM volume in certain brain areas in children with ADHD.
- Treatment may also lead to deviations in GM volume in previously unexplored brain structures.
- Treatment history correlates positively with GM volume in the nucleus accumbens, a critical region for reward processing.
Abstract:
Psychostimulants are the first-line treatment in attention deficit/hyperactivity disorder (ADHD), but their effects on brain development remain poorly understood. In particular, previous structural magnetic resonance imaging (sMRI) studies only investigated treatment effects on grey matter (GM) volumes in selected regions of interest (ROIs). In this study, voxel-based morphometry (VBM) was used to assess medication-related GM volume differences across the entire brain. Automated tracing measurements of selected ROIs were also obtained. Three groups (77 participants aged 7-to-13 year old) underwent MRI scans and were compared: never-medicated children with ADHD (n=33), medicated (methylphenidate) children with ADHD (n=20) and typically developing children (TD; n=24). Optimised VBM was used to investigate regional GM volumes, controlling for age and gender. Automated tracing procedures were also used to assess the average volume of the caudate nucleus, the amygdala and the nucleus accumbens. When compared to both medicated children with ADHD and TD children, never-medicated children with ADHD exhibited decreased GM volume in the insula and in the middle temporal gyrus. When compared to TD children, medicated children with ADHD had decreased GM volume in the middle frontal gyrus and in the precentral gyrus. Finally, ROI analyses revealed a significant association between duration of treatment and GM volume of the left nucleus accumbens in medicated children with ADHD. In conclusion, this study documents potential methylphenidate-related GM volume normalization and deviation in previously unexplored brain structures, and reports a positive association between treatment history and GM volume in the nucleus accumbens, a key region for reward-processing.
