Meta-analysis of structural MRI studies in children and adults with attention deficit hyperactivity disorder indicates treatment effects.
Level 3 - non-randomized controlled study
Meta-analysis of observational (case-control/cross-sectional) neuroimaging studies
PubMed 22118249 · doi:10.1111/j.1600-0447.2011.01786.x
What was done
Authors conducted a meta-analysis of structural MRI voxel-based morphometry (VBM) and manual tracing studies to examine brain structural differences between ADHD patients and controls in children and adults, as well as between treated and untreated individuals. Databases were searched for 'attention-deficit and MRI' and 'ADHD and MRI'. Gray matter volumes from VBM and caudate volumes from tracing studies were analyzed using signed differential mapping.
What was found
No numerical values, sample sizes, or effect estimates were provided in the abstract. Meta-analyses showed reduced right globus pallidus and right putamen volumes in VBM studies and decreased caudate volumes in manual tracing studies in children with ADHD. Adults with ADHD showed volume reduction in the anterior cingulate cortex. A higher percentage of treated participants was associated with fewer structural changes.
Why it matters
The findings indicate that structural brain alterations in ADHD may differ across development—primarily involving basal ganglia in childhood and anterior cingulate cortex in adulthood—and suggest that treatment may attenuate these neuroanatomical differences.
Limits
The abstract reports no numeric values, effect sizes, confidence intervals, or counts for included studies and participants. Because the underlying imaging studies are observational and cross-sectional, the association between treatment and reduced structural differences cannot establish causality or exclude confounding by illness severity or medication type.
Cited by
- supports Neuroimaging and neuroscience research indicate that ADHD is associated with dysfunction in the basal ganglia.