Anterior cingulate cortex gray matter abnormalities in adults with attention deficit hyperactivity disorder: a voxel-based morphometry study

Attention deficit hyperactivity disorder (ADHD) is a psychiatric disease that affects children and persists in 50% of cases into adulthood. Magnetic Resonance Imaging (MRI) studies in children suggest that ADHD is associated with structural abnormalities in the brain. However, very little research has been carried out on adult ADHD. Using high-resolution MRI, we tested the hypothesis that adult ADHD patients exhibit gray and/or white matter volume (GMV, WMV) abnormalities in the prefrontal cortex (PFC), cingulate cortex (CC), hippocampus and amygdala, also evaluating putative associations between volumetric data and symptoms of ADHD. We investigated 20 adult patients with ADHD and 20 age-matched healthy controls. We found significantly smaller GMV in the right and left anterior cingulate cortex (ACC) but no GMV/WMV difference in the PFC, hippocampus and amygdala. No correlation was found between ADHD behavioral measures and MRI data. Our results might suggest that adults with ADHD exhibit smaller GMV in the ACC, as measured by VBM. Volumetric abnormalities in the brain of adult ADHD patients might be less pronounced than those found in children and adolescents, although the role played by chronic stimulant treatment needs further investigation.