No abstract

reduction in patients with ADHD compared with major depression and healthy volunteers.Objective: Results in adult attention deficit hyperactivity disorder (ADHD) on structural brain changes and the clinical relevance are contradictory. The aim of this study was to investigate whether in adult patients with ADHD hippocampal or amygdala volumes differs from that in healthy controls and patients with major depression (MD). Method: Twenty patients with ADHD, 20 matched patients with MD and 20 healthy controls were studied with high resolution magnetic resonance imaging. Results: Amygdala volumes in patients with ADHD were bilaterally smaller than in patients with MD and healthy controls. In ADHD, more hyperactivity and less inattention were associated with smaller right amygdala volumes, and more symptoms of depression with larger amygdala volumes. Conclusion: This study supports findings that the amygdala plays an important role in the systemic brain pathophysiology of ADHD. Whether patients with ADHD and larger amygdala volumes are more vulnerable to affective disorders needs further investigation. Significant outcomes• Amygdala volumes were smaller in adult patients with attention deficit hyperactivity disorder (ADHD) than in patients with major depression and healthy controls, supporting a role of the amygdala in emotional dysregulation in ADHD.• More hyperactivity and less inattention were related to smaller right amygdala volumes.• The presence of more depressive symptoms in ADHD patients was associated with larger amygdala volumes in line with findings that the amygdala increases in size with major depressive disorder.• Hippocampal volumes were not altered in adult patients with ADHD. Limitations• The cross-sectional design does not allow changes in amygdala volume to be assessed.• The relatively small sample size does not allow generalization of the results, which would first need to be replicated.• Associations between clinical data and structural volumes are limited to the ADHD group • Current medication may have confounded the results.