Fig. 3.

Comparison by sex of the volume of the portion of the right caudate where voxel-based morphometry (VBM) showed differences in the concentration of grey matter between healthy controls and patients with attention deficit hyperactivity disorder (ADHD). The bars represent the mean volume of the portion of the right caudate where VBM showed differences in concentration between healthy and ADHD individuals. *t₁₈ = 2.36, p = 0.029, difference between means = 36 mm³, 95% confidence interval (CI) 4–68 mm³, Cohen d = 1.11. **t₁₈ = 2.32, p = 0.032; difference between means = 20 mm³, 95% CI 2–48 mm³, Cohen d = 1.09. SE = standard error.