Girls ages 8 to 12 with ADHD showed differences in the volume of various regions of their cerebellum compared with girls without the condition, MRI scans revealed. A similar comparison of boys showed abnormalities, too. But those differences didn’t match what’s seen between girls, preliminary analyses suggest. So far, researchers have looked at 18 subjects in each of the four groups, but plan to quintuple that number in the coming months.
Differences seem most prominent in areas of the cerebellum that control higher-order motor functions, Mostofsky said. Those circuits help regulate attention and plan out behavior, versus directing basics like hand-eye coordination. That could help explain why ADHD affects girls’ behavior differently than boys’.