Shaw P, et al. - Researchers wanted to characterize cerebellar development in attention deficit hyperactivity disorder (ADHD) via a multicohort study using longitudinal data. Four independent cohorts, containing predominately longitudinal data, demonstrated diagnostic differences in the growth of cerebellar white matter. They noted slower white matter growth in early childhood followed by faster growth in late childhood in ADHD patients. Findings are consistent with the concept of ADHD as a disorder of the brain's structural connections, formed partly by developing cortico-cerebellar white matter tracts.