What resolves this contention: Patient age (pediatric vs adult); medication exp…

What resolves this contention: Patient age (pediatric vs adult); medication exposure differences — The two ENIGMA-OCD analyses agree that age-of-onset modulates structural endophenotypes: pediatric OCD has enlarged thalamus, adult OCD has subtle hippocampal/pallidal differences. The conflict is interpretive rather than empirical and points to neurodevelopmental trajectory. / The pediatric mega-analysis showed larger thalamus volume in OCD based on the main group comparison, whereas the meta-analysis showed this only in unmedicated pediatric OCD patients compared with controls. / In the subcortical analyses, we found clear differences between the pediatric OCD patients (compared with healthy controls, n = 335 and 287, respectively) and the adult OCD patients (compared with healthy controls, n = 1,495 and 1,472, respectively) (Boedhoe et al., ).