Thus, while both COS probands and their unaffected SIBs showed an inversion of the relationship between Val dose and rate of CT loss in adolescence, compared to HCs, the regions where this inversion was most marked were different in COS and SIBs. Furthermore, visual comparison (inset plots on Figs. 2 and 3) shows that the timing of Val influences on CT change was different in COS and SIB groups because the three genotype groups “crossed-over” earlier in COS probands than in SIBs. Resultantly, greater Val dose resulted in persistence of CT deficits in early adulthood amongst COS probands (e.g. t = −3.0, p = 0.003 for CT difference at age 20 years in dlPFC), but not amongst healthy SIBs where they disappeared by age 20 (t = 0.4, p = 0.7 for CT differences in inferior temporal cortex).
