Longer intervals between MRI sessions could herald advance in Tanner stage. Of the 28 adolescents, 5 advanced by one step: 3 girls changed from 3 to 4, and 2 boys changed from 2 to 3. Consistent with the known developmental pattern, all 5 adolescents who advanced by Tanner stage showed volume loss in lateral frontal, anterior cingulate, precuneus, and parietal gray matter and expansion of the lateral ventricles and cortical sulci (Figure 8). Of these 6 regions, Mann-Whitney tests indicated a decline (one-tailed) in anterior cingulate (p=.0223) and precuneus (p=.0256) gray matter volume and an increase in cortical sulcal volume (p=.0223) in the 5 who changed compared with those who did not.
