Mean absolute and relative area values for the five corpus callosum segments are shown for the four groups. Top: The adolescent and adult patient groups showed reduced absolute area in nearly all the callosal segments, with the adolescent patients showing more marked reductions (diagnosis × age × lateromedial section × anteroposterior segment, F(4,92)=3.07, p<0.03). Bottom: The adult patient group showed decreased relative area in all the segments while the adolescents showed a less consistent pattern, with increases in the anterior portions but clear decreases in the posterior regions, including the body and splenium (diagnostic group × age × lateromedial section × anteroposterior segment, F(4,92)=2.42, p=0.06).