Group comparison of fractional anisotropy (FA). Scatterplots of FA indicates in the left and right uncinate fasciculus (upper) and cingulum bundle (lower) of schizophrenia, affective psychosis, and healthy control groups are shown. Solid triangles indicate patients with bipolar disorder in a manic phase, whereas open triangles indicate patients with major depressive disorder. Repeated-measures analysis of variance showed a significant difference in mean FA bilaterally for uncinate fasciculus among the three groups [F(2, 42) = 3.68, p = 0.03]. Post hoc Tukey’s Significant Difference tests revealed that the patients with schizophrenia showed lower mean FA compared with healthy control subjects [p = 0.03] but not with the patients with affective psychosis [p = 0.73]. In contrast, there were no significant group differences in mean FA for cingulum bundle [F(2, 42) = 0.55, p = 0.58], but there was significant left > right asymmetry [F(1, 42) = 35.33, p < 0.001]. Group-by-hemisphere interactions were not significant for mean FA in cingulum bundle [F(2, 42) = 0.15, p = 0.87]. SZ, schizophrenia; AFF, affective psychosis; HC, healthy control.