The size and fibre composition of the corpus callosum with respect to gender and schizophrenia: a post-mortem study

In this study the cross-sectional area (in n = 14 female controls, 15 male controls, 11 female patients with schizophrenia, 15 male patients with schi zophrenia) and fibre composition (in n = 11 female controls, 10 male contro ls, 10 female patients with schizophrenia, 10 male patients with schizophre nia) of the corpus callosum in post-mortem control and schizophrenic brains was examined. A gender x diagnosis interaction (P = 0.005) was seen in the density of axons in all regions of the corpus callosum except the posterio r midbody and splenium, Amongst controls, females had greater density than males; in patients with schizophrenia this difference was reversed. A reduc tion in the total number of fibres in all regions of the corpus callosum ex cept the rostrum was observed in female schizophrenic patients (P = 0.006; when controlling for brain weight, P = 0.053), A trend towards a reduced cr oss-sectional area of the corpus callosum was seen in schizophrenia (P = 0. 098); however, this is likely to be no more than a reflection of an overall reduction in brain size, With age, all subregions of the corpus callosum e xcept the rostrum showed a significant reduction in cross-sectional area (P = 0.018) and total fibre number (P = 0.002), These findings suggest that i n schizophrenia there is a subtle and gender-dependent alteration in the fo rebrain commissures that may relate to the deviations in asymmetry seen in other studies, but the precise anatomical explanation remains obscure.