Background. Morphometric studies on the corpus callosum (CC) in schizophrenia have yielded contradictory results. The aim of the present study was to investigate magnetic resonance imaging (MRI) abnormalities of the CC in first-episode patients with schizophrenic psychoses.

Method. We assessed volumetric MRI in 31 patients with diagnoses of schizophrenia, schizophreniform or schizoaffective disorder (DSM-IV) and a maximum exposure to neuroleptics of 2 weeks. As a control group, 12 healthy age- and sex-matched individuals were included in the study. A whole body scanner at 1.5 Tesla was used to obtain 3D T1- and T2-weighted MR datasets. The data were evaluated semi-automatically (intracranial volume, total brain volume) and manually (CC) with the software NMRwin.

Results. Patients had smaller CC and CC subdivisions than controls. Schizophrenic and unaffected women exhibited larger total CC and rostral subdivisions than men in both groups. Handedness did not exert an influence.

Conclusions. Our findings are in line with other in vivo morphometric studies on the CC in schizophrenia. The larger CC area in women may reflect general gender-related differences in CC size as described in healthy individuals.