Mapping of grey matter changes in schizophrenia.

Studies of brain changes in schizophrenia have suggested that the disorder is associated with reductions in both global and regional grey matter. In this study, we used structural neuroimaging to differentiate between these two types of change and to examine regional grey matter throughout the whole brain. Grey matter from magnetic resonance images was segmented and transformed into stereotactic space, and patients with schizophrenia and controls were compared with respect to regional grey matter (after compensating for global grey matter differences). In two preliminary analyses to test our methodology, we demonstrated that: (1) in the transformed grey matter maps, voxel values at the location of the caudate nuclei were correlated with region-of-interest measurements of caudate area in native image space, and (2) the technique detected regional grey matter changes resulting from artificial lesions created in the native images. We then used a factorial design to examine data from two studies, comprising a total of 42 schizophrenics and 52 controls. Analysis of the main effect of schizophrenia on regional grey matter revealed significant reductions in (a) the right temporal pole, insula and amygdala, (b) the left temporal pole, insula and dorsolateral prefrontal cortex.