Published online by Cambridge University Press: 06 November 2009
African-Caribbean and black African people living in the UK are reported to have a higher incidence of diagnosed psychosis compared with white British people. It has been argued that this may be a consequence of misdiagnosis. If this is true they might be less likely to show the patterns of structural brain abnormalities reported in white British patients. The aim of this study therefore was to investigate whether there are differences in the prevalence of structural brain abnormalities in white and black first-episode psychosis patients.
We obtained dual-echo (proton density/T2-weighted) images from a sample of 75 first-episode psychosis patients and 68 healthy controls. We used high resolution magnetic resonance imaging and voxel-based methods of image analysis. Two separate analyses were conducted: (1) 34 white British patients were compared with 33 white British controls; (2) 41 African-Caribbean and black African patients were compared with 35 African-Caribbean and black African controls.
White British patients and African-Caribbean/black African patients had ventricular enlargement and increased lenticular nucleus volume compared with their respective ethnic controls. The African-Caribbean/black African patients also showed reduced global grey matter and increased lingual gyrus grey-matter volume. The white British patients had no regional or global grey-matter loss compared with their normal ethnic counterparts but showed increased grey matter in the left superior temporal lobe and right parahippocampal gyrus.
We found no evidence in support of our hypothesis. Indeed, the finding of reduced global grey-matter volume in the African-Caribbean/black African patients but not in the white British patients was contrary to our prediction.