Race and schizophrenia

Black patients with schizophrenia show reduced global gray matter volume compared with ethnically-matched mentally healthy controls, report British researchers who found no such deficits in white patients. The findings may shed light on the increased rate of psychosis in the black community in Britain, which has been variously reported to be 2–18 times higher than in the white population. To investigate, researchers recruited 34 white British patients and 33 ethnically-matched mentally healthy controls alongside 41 African-Caribbean and black African patients and 35 matched controls. They scanned all patients using high-resolution magnetic resonance imaging and voxel-based morphometry image analysis. Both white patients and black patients with schizophrenia showed ventricular enlargement and increased lenticular nucleus volume compared with their respective ethnic controls. The researchers note that increased ventricular volume is one of the most frequently found structural brain abnormalities in studies of schizophrenia. Meanwhile, the lenticular nucleus is part of the striatum, and striatal enlargement has been reported in the early stages of psychosis following antipsychotic exposure. Contrary to their predictions, however, the researchers found that black patients also showed reduced global gray matter and increased lingual gyrus gray-matter volume relative to the mentally healthy ethnically matched controls. The white patients had no regional or global gray-matter loss compared with their controls, but showed increased gray matter in the left superior temporal lobe and right parahippocampal gyrus.