Cytoarchitectural abnormalities have been reported in the cortex in schizophrenia. These suggest a developmental origin for this disorder. The Wnt signalling pathway is involved in the regulation of brain development; disruption of this pathway may lead to abnormal cortical development. In this study levels of three components of the Wnt signalling pathway; glycogen synthase kinase-3 beta (GSK-3 beta), beta -catenin and dishevelled-2 (Dvl-2) were determined in the prefrontal cortex of ten schizophrenic and ten control individuals using immunoblotting. GSK-3 beta levels were significantly reduced in the schizophrenic group, while levels of beta -catenin and Dvl-2 did not differ between groups. This provides further evidence for an abnormality of the Wnt signalling pathway in schizophrenia. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.