To investigate metabolic relationships between different brain regions in schizophrenia, we measured regional brain metabolism using positron emission tomography (PET) and [18F]fluorodeoxyglucose (FDG) in 15 unmedicated schizophrenic patients and 15 healthy subjects. We analyzed correlations between glucose metabolism data of multiple brain regions using factorial analysis and correlation coefficient comparisons. Absolute regional intercorrelations in schizophrenic brains were found to be significantly stronger than in controls, in relationship to the greater variability of metabolic rates in schizophrenic patients. Variability of normalized metabolic rates and regional intercorrelations were not significantly different between schizophrenic patients and control subjects. We conclude that a global metabolic factor accounts for the variability of metabolic data in untreated schizophrenia.