Several previous studies have demonstrated differences in regional brain density (as derived from CT scan attenuation values) between patients with schizophrenia and normal controls. Interpretation of these studies has been hindered by methodological shortcomings such as failure to control for head size,scanner calibration differences and other confounding variables. The present study offered methodological advances over earlier studies by controlling for head size and normalizing the attenuation values for each scan to an internal standard. CT attenuation values in multiple brain regions in 20 patients with chronic schizophrenia were compared with those of 20 age and sex matched controls. No significant differences emerged between the schizophrenics and normal controls. The results confirm the importance of controlling for artifacts in analysis of CT scan attenuation values and raise questions about the validity of regional CT attenuation values in detecting subtle anatomical abnormalities in schizophrenia.
