Quantitative computed tomography in elderly depressed patients

An index of brain tissue density was obtained from the CT scans of 37 elderly depressed patients by measuring Hounsfield Units (HU) in 12 predefined brain areas. Comparisons were made with 23 patients suffering from senile dementia and 36 healthy controls. As a group the depressed patients resembled the dements more than the controls, although analysis of variance indicated differences between all three groups, controls showing the highest HU values and dements the lowest. In the depressed patients ventricular dilatation, which had already been shown to predict increased mortality, was also associated with lower HU levels. The significance of these and other findings is discussed.