Regional Cerebral blood flow (rCBF) and metabolism in major depression have been studied intently. Those studies are expected to reveal the mechanisms of the mood disorders, and also to give us valuable informations that the specific brain regions participating mood regulation. However, the data still have been inconsistent. In the present study we measured rCBF in patients with major depression and depressive state using xenon-CT CBF method. There is a tendencies that the rCBF values of normal control is the highest, and those of major depression is the lowest in most of the regions. The rCBF values in the patients with major depression are significantly lower than those in normal control in the right anterior frontal cortex, temporal cortex, putamen and thalamus. We also measured rCBF before and 90 minutes after giving calcium antagonist nilvadipine (4 mg, p.o.) in those subject. There is a tendency that nilvadipine increased in rCBF in normal control, however, it decreased in rCBF in major depression.