[Xe-133 inhalation single photon emission computerized tomography in manic-depressive illness].

We measured regional cerebral blood flow (rCBF) in depressed patients using Xe-133 inhalation single photon emission computerized tomography (SPECT; HEADTOME). Thirty-two medicated mildly depressed patients, six bipolar (BP) and 26 unipolar (UP), and 20 control subjects participated in the study. Compared to the controls, UP patients showed a significant decrease of rCBF in the bilateral frontal and the parietal regions, which were dominant in the left hemisphere, while BP patients showed no decrease of rCBF and mean CBF. Comparison of rCBF between before and after treatment with antidepressants in 8 depressed patients revealed an increased rCBF after the improvement in the left superior frontal, the left parietal and the right temporal regions which are critical areas for the development of depression.