Regional cerebral blood flow in patients with affective disorders.

Regional cerebral blood flow at rest was measured in 38 patients with major depressive disorders and 16 controls by SPECT with inhalation of xenon-133. All subjects had been withdrawn from medication. The mean hemispheric cerebral blood flow was not statistically different between the controls and the different subgroups of depressed patients defined either by biological markers or clinical characteristics. However, the predominantly cortical blood flow, measured on the outer cerebral rim of the third tomographic slice, was significantly lower on the left hemisphere in bipolar patients when compared with normals and unipolar patients. The same lateralisation was observed in patients with an endogenous depression according to the Newcastle scale.