STATE CHANGES IN BRAIN ACTIVITY SHOWN BY THE UPTAKE OF TC-99M-EXAMETAZIME WITH SINGLE-PHOTON EMISSION TOMOGRAPHY IN MAJOR DEPRESSION BEFOREAND AFTER TREATMENT

Twenty-eight patients with a major depressive episode previously inves tigated at rest using Single Photon Emission Tomography (SPET or SPECT ) with Tc-99m-exametazime, were followed up at an interval of 9-28 mon ths with the same investigation after full recovery. All patients were unipolar and were rated on the Newcastle scale and with the 17-item H amilton scale. The uptake of Tc-99m-Exametazime was expressed relative to calcarine/occipital cortex. Sixteen patients were scanned when opt imally matched for drug treatment (4) or on both occasions drug free ( 12). The other 12 patients were fully recovered but could not be match ed for drug status; these patients showed significantly more retardati on, diurnal mood variation and guilt at presentation. Significant bila teral increases in tracer uptake were confined to basal ganglia and in ferior anterior cingulate cortex in the matched group, where there wer e additional increases in thalamus and posterior cingulate cortex on t he right side. There were no statistically discernible changes in the neocortex in the matched sample. The unmatched sample yielded inconclu sive evidence of increased tracer uptake in left temporal cortex. The findings give a potential focus to the neuropharmacological analysis o f depressive illness because the topography of the state change in bra in function implicates dopamine function.