Distribution volume ratio of serotonin and dopamine transporters in euthymic patients with a history of major depression — a dual-isotope SPECT study

Serotonin transporter (SERT) and dopamine transporter (DAT) levels differ in patients with major depression who are in a depressed state in comparison with healthy controls. The aim of this study was to examine the distribution volume ratios (DVRs) of SERT and DAT in drug-free and euthymic patients with a history of major depression. Subjects comprised 13 patients with a history of major depression and 26 sex- and age-matched healthy controls. The euthymic state of depression was defined as a score of 7 or less on the Hamilton Depression Rating Scale. The DVRs of SERT and DAT were approximated using SPECT, with [123I] 2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine (ADAM) and [99mTc] TRODAT-1 as the ligands, respectively. There were no significant differences in the DVRs of SERT or DAT between healthy subjects and euthymic patients with a history of major depression; hence, the SERT and DAT DVRs may not therefore be trait markers for patients with major depression, which helps us to understand more about the pathophysiology of depression.