Serotonin transporter binding in patients with mood disorders: a PET study with [11C](+)McN5652.
BACKGROUND
Several lines of studies have suggested the involvement of serotonin transporter (5-HTT) in the pathophysiology of mood disorders. The aim of this study was to examine whether 5-HTT binding was altered in patients with mood disorders using positron emission tomography (PET).


METHODS
Thirteen antidepressant-naive or -free patients with mood disorders and 21 age-matched healthy control subjects participated in this study. The patients consisted of 7 with major depressive disorder (MDD) and 6 with bipolar disorder (BD). Positron emission tomography scans were performed using a selective ligand for 5-HTT, [11C](+)McN5652. The uptake was quantified in the thalamus and midbrain by graphical method with reference tissue, and binding potential (BP) was used for the index of 5-HTT binding.


RESULTS
Binding potential in the thalamus was significantly increased in patients with mood disorders as compared to control subjects, whereas BP in the midbrain did not differ between the groups. Subgroup comparison showed that MDD patients had significantly higher BP in the thalamus compared to control subjects. Binding potential of the thalamus was higher by approximately 22% in the combined patients and 23% in MDD patients relative to control subjects.


CONCLUSIONS
These findings may suggest the possibility of altered 5-HTT in patients with mood disorders. Functional abnormality in the thalamus may be involved in the pathophysiology of mood disorders.
Ichimiya
Tetsuya
T
Brain Imaging Project, National Institute of Radiological Sciences, Chiba, Japan
Suhara
Tetsuya
T
Sudo
Yasuhiko
Y
Okubo
Yoshiro
Y
Nakayama
Kazuhiko
K
Nankai
Masahiro
M
Inoue
Makoto
M
Yasuno
Fumihiko
F
Takano
Akihiro
A
Maeda
Jun
J
Shibuya
Haruo
H
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D002352:Carrier Proteins / Q000378:metabolism*; D006801:Humans; D007546:Isoquinolines / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008636:Mesencephalon / Q000000981:diagnostic imaging; D008875:Middle Aged; D019964:Mood Disorders / Q000000981:diagnostic imaging* / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D012702:Serotonin Antagonists / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins; D013788:Thalamus / Q000000981:diagnostic imaging; D014041:Tokyo; D014055:Tomography, Emission-Computed
D002352:Carrier Proteins; D007546:Isoquinolines; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D012702:Serotonin Antagonists; D050486:Serotonin Plasma Membrane Transport Proteins; C058079:McN 5652