Electroconvulsive therapy decreases dopamine D₂receptor binding in the anterior cingulate in patients with depression: a controlled study using positron emission tomography with radioligand [¹¹C]FLB 457.
OBJECTIVE
Electroconvulsive therapy (ECT) has been confirmed as one of the most effective treatments in drug-resistant major depression. However, the mechanism of ECT is still poorly understood. Although several lines of studies have focused on its effect on dopamine neurotransmission, the effects of ECT on dopamine D(2) receptors in a living human brain have not been investigated. Using positron emission tomography (PET) scans with the radioligand [(11)C]FLB 457, we aimed to evaluate the effect of ECT on extrastriatal D(2) receptor binding in medicated patients with major depressive disorder (MDD).


METHODS
Seven patients with a DSM-IV diagnosis of MDD underwent PET scans before and after a series of 6-7 treatments with bilateral ECT. Eleven healthy controls were scanned for comparison. All participants were scanned at the National Institute of Radiological Sciences, Chiba, Japan, between November 2000 and September 2005. The parametric images of [(11)C]FLB 457 binding were generated on the basis of a simplified reference tissue model. Voxel-based methods were used to assess the effect of ECT on D(2) receptor binding.


RESULTS
There were no significant differences in D(2) receptor binding between patients with MDD and controls. All 7 patients showed clinical improvements in response to ECT treatment (P < .001). Significant changes in D(2) receptor binding, a mean of 25.2% reduction, were found in the right rostral anterior cingulate (AC) following ECT (P < .001).


CONCLUSIONS
Electroconvulsive therapy decreased D(2) receptor binding in the rostral AC in MDD patients responding to ECT. Our finding suggests that one of the biologic mechanisms of ECT could be related to dopaminergic alteration in the rostral AC.
Saijo
Tomoyuki
T
Department of Neuropsychiatry, Nippon Medical School, Tokyo, Japan.
Takano
Akihiro
A
Suhara
Tetsuya
T
Arakawa
Ryosuke
R
Okumura
Masaki
M
Ichimiya
Tetsuya
T
Ito
Hiroshi
H
Okubo
Yoshiro
Y
D000328:Adult; D002250:Carbon Radioisotopes; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000628:therapy*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D018492:Dopamine Antagonists; D004565:Electroconvulsive Therapy; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D011759:Pyrrolidines; D011869:Radioligand Assay; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012457:Salicylamides; D016896:Treatment Outcome
D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D012457:Salicylamides; C065065:FLB 457