The Serotonin Transporter Availability for Prognosing Major Depressive Disorder (MDD) Treatment and Detecting MDD

Background: Serotonin transporter (SERT) plays an important role in the pathophysiology of psychiatric disorders such as anxiety and depression and is the primary target of the selective serotonin reuptake inhibitors (SSRIs) which are posited to exert their effect in treating psychiatric disorders aforementioned by this mechanism. I-123-ADAM is a selective radioligand for imaging SERT using SPECT. Research showed that it displayed an extremely high binding affinity to SERT sites. Previous literature also suggested the potential role of I-123-ADAM SPECT as useful in understanding how serotonin system affected depression. This study aims to evaluate the SERT availability by means of I-123-ADAM SPECT imaging study in drug-free subjects for prognosing MDD treatment and assisting in detecting MDD. Methods: We enrolled patients who had major depressive disorder but was free from prior antidepressant medication for at least 5 times of elimination half-lives and healthy controls. The patients with major depressive disorder (N=20) received I-123-ADAM SPECT before and after the pharmacological intervention with Sertraline HCl for a treatment period of six weeks. All healthy subjects (N=17) had only basal I-123-ADAM SPECT. The relationship between improvement of depressive symptoms and basal SERT availability for the prognosis of MDD subjects being treated with Sertraline HCl will be analyzed. In addition, the association between the efficacy of treatment with Sertraline HCl and the change of SERT availability will also be investigated. The control group were selected in order to distinguish the difference of basal SERT binding potential of I-123-ADAM between healthy and MDD subjects.