Probing the association between dexamethasone-induced cortisol suppression and serotonin transporter availability among drug-free patients with major depressive disorder-A small-sample SPECT study with [123I]ADAM

The association between hypothalamo-pituitary-adrenal (HPA) axis function and the serotonergic system could be involved in the mechanism of depression. However, neuroimaging evidence is scarce. The aim of the present study was to probe the association between dexamethasone suppression test response and serotonin transporter (SERT) availability in drug-free patients with major depressive disorder (MDD). Seventeen MDD patients (five males and twelve females) were recruited. SPECT with [123I] ADAM was used to measure the midbrain SERT availability, and HPA axis function was measured by the dexamethasone suppression test (DST). The association was significant when considering all participants (ρ = 0.69, p = 0.002). This association may have clinical implications for the treatment of MDD.