【Abstract】 Objective To research the correlation between plasma acylated ghrelin and depression. Methods Patients were eligible for the trial if they were first diagnosed with depression, as defined by criteria of DSMIV. They were treafecl with escitalopram (daily dose of 10~20 mg of escitalopram for 6 months). The concentration of plasma total ghrelin and acylated ghrelin were determined by radioimmunoassay at the point of preand posttreatment. The severity of symptoms for patients was assessed by Hamilton depression scale (HAMD). Thirty healthy volunteers were classified into the control group. Results Before escitalopram treatment, the level of acylated ghrelin in depressive patients was lower than that of control group. However, after treatment, the plasma acylated ghrelin level was increased. No changes in total ghrelin levels of patients with depression were found at before and after treatment. Spearman correlation analysis showed that the plasma acylated ghrelin level was negatively correlated with the HAMD score at the baseline. No significant difference was found among the plasma acylated ghrelin leveland HAMD score after treatment. The age was positively correlated with acylated ghrelin level. Meanwhile HAMD was negatively correlated with acylated ghrelin level. Conclusion Decreased acylated ghrelin levels may be involved in the etiology of depressive disorders. The plasma acylated ghrelin levels are negatively correlated with the severity of depression before treatment. After the treatment of escitalopram, the HAMD score is ameliorated, and the acylatedghrelin level is obviously recovered as well. There are various mechanisms could be involved in the regulation of the expression of acylated ghrelin.