Methylation Status of the Serotonin Transporter Promoter CpG Island Is Associated With Major Depressive Disorder in Chinese Han Population

This study was aimed to investigate the relationship between the methylation status of serotonin transporter (5-HTT) and major depressive disorder (MDD) in Chinese Han population. A total of 96 patients with MDD and 55 healthy volunteers were recruited, and the methylation index (MtI) at six positions in the cytosine-phosphate-guanosine island of 5-HTT gene was measured for each subject using bisulfite pyrosequencing. MtIs at positions 5 and 6 were higher in patients with MDD than those in controls. According to the multivariable logistic regression analysis, MtIs at positions 4 and 5 were significantly associated with MDD. Besides, depression education was an independent risk factor, whereas higher educational levels were protective factors for MDD. In addition, positions 1 and 4 were negatively correlated with weight and diurnal variation. Therefore, 5-HTT methylation might be closely related with MDD in Chinese Han population because of the correlation with diurnal variation and weight.