No Association between Serotonin Receptor 2C-759C/T Polymorphism and Weight Change or Treatment Response to Mirtazapine in Korean Depressive Patients

OBJECTIVE: Activation of one or more serotonin (5-HT) receptors may play a role in mediating the antidepressant effects of serotonergic antidepressants. The serotonin 2C (5HT 2C) receptor is known to be associated with antidepressant action and weight gain. We sought to determine whether the 5-HTR 2C receptor -759C/T polymorphism was associated with weight gain and treatment response to mirtazapine in major depressive disorder (MDD) patients. METHODS: The 5-HT 2C receptor -759C/T polymorphism was analyzed in 323 MDD patients. All patients were evaluated using the 21-item Hamilton Depression Rating Scale at the beginning of the study and at 1, 2, 4, and 8 weeks of mirtazapine treatment. RESULTS: There was no significant difference in the 5-HT 2C receptor -759C/T genotype distribution between responder and non-responder groups. The 5-HT 2C receptor -759C/T polymorphism was not associated with weight change over time after mirtazapine administration. CONCLUSION: The 5-HT 2C receptor -759C/T polymorphism does not appear to be a predictor of treatment response to mirtazapine. This polymorphism was not associated with weight change after 8 weeks of mirtazapine treatment. Further investigation on other polymorphisms of the 5-HT 2C gene is required to determine whether the 5-HT 2C gene influences treatment response and weight change after mirtazapine administration in patients with major depressive disorder.