An Association Study between Various Monoamine Transporter Gene Polymorphisms and Treatment Response to Mirtazapine in Major Depression / 대한정신약물학회지

ABSTRACT

OBJECTIVE: Genetic differences may contribute to the inter-individual differences in treatment response to antidepressants among patients suffering from major depression. This study investigated a possible association of various monoamine transporter genetic polymorphisms with treatment response to mirtazapine in major depressive patients in elderly. METHODS: In this study, three genetic polymorphisms were selected: serotonin transporter 5- HTTLPR, serotonin transporter 5-HTT intron 2 VNTR, and norepinephrine transporter NET (G1287A). The patients with major depression diagnosed by DSM-IV were recruited to a 6 week naturalistic mirtazapine treatment study in Samsung Medical Center. Treatment response to mirtazapine was defined as > or =50% decrease in HAMD-17 scores at 6 weeks, and the genotypes in the patients were determined using the polymerase chain reaction. RESULTS: Our results showed that ss allele carriers were included more in responder group (ss allele in responder vs. non responder group; 69.4% vs. 40.0%). In addition, l-allele (sl/ll) carriers were included less in responder group (sl/ll allele in responder vs. non responder group; 30.6% vs. 60.0%). Multiple logistic regression analyses showed the 5-HTTLPR polymorphism as an predictor of the mirtazapine response (5HTTLPR ss allele carrier vs. l-allele (sl/ll) carrier; odds ratio: 3.81; 95% confidence interval [CI], 1.32-11.0; p=0.013). However, 5-HTT intron 2 VNTR l/s (p=0.33 by multiple logistic regression; [OR], 0.53; 95% [CI], 0.15-1.88), and NET (G1287A) G/A (p=0.68 by multiple logistic regression; [OR], 1.25; 95% [CI], 0.44-3.53) showed no statistical significant influences on response rate. CONCLUSION: In conclusion, 5HTTLPR polymorphism may predict treatment response to mirtazapine in major depressive patients in elderly.