Interaction between two HTR2A polymorphisms and gender is associated with treatment response in MDD.

The 5HT2A receptor gene (HTR2A) polymorphisms rs7997012 and rs6311 have in some earlier studies been associated with serotonin selective reuptake inhibitor (SSRI) treatment response in major depressive disorder (MDD), but the findings are inconsistent. The aim of the present study was to test for an association between two HTR2A polymorphisms (rs7997012 and rs6311), their interaction and the Montgomery and Åsberg Depression Rating Scale (MADRS) score change after ECT or SSRI treatment. The total number of patients was 218. All were treated in outpatient care. Of these, 119 subjects had treatment-resistant MDD and were treated with ECT and 99 were depressive patients treated with SSRI. Treatment response was assessed by MADRS. Patients scoring <8 on post-treatment MADRS were considered remitters. Neither rs7997012 nor rs6311 HTR2A polymorphism was significantly associated with MADRS score change alone, but the interaction between them and gender explained 14% of the variance in MADRS score change. The finding suggests an association between MADRS score change and interaction of HTR2A polymorphisms, rs7997012 and rs6311 and gender.