Serotonin transporter (5-HTTLPR) and norepinephrine transporter (NET) gene polymorphisms: Susceptibility and treatment response of electroconvulsive therapy in treatment resistant depression

Abstract

Serotonin transporter (5-HTTLPR) and norepinephrine transporter (NET182C) polymorphisms are associated with susceptibility and treatment response in major depressive disorder (MDD). Thus, we examined association between these polymorphisms and susceptibility to treatment resistant depression, and treatment response in severe MDD patients treated with electroconvulsive therapy (ECT).In total, 119 Finnish patients with treatment resistant depression and 395 healthy volunteer blood donors were genotyped. Depression severity was assessed using the Montgomery–Åsberg Depression Scale (MADRS), with MADRS score change during ECT the treatment response indicator.Underrepresentation of the 5-HTTLPR l/l genotype in the NET TT subgroup was observed in patients compared with controls. There were no genotype or allele frequency differences between patients and control groups separately. Patients with combined 5-HTTLPR l/l and NET TT genotypes also had poorer treatment responses than other patients. No differences in ECT response were observed when the polymorphisms were examined separately.Our results suggest that a NET 182C and 5-HTTLPR polymorphism interaction is associated with susceptibility to treatment resistant depression and ECT treatment response in antidepressant resistant depression patients.