1. Clinical: P1.1 Autonomic nervous system and its association with brain function in major depressive disorder

Abstract

We recently demonstrated elevated brain serotonin turnover in untreated major depressive disorder (MDD), with over a 2-fold increase in turnover being associated with carriage of the s allele of the serotonin transporter (5-HTT) gene. Further, sympathetic nervous activity (SNA) followed a bimodal distribution, with some extraordinarily high values and some marginally lower than in healthy subjects. Therefore, we hypothesized that the bimodal distribution of SNA may be related to the 5-HTT genotype and hence, the degree of SNA in MDD may be dependent upon the level of brain serotonin turnover.