The role of brain-derived neurotrophic factor and serotonin polymorphisms in stress-related personality and psychiatric symptoms: Implications for cardiovascular health

Background: Diathesis-stress perspectives of cardiovascular (CV) health and disease have long identified the important role of a host of mental health risk and protective factors in both illness course and recovery. Few studies, however, have investigated these factors within the same sample of healthy people. Aims and Objectives: Accordingly, we focused on the inter-relationships among well-established CV mental health risk factors, specifically childhood adversity, stress-related adult personality traits and psychiatric symptoms, and naturally occurring genetic polymorphisms. Materials and Methods: Here 100 college students completed the NEO Five Factor Model of personality in conjunction with measures of childhood adversity, psychiatric symptoms as well as genetic variables derived from assays of the serotonin transporter (5-HTTLPR) and the brain-derived neurotrophic factor (BDNF). Results: Single gene comparisons pointed to lower CV risk, as reflected in personality and psychiatric symptom measures for BDNF Met versus Val/Val carriers. In addition, polygenic comparisons revealed a significant BDNF x 5-HTTLPR interactional effect, suggesting that this particular allelic combination may moderate the phenotypic expression of key personality traits, namely neuroticism and extraversion, as well as psychiatric symptoms, all linked to cardiovascular health. In fact, the data showed across personality and symptom measures, evidence of stress-resistance, resilience and protection for carriers of the allelic pair, BDNF Met and 5-HTTLPR-S. Conclusions: The findings suggested the Met variant of the BDNF gene had a risk-reducing and health-promoting effect when paired with the short serotonin allele, arguably reversing the commonly reported 5-HTTLPR-S association with stress vulnerability.