Interaction between brain-derived neurotrophic factor val66Met polymorphism and recent negative stressor in harm avoidance

There have been controversial results regarding the association between brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and anxiety-related traits such as harm avoidance (HA). We aimed to investigate the interaction between BDNF Val66Met polymorphism and negative life stressors in HA. BDNF Val66Met polymorphism was genotyped in 391 community-dwelling Koreans (152 males, 239 females; 43.2 ± 14.1 years old). The Temperament and Character Inventory (TCI) and the Center for Epidemiological Studies for Depression Scale (CES-D) were self applied. The Structured Clinical Interview for DSM-IV axis I disorders and face-to-face interviews investigating negative life stressors within the last 6 months were also performed. There was no significant difference in TCI score, major depressive disorder prevalence and CES-D score among the 3 genotypes (94 Met/Met, 188 Val/Met and 109 Val/Val subjects). There was no significant difference in TCI scores between subjects with stressors and those without stressors, while more common major depressive episodes (p = 0.03) and higher CES-D scores (p < 0.001) were found in subjects with stressors. However, there was a significant interaction between the BDNF genotype and negative life stressors in HA (p = 0.02). Only subjects with the Val/Val genotype showed higher HA with recent negative stressors. Our finding suggests that BDNF Val66Met polymorphism might influence HA by interacting with recent negative stress experience.