BDNF Val66Met polymorphism is associated with higher anticipatory cortisol stress response, anxiety, and alcohol consumption in healthy adults.

BACKGROUND: The brain-derived neurotrophic factor (BDNF) is a key protein in maintaining neuronal integrity. The BDNF gene is thought to play an important role in the pathophysiology of mood and anxiety disorders. The aim of this study was to investigate, for the first time in a single study, the association between BDNF Val(66)Met polymorphism, anxiety, alcohol consumption, and cortisol stress response.

METHOD: 98 healthy university students (54 females and 44 males), genotyped for the Val(66)Met polymorphism, participated in a physical-stress procedure (cold pressure test, CPT) after having been informed that they would undergo a painful experience. Indices of anxiety and of stress were collected from repeated measurement of salivary cortisol, blood pressure, and heart rate.

RESULTS: BDNF Met carriers, were more anxious during the CPT (p<0.001), drank more alcohol per week, (p<0.05), and showed significantly higher anticipatory cortisol response (p<0.05), but not in response to the CPT, than Val/Val homozygotes. The association of BDNF Val(66)Met polymorphism with HPA axis reactivity to stress was not modulated by gender. These results suggest that Met carriers are particularly sensitive in anticipating stressful events, which extends previous findings on the moderating role of the BDNF Val(66)Met polymorphism in the face of stressful life events.