Association of the met66 allele of brain-derived neurotrophic factor (BDNF) with smoking

Rationale: It has been suggested that a susceptibility locus near the gene encoding the brain-derived neurotrophic factor (BDNF) contributes to individual differences in human addiction vulnerability. BDNF modulates several behaviors that are associated with addictive drugs, and upregulation of BDNF was found to be associated with several drugs of abuse such as amphetamine, cocaine, and nicotine. In this study, we addressed the question if a common BDNF missense variation (Val66Met) influences the risk for smoking behavior in otherwise healthy human volunteers. Materials and methods: In total, 320 healthy unrelated volunteers (155 male, 165 female, mean age: 38.4 ± 14.1 years) consisting of 43.3% never smokers, 20.9% former smokers, and 35.6% current smokers were investigated. Results: The frequency of both Met/Met genotype and Met allele was significantly increased in current and in former smokers when compared to never smokers (χ 2 = 10.856, df = 2, p = 0.004 and χ 2 = 4.350, df = 1, p = 0.045, respectively). Conclusions: Our results suggest that humans who carry the Met allele of the BDNF missense polymorphism might be more vulnerable to initiate and also maintain smoking