Abstract
Brain-derived neurotrophic factor (BDNF) and personality traits play a crucial role in the development of alcohol use disorder (AUD). However, the relationship between the BDNF gene, personality and AUD remains unclear. This study aimed to explore the role of BDNF gene variants, personality traits and impulsivity in both the presence of AUD and the age of onset of alcohol dependence. We also examined the interaction between BDNF gene variants and personality traits among individuals with AUD. Eleven polymorphisms encompassing the whole BDNF gene region were genotyped. The Tridimensional Personality Questionnaire (TPQ) and the Barratt Impulsiveness Scale-11 (BIS-11) assessed personality traits and impulsivity. Pearson's Chi-square, HAPLOVIEW software, logistic regression, independent t tests and linear regression were conducted to investigate the associations between BDNF variants, personality traits and impulsivity in patients with AUD. Five-hundred eighty-five AUD patients and 546 normal controls (NC) were recruited for the study. Although no polymorphisms were significantly associated with AUD after Bonferroni correction in gender- or age-stratified analyses, one specific haplotype block (TCA haplotype of rs1519480/rs6265/rs11030101) was related to AUD (p = 6.16 × 10(-5)). TPQ and BIS-11 results revealed that AUD patients, particularly those with early-onset AUD (EOAUD), exhibited significantly higher scores in Novelty Seeking (NS) and Harm Avoidance (HA) compared to NC. Additionally, the BDNF SNP rs6484320 was significantly associated with higher BIS-11 scores in the AUD group. High HA, NS, impulsivity, and the BDNF gene's specific haplotype may influence AUD's development. The findings may provide new insights into the genetic and psychological factors contributing to AUD.