Do changes in the BDNF promoter methylation indicate the risk of alcohol relapse?

The neurotrophic growth factor brain derived neurotrophic factor (BDNF) was linked to the risk of alcohol relapse in clinical studies. In this study we investigated alterations in the methylation of the BDNF gene during alcohol withdrawal (day 1, 7 and 14) in 99 male alcohol-dependent patients compared to age matched healthy males (n=33). In particular, we aimed to investigate a possible association between the BDNF promoter methylation and the self-reported duration of alcohol abstinence before relapse. Mean methylation of the BDNF promoter was significantly increased in alcohol-dependent patients compared to the healthy controls (F=10.014, p<0.001) and decreased significantly during alcohol-withdrawal (F=10.014, p<0.001). Moreover, mean methylation was associated with depressive (F=2.014, p<0.001) and anxious symptoms in the alcohol-dependent patients (F=2.228, p<0.001). On day 14 of alcohol-withdrawal we found significantly higher methylation rates in those patients who abstained longer before relapse compared to those patients who abstained shorter (F=9.938, p<0.001). Our results suggest an association between BDNF expression and the symptomatology of alcohol withdrawal and imply that changes in the methylation of the BDNF IV gene may contribute to alcohol consumption.