BDNF and depressive disorder: Interestingly, although still a matter of debate, BDNF has been hypothesized to be involved in ethanol–induced neurodegeneration in the adult brain, and high alcohol intake has been associated with lower serum BDNF levels.39, 40 Depression is furthermore known to predispose for alcohol abuse.41 As information on alcohol intake in the present study was obtained from the questionnaire, the risk of biased reporting is, however, increased.