BDNF and alcohol dependence: Furthermore, the relative ratio of proBDNF to mBDNF in the alcohol dependence group (n = 27) to the control group was significantly higher than that in the control group (n = 45; t = 4.135, P < 0.001, Student’s t-test; Fig. 5b), which indicated that the balance of proBDNF and BDNF pathways were dysregulated in patients with chronic ethanol consumption.