Association between plasma proBDNF levels and cognitive impairment in patients with alcohol dependence: a case–control and longitudinal study

Background Alcohol dependence is frequently accompanied by cognitive impairment. Brain-derived neurotrophic factor (BDNF) signaling plays a critical role in synaptic plasticity, while the precursor form, proBDNF, has been increasingly implicated in neurodegenerative and psychiatric disorders. However, the association between plasma proBDNF levels and cognitive impairment in alcohol dependence remains unclear. Methods Eighty male patients with alcohol dependence and forty-two matched healthy controls were enrolled. Plasma proBDNF levels were measured via enzyme-linked immunosorbent assay (ELISA). Cognitive function was assessed using the Mini-Mental State Examination (MMSE), the Modified Wisconsin Card Sorting Test (M-WCST), and the Verbal Fluency Test (VFT). Forty-one patients were reassessed after four weeks of abstinence. Group comparisons and correlation analyses were performed. Results Patients with alcohol dependence exhibited significantly elevated plasma proBDNF levels and impaired cognitive performance compared with controls. Plasma proBDNF levels were positively correlated with alcohol consumption severity, and linked to global cognitive deficits alongside nuanced executive performance variations. After four weeks of abstinence, plasma proBDNF levels decreased and cognitive performance improved; however, changes in proBDNF were weakly associated with cognitive recovery. Conclusions Elevated plasma proBDNF levels are associated with alcohol dependence severity and cognitive impairment, suggesting that proBDNF may serve as a peripheral biomarker reflecting the dynamic neurocognitive status in alcohol dependence.