The relationship between serum brain-derived neurotrophic level and neurocognitive functions in chronic...

Methamphetamine (METH) is a highly addictive psychostimulant with serious neurotoxic effects. Given evidence indicating that brain-derived neurotrophic factor (BDNF) is associated with addictive behaviors, this study aimed to investigate the serum level of BDNF and cognitive functions in chronic METH users and healthy participants. Thirty-seven chronic METH users and 37 healthy participants were recruited in this study. Cognitive functioning, including executive functions and working memory, were assessed using the Wisconsin Card Sorting Test (WCST) and Wechsler Memory Scale (WMS), respectively. The levels of serum BDNF were also examined using an enzyme-linked immunosorbent assay kit. METH users showed significant impairment in executive function and working memory compared to healthy participants. The serum BDNF concentrations of METH users were significantly higher than healthy participants (42 ± 13.34 ng/ml vs. 24 ± 7 ng/ml). BDNF concentration was significantly correlated with duration (r = 0.37, p = 0.02) and dose of METH use (r = 0.35, p = 0.02). Besides, the BDNF level was not associated with any subscales of WCST and WMS. These results provide further evidence regarding the role of BDNF in the pathophysiology of METH addiction. Besides, these findings suggest that increased BDNF level is not related to cognitive impairments in METH users.