Serum brain-derived neurotrophic factor and nerve growth factor decreased in chronic ketamine abusers.

This study investigated the serum levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in a group of chronic ketamine abusers in comparison to healthy controls. The correlations between the serum BDNF, NGF level with the subjects' demographic, pattern of ketamine use were also examined. 93 subjects who met the criteria of ketamine dependence and 39 healthy subjects were recruited. Serum BDNF and NGF levels were assayed by enzyme-linked immunosorbent assay (ELISA). Psychopathological symptoms were assessed using Positive and Negative Syndrome Scale (PANSS), Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). Both serum levels of BDNF and NGF were significant lower in the ketamine users compared to the healthy control subjects (9.50±6.68 versus 14.37±6.07 ng/ml, p=0.019 for BDNF; 1.93±0.80 versus 2.60±1.07 ng/ml, p=0.011 for NGF). BDNF level was negatively associated with current frequency of ketamine use (r=-0.209, p=0.045). Both BDNF and NGF serum concentrations were significantly lower among chronic ketamine users than among health controls.