Serum levels of growth factors in alcohol-dependent patients according to comorbid depressive symptoms

Objective: This study aims to reveal the relationship of depression with growth factors such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and insulin-like growth factor-1 (IGF-1) in inpatients diagnosed with alcohol dependence, and to identify candidate growth factors as biological markers to indicate the comorbid of alcohol dependence and depression. Methods: This study examined demographic factors in 45 alcohol-dependent patients. The ADS (Korean version of the Alcohol Dependence Scale) and BDI (Korean version of Beck's Depression Inventory) were used. BDNF, NGF, and IGF-1 were measured through ELISA. Results: The average drinking quantity and the ADS score were significantly more severe in alcohol-dependent patients with depression than in those without depression. Linearly comparing BDNF, NGF, and IGF-1 with BDI values, IGF-1 was the growth factor significantly correlated with BDI scores. BDI scores were significantly correlated with ADS scores. IGF-1 was significantly higher in alcohol-dependent patients with depression. Alcohol-dependent patients with depression had greater alcohol use and more severe ADS scores. BDNF and NGF showed no significant difference between alcohol-dependent patients with and without depression, but IGF-1 was significantly higher in those with than in those without depression. Conclusion: IGF-1 was found to be associated with depression in alcohol-dependent patients, suggesting that IGF-1 in alcohol- dependent patients could be an important biomarker to indicate whether alcohol-dependence is accompanied by depression.