Some recent studies show an association between a functional polymorphism of BDNF gene (Val66Met) and the susceptibility to nicotine dependence and we hypothesized that this polymorphism was associated with smoking in both schizophrenia patients and healthy controls.
Nicotine dependence and number of cigarettes smoked per day did not add to the prediction of serum BDNF; however, total number of smoking years was a significant predictor of serum BDNF.
Recent studies demonstrate that brain-derived neurotrophic factor (BDNF) might be associated with nicotine addiction, and circulating BDNF is a biomarker of memory and general cognitive function.
By using a generalized multifactor dimensionality reduction algorithm recently developed by us, we found highly significant gene-gene interactions for the gene pairs of CHRNA4 and CHRNB2, CHRNA4 and NTRK2, CHRNB2 and NTRK2, and BDNF and NTRK2 (p < .01 for all four gene pairs) and significant gene-gene interaction between CHRNA4 and BDNF (p = .031) on ND.
Association studies have also suggested that the BDNF gene might play a role in the susceptibility to nicotine dependence but results appear contradictory.
In patients with a current diagnosis of depression or anxiety, the relationship between nicotine dependence and symptom severity may be moderated by BDNFVal(66)Met.
In application to a real dataset, we detected one significant tetragenic interaction among CHRNA4, CHRNB2, BDNF, and NTRK2 associated with nicotine dependence in the Study of Addiction: Genetics and Environment sample, suggesting the biological role of these genes in nicotine dependence development.
The significant association of BDNF variants with ND implies that this gene plays a role in the etiology of ND in EAs and that its involvement is gender specific.