Objective: Noradrenergic pathways have been suggested to play a crucial role in the motivation-reward system of heroin dependence (HD), but so far, the role of the human norepinephrine transporter (NET; SLC6A2) gene in the pathogenesis of HD has never been investigated. The purpose of this study was to examine whether the NET gene is associated with the development of HD, and whether the NET gene influences specific personality traits.
Methods: Twelve single-nucleotide polymorphisms of the NET gene were analyzed in a case-control study of 965 Han Chinese participants (603 patients and 362 controls). All participants were screened using a Chinese version of the modified Schedule of Affective Disorder and Schizophrenia-Lifetime and all patients met the criteria for HD. A Chinese version of the Tridimensional Personality Questionnaire was used to assess personality traits and examine the association between specific personality traits and NET polymorphisms.
Results: No statistically significant differences in allele or genotype frequencies were observed in any of the investigated NET variants between HD patients and controls. After logistic regression analyses, no statistically significant effect of NET variants in the development of HD was found. In haplotype analysis, the frequency of AATA haplotype in rs1532701-rs40434-rs13333066-rs187714 was significantly different between HD patients and controls. These NET polymorphisms did not influence novelty seeking and harm avoidance scores.
Conclusion: This study suggests that the NET gene may be associated with the development of HD, but not associated with specific personality traits among Han Chinese.