Polymorphism G861C of 5-HT receptor subtype 1B is associated with heroin dependence in Han Chinese

The serotoninergic (5-HT) system regulates neuronal activity in broad brain regions, and appears to be particularly important for modulating behavioral and physiological functions such as mood, emotion, sleep and appetite. Central 5-HT deregulation may be involved in many neuropsychological disorders, which include substance abuse and addiction. Previous studies suggest that genetic polymorphisms in some 5-HT receptor genes may relate to heroin dependency. Here we examined potential association between heroin dependence and four single nucleotide polymorphisms (SNPs) of 5-HT receptors (A-1438G and T102C of HTR _2A, and G861C and A1180G of HTR _1B) in a cohort of Han Chinese. Participants included 303 heroin-dependent subjects who were recruited into the Methadone Maintenance Treatment (MMT) Program in the Xi'an Mental Health Center, and 300 healthy controls. The resulting data yielded a significantly higher frequency of the HTR _1B G allele with G861C among the heroin-dependent subjects relative to controls (p=0.001 after Bonferroni correction). Further genotype and clinical phenotype correlation study of the G861C carriers showed that the amount of heroin self-injection was higher in patients with the GG genotype relative to CC and CG genotypes (p<0.01). These findings point to a role for HTR _1B polymorphism in heroin dependence among Han Chinese, and may be informative for future genetic or neurobiological studies on heroin dependence.