Effect of PDYN rs2281285, rs2235749 and rs910080 gene polymorphisms on the intensity of depression symptoms and negative craving in heroin addicts

The present study was undertaken to explore whether prodynorphin (PDYN) polymorphisms have an effect on the intensity of depressive symptoms and negative craving in heroin addicts in a sample of 100 heroin addicts and 108 controls. PDYN rs2281285, rs2225749 and rs910080 polymorphisms were analyzed by PCR-RFLP. Craving and the intensity of depressive symptoms were measured by the Substance Craving Scale and the Beck Depression Inventory-II, respectively. A significant association between depression severity and PDYN rs2281285 (P=0.026) and rs2225749 (P=0.038) polymorphisms was detected. PDYN rs2225749 variation showed a trend association with increased negative craving (P=0.066). We also examined the associations between heroin dependence and PDYN rs2281285, rs2225749 and rs910080 gene polymorphisms at the gene and haplotype levels. The AAA haplotype was more frequent in heroin addicts and shown to be significantly associated with increased risk for heroin dependence (OR, 8.922; 95% CI, 1.116-71.313; P