The effect of PDYN RS2281285 gene polymorphism on depressive symptoms in individuals diagnosed with alcohol use disorder

Alcohol use disorder (AUD) is associated with changes in reward and stress pathways in the brain. These changes can lead to emotional stress in individuals with alcohol use disorder and thus to an uncontrolled search for alcohol. Dynorphins (DYN), endogenous peptide ligands of kappa opioid receptors (KORs), are encoded by the PDYN gene. KOR/DYN interaction causes anhedonic/dysphoric (reluctance, not enjoying life) effects in humans. The KOR/DYN system may affect the strong desire to consume alcohol occuring as a result of negative emotional states in individuals with alcohol use disorder. In this study, the effect of PDYN rs2281285 gene polymorphism on depressive symptoms was investigated in individuals with alcohol use disorder. For this purpose, Turkish men (n=100) with AUD diagnosis who applied to Ankara University Faculty of Medicine, Department of Mental Health and Diseases were included in the study. PDYN rs2281285 gene polymorphism was analyzed by Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphism (RFLP) method. Depressive symptoms in individuals were measured with the Beck Depression Inventory-II. The frequencies of the A and G alleles of the PDYN rs2281285 gene polymorphism were found to be 80% and 20%, respectively. Genotype frequencies were calculated as 62% for AA, 36% for AG and 2% for GG. Genotype and allele frequencies for this polymorphism are consistent with Hard-Weinberg equilibrium (p>0.05). The intenstiy of depressive symptoms of individuals with AUD were found to be lower in individuals with AA genotype (21.84±11.38) as compared to individuals with AG+GG genotype (24.00±12.36). However, this difference between PDYN rs2281285 gene polymorphism genotypes was not statistically significant (p>0.05). In conclusion, this study showed that the PDYN rs2281285 gene polymorphism had no effect on depressive symptoms in Turkish men with alcohol use disorder.