Functional Polymorphism of Cyclooxygenase-2 Gene (G–765C) in Depressive Patients

Background: Depressive disorder (DD) is characterized by an inflammatory process and oxidative stress. Cyclooxygenase-2 (COX-2), the expression of which increases in depression, is an enzyme involved in inflammation and free radical processes. The aim of our study was to assess the correlation between single nucleotide polymorphism G–765C of the COX-2 gene and recurrent DD. Methods: The study was carried out in a group of 181 patients treated for recurrent DD, and in 149 healthy subjects of the control group (CG). Polymerase chain reaction/restriction fragment length polymorphism was used for genotyping. Results: A statistically significant difference in genotype distribution was observed as a result of the comparison between the CG and the patients with DD. We demonstrated that the presence of the –765G allele in the COX-2 gene increased 2.1-fold the risk of DD development, whereas the presence of a homozygote (G–765G) in the analyzed gene increased the risk of DD development 2.5-fold. Conclusion: According to the obtained results, it may be proposed with some caution that the presence of both the –765G allele and the G–765G genotype in the COX-2 gene may confer a susceptibility to an increased risk of recurrent DD in the Polish population.