The role of interleukin genes in the course of depression

Background: Research studies conducted in recent years have confirmed that in the absence of medical illnesses, depressive disorders are associated with upregulation of many inflammatory cytokines such as tumor necrosis factor-aplha (TNF-alpha), interleukin-1 and 6 (IL-1, IL-6). The main objective of the study was to examine whether recurrent depressive disorders (rDD) are accompanied by more profound inflammatory disturbances than the first episode of depression (ED-I). The analysis included the expression of mRNA and protein levels of three interleukins namely. IL-1, IL-6 and IL-10. Methods: The study was carried out in a cohort of 130 patients: ED-I group - 44 patients, rDD group - 86 patients respectively. Results: Our results suggest that there was no significant statistical difference between the analyzed groups as regards the intensity of the depressive disorders. Furthermore, No differences in the expression of IL-1, IL-6 and IL-10 genes on the level of both mRNA and protein were observed among the groups. Additionally, there was no significant interrelation been documented between the number of depression episodes experienced v/s the expression of selected genes. Conclusions: There is no significant difference in IL-1, IL-6 and IL-10 expression between patients with recurrent depressive disorders and those suffering from the first episode of depression. 2. There seems to be no difference in acute first episode depression vs. acute episode of depression in patients with a recurrent disorder. Further larger trials are needed.