Plasma Indolamine 2,3 dioxygenase and serum neopterin levels in patients with first episode major depressive disorder and recurrent major depressive disorder

Objective: The aims of this study were to determine whether the plasma Indolamine 2,3 dioxygenase and neopterin levels in patients with major depression differ from a healthy control group and to investigate the relationship between previous major depression episodes and plasma indolamine 2,3 dioxygenase and serum neopterin levels. Methods: Thirty eight first episode major depression patients, sixty four recurrent major depression patients and forty one healthy control participant included the study. Plasma indolamine 2,3 dioxygenase and serum neopterin levels compared in these three groups. Results: Plasma indolamine 2,3 dioxygenase and serum neopterin levels in recurrent major depression group were statistically higher than first episode major depression and healthy control group. There was a positive correlation between plasma IDO levels and number of depressive episodes in major depression group (rho=0.36, p<0.001). Conclusion: According to these findings previous major depression episodes can promote response of the immune system associated with proinflamatuar cytokine activity. This sensitizing effect of previous depressive episodes may increase the recurrence risk of depression.