Background: Mounting data are indicating that major depression is related to diverse functions of the immune system. Several observations indicate that cytokine concentrations might also relate to the intensity of depressive manifestations. In this study we assessed whether inflammatory and anti-inflammatory cytokine concentrations are associated with the intensity of the depressive features in a cohort of patients with major depression and in healthy normal controls.
Methods: A group of 25 patients with major depression all suffering from an acute deterioration of their mental status and all hospitalized in a psychiatric ward were assessed for the intensity of their depressive manifestations according to the Hamilton rating scale for depression and by the clinical global impression scale (CGI). In parallel, concentrations of serum IL-2R, IL-6, IL-8, IL-10 were analyzed by commercial ELISA kits. As comparators, a group of 25 healthy controls was analyzed.
Results: The levels of IL-6 were higher among patients with depression. A high degree of correlation was found between the scores measured by the Hamilton and CGI scales by which the intensity of depressive symptoms were ranked. Interestingly, within the group of patients with depression a negative correlation was detected between the IL-6 concentrations and the CGI scores while a positive correlation was found between the IL-10 concentration and IL-6 concentration.
Conclusions: Our data indicate that the patients with depression differ from healthy individuals by their cytokine profile. Within this group of patients depressive features have a specific pattern and linkage to inflammatory and anti-inflammatory scores.