Neuroimmunoendocrine interactions in patients with recurrent major depression, increased early life stress and long-standing posttraumatic stress disorder symptoms

Background: Traumatic events experienced in childhood may lead to psychiatric diseases in adult life, including major depressive disorder (MDD). It remains obscure to what extent early life stress (ELS) is associated with biologically relevant changes in MDD. Objective: We investigated both neuroendocrine and immunological correlates in recurrent MDD with ELS and current posttraumatic stress disorder symptoms. Methods: Thirty-eight female MDD patients with or without childhood trauma and 15 healthy controls took part in this study. Salivary cortisol and dehydroepiandrosterone sulfate (DHEAS) were assessed by radioimmunoassays. Peripheral blood mononuclear cells (PBMCs) were isolated and T cell proliferation and cellular sensitivity to steroids and DHEAS were evaluated by colorimetric assays. Th1/Th2 cytokines were assessed by cytometric bead arrays. Results: MDD patients with or without previous trauma had similarly lower salivary cortisol and DHEAS in parallel with blunted T cell proliferation. PBMCs of depressives were significantly less sensitive to dexamethasone or epinephrine than those of the controls. PBMCs of MDD patients produced significantly lower interleukin (IL)-2, IL-4 and tumor necrosis factor-α levels when compared to healthy controls. Conclusion: We found that a history of ELS did not modify the blunted neuroendocrine and immunological alterations presented by recurrent depressed patients.