Immune-neuroendocrine interactions and their influence on the immune function in patients with depressive disorders

An activation of the hypothalamo-pituitary-adrenal (HPA-) system is a widely accepted neurobiological finding in depressive patients, which is closely linked to psychopathological phenomena like anxiety. In contrast, there is not so much evidence for the clinical relevance for the proposed immunological abnormalities in this patients.

This might be due to the fact that basal immunolregulatory mechanisms like the regulation of immune function by glucocorticoids is not altered in the patients, as we demonstrated in a series of experiments on the immunosuppressive effects of dexamethasone or hydrocortisone in patients and healthy subjects. On the other hand we observed that basal cytokine levels seem to depend on the activity of the HPA-system. Thus it might be possible that the postulated immunological abnormalities in major depression might be a secondary phenomenon due to disease-associated HPA-activation.