Increased serum IL-6 and IL-1 receptor antagonist concentrations in major depression and treatment resistant depression

Cytokine. 1997 Nov;9(11):853-8. doi: 10.1006/cyto.1997.0238.


There is now some evidence that major depression is accompanied by an immune response with an increased production of pro-inflammatory cytokines, such as interleukin 1(IL-1), IL-6 and interferon gamma (IFN-gamma). The aims of the present study were to examine serum IL-6, IL-1 receptor antagonist (IL-1Ra), IL-6R, Clara cell protein (CC16) and the soluble CD8 (sCD8) molecule in chronic, treatment resistant depression (TRD) both before and after subchronic treatment with antidepressants. Serum IL-6 and IL-1Ra were significantly higher in subjects with major depression and TRD than in normal controls. Subchronic treatment with antidepressants had no significant effects on serum IL-6, IL-1Ra, CC16 or sCD8, but reduced serum sIL-6R levels significantly. There were significant and positive correlations between serum IL-6, on the one hand, and sIL-6R, IL-1Ra, sCD8, number of peripheral blood leukocytes, neutrophils, CD2(+)T and CD19(+)B cells (all positive) and serum zinc (negative), on the other. These results suggest that: (1) major depression and TRD are accompanied by an activation of the monocytic arm of cell-mediated immunity; (2) the latter may be related to the immune an acute phase response in major depression; and (3) the above disorders may persist despite successful antidepressive treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antidepressive Agents / therapeutic use*
  • CD8 Antigens / analysis
  • Depressive Disorder / blood
  • Depressive Disorder / drug therapy
  • Depressive Disorder / immunology*
  • Drug Resistance
  • Enzyme Inhibitors / metabolism
  • Humans
  • Interleukin-6 / blood*
  • Lymphocyte Subsets / cytology
  • Middle Aged
  • Phospholipases A / antagonists & inhibitors
  • Proteins / metabolism
  • Receptors, Interleukin-1 / antagonists & inhibitors*
  • Receptors, Interleukin-6 / blood
  • Uteroglobin*
  • Zinc / blood


  • Antidepressive Agents
  • CD8 Antigens
  • Enzyme Inhibitors
  • Interleukin-6
  • Proteins
  • Receptors, Interleukin-1
  • Receptors, Interleukin-6
  • SCGB1A1 protein, human
  • Uteroglobin
  • Phospholipases A
  • Zinc