Psychiatry Research 105 2001 165᎐174
Immunological differences between patients with major
depression and somatization syndrome
, Florian Pilger
, Daniel Ihle
, Eugene Bosmans
, Michael Maes
Klinik Roseneck, Center for Beha
ioral Medicine, Prien am Chiemsee, Germany
Department of Psychiatry and Neuropsychology, Uni
ersity Hospital of Maastricht, Maastricht, The Netherlands
Eurogenetics, Tessenderlo, Belgium
ersity of Marburg, Department of Clinical Psychology and Psychotherapy, Marburg, Germany
Received 20 February 2001; received in revised form 12 September 2001; accepted 26 September 2001
There is some evidence that major depression is accompanied by activation of the inﬂammatory response system
IRS . There is also evidence that proinﬂammatory cytokines and induction of IRS activation are associated with
sickness behavior in experimental animals. However, no research has examined the IRS in somatization disorder.
The aim of this study was to examine possible immunological differences between major depression, somatization
and healthy controls. We measured the following IRS variables in patients with major depression ns36 ,
Ž . Ž. Ž.
somatization syndrome SSI-8; ns37 , major depression and somatization ns40 and healthy controls n s 37 :
Ž. Ž . Ž .
interleukin-6 IL-6 ; interleukin-1-receptor-antagonist IL-1RA ; plasma soluble interleukin-6 receptor IL-6R ;
Ž. Ž . Ž .
soluble suppressorrcytotoxic antigen CD8 ; leukemia inhibitory factor LIF-R ; and Clara cell protein CC16 , an
endogenous anticytokine. Serum CD8 concentrations were signiﬁcantly increased in patients with major depression
compared with concentrations in patients with somatization syndrome, whereas concentrations in normal controls
were intermediate between those of the two groups of patients. Serum CC16 was signiﬁcantly lower in major
depression than in healthy controls. The highest CC16 scores were found in patients with somatization syndrome.
Somatizing patients have signiﬁcantly lower serum IL-6 values than normal controls and depressed patients. The
Ž. Ž .
present results indicate 1 an activation of the IRS in depression with signs of T-cell activation increased CD8 ,
iations: IRSsinﬂammatory response system; IL sinterleukin; SSIs Somatic Symptom Index; IL-1-RA sinterleukin-1-
receptor-antagonist; IL-6R s plasma soluble interleukin-6 receptor; LIF-Rs leukemia inhibitory factor; CC16 sClara cell protein;
TNFstumor necrosis factor; SOMSsScreening for Somatoform Symptoms; BDIsBeck Depression Inventory; SCIDsStructured
Clinical Interview for DSM-IV; IDCL sInternational Diagnostic Checklists
Corresponding author. Department of Clinical Psychology and Psychotherapy, University of Marburg, Gutenbergstr. 18,
D-35032 Marburg, Germany.
E-mail address: firstname.lastname@example.org W. Rief .
0165-1781r01r$ - see front matter ᮊ 2001 Elsevier Science Ireland Ltd. All rights reserved.
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