Interleukin-6 Is Elevated in the Cerebrospinal Fluid of Suicide Attempters and Related to Symptom Severity
2009 (English)In: BIOLOGICAL PSYCHIATRY, ISSN 0006-3223, Vol. 66, no 3, 287-292 p.Article in journal (Refereed) Published
Background: Depressive disorders are associated with immune system alterations that can be detected in the blood. Cytokine concentrations in cerebrospinal fluid (CSF) and their relationship to aspects of suicidality have previously not been investigated. Methods: We measured interleukin-1 beta interleukin-6 (IL-6), interleukin-8, and tumor necrosis factor-a (TNF-alpha) in CSF and plasma of suicide attempters (n = 63) and healthy control subjects (n = 47). Patients were classified according to diagnosis and violent or nonviolent suicide attempt. We evaluated suicidal ideation and depressive symptoms using the Suicide Assessment Scale and the Montgomery-Asberg Depression Rating Scale (MADRS). We also analyzed the relation between cytokines and monoamine metabolites 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in CSF, as well as the integrity of the blood-brain barrier as reflected by the CSF:serum albumin ratio. Results: IL-6 in CSF was significantly higher in suicide attempters than in healthy control subjects. Patients who performed violent suicide attempts displayed the highest IL-6. Furthermore, there was a significant positive correlation between MANS scores and CSF IL-6 levels in all patients. IL-6 and TNF-a correlated significantly with 5-HIAA and HVA in CSF, but not with MHPG. Cytokine levels in plasma and CSF were not associated, and patients with increased blood-brain barrier permeability did not exhibit elevated cytokine levels. Conclusions: We propose a role for CSF IL-6 in the symptomatology of suicidal behavior, possibly through mechanisms involving alterations of dopamine and serotonin metabolism.
Place, publisher, year, edition, pages
2009. Vol. 66, no 3, 287-292 p.
5-HIAA; attempted suicide; cytokines; HVA; interleukin-6; major depressive disorder
National CategoryMedical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-20208DOI: 10.1016/j.biopsych.2009.01.030OAI: oai:DiVA.org:liu-20208DiVA: diva2:233788