Interleukin-6 and Interleukin-10 in mood disorders: A population-based study.

OBJECTIVE

The aim of this study was to assess if cytokines levels (IL-6 and IL-10) are related to major depressive disorder (MDD) and bipolar disorder (BD), in a population-based study.

METHODS

This was a cross-sectional study population-based, involving 1037 people aged 18-35. MDD, BD, anxiety and suicide risk were assessed using the Mini International Neuropsychiatric Interview. Serum IL-6 and IL-10 were measured by ELISA using a commercial kit.

RESULTS

The total sample comprised 1034 young adults, being 14.4% with MDD and 13.7% with BD. MDD and BD groups showed significantly higher serum IL-6 levels (p ≤ 0.001) and IL-10 levels (p ≤ 0.001) when compared to healthy control group. No correlation was found between serum IL-6 and IL-10 levels in health control group (p = 0.830; r = -0.008), non-suicide risk (p = 0.337; r = 0.032) and non-anxiety disorder (p = 0.375; r = 0.031). Covariance analysis showed that mood disorders alone, increase both interleukin levels (IL-6, p = 0.019; and IL-10, p = 0.026), whilst the interaction of mood disorders and suicide risk or anxiety disorders did not.

CONCLUSION

Our results suggest that inflammatory dysregulation may be involved in the physiopathology of mood disorders and serum IL-6 and IL-10 levels are putative biomarkers for these disorders.