Is Depression an Inflammatory Disease? Findings from a Cross-Sectional Study at a Tertiary Care Center.
BACKGROUND
Evidence linking inflammation and depression is marred by several methodological inconsistencies. Further, varying information is present on the role of gender as a potential confounder in this association.


OBJECTIVE
To assess systemic inflammation in drug naοve depression by measuring selected pro-inflammatory (tumor necrosis factor-alpha [TNF-α], interleukin-6 [IL-6]) and anti-inflammatory cytokines (transforming growth factor-beta [TGF-β]) and comparing them with a matched control group. We also aimed at exploring the differences in these markers between genders.


METHODS
The study was a cross-sectional one carried out a teaching cum Tertiary Care Hospital.


METHODS
We recruited 55 drug naοve cases diagnosed with major depression and compared them for inflammatory markers with a matched apparently healthy control group (n = 42) at baseline. The inflammatory markers were also compared between the genders. Baseline depression and stress levels were assessed using standard measures.


METHODS
Mann-Whitney U-test.


RESULTS
In comparison with healthy controls, drug naοve depressed individuals demonstrated significantly raised baseline levels of TNF-α and IL-6 (P < 0.001 for both) but no difference in levels of TGF-β (P = 0.433). Neither the baseline depression nor the stress scores correlated with any of the inflammatory markers (P = 0.955 and 0.816 for TNF-α respectively). Males and females were comparable on the levels of markers studied (P = 0.986, 0.415, and 0.430 for TNF-α, IL-6 and TGF-β respectively).


CONCLUSIONS
There is evidence for higher baseline inflammation in depression prior to starting anti-depressant therapy. Gender does not mediate this observed link between inflammation and depression.
Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Avin
A
Muthuramalingam
Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Vikas
V
Menon
Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Ravi Philip
RP
Rajkumar
Department of Clinical Immunology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Vir Singh
VS
Negi
Anti-depressant; depression; drug naοve; gender; inflammation