Having in mind the hypothesis of impaired cytokine regulation in depressive disorder, as well as the diverse population-dependent results for cytokine polymorphisms, we investigated the relation between the cytokine gene polymorphisms of key pro- and anti-inflammatory cytokines (TNF-α, TGF-β, IL-10, IL-6, IFN-γ) and susceptibility as well as clinical course of depression in Bulgarians.
This study evaluated the chronic effects of fluoxetine, a commonly prescribed SSRI antidepressant, on the peripheral and central levels of inflammatory cytokines including IL-1β, IL-6, TNF-α and IL-17 over a 4-interval in a rat model of chronic mild stress (CMS) which resembles the human experience of depression.
During late phase, LPS-induced increases in cortisol and IL-6 plasma concentrations and baseline depression were significant predictor variables, explaining 38.5% of variance.
These findings suggest that chronic social stress alters BBB integrity through loss of tight junction protein Cldn5, promoting peripheral IL-6 passage across the BBB and depression.
Individuals with depression (current MDD or high depressive symptoms) had lower IL6 methylation levels at one of the four sites investigated, however the effect size was small (∆ 2.4%, SE 0.009, p = 0.006).
Improvement in depression scores was associated with improvement in 3 biomarkers of insulin resistance (homeostatic model assessment [HOMA-IR], oral glucose tolerance test, and fasting plasma glucose) and 1 biomarker of inflammation (interleukin-6) among 21 biomarkers studied.
Overall, this suggests that our results failed to support the hypothesis that IL6, CRP and BDNF are directly involved in the therapeutic mechanism of NAC in depression.
The present study suggests that changes in the GSH-dependent defense system, NF-κB activation and increased IL-6 protein expression may have a role in social isolation-induced changes in a rat model of depression and anxiety, and contributes to our understanding of the mechanisms that underlie the antidepressant and anti-inflammatory activity of Flx in socially isolated rats.
In a model additionally adjusted for depression, vascular factors, BMI, and smoking status, the association between IL6 and brain volumes remained, and a doubling in ACT was marginally associated with 0.054 (p=0.001) millimeter thinner mean cortical thickness, equivalent to that of approximately 2.7years of aging.
Here, in a sample of 88 healthy female participants, we first assessed the effect of an acute laboratory stress paradigm on levels of plasma interleukin-6 (IL-6), a cytokine known to be both responsive to stress and elevated in depression.
It was observed that Interleukin-6, salivary cortisol, arachidonic acid / eicosapentaenoicacid plus docosahexaenoic acid ratio, and genetic polymorphisms may present variations which are linked to a predisposition to INF-α-induced depression.
A significant correlation was observed between the patients' plasma IL-6 levels and their 17-item Hamilton Rating Scale for Depression (HAMD17) scores (<i>r</i> =0.4555, <i>P</i>=0.0010).
This study is clinically relevant because we highlight that, in agreement with the previous literature, IL-6 appears to be a useful marker in depression, and we show for the first time that its reduction is closely related to the use of ECT.
Explorative analyses revealed significant associations between the IL-6 response on the second exposure with perceived stress (r=0.58; p=0.004), vital exhaustion (r=0.57; p=0.009), depression (r=0.47; p=0.026) and purpose in life (r=-0.50; p=0.04).
Proinflammatory cytokines such as interleukin (IL)-1 and IL-6 are elevated in both psoriasis and depression, indicating that the inflammatory process may be involved in the progression of both diseases.
However, the underlying mechanism of this relationship is still not fully explained, while interleukin-6 (IL-6) and interleukin-18 (IL-18) are associated with depression and exercise.
Furthermore, AD patients with depression have even significantly higher levels of IL 6 or TNF α and a lower level of 25-hydroxyvitamin D in circulation than in AD patients without depression.