Cytokines

Chronic stress, Glucocorticoids and Th1/Th2 Cytokines
Individuals experience low cortisol levels or blunted levels in chronic stress (17, 32, 48) This proposes that chronic stress alters the ability for cortisol to regulate the immune system. Specifically the model argues that increased cortisol secretion in the presence of chronic unrelenting stress forces the immune system to adapt by down-regulating it Glucocorticoids receptors, thus leading to an inability of immune cells to respond effectively to Glucocorticoids signals. This results in an inability to shut down certain immune responses that in turn elevates levels of Cytokines as IL-6 (47).

Rheumatoid Arthritis and Th1/Th2 Cytokines
Psychological stress has been associated with exacerbations of RA(84) Daily studies revealed that weeks of high stress were associated with more clinician-rated disease activity than weeks of low stress among patients with RA.(85)Finally patients with RA reported high levels of social support and coping behaviors during times of chronic stress or major lif events. RA symptoms did not change, suggesting that while stress can exacerbate disease severity, coping and social support may migrate its affects on RA out comes(87)

Cytokines and depression
A relationship between altered immune function and depression has been suggested. Changes in immune function are followed by the release of cytokines, which caused various behavioral changes called” sickness behavior”, which appears to be very similar in depression. That cytokines may play an important role in the pathophysiology of depression is inferred from many observations (1). Levels of several cytokines, both pro-inflammatory and anti-inflammatory, have been found to be increased in the serum of patients with depression.(2) Administration of cytokines for example IFN-a, to cancer patients or to patients with hepatitis C, produced depression in some patients, as diagnosed by DSM Criteria: and (3)indirect evidence suggesting a role of cytokines in depression is the observation that stress, which is a major risk factor for depressive illness, alters not only the immune system but also the levels of several cytokines. Cytokines have also been shown to interact with components of the neuroendro-crine system such as the hypothalamic–pituitary-adrenal(HPA)axis (50,51)as well as some of the neurotransmitter systems such as serotonin(5HT)(29,52,53)and Norepinephrine(NE)(54,55) Abnormalities of the HPA axis(57) and NE(58) have been implicated in the pathophysiology of depression.(44-49)