At the turn of the century, Capuron et al. Discovered the ability of cytokines to induce depression.
Cytokines began to be used to treat cancer, in particular metastatic melanomas and viral hepatitis C. Cytokines IL-2 and IFN-alpha were used.
Patients with cancer often fall into depression, which is manifested by low self-esteem and psychomotor retardation. Patients with hepatitis C have episodes of depression interspersed with manias.
For cancer patients and patients with hepatitis C, anxiety, a violation of the autonomic nervous system in the form of weakness, loss of appetite, and sleep disturbance are characteristic. A third of patients who received cytokine immunotherapy complained of depression. This fact reflects the presence of some personal and constitutional factors that predispose to the development of depression. The risk of depression is also based on a hereditary predisposition to the disease. Depression is also recorded in patients with dysfunction of the “stress axis” (hypothalamus – pituitary gland – adrenal glands). A marker of the development of depression upon administration of cytokines may be the change in indicators characterizing the functioning of the “stress axis” after injection of the cytokine IFN alpha.
With the introduction of endotoxins of some bacteria, for example, Salmonella, a significant decrease in mood and various disorders of the autonomic nervous system were found. This is due to an increase in the blood plasma of interleukins (cytokines), in particular, interleukin IL-6. Moreover, the severity of affective disorders is directly proportional to the level of the cytokine IL-6.