CHAMPAIGN, Ill., July 28 (UPI) -- U.S. researchers said they have found evidence of a strong chemical relationship between inflammatory diseases, immunotherapy and depression.
Researchers at the University of Illinois at Urbana-Champaign found a molecular pathway affected by inflammatory diseases and immunotherapy that is associated with the brain chemical serotonin. Serotonin is a mood regulator that tends to be depleted by such diseases and by cytokines, which are injected in immunotherapy.
Depressive disorders occur in 12 percent to 30 percent of patients with inflammatory conditions such as coronary heart disease, as well as autoimmune diseases such as rheumatoid arthritis. The disorders usually are attributed to psychological problems brought on by the diseases, but the researchers said their studies indicate the depression actually may originate in the immune system.
Immunotherapy is used to treat thousands of cancer patients and hundreds of thousands of hepatitis C patients.
"The occurrence of depression in cytokine-treated patients indicates that treatment must be discontinued since depressed patients can commit suicide," researchers said.
