"For the first time, we have evidence of a strong relationship between a molecular event and the development of psychopathology," Dantzer said.
The two scientists, who have collaborated for 25 years, have identified how a molecular pathway in the brain may explain why some patients suffering from inflammatory diseases develop depression. "The goal of our research is to understand the mechanisms that are responsible for causing depression in patients with inflammatory diseases," Dantzer said.
Depressive disorders occur in 12 to 30 percent of patients who suffer from various diseases with an inflammatory component, including coronary heart disease and autoimmune diseases such as rheumatoid arthritis and inflammatory bowels. These mood disorders usually are attributed to psychological problems encountered by patients having to deal with the suffering and disability brought about by their diseases.
However, Dantzer and Kelley explained, research on patients whose immune systems are boosted by immunotherapy challenge this view and suggest that depression may originate in the immune system. Immunotherapy is used to treat patients who suffer either from kidney cancer or melanoma with metastasis, or from viral infections such as hepatitis C and AIDS.
"A few thousand cancer patients and several hundreds of thousands of hepatitis C patients are treated each year with immunotherapy," Dantzer said.
Immunotherapy involves the injections of cytokines, which are chemicals normally made by immune cells that boost the immune system to fight infectious pathogens and kill cancer cells. Unfortunately, immunotherapy also causes depression in 33 percent of patients,
Contact: Molly McElroy or Jim Barlow, News Bureau
University of Illinois at Urbana-Champaign