Questions And Answers: The Nature Of Disease

A recent study by German researchers reportedly found that the Borna virus, an infection that is known to cause behavioral changes in some animals, was present in up to 100 percent of people experiencing severe mood disorders, but in only 30 percent of people who were healthy. The results prompted new speculation as to whether or not the Borna virus causes depression. Neuroscientist Dr. Ian Lipkin, director of the Emerging Diseases Laboratory at the University of California, Irvine, is not convinced that the link between the two has been proven. Still, Lipkin does believe that infections may be at least in part responsible for the development of many diseases. NEWSWEEK's Laura Fording asked Lipkin, who will soon be moving to the Mailman School of Public Health at Columbia University, to elaborate.

NEWSWEEK: You say that more and more evidence points to environmental triggers for chronic diseases. Can you explain?

Dr. Ian Lipkin: Chronic diseases affect some 90 million people in the United States alone. Chronic infections have been implicated in some types of cancer and in peptic ulcer disease. Prior to 1984, peptic ulcer disease was attributed to stress. With the recognition of a bacterium called Helicobacter pylori, we now know that the vast majority of peptic ulcer disease is due to infection. This discovery has changed the whole approach to treatment of this disorder, from surgical to antimicrobial. Another example is the role of the Human Papilloma Virus [HPV] in cervical cancer. [I believe] that the same thing is going to pertain to mental illnesses, multiple sclerosis and to a variety of other disorders. They are perhaps due to chronic infections as well.

Tell me about how your research with infectious diseases and the central nervous system.

In the mid '80s I started working with the Borna virus, with the notion that infectious agents might be important in a variety of chronic central-nervous-system disorders, including depression, schizophrenia and autism.... We have continued to develop and expand, [with the hope] that we'll be able to find infectious agents that are going to be important in a wide variety of disorders, ranging from cancer to central-nervous-system disorders. We were also the group that discovered that it was the West Nile virus as opposed to St. Louis Encephalitis in the 1999 outbreak in New York City.

What have you discovered about mental illnesses in the course of your research?