From the front page of today's Baltimore Sun: Researchers Explore Link Between Schizophrenia, Cat Parasite.
Frank D. Roylance writes:
Johns Hopkins University scientists trying to determine why people develop serious mental illness are focusing on an unlikely factor: a common parasite spread by cats. The researchers say the microbes, called Toxoplasma gondii, invade the human brain and appear to upset its chemistry — creating, in some people, the psychotic behaviors recognized as schizophrenia. If tackling the parasite can help solve the mystery of schizophrenia, "it's a pretty good opportunity … to relieve a pretty large burden of disease," said Dr. Robert H. Yolken, director of developmental neurobiology at the Johns Hopkins Children's Center.
A University of Maryland study last year found that people with mood disorders who attempt suicide had higher levels of T. gondii antibodies than those who don't try to take their own lives. Still, the links between schizophrenia and toxoplasmosis are not simple. For example, most people infected with T. gondii never become schizophrenic. And not all schizophrenics have been exposed to toxoplasma. Yolken believes additional factors, such as an unlucky combination of genes, are probably needed to produce schizophrenia among Toxoplasma-infected people. The parasite's DNA may also be important, since some strains are known to cause more disease.