Tulsi A. Malavia

Timothy K Hamilton / Flickr

Scientists have long known that there is a link between schizophrenia and rheumatoid arthritis. People who suffer from schizophrenia tend not to develop rheumatoid arthritis, and people with rheumatoid arthritis are at low risk for schizophrenia.

Though this relationship has been clear for more than 50 years, nobody really knew why the link existed, according to University of Pittsburgh professor of psychiatry and human genetics Vishwajit Nimgaonkar.

“We thought that there might be genetic factors that might explain this phenomenon,” he said.