title: The schizophrenia-rheumatoid arthritis connection: infectious, immune, or both?
abstract: Schizophrenia and rheumatoid arthritis share an impressive number of similarities. Both are chronic, relapsing diseases of unknown etiology. Both became prominent in the early 19th century and have prevalences of approximately 1% in North America and Europe. Both run in families, have pairwise concordance rates of approximately 30% among monozygotic twins, and are more common among individuals born in urban areas. For both diseases, studies have reported greater exposure to cats in childhood than in controls. Both diseases have been associated with similar class II HLA antigens. Both have also been suspected of having infectious etiology, with similar agents--retroviruses, herpesviruses including EBV, and Toxoplasma gondii--having been associated in some cases. Since there is also a well-documented inverse correlation between these two diseases, it is possible that they share a common infectious and/or immune etiology and that once a person gets one of the diseases then they are relatively immune to the other.
authors.affiliation: Stanley Foundation and Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA.
authors.forename: E F
authors.initials: EF
authors.lastname: Torrey
authors.forename: R H
authors.initials: RH
authors.lastname: Yolken
mesh_terms: D001172:Arthritis, Rheumatoid / Q000209:etiology* / Q000276:immunology* / Q000469:parasitology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D012559:Schizophrenia / Q000209:etiology* / Q000276:immunology* / Q000469:parasitology; D014123:Toxoplasmosis / Q000276:immunology; D014777:Virus Diseases / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II