Schizophrenia and rheumatic disease. A study on the concurrence of inflammatory joint diseases and a review of 58 case-records.

The coincidental occurrence of schizophrenia and rheumatoid arthritis is considered to be low in relation to the prevalence of the two diseases. In the present study, data from the patient statistics prepared by the Swedish Social Welfare Board were examined for the occurrence of rheumatic disease in schizophrenic patients. With the aid of the statistics and of questionnaires, 58 case-records were collected and studied. Very few cases were found of co-existing schizophrenia and inflammatory joint disease, rheumatoid arthritis in particular. There were, however, some cases of genuine schizophrenia and definite seropositive rheumatoid arthritis in the same patient. Rheumatoid arthritis is possibly uncommon also in combination with other psychiatric diseases that require hospital care. The ankylosing-spondylitis cases were over-represented in relation to the rheumatoid-arthritis cases included in the statistics from psychiatric care. Most of the 13 ankylosing-spondylitis patients whose case-records were studied had schizoaffective psychosis or atypical psychosis. The results of the investigation should be confirmed by epidemiological studies; this may contribute to the understanding of the aetiology of rheumatoid arthritis and of schizophrenia.