Stress and rheumatoid arthritis: a survey of empirical evidence in human and animal studies.

Literature concerning rheumatoid arthritis (RA) was reviewed with regard to the empirical evidence for the widely held view that the onset and course of the disease are influenced by stress variables. Human studies yielded contradictory results; there are at least two large well-controlled investigations that were not able to find a preponderance of life stress variables prior to the onset of the disease in RA patients compared to other patients or healthy subjects. Findings of animal studies are inconsistent, too: Some kinds of stress seem to abrogate, whereas others may rather enhance the development of rheumatic symptoms. Possible pathogenetic models are discussed to explain the influence of stress on the disease. For further research, the use of more sophisticated methods to assess life events, and prospective longitudinal studies in RA patients are suggested to find out whether stressful events antedate relapses. Such correlations should be examined for patients with seronegative and seropositive RA separately.