Purpose: The influence of a cheerful mood on disease activity levels in rheumatoid arthritis is investigated in this cross-sectional study.
Method: State cheerfulness (i.e., how individuals feel at the time of the assessment) and trait cheerfulness (i.e., how individuals usually feel) were assessed at the same time as the clinical indicators of disease activity and just before measuring patient-reported disease activity with the Disease Activity Score-28 (DAS-28).
Results: State cheerfulness contributed significantly to the variance in the DAS-28 scores that was not accounted for by trait cheerfulness or demographic or clinical variables. Higher state cheerfulness was associated with lower values of self-reported disease activity and C-reactive protein. The patient-reported disease activity was not uniquely caused by the clinical indicators of disease, but it also depended on patients' cheerful mood at the moment of assessment.
Conclusion: The findings suggest interesting possibilities for the diagnosis and monitoring of disease activity in rheumatoid arthritis.
Keywords: Cheerfulness; Disease activity; Rheumatoid arthritis; Sense of humor.