Affective distress and fibromyalgia
Principles: Elevated rates of lifetime and current psychiatric disorders, elevations of psychological self-report measures assessing depression, anxiety and hypochondriasis have been reported in fibromyalgia syndrome (FMS) patients as well as studies refuting these findings. Studies comparing FMS patients with rheumatoid arthritis (RA) patients provide discrepant data. The aim of this paper is to compare FMS patients with RA patients and healthy controls with respect to psychological measures in a case control design. Methods: Fifty subjects with FMS, 20 with RA and 42 healthy controls were assessed with respect to anxiety, depression, pain intensity and disability. Three logistical regression models were performed to test whether higher levels of a psychological measure (disability, depression or anxiety) are associated with one disease rather than another, or with one disease rather than with healthy controls. For each regression model, the best exploratory covariates were determined using receiver operating characteristic (ROC) curves. Results: In the logistic regression, anxiety scores were the most important covariate determining the likelihood of having FMS whereas depression scores increased the chances of being an RA patient. Age and disability scores did not differ between FMS and RA. Conclusions: Affective distress is not specific to FMS patients, but the manner in which affective distress is incorporated into the patient's life is worth studying. FMS seems to be associated with anxiety rather than depression.