Pain in primary Sjögren's syndrome: the role of catastrophizing and negative illness perceptions.

OBJECTIVES: Pain is a major factor in health quality in Sjögren's syndrome (SS), but little is known about the factors that contribute to pain severity. Because pain perception has been linked to catastrophizing in other diseases, we assessed subjects with primary SS (pSS) to explore a possible link between pain, illness appraisal, and catastrophizing. METHOD: A total of 92 subjects who met American-European consensus criteria for the diagnosis of pSS completed a questionnaire that included health history, medication use, illness perceptions, pain severity, mood, fatigue, pain anxiety, and pain catastrophizing. Linear regression was used to test the effect of each variable on pain severity. Multivariate models were constructed using backwards elimination to assess the significant predictors of pain severity. RESULTS: From linear regression analysis, catastrophizing was more strongly predictive of pain severity than age, fatigue, depression, or anxiety in both seropositive and seronegative pSS patients. In the multivariate model identified using backwards selection, four variables (pain catastrophizing, fibromyalgia status, serological status, and the conviction that illness would have severe consequences) predicted 55% of the variance in pain severity. CONCLUSIONS: Pain catastrophizing was a significant predictor of pain severity in both seropositive and seronegative pSS patients. This study suggests that behavioural interventions designed to reduce pain catastrophizing and negative appraisal of illness could be of benefit in pSS patients. Research is needed to test the effect of psycho-educational therapies on key patient-reported outcomes, particularly pain, depression, and fatigue, in pSS.

Primary Sjogren's syndrome: cognitive symptoms, mood, and cognitive performance.

OBJECTIVE: To investigate the relationships between self-reported cognitive abilities, psychological symptoms and neuropsychological outcomes in PSS. METHODS: Patients with Primary Sjogren's syndrome (PSS) and healthy controls completed a comprehensive neuropsychometric battery and questionnaires: the Centers for Epidemiological Scale-Depression, the Profile of Fatigue-mental domain (Prof-M) for cognitive symptoms, Fatigue Severity Scale, and the Short-Form McGill Pain Questionnaire. RESULTS: Female patients with PSS (N = 39) were similar to controls (N = 17) in estimated premorbid intellectual function, age and education. Depression (P = 0.002), cognitive symptoms (P = 0.001), fatigue (P = 0.000003), and pain (P = 0.024) scores were greater in the patient group. Patients with PSS demonstrated inferior performance relative to controls in psychomotor processing (P = 0.027) and verbal reasoning (P = 0.007). Patients with PSS with and without depression had similar performance on multiple tests, but depressed patients had significantly lower scores for executive function (P = 0.041). Cognitive symptoms correlated with verbal memory (P = 0.048), whereas pain correlated with executive function measures (Stroop, P = 0.017) and working memory (Trails B, P = 0.036). In the regression model, depression and verbal memory were independent predictors that accounted for 61% of the variance in cognitive symptoms. CONCLUSION: The Prof-M is a simple self-report measure which could be useful in screening PSS subjects who may benefit from detailed psychometric evaluation. Our results are consistent with the hypothesis that depression and verbal memory impairment are overlapping but independent aspects of neural involvement in PSS. While pain and depression are significant confounders of cognitive function in PSS, this study suggests that impaired verbal reasoning ability in PSS is not attributable to pain or depression.