The longitudinal relation between pain and positive and negative affect in people with polyarthritis

Objective: Due to their disease, patients with polyarthritis experience pain in their joints, which is interfering with their daily lives and which can cause problems in mental health. Previous research suggests that positive emotions may be a factor which has influence on the relationship between pain and its consequences on mental health such as anxiety and depression. The objective of this study was to explore the relationship between pain, positive and negative affect. Method: A longitudinal questionnaire study with two measurements of pain, positive affect, anxiety and depression have been conducted among 331 patients with polyarthritis (61 % female, mean age: 62 years). The relationship between the variables were analyzed with mediation analyses. Results: The relationship of pain with anxiety and depression was partially mediated by positive affect. Also, the relationships of changes in pain with changes in depression and anxiety were mediated by changes in positive affect. Conclusion: The results support models and theories about the relationship between positive and negative affect. Therefore, further research is implicated to be able to make cause-effect statement about the relationship between pain, positive and negative affect.