Abstract
BACKGROUND: Numerous investigations report that depressive symptoms frequently coexist with persistent pain. However, evidence suggests that symptoms of depression are not an inevitable consequence of pain. Diathesis-stress formulations suggest that psychological factors interact with the stress of pain to heighten the risk of depressive symptoms. Perceptions of injustice have recently emerged as a factor that may interact with the stress of pain to increase depressive symptoms. OBJECTIVES: The purpose of the present study was to examine whether perceived injustice moderates the relationship between pain and depressive symptoms. METHODS: A total of 107 individuals with persistent musculoskeletal pain completed self-report measures of pain severity, depressive symptoms, perceived injustice and catastrophizing. RESULTS: A hierarchical regression analysis revealed that the interaction between pain severity and perceived injustice uniquely contributed an additional 6% of the variance to the prediction of depressive symptoms, beyond the main effects of these variables. Post hoc probing indicated that pain was significantly related to depressive symptoms at high, but not low levels of perceived injustice. This finding remained statistically significant even when controlling for pain catastrophizing. CONCLUSIONS: The results suggest that perceived injustice augments the relationship between pain severity and depressive symptoms. The inclusion of techniques specifically targeting perceptions of injustice may enhance the effectiveness of interventions aimed at reducing symptoms of depression for individuals presenting with strong perceptions of injustice.