Anger differentially mediates the relationship between perceived injustice and chronic pain outcomes.

Emerging evidence suggests that perceived injustice is a risk factor for adverse outcomes associated with chronic pain. To date, however, the processes by which perceived injustice impacts on pain outcomes remain speculative. Evidence from several lines of research suggests that anger may mediate the relationship between injustice and pain outcomes. However, this relationship has not been empirically tested in patients with chronic pain. Thus, the purpose of this study was to examine whether anger mediates the relationships between perceived injustice and pain intensity, depressive symptoms, and self-reported disability. One hundred and seventy-three individuals with chronic musculoskeletal pain completed self-report measures of perceived injustice, anger, pain intensity, depressive symptoms, and disability. Consistent with previous research, high scores on a measure of perceived injustice were associated with greater pain, more severe depressive symptoms, and more pronounced disability. Hierarchical regression analyses indicated that anger variables completely mediated the relationship between perceived injustice and pain intensity, and partially mediated the relationship between perceived injustice and depressive symptoms. Anger did not mediate the relationship between perceived injustice and self-reported disability. The Discussion addresses the theoretical and clinical implications of the findings.