Emotional processing and its relationship to chronic low back pain: results from a case-control study.

Chronic low back pain (CLBP) is a common, yet challenging condition for both patients and clinicians. Several studies have demonstrated a strong association between CLBP and psychological factors such as anxiety, fear-avoidance, self-efficacy, catastrophizing and depression. These factors are closely linked with emotional states; however, it is unknown whether CLBP patients process their emotions differently from asymptomatic individuals. The aim of this case-control study was to investigate the relationship between CLBP and emotional processing. A sample of 110 participants comprising of 55 patients with chronic back pain and 55 individuals without a history of CLBP were assessed using the Emotional Processing Scale (EPS-25). The EPS-25 generates an overall score, and also scores pertaining to five individual emotional processing factors--avoidance, suppression, unregulated emotion, impoverished emotional experience and signs of unprocessed emotion. Chronic back pain patients scored significantly higher in the overall EPS-25 score (p < 0.001) with an effect size of 0.33. In addition, there were significant differences in four factors--impoverished emotional experience, unregulated emotion, unprocessed emotion, and suppression, with effect sizes ranging from 0.20 to 0.44. The results suggest that dysfunctional emotional processing, particularly with regard to the suppression of emotions, is associated with CLBP. Clinicians should critically consider the role of emotional processing in their patients' evaluation and management. Future research using a prospective cohort should assess the role of emotional processing as a predictor in the development of chronic back pain.