Pain and Depression in Injured Workers and Their Return to Work: A Longitudinal Study

This study investigated the long-term relationships between depression, pain, and return to work in injured workers with chronic pain. Clients (N = 185) completing the Pain Disability Prevention Program were evaluated for pain and depression at three points in time: on admission to the treatment program, at mid-treatment, and at the end of treatment. The return to work (RTW) was assessed at four weeks after the intervention ended. Correlation and logistic regression analyses showed that depression and pain were significantly associated over time, and that depression and affective pain were the most significant variables for predicting RTW regardless of the time of assessment. An initial cluster analysis divided the sample into four groups reflecting fluctuations of depression and pain over time. Chi-square results indicated that individuals with severe or moderate depression and high levels of affective pain were less likely to RTW (from 18% to 21%) compared to individuals with mild depression or normal emotional "ups and downs" and lower affective pain scores (from 61% to 85%). These results highlighted the importance of considering the clinical symptoms profiles over time when determining the probability of RTW.