Initial depression severity and the trajectory of recovery following cognitive-behavioral intervention for work disability

Introduction: The present study examined the recovery trajectories of a group of mildly depressed and moderately-severely depressed injured workers enrolled in a 10-week community-based rehabilitation program. Methods: A sample of 168 individuals (75 women, 93 men) with a disabling musculoskeletal pain condition participated in the research. On the basis of BDI-II (1) scores at pre-treatment assessment, patients were classified as either mildly (BDI-II =9-16; N=68) or moderately-severely depressed (BDI-II >16; N: 100). Results: Both groups showed significant reductions in depression, but individuals in the (initially) moderately-severely depressed group were more likely to score in the depressed range of the BDI-II at post-treatment than individuals who were initially mildly depressed. For the mildly depressed group, early treatment reductions in pain catastrophizing, and perceived disability predicted improvement in depression scores. For the moderately-severely depressed group, none of the early treatment changes predicted improvement in depression; only late treatment reductions in pain catastrophizing and fear of movement/re-injury predicted improvement in depression. Chi-square analysis revealed that patients who were no longer depressed at post-treatment had the highest probability of returning to work (91%), followed by (post-treatment) mildly depressed patients (60%), and finally (post-treatment) moderately-severely depressed patients (26%), χ²=38.9, p < 0.001. Conclusion: In order to maximize return to work potential, the content, structure and duration of rehabilitation programs requires modification as a function of the injured workers level of the depression severity.