Depression Correlated Higher with Functional Impairment of Chronic Pain than Pain Severity in Both Veterans with and without PTSD

Objective: Several studies have examined the correlation of either Post-Traumatic Stress Disorder (PTSD) or depression to chronic pain and disability and yielded varying and sometimes contradicting results. The objective of this study was to investigate this correlation and the possible additive effect of PTSD and depression on pain and functional disability. Methods: All patients evaluated in the Chronic Pain clinic completed a pre-assessment questionnaire that included Visual Analogue Scale (VAS) scores for pain, Brief Pain Inventory (BPI), and pain interference with daily functioning. We also assessed level of depression and presence of PTSD. We then performed statistical analyses using Pearson’s correlation to compare the correlations in PTSD group versus non-PTSD group. Results: We examined 182 patients presenting to the Durham VA Medical Center Chronic Pain clinic. The correlation between depression and pain severity in patients with PTSD is 0.43 (p < 0.0048) while the correlate in those without PTSD is 0.45 (p < 0.0001). The correlation between depression and pain interference with daily functioning in patients with PTSD is 0.62 (p < 0.0001) versus those without PTSD is 0.66 (p < 0.0001). Conclusion: This study suggests significant correlation between pain and depression, both in patients with and without PTSD. PTSD did not have an additive effect on that correlation of depression with pain. Depression correlated stronger with pain interference than with pain severity.