http://elynsgroup.com Copyright: © 2016 Ribas-Roca JA, et al. http://dx.doi.org/10.19104/jpbd.2016.106 Open Access Research Article J Psy Neuro Dis Brain Stim Journal of Psychology, Neuropsychiatric Disorders and Brain Stimulation Page 1 of 5 Depression Correlated Higher with Functional Impairment of Chronic Pain than Pain Severity in Both Veterans with and without PTSD Ribas-Roca JA 1 , Nagy A. Youssef 2 and Srinivas Pyati 3* 1 Department of Psychosomatic Medicine, Boston Medical Center, 1 Boston Medical Center Pl, Boston, MA 02118, USA 2 Department of Psychiatry and Health Behavior, Medical College of Georgia, Augusta University, 997 St. Sebastian Way, Augusta, GA 30912, USA 3 Department of Anesthesiology and Pain Medicine, Duke University School of Medicine, Veterans Affairs Medical Center, Durham, 508 Fulton Street, Durham, NC 27708, USA Abstract 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. Keywords: Chronic Pain; Veterans; Post-traumatic Stress Disorder; Depression Abbreviations PTSD: Post-Traumatic Stress Disorder; BPI: Brief Pain Inventory; VAS: Visual Analogue Scale; PHQ-9: Patient Health Questionnaire; DSM-IV: Diagnostic and Statistical Manual of Mental Disorders; OIF: Operation Iraqi Freedom; OEF: Operation Enduring Freedom; PHQ: Patient Health Questionnaire. Introduction The lifetime prevalence of Post-Traumatic Stress Disorder (PTSD) in the general population is about 8% [1], but it can range from 20-50% in high risk groups [2]. PTSD is associated with high comorbidity of depression and several physical health problems including chronic pain [3]. In chronic pain patients, the prevalence of depression is 44%; and the prevalence of PTSD is 29% [4], resulting in significant decrease in daily functioning and quality of life [5-7]. Several studies have examined the correlation of either PTSD or depression to chronic pain and disability yielding varying and sometimes contradicting results [8-13]. PTSD is uniquely associated with several physical disorders, disability, and suicidality. It is also significantly associated with several physical health problems including chronic pain [3]. A meta-analysis by Pacella et al. found significantly greater general health symptoms, general medical conditions, and poorer health related quality of life for PTSD patients [14]. Geisser et al. studied the correlation between symptoms of PTSD, pain and disability and found that patients with accident related pain and high PTSD symptoms displayed higher levels of self-reported pain, affective disturbance and disability compared to patients whose pain was not accident related [11]. Another study in civilians, demonstrated that patients with a current PTSD diagnosis had significantly higher pain and pain-related functional impairment ratings per SF-36 Health Questionnaire than those with no PTSD [15]. Regarding depression, many studies show that comorbidity with chronic pain also has an effect on daily functioning and quality of life [6,13,16]. For example, Holzberg et al. [17] found in pain clinic patients, that somatic and cognitive symptoms of depression significantly correlate with psychosocial functioning even after controlling for the effects of pain level. Veterans with chronic pain and PTSD have more severe depression, pain, and disability compared to those without PTSD [12]. Bras et al found that quality of life measured by the World Health Organization Quality Of Life-BREF questionnaire, was reduced by 9.9% in war veterans with low back pain, 26.0% in those with PTSD, and 37.0% in combined PTSD and low back pain; suggesting strong synergistic effect of PTSD and low back pain [5]. Taken together, the above studies indicate independent effects of depression and PTSD in the functioning of chronic pain patients. However, there remains a gap in our knowledge in understanding how much PTSD contributes to chronic pain and pain disability beyond what is attributed to depression; and if there is an additive effect in disability for patients suffering from both psychiatric disorders. Limited studies address the interplay between pain, PTSD, and depression and no studies examined the direct effect of PTSD in the relationship between depression and pain in a cohort of veterans. Understanding such relationship can have important prognostic and treatment implications. Thus, the objective of this study was to investigate this correlation and the possible additive effect of PTSD and depression on pain and disability in the veteran population. A related objective was also to examine if there was an additive effect of comorbid depression and PTSD on pain intensity and interference with functioning. We hypothesized that depressed patients with PTSD would have significantly more pain and functional disability than those with depression but without PTSD. Received Date: May 02, 2016, Accepted Date: July 11, 2016, Published Date: July 18, 2016. *Corresponding author: Srinivas Pyati, Department of Anesthesiology and Pain Medicine, Duke University School of Medicine, Veterans Affairs Medical Center, Durham, 508 Fulton Street, Durham, NC 27708, USA; E-mail: srinivas.pyati@duke.edu