Longitudinal Associations Between Depression, Anxiety, Pain, and Pain-Related Disability in Chronic Pain Patients Sheera F. Lerman, PhD, Zvia Rudich, MD, Silviu Brill, MD, Hadar Shalev, MD, and Golan Shahar, PhD ABSTRACT Objective: The current study sets out to examine the longitudinal relationship between pain, pain-related disability, and symptoms of depression and anxiety. The latter symptoms are highly prevalent in chronic pain and seriously impede func- tioning and quality of life. Nevertheless, the direction of the relationship involving these variables among individuals with chronic pain is still unclear. Methods: Four-hundred twenty-eight individuals with chronic pain (238 women, mean age 54.84 years, mean pain duration 85.21 months) treated at two pain clinics completed questionnaires regarding their pain (Short-Form McGill Pain Question- naire), depression (Center for Epidemiological Studies–Depression Scale), state anxiety (State-Trait Anxiety Inventory), and pain-related disability (Pain Disability Index) at four time points, with an average of 5 months between measurements. Cross-lagged, structural equation modeling analyses were performed, enabling the examination of longitudinal associations between the variables. Results: Significant symptoms of both depression and anxiety were reported by more than half of the sample on all waves. A latent depression/anxiety variable longitudinally predicted pain (β = .27, p < .001) and pain-related disability (β = .38, p < .001). However, neither pain (β = .10, p = .126) nor pain-related disability (β = -.01, p = .790) predicted depression/anxiety. Conclusions: Among adult patients with chronic pain treated at specialty pain clinics, high levels of depression and anxiety may worsen pain and pain-related disability. Key words: chronic pain, depression, anxiety, pain-related disability. INTRODUCTION D epression and anxiety are highly prevalent among in- dividuals with chronic pain (ICPs), derailing function- ing and quality of life (1–5), affecting treatment outcome (6), and increasing health care costs (7). Although most re- search in ICP has focused on depression (4,8,9), mounting evidence indicates the high comorbidity of pain and anxiety and the significant contribution of anxiety to pain (10,11). Most research in the field has focused on the general pop- ulation, finding that depression increases the risk for devel- oping chronic back and neck pain in the general population (12,13), in older adults (14), and in a sample of asymptom- atic Veterans Affairs outpatients (15). In contrast, pain was the strongest predictor of depression after controlling for other variables (12,16), and other studies demonstrated a reciprocal relationship between pain on the one hand, and depression or anxiety on the other hand (17–23). Unfortunately, these findings have little bearing on the depression and anxiety experienced by ICP. These patients are usually treated at specialty pain clinics, commonly ar- riving for treatment already suffering from significant emo- tional distress. The few studies that exist suggest that depression and anxiety predict a worsening in pain over time (24–26). Other studies, however, indicate that the lon- gitudinal relationship between pain and depression was strong and similar in both directions (18,27). Supplemental Content From the Department of Psychology (Lerman, Shahar), Ben-Gurion University of the Negev, Beer-Sheva, Israel; Pain Specialty Clinic (Rudich, Shalev), Soroka University Medical Center, Beer-Sheva, Israel; Chaim Sheba Medical Center (Lerman), Tel Hashomer, Israel; and Pain Specialty Clinic (Brill), Sourasky Medical Center, Tel-Aviv, Israel. Address correspondence and reprint requests to Sheera F. Lerman, PhD, The Stress, Self & Health (STREALTH) Lab, Department of Psychology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel. E-mail: sheera@post.bgu.ac.il Received for publication April 8, 2014; revision received October 21, 2014. DOI: 10.1097/PSY.0000000000000158 Copyright © 2015 by the American Psychosomatic Society CES-D = Center for Epidemiological Studies–Depression Scale, ICP = individuals with chronic pain, PDI = Pain Disability Index, SEM = structural equation modeling, SF-MPQ = Short-Form McGill Pain Questionnaire, STAI = State Anxiety Inventory ORIGINAL ARTICLE Psychosomatic Medicine, V 00 • 00-00 1 Month 2015 Copyright © 2015 by the American Psychosomatic Society. Unauthorized reproduction of this article is prohibited.