This cross-sectional study examined the associations among optimism, psychological resilience, endogenous pain inhibition, and clinical knee pain severity. Two hypotheses were tested. First, we hypothesized that experimentally tested endogenous pain inhibition would mediate the relationship between optimism and clinical knee pain severity. Second, it was also hypothesized that optimism would moderate the relationships of psychological resilience with endogenous pain inhibition and clinical knee pain severity, particularly for individuals with high optimism.
A total of 150 individuals with or at risk for symptomatic knee osteoarthritis completed the Life Orientation Test-Revised, the Brief Resilience Scale, and the revised Short-Form McGill Pain Questionnaire-2 to assess optimism, psychological resilience, and clinical knee pain severity, respectively. Endogenous pain inhibition was examined experimentally using a conditioned pain modulation (CPM) protocol with algometry (test stimulus) and a cold pressor task (conditioning stimulus).
As hypothesized, results showed that increased CPM significantly mediated the association between higher optimism and lower clinical knee pain severity. Further, optimism moderated the association between psychological resilience and CPM. However, contrary to our hypothesis, greater psychological resilience was associated with enhanced CPM in individuals with low optimism only.
This study suggests that an optimistic outlook may beneficially impact clinical pain severity by altering endogenous pain modulatory capacity. Furthermore, individuals with low optimism (ie, pessimists) may be more adept at engaging resources that promote psychological resilience, which in turn, enhances endogenous pain modulatory capacity. Therefore, this study supports consideration of psychological resilience factors when evaluating experimental and clinical pain outcomes.
Departments of *Psychology
∥Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL
†Department of Health Outcomes and Behavior, Moffitt Cancer Center, Tampa
‡Pain Research and Intervention Center of Excellence (PRICE)
§College of Nursing, University of Florida, Gainesville, FL
Supported by NIH/NIA Grants R37AG033906-14 (R.B.F.) and R01AG054370 (K.T.S.); UF CTSA Grant UL1TR001427 and UAB CTSA Grant UL1TR001417 from the NIH Center for Advancing Translational Sciences; NIH Training Grants TL1TR001418 provided to the University of Alabama at Birmingham, Birmingham, AL (K.A.T.), R25CA090314 provided to the Moffitt Cancer Center, Tampa, FL (H.W.B.), T32AG049673 provided to the University of Florida, Gainesville, FL and NIH/NINDS K22NS102334 (E.L.T.), and NIH/NIA Grant K99AG052642 (E.J.B). The authors declare no conflict of interest.
Reprints: Burel R. Goodin, PhD, University of Alabama at Birmingham, 1300 University Boulevard, Campbell Hall, Room 237E, Birmingham, AL 35294 (e-mail: email@example.com).
Received February 4, 2018
Received in revised form June 28, 2018
Accepted July 10, 2018