Thought Intrusion Among Adults Living With Complex Regional Pain Syndrome Jessica A. Lohnberg VA Palo Alto Health Care System, Palo Alto, California Elizabeth M. Altmaier University of Iowa Purpose: This study investigated the presence and influence of intrusive thoughts among adults previously diagnosed with complex regional pain syndrome. Method: The present study used an Internet-based survey completed by a sample (N = 326) from two national organizations. Results: After controlling for age, gender, and pain level, intrusive thoughts were significantly related to disability and health-related quality of life. Conclusions/Implications: Intrusive thoughts about the inciting event that caused CRPS uniquely influenced pain and quality of life, suggesting a potential mechanism to target for intervention. Understanding factors that relate to maintenance of CRPS and its resulting disability will help in the development of treatments to improve quality of life. Keywords: chronic pain, complex regional pain syndrome, cognitions, quality of life Impact • Complex regional pain syndrome (CRPS) is a painful condition often resulting from a relatively benign injury event and yet frequently leads to significant physical disability and impaired quality of life. Little is known about what factors predict this impairment; this study is the first to examine the role of intrusive thoughts related to the inciting event that caused CRPS in physical disability and quality of life among individuals living with CRPS. • This study confirms that intrusive thoughts uniquely influenced pain and quality of life. • Results of this study suggest that intrusive thoughts may be a modi- fiable target for intervention to influence the onset, maintenance, or exac- erbation of physical disability and impaired quality of life in patients with CRPS. Introduction Complex regional pain syndrome (CRPS) is a chronic pain condi- tion that develops following a seemingly innocuous injury or incident, such as fracture, soft tissue damage, low-grade infection, and frostbite, or after stroke or myocardial infarction (Baron, Levine, & Fields, 1999). This condition, first described during the American Civil War, has a complex history characterized by multiple name changes at- tempting to capture a poorly understood pathophysiology. Labels such as causalgia, osteodystrophy, and reflex sympathetic dystrophy have been used to reflect varying conjectures on causes. The currently accepted set of criteria, according to the International Association for the Study of Pain (IASP), are the following: (a) the presence of an initiating noxious event or cause of immobilization; (b) continuing pain, allodynia, or hyperalgesia in which the pain is disproportionate to any known inciting event; (c) evidence at some time of edema, changes in skin blood flow, or abnormal sudomotor activity in the region of pain; and (d) no other conditions that would account for the degree of pain and dysfunction (Merskey & Bogduk, 1994). There are two forms of CRPS: Type I, previously known as reflex sympathetic dystrophy, and Type II, or causalgia (Baron & Wasner, 2001); both types share signs and symptoms, however Type II has an identifiable nerve injury. Many individuals with CRPS experience intractable pain for years and undergo many failed treatments (Allen, Galer, & Schwartz, 1999). The condition has been associated with decreased quality of life (Galer, Henderson, Perander, & Jensen, 2000), job inactivity (Rauïs, 1999), and reduced physical functioning (Bruehl & Chung, 2006; see Lohnberg & Altmaier, 2013, for review). The difficulties experienced by these patients— compounded by uncertainty over factors in the development of the disorder— have stimulated research aimed at identifying potentially modifiable variables that interfere with return to function. One such influencing variable is that of patient cognitions. Cogni- tive processing theory (Horowitz, 1986; Janoff-Bulman, 1989) posits that in response to a distressing event, persons engage in a struggle to accommodate the event into their world view. When the event chal- lenges a person’s view of the world, that discrepancy forces either an alteration in the original worldview or an alteration of the perception of the event. For example, the death of a child deeply challenges the worldview that “life is fair” or that “good people receive what they deserve.” The cycle of cognitive processing that then occurs is rumi- nation, an ongoing emotional and cognitive review of the event and its consequences. For most persons, the result of this process concludes with finding meaning and/or benefit from the difficult event or rede- This article was published Online First March 10, 2014. Jessica A. Lohnberg, Psychology Service, VA Palo Alto Health Care System, Palo Alto, California; Elizabeth M. Altmaier, Department of Psychological and Quantitative Foundations and Department of Commu- nity and Behavioral Health, University of Iowa. Correspondence concerning this article should be addressed to Jes- sica A. Lohnberg, PhD, VA Palo Alto Healthcare System, Psychology Service (116B), 3801 Miranda Avenue, Palo Alto, CA 94304. E-mail: jessica.lohnberg@va.gov This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Rehabilitation Psychology © 2014 American Psychological Association 2014, Vol. 59, No. 2, 171–175 0090-5550/14/$12.00 DOI: 10.1037/a0035945 171