The experimental analysis of the interruptive, interfering, and identity-distorting effects of chronic pain

Highlights

• Pain is an unpleasant sensory and emotional experience urging the individual to take action to restore the integrity of the body.

• Pain urges to interrupt ongoing activity, elicits protective responses that paradoxically increase interference with daily activities, and compromises the sense of self.

• Pain as a strong motivator for learning.

• Exposure in vivo can reverse the paradoxical effects of pain avoidance.

• Replicated-Single-Case designs are recommended in the search for more effective, customized treatments for individuals suffering chronic pain.

Abstract

Pain is an unpleasant sensory and emotional experience urging the individual to take action to restore the integrity of the body. The transition from a common episode of acute pain to a state of intermittent or chronic pain has been a constant preoccupation of researchers and clinicians alike. In this review, we approach chronic pain from a modern learning perspective that incorporates cognitive, affective, behavioral and motivational aspects. We view pain as a biologically hard-wired signal of bodily harm that competes with other demands in the person's environment. The basic tenet is that pain urges people to interrupt ongoing activity, elicits protective responses that paradoxically increase interference with daily activities, and compromises the sense of self. Here we briefly summarize existing evidence showing how pain captures attention, and how attention for pain can be controlled. We also consider pain as a strong motivator for learning, and review the recent evidence on the acquisition and generalization of pain-related fear and avoidance behavior, which are likely to interfere with daily life activities. We highlight the paradoxical effects of pain avoidance behavior, and review treatment effects of exposure in vivo. A generally neglected area of research is the detrimental consequences of repeated interference by pain with daily activities on one's sense of “self”. We end this review with a plea for the implementation of single-case experimental designs as a means to help customize and develop novel cognitive-behavioral treatments for individuals for chronic pain aimed at reducing the suffering of this large group of individuals.

Introduction

Pain is a biologically relevant and vital signal of bodily threat, urging the individual to protect him/herself. Immediate protective responses to acute pain include increased arousal, orientation to the sources of threat, and various safety-seeking behaviors including escape and avoidance. Acute pain usually disappears within days or weeks, but in some individuals, pain persists despite the alleged healing of the initial injury. The transition from a common episode of acute pain to a state of intermittent or chronic pain has been a constant preoccupation of researchers and clinicians alike. Despite the difficulty to provide precise estimates of prevalence and incidence, the burden of chronic pain is unquestionably large, both in youth as in adults. For example, a survey in 400,000 children and adolescents aged 11–15 years reported the 1-month prevalence of low back pain to be no less than 37.0% (Swain et al., 2014). In adults, the median prevalence of chronic low back pain, which is back pain that lasts for at least 12 weeks lies between 5.6 and 18.1% (Henschke, Kamper, & Maher, 2015). Pain problems have been viewed as complex, multidimensional developmental processes where various biological, psychological and social factors are considered of utmost importance (Gatchel, Peng, Peters, Fuchs, & Turk, 2007). However, it has been difficult to specifically spell-out the mechanisms by which pain acute problems become chronic. In this invited review, we will approach this question from a modern learning perspective in which attention, memory, behavior, and individual goals take a prominent place. We start from the idea that pain has an inherent interruptive function, and that the extent to which pain interrupts depends on the threat value as well as the environmental demands. Pain interrupts individuals to prepare for escape and avoidance of potentially harmful stimuli, which is adaptive. However, the general tenet of our approach is that prolonged protective and recuperative behavior that usually is adaptive in the short term, may in the long term paradoxically maintain the problem through the adverse effects of avoidance and the spreading of these behaviors to an increasing set of situation that share perceptual features with the initial event during the original pain episode. The longer the problem persists, the greater the discrepancy between the actual situation and the valued goals of the individual thereby compromising the sense of “self”. In this paper we will review the recent research on the interruptive function of pain, the role of learning and memory in the maintenance of avoidance behavior, and the effects of chronic pain on individual goals and identity.