Changes in Pain-Related Fear and Pain When Avoidance Behavior is no Longer Effective

Working hard to avoid: Fixed-ratio response effort and maladaptive avoidance in humans

Maladaptive avoidance of safe stimuli is a defining feature of anxiety and related disorders. Avoidance may involve physical effort or the completion of a fixed series of responses to prevent occurrence of, or cues associated with, the aversive event. Understanding the role of response effort in the acquisition and extinction of avoidance may facilitate the development of new clinical treatments for maladaptive avoidance. Despite this, little is known about the impact of response effort on extinction-resistant avoidance in humans. Here, we describe findings from two laboratory-based treatment studies designed to investigate the impact of high and low response effort on the extinction (Experiment 1) and return (Experiment 2) of avoidance. Response effort was operationalised as completion of fixed-ratio (FR) reinforcement schedules for both danger and safety cues in a multi-cue avoidance paradigm with behavioural, self-report, and physiology measures. Completion of the FR response requirements cancelled upcoming shock presentations following danger cues and had no impact on the consequences that followed safety cues. Both experiments found persistence of high response-effort avoidance across danger and safety cues and sustained (Experiment 1) and reinstated (Experiment 2) levels of fear and threat expectancy. Skin conductance responses evoked by all cues were similar across experiments. The present findings and paradigm have implications for translational research on maladaptive anxious coping and treatment development.

The Good, the Bad, and the Ugly-Chances, Challenges, and Clinical Implications of Avoidance Research in Psychosomatic Medicine

Avoidance behaviors are shaped by associative learning processes in response to fear of impending threats, particularly physical harm. As part of a defensive repertoire, avoidance is highly adaptive in case of acute danger, serving a potent protective function. However, persistent or excessive fear and maladaptive avoidance are considered key factors in the etiology and pathophysiology of anxiety- and stress-related psychosomatic disorders. In these overlapping conditions, avoidance can increase the risk of mental comorbidities and interfere with the efficacy of cognitive behavioral treatment approaches built on fear extinction. Despite resurging interest in avoidance research also in the context of psychosomatic medicine, especially in conditions associated with pain, disturbed interoception, and disorders of the gut-brain axis, current study designs and their translation into the clinical context face significant challenges limiting both, the investigation of mechanisms involved in avoidance and the development of novel targeted treatment options. We herein selectively review the conceptual framework of learning and memory processes, emphasizing how classical and operant conditioning, fear extinction, and return of fear shape avoidance behaviors. We further discuss pathological avoidance and safety behaviors as hallmark features in psychosomatic diseases, with a focus on anxiety- and stress-related disorders. Aiming to emphasize chances of improved translational knowledge across clinical conditions, we further point out limitations in current experimental avoidance research. Based on these considerations, we propose means to improve existing avoidance paradigms to broaden our understanding of underlying mechanisms, moderators and mediators of avoidance, and to inspire tailored treatments for patients suffering from psychosomatic disorders.

Pain psychology in the 21st century: lessons learned and moving forward

Background and aims In the spring of 2019, Professor Steven J. Linton, the founder of the Center for Health and Medical Psychology (CHAMP) at Örebro University, Sweden, formally retired. As a tribute to his scholarly work covering decades of influence and inspiration to the field of pain psychology, the research center organized a topical conference titled "Pain in the 21st century: Where do we come from and where are we going?", which resulted in this state-of the-art synthesis. The aim of this declaration is to highlight lessons learned but not in the least is meant to inspire and guide our continued journey forward, developing pain psychology into the 21st century. Methods Several collaborators of Professor Linton have summarized and reflected on the current state-of-the-art of pain psychology from the perspective of his input to the field, as well as on developments from the last years of advancements in pain psychology. Results The topics have been divided into six themed sections covering the fear avoidance model, transdiagnostics, secondary prevention, risk- and protective factors, communication and contextual factors. The sections cover a broad spectrum, from basic experimental studies, integrating emotion and motivational theories into current theoretical models, to applied research on the effect of early interventions as well as sophisticated emotion-focused treatment models for pain patients with concurrent emotional ill-health. Conclusions There have been major advancements within pain psychology research during the last decades, moving the field towards a more comprehensive picture, taking emotional and motivational aspects into account to understand pain sufferers. Although psychologically informed interventions in general mainly focus on the individual, it has been put forward that pain management is highly influenced by the surrounding environment, including communication with health care providers, and the occupational and social context. Implications Professor Steven J. Linton has been at the forefront of pain psychology research during the last decades, and inspired by his work this journey will continue into the 21st century, with the ultimate goal of enhancing the understanding and treatment for all people suffering from persistent and disabling pain.

Avoidance behaviour performed in the context of a novel, ambiguous movement increases threat and pain-related fear

ABSTRACT

The fear-avoidance model of chronic pain predicts that catastrophic (mis)interpretation of pain elicits pain-related fear that in turn may spur avoidance behaviour leading to chronic pain disability. Here, we investigated whether performing a movement to avoid a painful stimulus in the context of a novel movement increases threat and pain-related fear towards this novel movement and whether avoidance behaviour persisted when given the choice between performing the acquired movement to avoid a painful stimulus or an alternative, novel movement. Applying a robotic arm-reaching task, participants could choose between 2 movements to reach a target location: a short, but painful movement trajectory, or a longer nonpainful movement trajectory. After avoidance acquisition, the option to choose the painful trajectory was removed. The experimental group (N = 50) could choose between the longest trajectory or a novel intermediate trajectory, whereas the control group (N = 50) was allowed to only perform the novel trajectory. In a final test, participants of both groups were allowed to choose any of the 3 trajectories. After acquisition, experimental group participants showed elevated pain expectancy and pain-related fear towards the novel trajectory, compared with the control group. During test, the experimental group participants persisted in performing the longest pain-free (avoidance) trajectory and were less likely to choose the novel trajectory. In addition, these participants maintained higher levels of pain-related fear for the novel trajectory compared with the control group. These findings suggest that avoidance in the context of other neutral activities/movements may lead to the development and maintenance of threat appraisals and irrational fears.