Is it better to have controlled and lost than never to have controlled at all? An experimental investigation of control over pain

The Science and Social Validity of Companion Animal Welfare: Functionally Defined Parameters in a Multidisciplinary Field

Social validity refers to the social significance and acceptability of intervention goals, procedures, and outcomes. Animal practitioners, who are often guided by the principles of ABA, lack the benefit of verbal participants (at least with respect to target animals) with which to assess a client's needs and preferences. The study of a learner's welfare is useful for determining areas where intervention is needed or how the learner feels about an intervention that is underway. Three tenets of animal welfare measurement include physiological function, naturalistic behavior, and affect, where affect refers to private events, including emotions, which are a function of the same variables and contingencies responsible for controlling public behavior. The development of new technologies allows us to look "under the skin" and account for subjective experiences that can now be observed objectively. We introduce the reader to tools available from the animal welfare sciences for the objective measurement of social validity from the learner's perspective.

The Role of Adaptive Goal Processes in Mental Wellbeing in Chronic Pain

Chronic pain, experienced as pain persisting for three months or longer, is associated with risk of poor mental health and disability. Research has implicated adaptive goal processes as important to mental wellbeing in a range of populations. However, research has rarely assessed these mechanisms in relation to pain characteristics and mental wellbeing in chronic pain populations. This study aimed to examine the potentially mediating roles of goal flexibility and goal tenacity in the relationships between pain intensity and pain interference and mental wellbeing among individuals with chronic pain. Community members who self-identified as experiencing non-cancer chronic pain (N = 315) completed an online self-report survey on goal tenacity, goal flexibility, mental wellbeing, pain intensity, and pain interference. Unexpectedly, pain intensity was not significantly related to mental wellbeing, when controlling for pain interference. However, pain interference was directly and significantly associated with mental wellbeing. Both goal flexibility and goal tenacity mediated the relationship between pain interference and mental wellbeing, whilst controlling for pain intensity. The results provide support for the protective role of adaptive goal processes in mental wellbeing in those with chronic pain and highlight the importance of pain interference in relation to mental wellbeing.

When pain becomes uncontrollable: an experimental analysis of the impact of instructions on pain-control attempts

ABSTRACT

Under some conditions, people persist in their attempts to control their pain even when no such control is possible. Theory suggests that such pain-control attempts arise from actual pain experiences. Across 3 experiments we examined how (1) losing control over pain and (2) instructions concerning pain, moderated pain-control attempts. In each experiment, participants completed a learning task. Before the task, one group of participants received instructions outlining a strategy through which they could control pain, whereas another group had to develop such a strategy through trial-and-error learning. During the first half of the task, the pain-control instructions allowed participants to successfully control pain, whereas during the second half of the task, this was no longer the case. Instead, participants lost control over pain because of an unannounced change in the learning task. Results indicated that when participants lost control over pain, they generally stuck to the previously effective pain-control strategy, and that this tendency was larger if they received instructions from others than when they developed a strategy by themselves. These findings suggest that when pain is no longer controllable, very persistent pain-control attempts might be the result of adherence to previously effective pain-control instructions.

Perception of repeated pain relief with controllable and uncontrollable pain

BACKGROUND

The ultimate goal of pain research is to provide effective routes for pain relief. Nevertheless, the perception pain relief as a change in pain intensity and un-/pleasantness has only been rarely investigated. It has been demonstrated that pain relief has rewarding and reinforcing properties, but it remains unknown whether the perception of pain relief changes when pain reductions occur repeatedly. Further, it remains an open question whether the perception of pain relief depends on the controllability of the preceding pain.

METHODS

In this study, healthy volunteers (N = 38) received five cycles of painful heat stimulation and reduction of this stimulation to a non-painful warm stimulation once in a condition with control of the stimulation and once without control. Participants rated perceived intensity and un-/pleasantness on visual analogue scales during the heat stimulation and immediately after its reduction.

RESULTS

Results showed that perceived pain relief, estimated by the difference in ratings during ongoing heat stimulation and after its reduction, increased with repetitions. However, this increase levelled off after two to four repetitions. Further, perceived pain relief was larger in the condition without control compared to the condition with control.

CONCLUSION

The perception of pain relief can be modulated similar to the perception of pain by stimulus characteristics and psychological factors. Mechanistic knowledge about such modulating factors is important, because they can determine, e.g., the amount of requested pain killers in clinical settings and the efficacy of pain relief as a reinforcing stimulus.

SIGNIFICANCE

When in pain, pain relief can become an all-dominate goal. The perception of such pain relief can vary depending on external and internal characteristics and thus modulate, e.g., requests for pain killers in clinical settings. Here, we show that perceived intensity and pleasantness of pain relief changes with repetitions and whether the preceding pain is perceived as uncontrollable. Such mechanistic knowledge needs to be considered to maximize the effects of pain relief as a rewarding and reinforcing stimulus.

Loss of control over mild aversive events produces significant helplessness in mice

Most of the pathophysiology of depression are still unknown because of its numerous disease states of distinct etiology and pathogenesis. Stressful rodent models have been used to test a number of hypotheses regarding the etiology of depression. The learned helplessness rodent model demonstrates that having no control at all over aversive events produces helplessness and depression, but the role of loss of control over aversive events in helplessness is still not reliably modelled or deeply investigated. A rodent model of helplessness produced by loss of control is closer to human conditions and is therefore more useful for novel mechanistic and pre-clinic studies. The present work proposed a triadic experimental design in which a Loss Of Control (LOC) group of mice was firstly exposed to escapable mild footshocks to acquire control, and then to inescapable shocks to lose control, with a yoked (L-Yoked) group receiving identical but always uncontrollable shocks. Although both the LOC and the L-Yoked groups developed helplessness, as compared with the naive control group, the helplessness exhibited in the LOC group was significantly more serious than that in the L-Yoked group. The difference in severity between the LOC and the L-Yoked groups demonstrates the effects of loss of control over aversive events, in addition to the effects of the aversive events per se. The LOC paradigm can be used to reproduce pathology of depression induced by loss of control over aversive life events, with a good constructive validity.

Pain here and now: physical pain impairs transcendence of psychological distance

Background

The ability to traverse psychological distance by going beyond the experienced reality of the self, here and now, is fundamental for effective human functioning. Yet, little is known about how physical pain affects transcendence of psychological distance. Using a construal level theory framework of psychological distance, the current research examines the hypothesis that pain impairs people’s ability to traverse any kind of psychological distance whether it be temporal, social, and spatial distance, or the hypothetical.

Methods

Using the cold pressor test, 151 participants participated in an experiment where they were either induced with acute pain (treatment group) or no pain (control group) while completing a battery of questions measuring to what extent their current thoughts were transcending psychological distance.

Results

The results were largely consistent with the hypothesis. Relative to the control group, pain induced participants showed significantly less transcendence of past temporal distance, social distance, spatial distance, and the hypothetical. Furthermore, greater self-reported pain intensity was significantly associated with less transcendence of temporal (past and future), social, and spatial distance.

Conclusion

Physical pain impairs the ability to traverse psychological distance. The research has practical implications for the pain clinic and for pain-afflicted individuals in everyday life.

Impact of controllability on pain and suffering

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Introduction:

Chronic pain and pain-related suffering are major health problems. The lack of controllability of experienced pain seems to greatly contribute to the extent of suffering. This study examined how controllability affects the perception of pain and pain-related suffering, and the modulation of this effect by beliefs and emotions such as locus of control of reinforcement, pain catastrophizing, and fear of pain.

Methods:

Twenty-six healthy subjects received painful electric stimulation in both controllable and uncontrollable conditions. Visual analogue scales and the “Pictorial Representation of Illness and Self Measure” were used to assess pain intensity, unpleasantness, pain-related suffering, and the level of perceived control. We also investigated nonverbal indicators of pain and suffering such as heart rate, skin conductance, and corrugator electromyogram.

Results:

Controllability selectively reduced the experience of pain-related suffering, but did not affect pain intensity or pain unpleasantness. This effect was modulated by chance locus of control but was unrelated to fear of pain or catastrophizing. Physiological responses were not affected by controllability. In a second sample of 25 participants, we varied the instruction. The effect of controllability on pain-related suffering was only present when instructions focused on the person being able to stop the pain.

Discussion:

Our data suggest that the additional measure of pain-related suffering may be important in the assessment of pain and may be more susceptible to the effects of perceived control than pain intensity and unpleasantness. We also show that this effect depends on personal involvement.

Emotional and Motivational Pain Processing: Current State of Knowledge and Perspectives in Translational Research

Pain elicits fear and anxiety and promotes escape, avoidance, and adaptive behaviors that are essential for survival. When pain persists, motivational priority and attention shift to pain-related information. Such a shift often results in impaired functionality, leading to maladaptive pain-related fear and anxiety and escape and avoidance behaviors. Neuroimaging studies in chronic pain patients have established that brain activity, especially in cortical and mesolimbic regions, is different from activity observed during acute pain in control subjects. In this review, we discuss the psychophysiological and neuronal factors that may be associated with the transition to chronic pain. We review information from human studies on neural circuits involved in emotional and motivational pain processing and how these circuits are altered in chronic pain conditions. We then highlight findings from animal research that can increase our understanding of the molecular and cellular mechanisms underlying emotional-motivational pain processing in the brain. Finally, we discuss how translational approaches incorporating results from both human and animal investigations may aid in accelerating the discovery of therapies.

Different Brain Circuitries Mediating Controllable and Uncontrollable Pain

Uncontrollable, compared with controllable, painful stimulation can lead to increased pain perception and activation in pain-processing brain regions, but it is currently unknown which brain areas mediate this effect. When pain is controllable, the lateral prefrontal cortex (PFC) seems to inhibit pain processing, although it is unclear how this is achieved. Using fMRI in healthy volunteers, we examined brain activation during controllable and uncontrollable stimulation to answer these questions. In the controllable task, participants self-adjusted temperatures applied to their hand of pain or warm intensities to provoke a constant sensation. In the uncontrollable task, the temperature time courses of the controllable task were replayed (yoked control) and participants rated their sensation continuously. During controllable pain trials, participants significantly downregulated the temperature to keep their sensation constant. Despite receiving the identical nociceptive input, intensity ratings increased during the uncontrollable pain trials. This additional sensitization was mirrored in increased activation of pain-processing regions such as insula, anterior cingulate cortex, and thalamus. Further, increased connectivity between the anterior insula and medial PFC (mPFC) in the uncontrollable and increased negative connectivity between dorsolateral PFC (dlPFC) and insula in the controllable task were observed. This suggests a pain-facilitating role of the mPFC during uncontrollable pain and a pain-inhibiting role of the dlPFC during controllable pain, both exerting their respective effects via the anterior insula. These results elucidate neural mechanisms of context-dependent pain modulation and their relation to subjective perception.

SIGNIFICANCE STATEMENT

Pain control is of uttermost importance and stimulus controllability is an important way to achieve endogenous pain modulation. Here, we show differential effects of controllability and uncontrollability on pain perception and cerebral pain processing. When pain was controllable, the dorsolateral prefrontal cortex downregulated pain-evoked activation in important pain-processing regions. In contrast, sensitization during uncontrollable pain was mediated by increased connectivity of the medial prefrontal cortex with the anterior insula and other pain-processing regions. These novel insights into cerebral pain modulation by stimulus controllability have the potential to improve treatment approaches in pain patients.

New approaches towards chronic pain: patient experiences of a solution-focused pain management programme

Research has suggested that Solution-Focused Brief Therapy (SFBT) may be effective in facilitating meaningful change for those living with chronic pain. This study aimed to further this understanding through exploring the experiences of people living with chronic pain, who had attended an 8-week solution-focused pain management programme. The design of this study was conducted in consultation with a service-user advisory group, and employed a qualitative and interpretative design rooted in critical community psychology, participatory research frameworks and emancipatory disability research. Five participants opted-in to the study following an opportunity sampling method of persons who had attended a programme in the last 18 months. Interviews were transcribed verbatim and analysed using inductive thematic analysis. Five main themes were identified: 'Accessing the pain management programme', 'A solution-focused group', 'The solution-focused clinician', 'Solutions and changes' and 'Challenges and improvements'. Clinical and research implications of the findings are discussed.

SUMMARY POINTS

There has been an international proliferation of pain management programmes (PMPs) aimed at helping those with chronic pain to live well, despite an unremitting condition.Arguably, the most popular psychological approaches used within PMPs are informed by cognitive behavioural therapy (CBT).Despite a supportive evidence base for psychological approaches in pain management, there is a recognised need for further research into alternative approaches and their effectiveness.Emerging research and policy recommendations are beginning to value the expertise of those living with chronic conditions, particularly how these perspectives can be used to develop effective treatments and services.SFBT is an approach aimed at achieving a patient's goals or 'preferred future' through identifying and utilising their expertise. SFBT may have significant efficacy in helping those with chronic conditions to live improved, meaningful lives.

Beliefs underlying pain-related fear and how they evolve: a qualitative investigation in people with chronic back pain and high pain-related fear

OBJECTIVES

The fear-avoidance model describes how the belief that pain is a sign of damage leads to pain-related fear and avoidance. But other beliefs may also trigger the fear and avoidance responses described by the model. Experts have called for the next generation of fear avoidance research to explore what beliefs underlie pain-related fear and how they evolve. We have previously described damage beliefs and suffering/functional loss beliefs underlying high pain-related fear in a sample of individuals with chronic back pain. The aim of this study is to identify common and differential factors associated with the beliefs in this sample.

DESIGN

A qualitative study employing semistructured interviews.

SETTING

Musculoskeletal clinics in Western Australia.

PARTICIPANTS

36 individuals with chronic back pain and high scores on the Tampa Scale (mean 47/68).

RESULTS

The overarching theme was a pain experience that did not make sense to the participants. The experience of pain as unpredictable, uncontrollable and intense made it threatening. Attempting to make sense of the threatening pain, participants with damage beliefs drew on past personal experiences of pain, societal beliefs, and sought diagnostic certainty. Met with diagnostic uncertainty, or diagnoses of an underlying pathology that could not be fixed, they were left fearful of damage and confused about how to 'fix' it. Participants with suffering/functional loss beliefs drew on past personal experiences of pain and sought help from healthcare professionals to control their pain. Failed treatments and the repeated failure to achieve functional goals left them unable to make 'sensible' decisions of what to do about their pain.

CONCLUSIONS

The findings raise the suggestion that sense-making processes may be implicated in the fear-avoidance model. Future research is needed to explore whether fear reduction may be enhanced by considering beliefs underlying fear and providing targeted intervention to help individuals make sense of their pain.

Psychosocial factors and central sensitivity syndromes

Central sensitivity syndromes (CSSs) represent a heterogeneous group of disorders (e.g., fibromyalgia [FM], irritable bowel syndrome [IBS], chronic headache, temporomandibular disorders [TMDs], pelvic pain syndromes) that share many common symptoms, with persistent pain being the most prominent feature. Although the etiology and pathophysiology of CSSs are currently incompletely understood, central sensitization has emerged as one of the significant mechanisms. Given that there are currently no known cures for CSSs, people living with these disorders must learn to cope with and manage their symptoms throughout their lives. Medical interventions alone have not proven to be sufficient for helping people with CSSs manage their symptoms. A biopsychosocial perspective that considers the ways that biological, psychological, and social factors work independently and jointly to affect a person's experience is the most effective conceptualization and guide for effective treatment. In this article, we discuss several psychological and social features that may influence the experience of a person with CSS and their symptom management, regardless of their specific diagnosis. We highlight the longitudinal aspect of adjustment to illness, the distinction between psychosocial factors as causes of symptoms versus modifiers and perpetuators of symptoms, dispel the notion that all patients with the same diagnosis are a homogeneous group (the "patient-uniformity myth"), and acknowledge the importance of environmental and situational context on symptom management for individuals with any CSS.

When pain meets … pain-related choice behavior and pain perception in different goal conflict situations

Individuals in pain often face the choice between avoiding pain and pursuing other equally valued goals. However, little is known about pain-related choice behavior and pain perception in goal conflict situations. Seventy-eight healthy volunteers performed a computerized task requiring repeated choices between incompatible options, differing in their effect on probability to receive painful stimulation and money. Depending on group assignment, participants chose between increased pain probability versus decreased money probability (avoidance-avoidance conflict situation); decreased pain probability versus increased money probability (approach-approach conflict situation); or decrease versus increase in both probabilities (double approach/avoidance conflict situation). During the choice task, participants rated painfulness, unpleasantness, threat, and fearfulness associated with the painful stimulation and how they felt. Longer choice latency and more choice switching were associated with higher retrospective ratings of conflict and of decision difficulty, and more equal importance placed on pain avoidance and earning money. Groups did not differ in choice behavior, pain stimulus ratings, or affect. Across groups, longer choice latencies were nonsignificantly associated with higher pain, unpleasantness, threat, and fearfulness. In the avoidance-avoidance group, more choice switching was associated with higher pain-related threat and fearfulness, and with more negative affect. These results of this study suggest that associations between choice behaviors, pain perception, and affect depend on conflict situation.

PERSPECTIVE

We present a first experimental demonstration of the relationship between pain-related choice behaviors, pain, and affect in different goal conflict situations. This experimental approach allows us to examine these relationships in a controlled fashion. Better understanding of pain-related goal conflicts and their resolution may lead to more effective pain treatment.

The Positive Consequences of Pain: A Biopsychosocial Approach

Pain is mostly thought of as a problem-as debilitating or harmful. Despite its unpleasantness, however, under some conditions pain can be associated with positive consequences. In this review, we explore these positive biological, psychological, and social consequences of pain. We highlight three different domains in which pain may be considered to have positive consequences. First, pain facilitates pleasure by providing an important contrast for pleasurable experiences, increasing sensitivity to sensory input, and facilitating self-rewarding behavior. Second, pain augments self-regulation and enhancement by increasing cognitive control, reducing rumination, and demonstrating virtue. Third, pain promotes affiliation by arousing empathy from others, motivating social connection, and enhancing group formation. Drawing on evidence scattered across a range of academic fields, we provide for reflection on how pain is represented, generate insights into pain-seeking behavior, and draw attention to the role of painful experiences in maximizing positive outcomes.

Does severe acute pain provoke lasting changes in attentional and emotional mechanisms of pain-related processing? A longitudinal study

Pain experiences, learning, and genetic factors have been proposed to shape attentional and emotional processes related to pain. We aimed at investigating whether a singular major pain experience also changes cognitive-emotional processing. The influence of acute postoperative pain after cosmetic surgery of the thorax was tested in 80 preoperatively pain-free male individuals. Acute pain was measured as independent variable during the first week postsurgery by pain intensity ratings and the requested analgesic boluses (Patient-Controlled Epidural Analgesia (PCEA)). Pain catastrophizing (Pain Catastrophizing Scale (PCS)), pain anxiety (Pain Anxiety and Symptom Scale (PASS)), pain hypervigilance (Pain Vigilance and Awareness Questionnaire (PVAQ)), and attentional biases to emotionally loaded stimuli (including pain) in a dot-probe task were assessed 1 week, 3 months, and 6 months postsurgery as dependent variables. Hierarchical regression analyses were performed to test whether the 2 acute pain parameters can predict these cognitive-emotional variables. As a rigorous test, significant prediction was required in addition to the prediction of the dependent variables by themselves with lag-1. Acute pain (mainly the pain ratings) appeared to be a significant predictor for PCS, PASS, and PVAQ 1 week after surgery (deltaR(2) = [8.7% to 11.3%]). In contrast, the attentional biases in the dot-probe task could not be predicted by the pain ratings. The levels of pain catastrophizing and pain hypervigilance increased in the acute phase after surgery when influenced by acute pain and declined, along with pain anxiety, during the next 3 months. In conclusion, a one-time intense pain experience, such as acute postoperative pain, appeared to produce at least short-lived changes in the attentional and emotional processing of pain.

Fear-avoidance model of chronic pain: the next generation

OBJECTIVE

The fear-avoidance (FA) model of chronic pain describes how individuals experiencing acute pain may become trapped into a vicious circle of chronic disability and suffering. We propose to extend the FA model by adopting a motivational perspective on chronic pain and disability.

METHODS

A narrative review.

RESULTS

There is ample evidence to support the validity of the FA model as originally formulated. There are, however, some key challenges that call for a next generation of the FA model. First, the FA model has its roots in psychopathology, and investigators will have to find a way to account for findings that do not easily fit within such framework. Second, the FA model needs to address the dynamics and complexities of disability and functional recovery. Third, the FA model should incorporate the idea that pain-related fear and avoidance occurs in a context of multiple and often competing personal goals.

DISCUSSION

To address these 3 key challenges, we argue that the next generation of the FA model needs to more explicitly adopt a motivational perspective, one that is built around the organizing powers of goals and self-regulatory processes. Using this framework, the FA model is recast as capturing the persistent but futile attempts to solve pain-related problems to protect and restore life goals.

Exercise-induced stress resistance is independent of exercise controllability and the medial prefrontal cortex

Exercise increases resistance against stress-related disorders such as anxiety and depression. Similarly, the perception of control is a powerful predictor of neurochemical and behavioral responses to stress, but whether the experience of choosing to exercise, and exerting control over that exercise, is a critical factor in producing exercise-induced stress resistance is unknown. The current studies investigated whether the protective effects of exercise against the anxiety- and depression-like consequences of stress are dependent on exercise controllability and a brain region implicated in the protective effects of controllable experiences, the medial prefrontal cortex. Adult male Fischer 344 rats remained sedentary, were forced to run on treadmills or motorised running wheels, or had voluntary access to wheels for 6 weeks. Three weeks after exercise onset, rats received sham surgery or excitotoxic lesions of the medial prefrontal cortex. Rats were exposed to home cage or uncontrollable tail shock treatment three weeks later. Shock-elicited fear conditioning and shuttle box escape testing occurred the next day. Both forced and voluntary wheel running, but not treadmill training, prevented the exaggerated fear conditioning and interference with escape learning produced by uncontrollable stress. Lesions of the medial prefrontal cortex failed to eliminate the protective effects of forced or voluntary wheel running. These data suggest that exercise controllability and the medial prefrontal cortex are not critical factors in conferring the protective effects of exercise against the affective consequences of stressor exposure, and imply that exercise perceived as forced may still benefit affect and mental health.

From the clinic to the lab (and back)-a call for laboratory research to optimize cognitive behavioural treatment of pain

Cognitive behavioural therapy (CBT) is the dominant psychological treatment for chronic pain. CBT covers a mixture of aims and a broad range of techniques, including attentional control, modification of maladaptive beliefs and coping strategies and flexible goal setting and acceptance. Patients are exposed to varying selections of these strategies, and a major challenge for clinical practice is to determine what works for whom in which context. We propose that incorporating laboratory research into translational behaviour medicine is a critical developmental step that will help optimizing CBT and provide examples of representative experimental research programs.

Psychological interventions for chronic pain: reviewed within the context of goal pursuit

SUMMARY In contemporary psychological interventions for chronic pain, cognitive-behavioral therapy takes a central role, covering a broad range of techniques and aims. To improve the effectiveness of cognitive-behavioral therapy and to refine its components, new theoretical approaches may help understand and arrange the mechanisms underlying pain perception, behavior and suffering. This article reviews processes of change in cognitive-behavioral therapies for chronic pain within the context of goal pursuit. Treatments are viewed from the perspective of the action phase model of goal attainment. With this model in mind, a distinction is made between goal ‘intentions’ and their ‘realization’. In addition, recent research findings on goal pursuit in the context of (chronic) pain are reviewed, with a special emphasis on their implications for clinical practice.

To control or not? A motivational perspective on coping with pain

Pain relief is often the primordial treatment objective in pain patients. However, an exclusive focus upon pain relief may have costs. Evidence is accumulating that persistent attempts to gain control over pain may, paradoxically, hinder successful adaptation to pain and increase frustration and limitations due to pain. To better understand these apparently paradoxical findings, we propose to adopt a motivational perspective on coping with pain. Within this perspective, pain control is recast as an attempt to protect and restore valued life goals threatened by pain. This framework explains why some patients engage excessively in pain control strategies despite the costs associated with this, such as overuse of medication. A clinical implication is that cautiousness is warranted in promoting strategies exclusively aimed at pain relief. Beyond standard medical care, interventions should also be aimed at the improvement of functioning despite pain. Certainly those patients for whom there is no definite or sound cure to pain and who increasingly experience emotional and physical problems due to pain might benefit from paramedical help by psychologists and/or physiotherapists.

5-hydroxytryptamine 2C receptors in the dorsal striatum mediate stress-induced interference with negatively reinforced instrumental escape behavior

Uncontrollable stress can interfere with instrumental learning and induce anxiety in humans and rodents. While evidence supports a role for serotonin (5-HT) and serotonin 2C receptors (5-HT(2C)R) in the behavioral consequences of uncontrollable stress, the specific sites of action are unknown. These experiments sought to delineate the role of 5-HT and 5-HT(2C)R in the dorsal striatum (DS) and the lateral/basolateral amygdala (BLA) in the expression of stress-induced instrumental escape deficits and exaggerated fear, as these structures are critical to instrumental learning and fear behaviors. Using in vivo microdialysis, we first demonstrated that prior uncontrollable, but not controllable, stress sensitizes extracellular 5-HT in the dorsal striatum, a result that parallels prior work in the BLA. Additionally, rats were implanted with bi-lateral cannula in either the DS or the BLA and exposed to uncontrollable tail shock stress. One day later, rats were injected with 5-HT(2C)R antagonist (SB242084) and fear and instrumental learning behaviors were assessed in a shuttle box. Separately, groups of non-stressed rats received an intra-DS or an intra-BLA injection of the 5-HT(2C)R agonist (CP809101) and behavior was observed. Intra-DS injections of the 5-HT(2C)R antagonist prior to fear/escape tests completely blocked the stress-induced interference with instrumental escape learning; a partial block was observed when injections were in the BLA. Antagonist administration in either region did not influence stress-induced fear behavior. In the absence of prior stress, intra-DS administration of the 5-HT(2C)R agonist was sufficient to interfere with escape behavior without enhancing fear, while intra-BLA administration of the 5-HT(2C)R agonist increased fear behavior but had no effect on escape learning. Results reveal a novel role of the 5-HT(2C)R in the DS in the expression of instrumental escape deficits produced by uncontrollable stress and demonstrate that the involvement of 5-HT(2C)R activation in stress-induced behaviors is regionally specific.

Interview: A normal psychology of pain

Christopher Eccleston is the Director of the Centre for Pain Research at The University of Bath, which is a wholly grant-funded research center focussed on innovation in behavioral science and pain. He is also Coordinating Editor of the Pain, Palliative and Supportive Care Cochrane Review Group.

Factors contributing to physical activity in a chronic low back pain clinical sample: a comprehensive analysis using continuous ambulatory monitoring

Back pain is one of the most common causes of disability in industrialized nations. Despite this, the variables that contribute to disability are not well understood and optimal measurement strategies of disability have not yet been determined. The present study sought to comprehensively assess the strongest predictors of physical activity as a proxy for disability. New patients in a chronic pain specialty clinic completed questionnaires to assess the predictors of physical activity and engaged in 5 days of home data collection wearing an accelerometer to assess physical activity in daily life, which is how disability was operationalized in this study. Analysis of repeated measures patient data revealed that, of 3 composite variables each representing a theoretical model, the model representative of operant factors significantly predicted physical activity. Subsequent analyses showed that pain sensitivity, fear avoidance, and solicitous spousal responses account for a significant amount of the variance in physical activity. These findings suggest that external sources of reinforcement or punishment may serve to influence physical behavior beyond that of internal cues such as fear avoidance or pain. Implications for treatment are discussed, including the potential benefits of specifically incorporating the patient's sources of operant reinforcement or punishment into treatment.

The mediation effect of experiential avoidance between coping and psychopathology in chronic pain

This study explores experiential avoidance as a mediator in the relationship between coping (rational coping, avoidant coping and detached/ emotional coping) and psychopathology (depression, anxiety and stress). A battery of self-report questionnaires was used to assess coping, experiential avoidance and depression, anxiety and stress in 70 participants with a chronic pain from Portuguese primary health care units. Regression analyses were performed and showed preliminary evidence supporting the mediation role of experiential avoidance in a Portuguese sample with chronic pain. Results show that experiential avoidance partially or fully mediate the effects of rational coping and detached/emotional coping on depression and stress. Implications for clinical practice were discussed and suggest that psychopathology is not necessary direct product of coping and other processes, such as experiential avoidance, are likely involved.

Medication use in patients with migraine and medication-overuse headache: the role of problem-solving and attitudes about pain medication

Excessive medication intake is a risk factor for the development of medication-overuse headache (MOH), a condition characterized by an increase of headache frequency to a daily or near-daily pattern. As yet, it is largely unknown why some patients overuse medication. In this study, we examined to what extent attitudes about pain medication, especially perceived need and concerns, and problem-solving are related to MOH. Patients with migraine (n=133) and MOH with a history of migraine (n=42) were recruited from a tertiary headache referral center and completed questionnaires measuring problem-solving and attitudes about pain medication. A problem-solving mode aimed at solving pain was associated with a higher need for and concerns about medication intake. Interestingly, in a model accounting for demographic factors and pain intensity, attempts to control pain, need for medication, and concerns about scrutiny by others because of medication intake all had a unique value in accounting for MOH. Results are discussed in terms of how repeated attempts to solve pain may trigger overuse of medication, even in the presence of clear negative consequences. Repeated attempts at solving pain may increase the need for analgesic medication, despite obvious costs. This mechanism might contribute to the problem of medication-overuse headache.

Born to choose: the origins and value of the need for control

Belief in one's ability to exert control over the environment and to produce desired results is essential for an individual's wellbeing. It has repeatedly been argued that perception of control is not only desirable, but is also probably a psychological and biological necessity. In this article, we review the literature supporting this claim and present evidence of a biological basis for the need for control and for choice-that is, the means by which we exercise control over the environment. Converging evidence from animal research, clinical studies and neuroimaging suggests that the need for control is a biological imperative for survival, and a corticostriatal network is implicated as the neural substrate of this adaptive behavior.