Suppressing and attending to pain-related thoughts in chronic pain patients

The role of spontaneous vs. experimentally induced attentional strategies for the pain response to a single bout of exercise in healthy individuals

OBJECTIVES

Exercise-induced pain and exercise-induced hypoalgesia (EIH) are well described phenomena involving physiological and cognitive mechanisms. Two experiments explored whether spontaneous and instructed mindful monitoring (MM) were associated with reduced exercise-induced pain and unpleasantness, and increased EIH compared with spontaneous and instructed thought suppression (TS) in pain-free individuals.

METHODS

Eighty pain-free individuals participated in one of two randomized crossover experiments. Pressure pain thresholds (PPTs) were assessed at the leg, back and hand before and after 15 min of moderate-to-high intensity bicycling and a non-exercise control condition. Exercise-induced pain and unpleasantness were rated after bicycling. In experiment 1 (n=40), spontaneous attentional strategies were assessed with questionnaires. In experiment 2, participants (n=40) were randomly allocated to use either a TS or MM strategy during bicycling.

RESULTS

In experiment 1, the change in PPTs was significantly larger after exercise compared with quiet rest (p<0.05). Higher spontaneous MM was associated with less exercise-induced unpleasantness (r=-0.41, p<0.001), whereas higher spontaneous TS was associated with higher ratings of exercise-induced unpleasantness (r=0.35, p<0.05), but not with pain intensity or EIH. In experiment 2, EIH at the back was increased in participants using instructed TS compared with participants using instructed MM (p<0.05).

CONCLUSIONS

These findings suggest that spontaneous and presumably habitual (or dispositional) attentional strategies may primarily affect cognitive-evaluative aspects of exercise, such as feelings of exercise-induced unpleasantness. MM was related to less unpleasantness, whereas TS was related to higher unpleasantness. In terms of brief experimentally-induced instructions, TS seems to have an impact on physiological aspects of EIH; however, these preliminary findings need further research.

Cognitive Coping Style and the Effectiveness of Distraction or Sensation-Focused Instructions in Chronic Pain Patients

AIM

This study set out to investigate whether cognitive coping strategies that match participants' preferred coping style effectively reduce pain intensity and situational anxiety in a population of people with chronic pain.

METHOD

Chronic pain patients (N = 43) completed questionnaires on coping style, pain intensity, self-efficacy, and situational/trait anxiety. Participants were classified as Monitors (n = 16) or Blunters (n = 19) based on their Miller Behavioural Style Scale score. Participants were then provided with an audiotaped intervention in which they were instructed to focus on pain sensations or to engage in a distraction task and then to rate the pain intensity and their anxiety during and after the attentional focus and distraction conditions. The two interventions were each completed by all participants, having been presented in counterbalanced order.

RESULTS

Findings revealed that Monitors' level of anxiety decreased following a congruent (i.e., sensation-focused) intervention. No effects were obtained in terms of perceived pain. For blunters, however, their perceived levels of anxiety and pain did not attenuate following a congruent, distraction-focused intervention.

CONCLUSION

Among persons experiencing chronic pain, tailoring coping strategies to match an individual's preferred coping style--in particular, those with a high level of monitoring--may enhance the benefit of psychological approaches to management of anxiety.

Comparison of acceptance and distraction strategies in coping with experimentally induced pain

BACKGROUND

This study compared an acceptance-based strategy with a control-based strategy (distraction) in terms of the ability of participants to tolerate a painful stimulus, across two experiments. In addition, participants were either actively encouraged, or not, to link pain tolerance with pursuit of valued goals to examine the impact of pursuing a personally meaningful goal or value on the extent to which pain will be tolerated.

METHODS

Participants in experiment 1 (n=41) and experiment 2 (n=52) were equally assigned to acceptance or distraction protocols. Further, half the participants in each group generated examples from their own lives in which they had pursued a valued objective, while the other half did not. In experiment 2, the values focus was enhanced to examine the impact on pain tolerance.

RESULTS

There were no significant differences overall between the acceptance and distraction groups on pain tolerance in either experiment. However, in experiment 2, individuals classified as accepting in terms of general coping style and who were assigned to the acceptance strategy showed significantly better pain tolerance than accepting individuals who were in the distraction condition. Across both experiments, those with strong goal-driven values in both protocols were more tolerant of pain. Participants appeared to have more difficulty adhering to acceptance than to distraction as a strategy.

CONCLUSION

Acceptance may be associated with better tolerance of pain, but may also be more difficult to operationalize than distraction in experimental studies. Matching coping style and coping strategy may be most effective, and enhancement of goal-driven values may assist in pain coping.

A daily process design study of attentional pain control strategies in the self-management of cancer pain

This study investigated the use of attentional control strategies in the self-management of pain using daily process design methodology. Twenty six cancer patients with pain completed diaries 3 times daily for 10 days. Diaries incorporated measures of pain intensity, affect, coping, coping efficacy, and the novelty and predictability of pain, and participants completed a cross-sectional measure of catastrophizing. At the across-person level, focusing on pain was associated with increased negative affect, and the use of pain focusing strategies was positively correlated with experiencing pain that was novel in its location or quality. Distractions that were interesting, important and pleasant were positively correlated with positive affect, perceptions of control over pain and ability to decrease pain. Over-prediction of pain was positively correlated with catastrophizing, and negatively correlated with perceptions of control over and ability to decrease pain. The within-person analysis (ARIMA modelling) showed that catastrophizing moderated the effects of pain focusing strategies, novel pain and over-predictions of pain. Meta-analysis of the ARIMA models revealed that the within-person effects of using attentional strategies did not generalize across the sample. These findings indicated that the effects of distraction strategies are influenced by their motivational-affective significance rather than the frequency with which they are used, and provided further evidence that the threat value of pain influences the way in which people cope with their pain. Theoretical and clinical implications are discussed.

The effects of acceptance versus thought suppression for dealing with the intrusiveness of tinnitus

The purpose of this study was to examine the effect of acceptance versus suppression of disruptions on a mental imagery task in a sample of tinnitus patients. Previous research has indicated that acceptance can be an effective strategy for dealing with unpleasant experiences such as pain and anxiety. The study used a between-group design, including 47 participants who completed a task involving mental imagery in a sound-proof booth. Participants were randomly assigned to three instruction conditions: acceptance, suppression, or a control condition. The results showed a significant difference between the acceptance group and the control group in that participants in the acceptance group were able to focus on the imagery task for a longer time without being interrupted. The study provides preliminary support for the notion that acceptance can be a helpful strategy for tinnitus patients.

Effects of suppression, acceptance and spontaneous coping on pain tolerance, pain intensity and distress

Wegner's Theory of Ironic Processes has been applied to study the effects of cognitive strategies to control pain. Research suggests that suppression contributes to a more distressing pain experience. Recently, the acceptance-based approach has been proposed as an alternative to cognitive control. This study assessed the tolerance time, the distress and the perceived pain intensity in three groups (suppression, acceptance and spontaneous coping groups) when the participants were exposed to a cold pressor procedure. Two hundred and nineteen undergraduates volunteered to participate. The suppression group showed the shortest tolerance time and the acceptance group showed the longest tolerance time. The acceptance group showed pain and distress immersion ratings that were significantly lower than in the other two groups, between which the differences were not significant. In the first recovery period, the suppression group showed pain and distress ratings that were higher than in the other two groups. In the second recovery period, although the acceptance group showed pain and distress ratings that were significantly lower than in the other two groups, the suppression and the spontaneous coping groups did not differ. The presence of a 'rebound' of physical discomfort and the effects of suppression on behavioural avoidance are discussed. These results support the acceptance approach in the management of pain.

Consequences of suppressing thoughts about tinnitus and the effects of cognitive distraction on brain activity in tinnitus patients

Tinnitus is the perception of sound in the absence of any appropriate external stimulus. Based on the clinical observation that tinnitus patients may distract themselves from their sounds, we performed an experimental test on the effects of suppressing thoughts about tinnitus with 45 tinnitus patients, to systematically evaluate the immediate consequences of suppressing thought vs. attending to tinnitus. Suppression instructions tended to lead to a subsequent decrease in tinnitus-related thoughts, whereas attention to tinnitus resulted in an increase in such thoughts. No effects were seen in a control group who neither suppressed nor attended to their tinnitus. In an independent positron emission tomography study of cerebral blood flow with 8 patients we found that silent backward counting ('serial sevens test') led to a decrease in neural activity in auditory cortex, as well as perceived decrease of tinnitus loudness and annoyance. Thus, distraction that altered the tinnitus experience seemed to attenuate auditory cortex activity.

An investigation of monitoring for sleep-related threat in primary insomnia

In Study 1, individuals with primary insomnia (n=32) and good sleepers (n=38), recruited from a university population, completed a semi-structured interview. The interview assessed monitoring for sleep-related threat, negative thoughts and safety behaviours, at night and during the day. Compared to good sleepers, individuals with insomnia reported more frequent monitoring at night and during the day, more negative thoughts associated with monitoring at night and during the day, and the use of more safety behaviours associated with monitoring at night. A path analysis showed that the total monitoring frequency was significantly positively related to the score for total negative thoughts, which in turn, was significantly positively related to the total number of safety behaviours used. Study 2 aimed to test the generalisability of these findings in a clinical sample of individuals with primary insomnia (n=23). The results indicated that the clinical sample also engaged in monitoring for sleep-related threat, experienced negative thoughts and used safety behaviours. Further, more severe insomnia was associated with more negative thoughts and the use of more safety behaviours associated with monitoring at night. Together, these results are consistent with the proposal that monitoring for sleep-related threat functions to maintain insomnia by triggering negative thoughts and the use of safety behaviours. Future research is required to verify the proposed causal status of monitoring, using prospective designs and experimental manipulations.

The prevalence of post-traumatic stress disorder in chronic pain patients

Several of the more common causes of chronic pain include traumatic events such as motor vehicle accidents and work-related incidents. Therefore, it is not unusual for patients presenting with chronic pain to also describe significant levels of distress including post-traumatic symptomatology and, in the more severe cases, post-traumatic stress disorder (PTSD). Throughout the past few decades, the literature relating to chronic pain and PTSD has become progressively more sophisticated, resulting in well-supported theories and treatments for sufferers. However, only a handful of studies have specifically attended to the co-occurrence of these two disorders. This review presents a summary of the literature relating to the two disorders in terms of symptoms, prevalence, and comorbidity. It also briefly describes the main empirically supported psychologic theories of chronic pain and PTSD and briefly reviews the evidence regarding what factors maintain the disorders. Treatment implications and issues for future research are considered.

Chronic pain and posttraumatic stress disorder: mutual maintenance?

Common sequelae following a traumatic event include chronic pain and posttraumatic stress disorder (PTSD). Over the last decade, the literature relating to PTSD has become progressively more sophisticated, resulting in well-supported theories and treatments for sufferers. Equivalent research relating to chronic pain has more recently gathered momentum. However, to date there has been minimal attention devoted to the concurrence of the two disorders, even though high comorbidity has been noted. This review begins by briefly summarizing the literature relating to the two disorders in terms of symptoms, prevalence and comorbidity. It explicates the major psychological theories of chronic pain and PTSD and reviews the evidence relating what factors maintain the disorders. A number of pathways by which chronic pain and PTSD may be mutually maintaining are highlighted. We conclude that chronic pain and PTSD are mutually maintaining conditions and that there are several pathways by which both disorders may be involved in the escalation of symptoms and distress following trauma. Treatment implications are considered, as are issues for future research.