Shirley Pearce

Memory for pain: a review

This paper reports a qualitative review of the literature on memory for pain. Most research has focused on the accuracy of memory for pain intensity. There is some evidence that recall is moderately accurate but this conclusion is tentative because of significant methodological problems. There is also some evidence that recall of acute pain is more accurate than recall of chronic pain and we make some suggestions as to why this difference might occur. We conclude that further research on memory for pain should be informed by reference to methodological practices developed in cognitive psychology and embedded within an appropriate theoretical framework.

Memory and pain: tests of mood congruity and state dependent learning in experimentally induced and clinical pain

&NA; The associative network theory of memory [2] is outlined along with the concepts of mood congruity and state dependent learning. Two experiments are reported which investigate the occurrence of these effects where memory for pain is concerned. In experiment 1 the performance of 25 chronic pain patients was compared with that of 25 non‐patient controls on a test involving both immediate and delayed recall of a mixed list of stimulus words of 3 types: pain‐related, negative or neutral. No significant group differences were found in overall rates of immediate recall. As predicted, however, pain patients recalled more pain‐related words than non‐patient controls (P < 0.001). On delayed recall the same significant group × word‐type interaction was obtained (P < 0.02), but in addition the non‐patient controls recalled significantly more words overall (P < 0.02). These results provide some evidence for the occurrence of a mood congruity effect. Experiment 2 investigated state dependent learning and mood congruity effects in experimentally induced pain. Twenty volunteer subjects were allocated to 1 of 4 conditions in which a wordlist (as in experiment 1) was presented following either a painful stimulus (cold pressor test) or a non‐painful one (warm water) and was then recalled immediately following further exposure to stimulus conditions which were congruent with the original stimulus (warm/warm and cold/cold conditions) or non‐congruent (warm/cold and cold/warm conditions). A 3‐way split plot ANOVA yielded no significant main effects for group or word‐type, but a significant interaction emerged between state at encoding and at recall (P < 0.04). The results provided some support for the occurrence of a state dependent learning effect but no evidence of a mood congruity effect. It is concluded that mood congruity effects in memory for pain may be more related to the status of being a chronic pain patient than to the state of being in pain.

The pain beliefs questionnaire : an investigation of beliefs in the causes and consequences of pain

&NA; This paper reports the development and validation of the Pain Beliefs Questionnaire (PBQ). This is a 20‐item questionnaire covering beliefs about the cause and treatment of pain. It was administered to 294 subjects, comprising 100 chronic pain patients and 194 controls. An exploratory factor analysis revealed 2 factors accounting for 68.15% of the variance. From the final solution 2 scales were derived: the first called Organic Beliefs and the second Psychological Beliefs scale, comprising 8 and 4 items, respectively. The construct validity of the questionnaire was assessed in 2 ways. First, the responses of chronic pain patients and non‐patient controls were compared: a significant difference (F(1,236) = 53.04, P < 0.0001) between these 2 groups emerged such that chronic pain patients were more likely to endorse the Organic Beliefs scale items, whereas non‐patients were more likely to endorse the Psychological Beliefs scale items. Secondly, as predicted significant associations were observed between scores on the Organic Beliefs scale and scores on the Chance and Powerful Others scales of the Multidimensional Health Locus of Control (MHLC), and also between the Psychological Beliefs and Internal scales of the MHLC. No relationship, however, emerged between these scales and measures of pain intensity. The implications of these findings for the assessment and management of chronic pain patients, and in the understanding of the development of chronic pain, are discussed.

Outpatient cognitive behavioral pain management programs: a randomized comparison of a group-based multidisciplinary versus an individual therapy model.

OBJECTIVE To compare the efficacy of 2 models of chronic pain management. DESIGN Randomized comparative trial with 2 active treatment arms. SETTING Outpatient pain management clinics. PARTICIPANTS A total of 113 adults with chronic pain of 0.5 to 38 years duration in (mean, 8.8y). INTERVENTIONS Cognitive behavioral therapy (including education, relaxation, use of cognitive coping strategies, pacing, exercise) delivered in group-based multidisciplinary program or in an individual therapy program. MAIN OUTCOME MEASURES Self-report of interference with daily activities and sense of control over pain (West Haven-Yale Multidimensional Pain Inventory [WHYMPI]) and depression (Beck Depression Inventory). Secondary outcome measures were state anxiety (Spielberger State-Trait Anxiety conventory), analgesic medication consumption, general activity, and pain severity (WHYMPI). Measurement points were 0 (before treatment), 2 months (end of treatment), and 3, 6 and 12 months (follow-up). RESULTS No significant differences were found between the 2 modes of treatment at any of the major time points (0, 2, 12mo). Both treatment conditions made significant and sustained improvements on all primary outcome measures, although sense of control over pain tended to decline by 1 year. Individually treated participants made slower gains in some areas, but showed a lesser tendency to rebound at the end of treatment. CONCLUSION The 2 programs appear to be equally efficacious for pain management in adults with chronic pain. In practical terms, the choice of model for service provision may rest more on local issues such as the availability of space and staff time.

Interpretation bias in responses to ambiguous cues in pain patients

Pain patients and control subjects responses to ambiguous cues were compared in two separate investigations. In the first, pain patients, control subjects and physiotherapists were asked to produce a list of spontaneous associations to ambiguous cues (such as terminal and growth). To control for mood effects the experiment was repeated with three more groups: Pain patients, osteopaths and a control group. Measures of anxiety and depression were incorporated in the analysis. Results indicate that pain patients systematically produce more pain related associations than the other groups, and that this effect is independent of anxiety and depression levels. The discussion concentrates on the implications of these findings both for the theory of pain processing and for clinical interventions.

Post-operative fatigue following coronary artery bypass surgery: relationship to emotional state and to the catecholamine response to surgery.

Post-operative fatigue is an important subjective problem for surgical patients, but its basis is unknown, and the possibility of a psychological component has been neglected. To investigate its putative physiological and psychological bases, 74 patients undergoing coronary artery bypass graft surgery were studied. Circulating catecholamine levels were measured at intervals perioperatively and questionnaires were used to measure fatigue, depression and anxiety up to 30 days post-operatively. We tested whether fatigue was related either to the catecholamine or to the emotional responses to surgery. The second element to the design was a controlled randomized study: patients underwent different forms of psychological preparation or a no-treatment control procedure in an attempt to test whether post-operative fatigue was amenable to psychological manipulation. Psychological preparation had no effect. Fatigue at 30 days was greatest in patients whose noradrenaline levels were greatest perioperatively. Independently of this relationship, fatigue at 30 days correlated with concurrent levels of depression and anxiety. Post-operative fatigue has both physiological and psychological correlates.

The pain cognitions questionnaire

This paper reports the development of the Pain Cognitions Questionnaire. This was administered to 90 mixed chronic pain patients and an exploratory factor analysis revealed two negative and two positive factors. Significant associations were observed between scores on the negative factors and measures of pain severity and mood. No clear relationship emerged, however, for positive cognitions and pain or mood variables. The implications of these findings for the assessment and treatment of chronic pain are discussed.

A review of cognitive-behavioural methods for the treatment of chronic pain

Cognitive-behavioural methods for the treatment of chronic pain are described. They are divided into two categories. Firstly, those directly concerned with modifying pain related cognitions. These include distraction or relabelling techniques derived largely from analogue studies on experimental pain which show that various cognitive strategies can increase pain tolerance levels. Secondly, those concerned with modifying cognitive responses to stress. These include stress management techniques derived from the research on anxiety management. Outcome studies for both categories of cognitive methods and for a range of chronic pain problems are reviewed. It is concluded that although outcome studies report favourable results for cognitive methods there is a paucity of well controlled and evaluated studies.

REMEDIATION OF PAIN-RELATED MEMORY BIAS AS A RESULT OF RECOVERY FROM CHRONIC PAIN

Cognitive biases are increasingly implicated as vulnerability factors in emotional and physical disorders. This issue is examined here in chronic pain sufferers using a recall memory paradigm. A sample of chronic pelvic pain patients undergoing hysterectomy and oophorectomy were assessed prior to the intervention, 8 weeks post-surgery, and again 6 months post-surgery. On each occasion patients were aurally presented four mixed lists of sensory, affective, neutral and gardening words, matched for frequency and length. No difference in the recall of neutral and gardening words was found, suggesting that selective memory for pain-related information cannot be attributed to superior recall of words belonging to a common semantic category. A clear pattern of more pain-related words being remembered before surgery, but better recall of non-pain-related words 6 months post-surgery when pain intensity ratings are significantly reduced, was evidenced. These results suggest that selective memory for pain-related words is more likely to be a secondary consequence of the long term experience of pain than a stable, enduring cognitive vulnerability factor.

The concept of psychogenic pain: A psychological investigation of women with pelvic pain

Women with pain occurring in the absence of pathology have been reported to have personality and mood disturbances which account for their pain. These studies suffer from both methodological and theoretical difficulties. A common methodological problem is the absence of comparison groups of women with pain of equivalent chronicity yet with diagnosed pathology. This study compares women with and without pathology, matched for pain chronicity, on a range of psychological measures. No differences were observed between “pathology” and “no pathology” groups on global measures of personality or mood. Differences do emerge in specific attitudes and exposure to illness. The implications of these findings for our understanding of pain mechanisms are discussed and the limitations of the notion of “psychogenic” pain are considered.