The relationship of depression and somatic focus to experimental and clinical pain in chronic pain patients

Self-regulatory ability, fatigue, and the experience of pain: Mechanistic insights from pain-free undergraduates

Self-regulatory (SR) ability is an important resource for managing pain, but chronic pain patients experience chronic self-regulatory fatigue even when they are not in pain. Pressure pain thresholds (PPT) and pain inhibition are two mechanisms that differentiate people with and without chronic pain. It was hypothesized that trait SR ability would be associated with higher PPT and better pain inhibition and that PPT and pain inhibition would be lower following high versus low SR fatigue. Three studies tested these hypotheses. Study 1 had 240 pain-free undergraduates complete measures of trait SR ability and PPT; 122 also provided data on pain inhibition. Study 2 had 38 of Study 1's participants return for two additional sessions in which they underwent PPT testing under conditions of high or low SR fatigue (within-person, counterbalanced). Study 3 repeated these procedures with pain inhibition as the outcome (n = 39). Results revealed that individual differences in SR ability were not associated with PPT or pain inhibition (all ps > 0.05). Within people, neither PPT (F(1, 36) = 1.57, p = 0.22) nor pain inhibition (F(1, 37) = 1.79, p = 0.19) were significantly different under conditions of low versus high SR fatigue. Results do not support the hypotheses that PPT or pain inhibition associate with individual differences in trait SR ability or transient changes in state SR fatigue in the absence of pain. Instead, the SR deficits in chronic pain patients may arise from the experience of chronic pain.

Self-focused attention in response to laboratory stressors among women with premenstrual disorders

The etiology of premenstrual disorders, including premenstrual syndrome (PMS) and premenstrual dysphoric disorders (PMDD), is not well understood. In the current study, the relationship between self-focused attention (SFA) and premenstrual disorders was examined to explore the hypothesis that women with premenstrual disorders tend to respond to symptoms in a maladaptive manner. Based on retrospective report, clinical interview, and 30-day prospective recording of premenstrual symptoms, women (N = 52) were categorized as meeting criteria for premenstrual disorders (PMD; n = 24) or not (controls; n = 28). Key findings indicated that women with premenstrual disorders reported greater use of SFA in response to negative affect elicited by laboratory tasks than controls, despite no significant differences in change in negative affect between the two groups. Women with premenstrual disorders also reported greater trait levels of SFA and maladaptive coping styles compared to controls. Women with premenstrual disorders may tend to respond to menstrual cycle changes using increased levels of SFA. The interaction between psychological and physiological menstrual cycle-related changes may lead to increased distress and impairment. Implications for psychological contributions to premenstrual distress and disorders are discussed.

Co-occurring depression and pain in multiple sclerosis

Depression and pain are highly prevalent among individuals with multiple sclerosis, and they often co-occur. The purpose of this article is to summarize the literature and theory related to the comorbidity of pain and depression and describe how their presence can impact individuals with multiple sclerosis. Additionally, the article discusses how existing treatments of pain and depression could be adapted to address shared mechanisms and overcome barriers to treatment utilization.

Evidence for a direct relationship between cognitive and physical change during an education intervention in people with chronic low back pain

BACKGROUND

Unhelpful pain cognitions of patients with chronic low back pain (LBP) may limit physical performance and undermine physical assessment. It is not known whether a direct relationship exists between pain cognitions and physical performance.

AIMS

To determine if a relationship exists between change in pain cognitions and change in physical performance when chronic LBP patients participate in a single one-to-one education intervention during which they have no opportunity to be active.

METHODS

In a quasi-experiment using a convenience sample, moderately disabled chronic LBP patients (n=121) participated in a one-to-one education session about either lumbar spine physiology or pain physiology. Multiple regression analysis evaluated the relationship between change in pain cognitions measured by the survey of pain attitudes (SOPA) and the pain catastrophising scale (PCS) and change in physical performance, measured by the straight leg raise (SLR) and standing forward bending range.

RESULTS

There was a strong relationship between cognitive change and change in straight leg raise (SLR) and forward bending (r=0.88 and 0.79, respectively, P<0.01), mostly explained by change in the conviction that pain means tissue damage and catastrophising.

CONCLUSIONS

Change in pain cognitions is associated with change in physical performance, even when there is no opportunity to be physically active. Unhelpful pain cognitions should be considered when interpreting physical assessments.

Somatic focus/awareness: Relationship to negative affect and pain in chronic pain patients

Somatic focus refers to the tendency to notice and report physical symptoms, and has been investigated in relation to chronically painful conditions. This study investigated the relationship between somatic focus, as measured by the Pennebaker Inventory of Limbic Languidness (PILL), negative affect and pain. A secondary purpose of the present study was to examine sex differences in these relationships. Participants included 280 chronic pain patients (69.6% females, 88.9% Caucasian), who completed a battery of self-report measures on somatic focus, pain, negative affect, coping, and dysfunction. Results for the overall sample revealed that the PILL shares considerable variance with measures of negative affect, particularly with the physiological components of anxiety and depression. When the results were analyzed separately for male and female patients, it was found that several components of negative affect and cognitive factors play a stronger role in predicting somatic focus among men compared to women. Additional analyses then examined whether somatic focus was predictive of male and female patients' pain reports. Results indicated that somatic focus explained a small, but unique amount of variance in female patients' pain reports, which differed from the relationship observed among male patients.

Somatic symptoms in patients with chronic non-cancer-related and cancer-related pain

This study describes and compares patients' reports of somatic symptoms and physicians' ratings of the same symptoms in patients with chronic non-cancer-related and cancer-related pain. Ninety-seven patients with chronic non-cancer-related pain and 100 patients with chronic cancer-related pain reported somatic symptoms using a newly developed checklist of somatic symptoms. Patients also completed the Brief Symptom Inventory-18, Courtland Emotional Control Inventory, Catastrophizing scale, two items from the Coping Strategies Questionnaire (one about efficacy to control and another about ability to decrease pain), and a numeric rating of average pain. After they completed medical histories and physical examinations on patients, physicians rated the degree to which the patients' reported somatic symptoms on the checklist were medically unexplainable. Over 80% of patients in both groups reported somatic symptoms that their physicians rated as not fully explainable. Strong associations existed between patient-reported somatic symptoms and negative mood states. For the majority of patients, results supported a concept of combined illness- and affect-related pathology rather than one of pure somatoform disorder. Assessing patients' reports of somatic symptoms and negative mood states and incorporating physicians' ratings of level of medically unexplainable somatic symptoms were useful for distinguishing these diagnoses.

The relationship between depression, clinical pain, and experimental pain in a chronic pain cohort

OBJECTIVE

Individuals with chronic pain frequently display comorbid depression, but the impact of symptoms of depression on pain processing is not completely understood. This study evaluated the effect of symptoms of depression and/or clinically diagnosed major depressive disorder (MDD) on pain processing in patients with fibromyalgia (FM).

METHODS

Results of quantitative sensory testing and neural responses to equally painful pressure stimuli (measured by functional magnetic resonance imaging [fMRI]) were compared with the levels of symptoms of depression and comorbid MDD among patients with FM.

RESULTS

Neither the level of symptoms of depression nor the presence of comorbid MDD was associated with the results of sensory testing or the magnitude of neuronal activation in brain areas associated with the sensory dimension of pain (primary and secondary somatosensory cortices). However, symptoms of depression and the presence of MDD were associated with the magnitude of pain-evoked neuronal activations in brain regions associated with affective pain processing (the amygdalae and contralateral anterior insula). Clinical pain intensity was associated with measures of both the sensory dimension of pain (results of sensory testing) and the affective dimension of pain (activations in the insula bilaterally, contralateral anterior cingulate cortex, and prefrontal cortex).

CONCLUSION

In patients with FM, neither the extent of depression nor the presence of comorbid major depression modulates the sensory-discriminative aspects of pain processing (i.e., localizing pain and reporting its level of intensity), as measured by sensory testing or fMRI. However, depression is associated with the magnitude of neuronal activation in brain regions that process the affective-motivational dimension of pain. These data suggest that there are parallel, somewhat independent neural pain-processing networks for sensory and affective pain elements. The implication for treatment is that addressing an individual's depression (e.g., by prescribing an antidepressant medication that has no analgesic properties) will not necessarily have an impact on the sensory dimension of pain.

Perception of noxious and innocuous heat stimulation among healthy women and women with fibromyalgia: association with mood, somatic focus, and catastrophizing

Recent studies have demonstrated that persons with fibromyalgia display abnormal processing of different types of painful stimulation, suggesting the disorder is characterized by a central pain-processing deficit not limited specifically to muscle pain. In the present study, 20 women with fibromyalgia and 20 normal, healthy women were compared on measures of pressure pain stimulation and response to contact thermal heat at both noxious and innocuous intensities. Women with fibromyalgia displayed significantly lower pressure pain thresholds at 18 tender point locations as defined by the American College of Rheumatology criteria, as well as lower pressure pain thresholds at five control sites. Women with fibromyalgia had significantly lower heat pain thresholds and tolerances when stimulated on the volar surface of the left forearm. When examining visual analog ratings of intensity and unpleasantness to constant stimuli, a multivariate analysis of variance performed on these ratings indicated that there were significant main effects of level of stimulation and group. Individual analysis of variances at each temperature revealed significant differences between the groups in pain intensity and unpleasantness ratings at both noxious and innocuous temperatures. Multiple regression analyses indicated that greater pain catastrophizing and diagnosis of fibromyalgia were associated with decreased pain thresholds and tolerances in the entire sample, whereas, self-report of depressive symptoms was associated with increased thresholds and tolerances. Self-report of somatic symptoms was not associated with these measures. These findings indicate that persons with fibromyalgia display altered perception of both pressure and thermal stimulation, even at innocuous levels. They also suggest that catastrophic thoughts about pain may play a role in increased pain perception in this population.

Catastrophizing, depression and expectancies for pain and emotional distress

The present research addressed the relation between catastrophizing, depression and response expectancies in anticipation of an experimental pain procedure. One hundred and twenty undergraduates (48 men, 72 women) participated in exchange for course credit. Prior to immersing one arm in a container of ice water, participants were asked to complete measures of catastrophizing and depression, and to estimate the degree of pain and emotional distress they expected to experience. After a 1-min immersion, participants rated their actual experience. Pain expectancies partially mediated the relation between catastrophizing and pain experience. Pain expectancies also mediated the relation between depression and pain experience. Catastrophizing, but not depression, was associated with a tendency to underestimate pain and emotional distress. The implications of these findings for the conceptual distinctiveness of catastrophizing and depression are discussed. Discussion also examines the potential implications of the present findings for pain management interventions.

Negative affect, self-report of depressive symptoms, and clinical depression: relation to the experience of chronic pain

OBJECTIVE

The goal of this study was to examine the relative importance of global affective distress, self-report of depressive symptoms, and presence or absence of major depression to the experience of chronic pain.

SETTING

A multidisciplinary pain program at a university medical center was the setting for this study.

PATIENTS

Subjects in this study were 211 consecutive patients with chronic pain.

OUTCOME MEASURES

Pain duration, compensation, and litigation status were controlled for in the statistical analyses, as each correlated significantly with at least one of the measures of affect. Global affective distress was assessed using the Global Severity Index (GSI) from the Brief Symptom Inventory. The Beck Depression Inventory and the Center for Epidemiological Studies Depression Scale were used as measures of self-report of depressive symptoms. Presence or absence of major depression was based on DSM-IV criteria.

RESULTS AND CONCLUSIONS

The GSI, Beck Depression Inventory, and Center for Epidemiological Studies Depression Scale were significantly correlated with each measure of the experience of pain, although clinical depression was only significantly related to self-reported disability and negative thoughts about pain. The self-report measures of depression maintained their relation to the dependent measures when the somatic items from the scales were removed, suggesting that the relations were not spuriously due to the influence of pain symptoms on the scales. When examining the unique contribution of each variable to the experience of pain (by simultaneously controlling for the other measures of affect), the GSI was uniquely related to the sensory and affective components of pain. Self-report of depressive symptoms was more highly related to a measure of the evaluative component of pain and uniquely related to self-reported disability and negative thoughts about pain. The results are discussed within the context of theoretical models of the relation between pain and affect, and suggestions for future research are presented.

Vulvodynia: an introduction and critical review of a chronic pain condition

Vulvodynia, or chronic vulvar discomfort, has become an increasingly recognized complaint in the medical literature. However, classification, assessment, and treatment for vulvodynia have not been universally established. There is a serious need for greater understanding of this disorder since evidence suggests, although not life-threatening, vulvodynia appears to have a significant impact on quality of life. This article reviews the medical and psychological literature on vulvodynia published since 1983, the first year vulvodynia was recognized as a diagnosis in the medical literature. The purpose of this article is to provide a review of the literature on diagnostic issues, treatment options, and psychosocial sequelae with the aim of highlighting areas in need of future research. Finally, suggestions are made for considering vulvodynia from a multidimensional, chronic pain perspective.

Recurrent headache, coping, and quality of life in children: a review

OBJECTIVES

To clarify the concepts of coping with pain and quality of life (QoL) and to present a literature review of the strategies that children with recurrent headaches use to cope with their pain, the impact of recurrent headaches on children's QoL, and the influence of personal and situational variables on headache, coping, and QoL in children.

METHODS

The literature search encompassed published articles that were found by means of a CD-ROM search of MEDLINE (1966 to December 1998) and PsycLIT (1974 to December 1998) and the snowball method.

RESULTS

In pediatric headache research, only three studies have been found in which children report the use of various coping strategies, and only two studies considered QoL. Demographic factors and psychological variables such as depression, anger, and anxiety influence headache prevalence. The impact of headache-related variables such as headache type, severity, perceived cause, and prior experience on QoL has only been studied in adults.

CONCLUSIONS

More research on coping and QoL is needed in pediatric headache. The conceptual model that is presented in this article may serve as a guide.

Ethnic differences in thermal pain responses

OBJECTIVE

Although numerous studies have reported ethnic differences in the prevalence and severity of clinical pain, little is known about how these differences affect the perception of experimental pain. The present experiment examined the effects of ethnicity (African American vs. white) on thermal pain responses in a healthy undergraduate population.

METHODS

Thirty white subjects (16 women and 14 men) and 18 African Americans (10 women and 8 men) participated in the study. Thermal testing included evaluation of the following: warmth thresholds, thermal pain thresholds, thermal pain tolerances, and magnitude estimates of both the intensity and unpleasantness of thermal pain (at 46 degrees, 47 degrees, 48 degrees, and 49 degrees C).

RESULTS

Although no group differences emerged for warmth thresholds, thermal pain thresholds, or pain intensity ratings, African Americans demonstrated lower thermal pain tolerances than whites. In addition, African Americans had smaller slopes and larger intercepts than whites for ratings of pain unpleasantness. Additional analyses suggested that these findings were a consequence of group differences in thermal pain unpleasantness ratings at the lowest temperatures assessed (46 degrees and 47 degrees C); at these temperatures, African Americans rated the stimuli as more unpleasant than whites. Finally, group differences in thermal pain tolerance and thermal pain unpleasantness ratings seemed to partially account for greater self-reported daily pain symptoms among African Americans.

CONCLUSIONS

Collectively, these findings seem to suggest ethnic differences in the perception of the affective-motivational dimension of thermal pain.

Assessing depression among persons with chronic pain using the Center for Epidemiological Studies-Depression Scale and the Beck Depression Inventory: a comparative analysis

OBJECTIVE

This study examined the ability of two self-report questionnaires, the Beck Depression Inventory (BDI) and the Center for Epidemiological Studies-Depression Scale (CES-D), to discriminate between chronic pain patients with and without major depression. Since previous research has suggested that medical conditions such as chronic pain can influence the endorsement of items that measure neurovegetative symptoms of depression, the accuracy of each of these questionnaires was also assessed eliminating these items.

SUBJECTS

These included 132 consecutive patients with chronic pain, 44 of whom were diagnosed as suffering from major depression according to DSM-IV criteria.

METHODS

Patients were administered a battery of questionnaires that included the CES-D and BDI. They were also interviewed by a clinical psychologist to determine the presence or absence of major depression.

RESULTS

Both questionnaires were able to discriminate significantly between persons with and without major depression. Removal of the somatic items on each questionnaire did not improve their accuracy. Discriminant function analysis revealed an optimal cut-off score of 21 for the BDI, and 27 for the CES-D. Overall hit rates at these cut-offs for the two questionnaires were comparable, while the CES-D had somewhat better sensitivity (81.8% vs. 68.2%). Conversely, the BDI had slightly better specificity (78.4% vs. 72.7%).

CONCLUSION

The results suggest that both questionnaires have good predictive validity among chronic pain patients, and decisions regarding the use of one questionnaire rather than the other may depend upon the goals of the user and the setting within which the questionnaire is used.

Sequential daily relations of sleep, pain intensity, and attention to pain among women with fibromyalgia

Fifty women with fibromyalgia syndrome (FS) recorded their sleep quality, pain intensity, and attention to pain for 30 days, using palm-top computers programmed as electronic interviewers. They described their previous night's sleep quality within one-half hour of awakening each day, and at randomly selected times in the morning, afternoon, and evening rated their present pain in 14 regions and attention to pain during the last 30 min. We analyzed the 30-day aggregates cross-sectionally at the across-persons level and the pooled data set of 1500 person-days at the within-persons level after adjusting for between-persons variation and autocorrelation. Poorer sleepers tended to report significantly more pain. A night of poorer sleep was followed by a significantly more painful day, and a more painful day was followed by a night of poorer sleep. Pain attention and sleep were unrelated at the across-persons level of analysis. But there was a significant bi-directional within-person association between pain attention and sleep quality that was not explained by changes in pain intensity.

The effects of depression and chronic pain on psychosocial and physical functioning

OBJECTIVE

The present study employed causal modeling to examine the impact of somatic and cognitive symptoms of depression on the functioning of patients with chronic pain.

DESIGN

Path analyses were conducted to determine whether pain level is directly related to the psychosocial and physical dimensions of functional status or whether this relationship is mediated by depression.

SETTING

Subjects were recruited from a facial pain clinic at the University of Florida, an outpatient clinic associated with a tertiary-care health center.

PATIENTS

Subjects were 70 patients with chronic pain, 53 of whom had primary facial pain.

MAIN OUTCOME MEASURES

All subjects completed a packet of self-report questionnaires, including the Beck Depression Inventory, McGill Pain Questionnaire, and Sickness Impact Profile.

RESULTS

Results of path analyses indicated that both somatic and cognitive symptoms of depression significantly correlate with psychosocial functioning even after controlling for the effects of pain level, trait anxiety, and trait anger. Somatic symptoms of depression were significantly correlated with physical functioning after pain level, anxiety and anger were controlled.

CONCLUSIONS

This study indicates that depression is directly related to both the physical and the psychosocial functioning of facial pain patients, while self-reported level of pain is not. A better understanding of the impact of depression on chronic pain and the relationship of these two disorders could lead to improved assessment and treatment of chronic pain disorders.

Catastrophizing, depression and the sensory, affective and evaluative aspects of chronic pain

Research has shown that catastrophizing is related to increased depression and chronic pain. However, some researchers have questioned the utility of catastrophizing as a separate construct, suggesting that it may just be a symptom of depression. The present investigation used path analysis to determine if catastrophizing was related to McGill Pain Questionnaire scores when controlling for depression as assessed by the Beck Depression Inventory in a group of 85 chronic pain patients. According to Fields' model of the relationship between pain and depression, we predicted that catastrophizing would mediate the the relationship between depression and the evaluative and affective aspects of pain, but not the sensory aspect. The resulting path coefficients appear to support these predictions. The results suggest that catastrophizing is a separate construct which may impact on pain perception and treatment. The data also provide some support for Field's neurobiological model of the relationship between depression and pain.