A double blind randomised controlled clinical trial on the effect of transcutaneous spinal electroanalgesia (TSE) on low back pain

A double blind randomised controlled clinical trial on the effect of transcutaneous spinal electroanalgesia (TSE) on low back pain was carried out in 58 patients attending a Pain Management Unit. Four TSE instruments, two active and two sham, were used and each patient was assigned randomly to one of these. Low back pain was rated by each patient using a visual analogue scale (VAS) immediately before and immediately after a single 20min treatment of TSE and also daily for the week prior to, and the week following, the treatment. No significant difference in mean pain score was detected between the active and sham treated groups immediately after treatment or during the subsequent week. The Hospital, Anxiety and Depression scale (HAD) and the General Health Questionnaire (GHQ) were completed by each patient and there was a positive correlation between the scores achieved on these scales and the mean pain scores in both the active and sham treated groups. A post‐trial problem was the discovery that the specification of the two active TSE machines differed from the manufacturer's specification. Thus, the output frequencies were either more (+10%) or less (?17%) while the maximum output voltages were both less (?40% and ?20%), respectively. However, additional statistical analysis revealed no significant differences between the results obtained with the two active machines.     

The effect of electroacupuncture on opioid‐like medication consumption by chronic pain patients: A pilot randomized controlled clinical trial

Opioid‐like medications (OLM) are commonly used by patients with various types of chronic pain, but their long‐term benefit is questionable. Electroacupuncture (EA) has been previously shown beneficial in reducing post‐operative acute OLM consumption. In this pilot randomized controlled trial, the effect of EA on OLM usage and associated side effects in chronic pain patients was evaluated. After a two‐week baseline assessment, participants using OLM for their non‐malignant chronic pain were randomly assigned to receive either real EA (REA, n=17) or sham EA (SEA, n=18) treatment twice weekly for 6 weeks before entering a 12‐week follow‐up. Pain, OLM consumption and their side effects were recorded daily. Participants also completed the McGill Pain Questionnaire (MPQ), SF‐36 and Beck Depression Inventory (BDI) at baseline, and at the 5th, 8th, 12th, 16th and 20th week. Nine participants withdrew during the treatment period with another three during the follow‐up period. Intention to treat analysis was applied. At the end of treatment period, reductions of OLM consumption in REA and SEA were 39% and 25%, respectively (p=0.056), but this effect did not last more than 8 weeks after treatment. There was no difference between the two groups with respect to reduction of side effects and pain and the improvement of depression and quality of life. In conclusion, REA demonstrates promising short‐term reduction of OLM for participants with chronic non‐malignant pain, but such effect needs to be confirmed by trials with adequate sample sizes.     

Psychosocial factors in chronic spinal cord injury pain.

Chronic pain is a problem among patients with spinal cord injuries, but the psychosocial factors associated with spinal cord injury (SCI) pain are not well understood. To understand SCI pain further, 54 patients (19 with quadriplegia and 35 with paraplegia) completed the Beck Depression Inventory, State-Trait Anxiety Inventory, Profile of Mood States, Acceptance of Disability Scale and SCI Interference Scale. Forty-two patients stated they had SCI pain and completed the Multidimensional Pain Inventory and the Pain Experience Scale. Results revealed that anger and negative cognitions were associated with greater pain severity. Patients who reported pain in response to a general prompt experienced more severe pain than patients who reported pain only when directly questioned about the presence of pain, but these different reporting groups did not differ on emotional variables. Those who were less accepting of their disability reported greater pain severity. Additionally, patients who perceived a significant other expressing punishing responses (e.g., expressing anger at the patients or ignoring the patients) to their pain behaviors reported more severe pain. Level of lesion, completeness of injury, surgical fusion and/or instrumentation and veteran status were not associated with pain severity. Finally, pain was associated with emotional distress over and above the distress associated with the SCI itself. Overall, psychosocial factors, not physiological factors, were most closely associated with the experience of pain. Multidimensional aspects of pain are used to explain these findings and suggest that treatment should be directed at the emotional and cognitive sequelae of chronic SCI pain.     

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.     

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.     

Psychopathology in individuals with post-traumatic headaches and other pain types

In this study, the psychological functioning of patients with chronic post-traumatic headache (PTH), chronic combination headache and chronic low back pain without headache, whose time of onset was similar, and a matched group of controls was investigated. The Symptom Checklist 90-Revised (SCL-90-R), State-Trait Anger Expression Inventory (STAXI), State-Trait Anxiety Inventory, Form Y (STAI-Y), and Beck Depression Inventory (BDI) were used to assess the degree of psychopathology. A MANOVA test indicated highly significant differences between groups. In general, the pain groups fell along a continuum with PTH subjects demonstrating the highest elevations, back pain subjects demonstrating the next highest elevations, and combination subjects demonstrating fewer elevations. A cluster analysis indicated that findings were best classified into four clusters, but no one pain diagnosis predominated in any cluster. Eighty-nine percent of controls were assigned to clusters 1 or 2, which revealed essentially normal scores on all tests. It is suggested that while chronic pain patients demonstrate more psychopathology than non-pain controls, a variety of coping styles exists within each pain group independent of diagnostic categorization.     

The impact of chronic pain on depression, sleep, and the desire to withdraw from dialysis in hemodialysis patients

Pain is a multidimensional phenomenon with physical, psychological, and social components and is a significant problem for 50% of hemodialysis (HD) patients. Failure to treat pain adequately may lead to disruption in many aspects of life. This study examines the relationship between moderate to severe chronic pain and depression, insomnia, and the desire to withdraw from dialysis in HD patients. In a cross-sectional study of 205 Canadian HD patients, patients completed a questionnaire that included the Brief Pain Inventory, Beck Depression Inventory, and the Pittsburgh Sleep Quality Index. One hundred and three patients (50.2%) reported chronic pain and 85 (41.4%), moderate to severe pain. There was a higher prevalence of depression in patients with moderate or severe chronic pain compared to patients with mild or no pain (34.1% vs. 18.3%, odds ratio [OR]=2.31, P=0.01). Severe irritability, anxiousness, and inability to cope with stress were all more common in patients with pain compared to patients without pain (P<0.001). There was a higher prevalence of insomnia in patients with moderate or severe chronic pain compared to patients with mild or no pain (74.7% vs. 53.0%, OR=2.32, P=0.02). Although consideration of withdrawal from dialysis was significantly associated with moderate or severe pain compared to no or mild pain (46% vs. 16.7%, P<0.001), death due to withdrawal from dialysis was not. Chronic pain in HD patients is associated with depression and insomnia and may predispose patients to consider withdrawal of dialysis.     

Obesity and the impact of chronic pain

OBJECTIVE: To evaluate obesity as a marker for increased pain severity, disability, and psychologic distress in treatment-seeking, mixed chronic pain patients. METHODS: Three hundred seventy-two consecutive chronic pain patients seeking evaluation at a university pain clinic were divided into 3 weight categories, based on body mass index (BMI): normal (BMI < 25 kg/m2), overweight (BMI between 25 kg/m and 30 kg/m2), and obese (BMI > or = 30 kg/m2). Patients completed questionnaires to identify pain severity, disability, depression, anxiety, and quality of life. RESULTS: Pain severity and days per week with pain were similar among the weight groups. Disability was related to increasing weight status, with increased BMI associated with more days per week with both reduced activity and complete disability. Depressive symptoms were also related to weight category, with an average Beck Depression Inventory score of 11.81 +/- 7.55 in normal, 12.88 +/- 11.64 in overweight, and 15.78 +/- 9.88 in obese patients. Anxiety scores were similar among the weight categories. Physical function domain of quality of life was also reduced in relation to weight. CONCLUSIONS: Weight is associated with co-morbid disability, depression, and reduced quality of life for physical function in chronic pain patients. Calculation of the BMI should become a routine part of the screening evaluation for chronic pain patients, with additional screening for disability and psychologic distress in patients with elevated BMIs.     

Morphine, nortriptyline and their combination vs. placebo in patients with chronic lumbar root pain

Although lumbar radicular pain is the most common chronic neuropathic pain syndrome, there have been few randomized studies of drug treatments. We compared the efficacy of morphine (15-90 mg), nortriptyline (25-100 mg), their combination, and a benztropine "active placebo" (0.25-1 mg) in patients with chronic sciatica. Each period consisted of 5 weeks of dose escalation, 2 weeks of maintenance at the highest tolerated doses, and 2 weeks of dose tapering. The primary outcome was the mean daily leg pain score on a 0-10 scale during the maintenance period. Secondary outcomes included a 6-point ordinal global pain relief scale, the Beck Depression Inventory (BDI), the Oswestry Back Pain Disability Index (ODI) and the SF-36. In the 28 out of 61 patients who completed the study, none of the treatments produced significant reductions in average leg pain or other leg or back pain scores. Pain reduction, relative to placebo treatment was, 14% for nortriptyline (95% CI=[-2%, 30%]), 7% for morphine (95% CI=[-8%, 22%]), and 7% for the combination treatment (95% CI=[-4%, 18%]). Mean doses were: nortriptyline alone, 84+/-24.44 (SD) mg/day; morphine alone, 62+/-29 mg/day; and combination, morphine, 49+/-27 mg/day plus nortriptyline, 55 mg+/-33.18 mg/day. Over half of the study completers reported some adverse effect with morphine, nortriptyline or their combination. Within the limitations of the modest sample size and high dropout rate, these results suggest that nortriptyline, morphine and their combination may have limited effectiveness in the treatment of chronic sciatica.     

Study of experimental pain measures and nociceptive reflex in chronic pain patients and normal subjects

This study evaluates (i) the effect of heterotopic chronic pain on various experimental pain measures, (ii) the relationship between experimental pain measures and chronic pain symptomatology assessment, and (iii) the influence of the various pain aetiologies on experimental pain measures. Fifty-three chronic pain patients were compared to 17 pain-free subjects with the following psychophysical and physiological indices: pain threshold (PTh), pain tolerance (PTol), verbal estimation of intensity and unpleasantness (intensity scale, IS; unpleasantness scale, US), threshold for intensity and unpleasantness (ITh and UTh), lower limb RIII nociceptive reflex (RIIITh and RIII frequency of occurrence). Chronic pain syndromes included neuropathic pain (n = 12), iodopathic pain (n = 12), myofascial syndromes (n = 9), headache (n = 9), and miscellaneous pain (n = 11). Chronic pain symptomatology was assessed with a visual analogue scale (VAS), a French MPQ adaptation (QDSA), Beck Depression Inventory (BDI), Spielberger State Trait Inventory (STAI) and Eysenck Personality Inventory (EPI). No significant difference was observed between chronic pain patients and pain-free control groups and between patient subgroups for PTh, PTol and RIIITh. No significant correlation was found between experimental pain measures and clinical pain, anxiety or depression scores. However, the chronic pain patients had a higher threshold for unpleasantness and judged the suprathreshold stimuli significantly less intense and less unpleasant than the control group. These results are discussed in relation to diffuse noxious inhibitory controls and the adaptation level theory of chronic pain experience.     

Muscle pain in myophosphorylase deficiency (McArdle's disease): the role of gender, genotype, and pain-related coping

Pain characteristics were examined in 24 patients with myophosphorylase deficiency (McArdle's disease). Pain parameters were related to mutation analyses as well as psychosocial data using a pain questionnaire including an assessment of psychosocial distress and coping measures (Beck Depression Inventory BDI; Kiel Pain Inventory KPI, Multidimensional Fatique Inventory MFI). Twenty-three patients complained of pain, which was intermittent and exercise-induced in 15 patients. Eight patients complained of permanent pain, which was superimposed by exercise-induced pain in 7 patients. Patients reported 3-7 different pain characters and various localisations. Patients with permanent pain were significantly more frequently female, experienced higher impact on general activities and sleep as well as higher scores on the MFI. Furthermore, these patients revealed higher scores regarding several psychosocial risk factors including avoidance behavior whereas patients with intermittent pain predominantly showed endurance coping. There was no correlation between age or disease duration, pain intensity as well as mutation type and development of permanent or intermittent pain. In addition, severity of the clinical phenotype did not correlate with ACE polymorphism. Although McArdle's disease is a muscle glycogenosis with marked biochemical homogeneity, the clinical presentation can be quite heterogeneous. A substantial number of patients revealed permanent pain as a major clinical symptom. As permanent pain is not related to age or disease duration, it might be a clinically important subgroup of McArdle's disease. Gender-related genetic factors as well as maladaptive pain-related coping may contribute to the development of such a chronic pain symptom.     

Early improvement during manual-guided cognitive and dynamic psychotherapies predicts 16-week remission status

This study examined the extent to which improvement from baseline to weeks 2, 3, and 4 on the Beck Depression Inventory and Beck Anxiety Inventory predict week 16 clinical remission for patients with major depressive disorder, generalized anxiety disorder, and/or obsessive-compulsive or avoidant personality disorders who were receiving manual-based psychotherapies. Logistic regression and receiver-operator characteristic analyses revealed relatively accurate identification of remitters and nonremitters based on improvement from baseline to sessions 2 to 4 in both original and cross-validation samples. Predictive success did not vary as a function of diagnosis, treatment type (cognitive or dynamic), or treatment status (short-term or long-term). The clinical implications of the results are discussed.     

Transcutaneous electrical nerve stimulation vs. transcutaneous spinal electroanalgesia for chronic pain associated with breast cancer treatments

Chronic pain associated with breast cancer treatment is becoming increasingly recognized. Patients with this condition can experience significant physical and psychological morbidity and may benefit from nonpharmacological interventions as part of a multidisciplinary team approach. We compared the effectiveness of transcutaneous electrical nerve stimulation (TENS), transcutaneous spinal electroanalgesia (TSE), and a placebo (sham TSE) in a randomized controlled trial. The study sample comprised 41 women with chronic pain following breast cancer treatment, and outcome measures included pain report, pain relief, pain interference, anxiety and depression, arm mobility, and analgesic consumption. There was little evidence to suggest that TENS or TSE were more effective than placebo. All three interventions had beneficial effects on both pain report and quality of life, a finding that may be due to either psychophysical improvements resulting from the personal interaction involved in the treatment or a placebo response. Although electrical stimulation appears to be well tolerated in this population, further research is needed to establish its effectiveness for chronic cancer treatment-related pain.     

Structure quality of independent physicians for pain management--is there a standard?

BACKGROUND: Evidence based standards for structure quality in out-patient management of chronic pain states do not exist. Therefore we tried to evaluate if german standards for outpatient management of chronic pain states which are based on opinions of experts for pain management influence the outcome quality of independent physicians for treatment of chronic low back pain. METHODS: 35 independent physicians, selected on a voluntary basis from 2100 physicians of a bavarian greater district with 1,6 Mio. inhabitants, and one outpatient treatment facility for pain patients of the university of Erlangen-Nuremberg have been evaluated by questionnaires. Questions examined certain structural conditions of the treatment facility as compared to german guidelines for outpatient treatment of pain patients ("Schmerztherapievereinbarung"). 157 patients suffering from chronic low back pain documented before and after a treatment interval of 6 months their pain intensity during the last 24 hours (numeric rating scale), the interference of pain with daily living (german version of the Brief Pain Inventory) and their quality of life (SF-36). Pre-post changes have been used as parameters for outcome quality. RESULTS: Neither baseline data nor pre-post differences of outcome parameter did correlate significantly with the scores of structure quality (17-71% of maximum) of the treatment facilities. However, multimodal therapy programs have not been used for pain management. CONCLUSIONS: Structural indicators of german guidelines for outpatient treatment of pain patients ("Schmerztherapievereinbarung") are not sufficient to improve outcome quality of patients with chronic back pain. Multimodal therapy programs have been shown to be effective in chronic back pain and should be implemented in the guidelines.     

Effects of Anodal Transcranial Direct Current Stimulation on Chronic Neuropathic Pain in Patients With Multiple Sclerosis

Neuropathic pain in patients with MS is frequent and is associated with a great interference with daily life activities. In the present study, we investigated whether anodal transcranial direct current stimulation (tDCS) may be effective in reducing central chronic pain in MS patients. Patients received sham tDCS or real tDCS in a 5-day period of treatment in a randomized, double blind, sham-controlled study. Pain was measured using visual analog scale (VAS) for pain and the short form McGill questionnaire (SF-MPQ). Quality of life was measured using the Multiple Sclerosis Quality of Life-54 scale (MSQoL-54). Depressive symptoms and anxiety were also evaluated as confounding factors using the Beck Depression Inventory (BDI) and VAS for anxiety. Evaluations were performed at baseline, immediately after the end of treatment, and once a week during a 3-week follow-up period. Following anodal but not sham tDCS over the motor cortex, there was a significant pain improvement as assessed by VAS for pain and McGill questionnaire, and of overall quality of life. No depression or anxiety changes were observed. Our results show that anodal tDCS is able to reduce pain-scale scores in MS patients with central chronic pain and that this effect outlasts the period of stimulation, leading to long-lasting clinical effects.PerspectiveThis article presents a new, noninvasive therapeutic approach to chronic, central neuropathic pain in multiple sclerosis, poorly responsive to current conventional medications. tDCS is known to cause long-lasting changes of neuronal excitability at the site of stimulation and in the connected areas in healthy subjects. This led us to hypothesize that pain decrease may be the result of functional plastic changes in brain structures involved in the pathogenesis of chronic neuropathic pain.     

Are Psychological Predictors of Chronic Postsurgical Pain Dependent on the Surgical Model? A Comparison of Total Knee Arthroplasty and Breast Surgery for Cancer

Anxiety, depression, and catastrophizing are generally considered to be predictive of chronic postoperative pain, but this may not be the case after all types of surgery, raising the possibility that the results depend on the surgical model. We assessed the predictive value of these factors for chronic postsurgical pain in 2 different surgical models: total knee arthroplasty for osteoarthritis (89 patients, 65% women, age = 69 ± 9 years, baseline pain intensity = 4.7 ± 2.1) and breast surgery for cancer (100 patients, 100% women, age = 55 ± 12 years, no preoperative pain). Data were collected before surgery, then 2 days and 3 months after surgery. Anxiety, depression, and catastrophizing were measured with the Spielberger State-Trait Anxiety Inventory, Beck Depression Inventory, and Pain Catastrophizing Scale, respectively. Pain was assessed with the Brief Pain Inventory. Neuropathic pain was detected with the DN4 questionnaire. Multivariate logistic regression analyses for the total knee arthroplasty and breast surgery models considered together indicated that the presence of clinically meaningful chronic pain at 3 months (pain intensity ≥3/10) was predicted independently by age (P = .04), pain intensity on day 2 (P = .009), and state anxiety (P = .001). Linear regression models also showed that pain magnification, one of the dimensions of catastrophizing, independently predicted chronic pain intensity (P = .04). These results were not affected by the surgical model or by the neuropathic characteristics of the pain. Thus, state anxiety and pain magnification seem to constitute psychological risk factors for chronic postsurgical pain relevant in all surgical models.PerspectiveThis prospective study performed in patients with total knee arthroplasty or breast surgery for cancer shows that state anxiety, amplification of pain, and acute postoperative pain independently predict postsurgical pain at 3 months and that this does not depend on the surgical model.     

Validation of the Turkish version of the Pain Sensitivity Questionnaire in patients with chronic pain

ObjectiveThe Pain Sensitivity Questionnaire (PSQ) is a clinically beneficial instrument that has been proven to be correlated with various experimental pain sensitivity assessments in healthy people and in patients with chronic pain. In this study, we aimed to translate the PSQ into Turkish (PSQ-T) and validate it for the measurement of pain sensitivity among Turkish people.MethodsSeventy-three patients with chronic back pain who were planning to undergo an interventional procedure completed the Brief Pain Inventory-Short Form (BPI-SF), Beck Depression Inventory (BDI), Beck Anxiety Inventory, Pain Catastrophizing Scale, and PSQ prior to their procedure. Subcutaneous infiltration of lidocaine was used as a standardized experimental pain stimulus. Pain was evaluated using a visual analog scale (VAS 1: infiltration in the hand, and VAS 2: infiltration in the procedure area)ResultsScores on the PSQ-T were significantly correlated with those on the BPI-SF. A significant positive relationship was observed between VAS 1 and VAS 2 values and the PSQ-T score, BPI pain score, and BPI interference score.ConclusionsThe PSQ-T can be used as a valid and reliable tool for the assessment of pain sensitivity in the Turkish population.     

Durchhaltestrategien—ein in Schmerzforschung und Therapie vernachlässigtes Phänomen?

Within a prospective longitudinal study of 111 patients with acute radicular pain and lumbar disc prolapse who underwent conservative or surgical treatment, we examined the importance of specific pain coping strategies, which have received little attention in psychological pain research: appeals to "stick it out" on the cognitive level and endurance strategies on the behavioural level. Prior to treatment we conducted a psychological and neurological examination. The psychological tests included the Kiel Pain Inventory (KPI) and the Beck Depression Inventory (BDI). Based on these scales we allocated patients to three groups: A (endurance strategies and positive mood;n=16), B (appeals to stick it out and depressive mood;n=20) and C (no psychological risk factors;n=40). The outcome variable was the intensity of pain (8-point self-rating scale), which was assessed prior to treatment, at the time of discharge, 1 week later and 6 months later. Additionally, 6 months later we assessed the ability to work and the attitude to application for early retirement. Results showed that patients in groups A and B had significantly more pain at the 6-month follow up than the patients in group C, who were painfree. Patients in group A were a specially high risk group: at the time of discharge they had no pain, but from the first week after discharge up to the 6-month follow up they had increasing pain. Additionally at the 6 month follow up they seemed less likely to return to work and 8 times more of them had applied for early retirement than in the groups of patients without psychological risk factors. The results suggested several suggestions for modification of medical and psychological therapy for chronic pain patients.     

Chronic low back pain, depression, and attributional style

Twenty consecutive, chronic low back pain patients admitted to our pain treatment unit completed the Attributional Style Questionnaire (an instrument that detects a cognitive style that is correlated with, and that predicts, depression) and the Beck Depression Inventory. An age, sex, and education-matched group of normal subjects, a group of patients with asymptomatic essential hypertension, and a group of patients with end-stage renal disease receiving dialysis treatment served as controls. The majority of the chronic-pain and renal-dialysis patients had elevated depression scores, whereas none of the normal subjects or hypertensive patients were outside the nondepressed range. The Attributional Style scores of the pain and renal dialysis patients were significantly deviant from the normal control group, but no more so than those of the patients with hypertension. The results of this study suggest that individuals with a chronic medical condition, either symptomatic (chronic low back pain or renal disease) or asymptomatic (essential hypertension) in nature, develop an attributional style characteristic of depression. These data neither lend support nor refute the thesis that chronic pain syndromes are a variant of, or a masked, depression. Rather, this research implies that a more important question is what identifiable risk factors (for example, attributional style) predispose patients with chronic pain to develop a depressive illness.     

Major depression and insomnia in chronic pain

OBJECTIVES: Insomnia and depression are common problems for people with chronic pain, and previous research has found that each is correlated with measures of pain and disability. The goal of this study was to examine the combined impact of major depression and insomnia on individuals with chronic pain. METHODS: The participants were patients with chronic musculoskeletal pain who underwent evaluation at an interdisciplinary treatment center. On the basis of semistructured interviews, participants were classified in three groups depending on whether they: (1) met criteria for major depression with insomnia (n = 38); (2) had insomnia without major depression (n = 58); or (3) had neither insomnia nor major depression (n = 47). The groups were then compared on self-report measures that included the McGill Pain Questionnaire, the Beck Depression Inventory, and the Multidimensional Pain Inventory. RESULTS: Participants with major depression and insomnia reported the most difficulty on measures of affective distress, life control, interference, and pain severity, although the insomniac patients without major depression also had elevated scores on some measures. In regression analyses, insomnia severity ratings did not contribute uniquely to the prediction of psychosocial problems when depression was controlled, but they did contribute to the prediction of pain severity. CONCLUSIONS: These results suggest that patients with chronic pain and concurrent major depression and insomnia report the highest levels of pain-related impairment, but insomnia in the absence of major depression is also associated with increased pain and distress.