Evidence for a motor mechanism of pain-induced aggression instigation in humans

The automatic skeletal motor responses of 20 male and 20 female student subjects (aged 20–36) receiving a painful stimulation (electric shock) were studied by examining voluntary concomitant extensions and flexions of the arm. These movements were either of long duration, allowing for an on-line control of their execution or, of short duration, requiring extensive pre-programming. Subjects were instructed either to push or to pull a lever upon receipt of an acoustic signal, which was paired or unpaired with an electric shock. Latencies for long duration movements (regardless of direction) were reduced by reception of painful stimulation. Latencies of short duration extensions and flexions were respectively reduced and increased by painful stimulation. Latencies of short duration movements were larger for females than males, regardless of movement direction. These data suggest that painful stimulation elicits automatic movements which affect programming of the termination of simultaneous voluntary movements. Implications of these findings for the study of aggressive behavior are discussed. © 1994 Wiley-Liss, Inc.     

Alterations in shock-induced fighting and locomotor activity following intracerebroventricular injection of hydrocortisone in the rat

Three experiments were conducted in an attempt to clarify the facilitatory influence of hydrocortisone on shock-induced fighting in rats. Results of the first experiment indicated a biphasic, dose-dependent action of intraventricularly-administered hydrocortisone. Low (25 μg) and intermediate (50 μg) doses both facilitated fighting whilst the high (100 μg) dose exerted a potent suppressant effect. Two control tests were performed to determine whether alterations in pain reactivity or locomotor activity could have accounted for the observed changes in fighting behaviour. None of the treatments altered shock thresholds (Experiment 2) but whilst neither low nor intermediate doses affected activity measures, the high dose preferentially reduced vertical activity (Experiment 3).     

Acceptance-based treatment for persons with complex, long standing chronic pain: a preliminary analysis of treatment outcome in comparison to a waiting phase

The concept of acceptance is receiving increased attention as an alternate approach to the suffering that is often associated with persistent and disabling pain. This approach differs from established treatments in that it does not principally focus on reducing pain, but on reducing the distressing and disabling influences of pain as they concern important areas in patients' lives. The present analyses represent a preliminary evaluation of an acceptance-based approach to chronic pain within an interdisciplinary treatment program. One hundred and eight patients with complex chronic pain conditions completed treatment and provided data for the current study. Treatment was conducted in a 3- or 4-week residential or hospital-based format. It included a number of exposure-based, experiential, and other behavior change methods focused on increasing (a) engagement in daily activity regardless of pain and (b) willingness to have pain present without responding to it. Significant improvements in emotional, social, and physical functioning, and healthcare use were demonstrated following treatment. The majority of improvements continued at 3-months post-treatment. Improvements in most outcomes during treatment were correlated with increases in acceptance, supporting the proposed process of treatment.     

MMPI-2 subgroups in a sample of chronic pain patients

MMPI-2 scores of 307 female and 161 male chronic pain patients were analyzed by gender using a multivariate clustering method. Two subgroups were found for both sexes replicating previous results. The major subgroup corresponded to the classical "Conversion V" and the minor corresponded to the "Generally elevated" profile. The results also indicated a satisfactory internal consistency and a high discriminant validity of the Swedish version of the MMPI-2.     

The Family Impact of Pain Scale: Preliminary Validation

A new questionnaire, the Family Impact of Pain Scale (FIPS), was designed in order to assess the effects of chronic pain on the significant other and family of the chronic pain patient. The FIPS is a 10-item self-report questionnaire examining the effect of pain on domestic duties, social functioning and communication within the family. It was administered to 177 chronic pain patients in two different samples to investigate its psychometric properties. Internal reliability (α = .94) and test–retest reliability (r = 0.79) were high. Exploratory factor analysis suggested a two-factor solution, relating to physical limitations and difficulties with communication. Construct validity was confirmed by significant Pearson correlations with pain intensity, pain distress, mood and the use of pain coping skills (r = −0.22–0.74, all at p < .05). Outcome data also showed that the measure is sensitive to the effects of a cognitive behavioural pain management intervention.     

Adjustment to chronic low back pain--the relative influence of fear-avoidance beliefs, catastrophizing, and appraisals of control

The present study investigated the relative extent to which patients' adjustment to chronic low back pain (CLBP) was influenced by their fear-avoidance beliefs, their tendency to catastrophize, and their appraisals of control. Eighty-three CLBP patients completed a series of self-report measures before participating in a physical therapist-led intervention. Hierarchical multiple regression analyses revealed that patients' perceptions of their ability to decrease pain explained a small, but statistically significant, proportion of the variance in pain intensity. In addition, patients' levels of catastrophizing, as well as their fear-avoidance beliefs about both work and physical activity, were independently associated with levels of disability. Interestingly, however, when exploring the relative predictive utility of these three psychological factors, it became evident that fear-avoidance beliefs about physical activity (FABs-PA) were the only significant predictor of patients' disability. Specifically, those patients who exhibited higher levels of FABs-PA tended to report greater levels of disability, even after adjusting for age, sex and pain intensity.     

Pain coping and social support as predictors of long-term functional disability and pain in early rheumatoid arthritis

Pain-related avoidance factors and social resources, as assessed by pain coping and social support, are supposed to have lasting effects on functional disability and pain in chronic pain disorders. As a follow-up to a prospective study demonstrating short-term effects after one year (Behaviour Research and Therapy, 36, 179-193, 1998), the role of pain coping and social support at the time of diagnosis was investigated in relationship to the long-term course of functional disability and pain after three and five years in 78 patients with rheumatoid arthritis (RA), taking into account personality characteristics of neuroticism and extraversion, clinical status and use of medication. In line with findings at the one-year follow-up, results showed that more passive pain coping predicted functional disability at the three-year, but not the five-year follow-up. In addition, low levels of social support at the time of diagnosis consistently predicted both functional disability and pain at the three and five-year follow-ups. Results indicate that pain coping and social support, assessed very early in the disease process, can affect long-term functional disability and pain in RA, and suggest that early interventions focusing on pain-related avoidance factors and social resources for patients at risk may beneficially influence long-term outcomes in RA.     

Pain anxiety among chronic pain patients: specific phobia or manifestation of anxiety sensitivity?

Rather than viewing anxiety among chronic pain patients as simply a component of negative affectivity, investigators have developed a model of "pain anxiety" in which patients develop fear and avoidance of activity linked to pain. We examined whether pain anxiety can be conceptualized as a specific phobia, or whether evidence supported the notion that pain anxiety is better understood as a manifestation of anxiety sensitivity in the context of chronic pain. Chronic musculoskeletal pain patients (N=70) underwent cold pressor and mental arithmetic tasks while cardiovascular, self-report, and behavior indexes were recorded. They completed measures of pain anxiety, anxiety sensitivity, fear of negative evaluation, depression and trait anxiety. Correlation analyses showed pain anxiety was related to pain-relevant responses during cold pressor, but it was also related to evaluation-relevant responses during cold pressor, and to pain- and evaluation-relevant responses (including subtraction accuracy) during mental arithmetic. Regression analyses showed that almost all effects of pain anxiety on task responses were accounted for by anxiety sensitivity. Fear of negative evaluation, in contrast, correlated only with evaluation-relevant responses, and mostly during mental arithmetic. These effects remained significant when depression, trait anxiety, or anxiety sensitivity were statistically controlled. Pain anxiety may be an expression of anxiety sensitivity rather than a circumscribed phobia; a distinction that could profitably guide treatment strategies.     

Pain and Pain-Related Impairment in Adults with Cystic Fibrosis

The Multidimensional Pain Inventory (MPI) was utilized in a sample of adult outpatients with cystic fibrosis (CF) to assess their perception of pain and its psychosocial consequences. Subsequently, the data were compared to the ratings of pain and pain-related impairment in these patients as perceived by two nurses from the CF treatment team, as well as to a quantitative measure of illness severity. The results of these comparisons demonstrate that the majority of adult outpatients with CF reported experiencing lower levels of pain and pain-related impairment than expected, although the male patients tend to report experiencing significantly less impact in these domains than do the female patients. Additionally, the nurses do not underestimate the degree to which patients, especially males, experience pain and pain-related interference from chronic illness. Finally, there was no significant relationship between patients' self-report of pain severity or pain-related interference and an objective measure of disease severity.