Filling the glass: Effects of a positive psychology intervention on executive task performance in chronic pain patients.

BACKGROUND: Chronic pain is associated with emotional problems as well as difficulties in cognitive functioning. Prior experimental studies have shown that optimism, the tendency to expect that good things happen in the future, and positive emotions can counteract pain-induced task performance deficits in healthy participants. More specifically, induced optimism was found to buffer against the negative effects of experimental pain on executive functioning. This clinical experiment examined whether this beneficial effect can be extended to a chronic pain population. METHODS: Patients (N = 122) were randomized to a positive psychology Internet-based intervention (PPI; n = 74) or a waiting list control condition (WLC; n = 48). The PPI consisted of positive psychology exercises that particularly target optimism, positive emotions and self-compassion. RESULTS: Results demonstrated that patients in the PPI condition scored higher on happiness, optimism, positive future expectancies, positive affect, self-compassion and ability to live a desired life despite pain, and scored lower on pain catastrophizing, depression and anxiety compared to patients in the WLC condition. However, executive task performance did not improve following completion of the PPI, compared to the WLC condition. CONCLUSIONS: Despite the lack of evidence that positive emotions and optimism can improve executive task performance in chronic pain patients, this study did convincingly demonstrate that it is possible to increase positive emotions and optimism in chronic pain patients with an online positive psychology intervention. It is imperative to further explore amendable psychological factors that may reduce the negative impact of pain on executive functioning. SIGNIFICANCE: We demonstrated that an Internet-based positive psychology intervention strengthens optimism and positive emotions in chronic pain patients. These emotional improvements are not associated with improved executive task performance. As pain itself often cannot be relieved, it is imperative to have techniques to reduce the burden of living with chronic pain.

Yoga and immune system functioning: a systematic review of randomized controlled trials.

Yoga is an ancient mind-body practice that is increasingly recognized to have health benefits in a variety of clinical and non-clinical conditions. This systematic review summarizes the findings of randomized controlled trials examining the effects of yoga on immune system functioning which is imperative to justify its application in the clinic. Fifteen RCTs were eligible for the review. Even though the existing evidence is not entirely consistent, a general pattern emerged suggesting that yoga can downregulate pro-inflammatory markers. In particular, the qualitative evaluation of RCTs revealed decreases in IL-1beta, as well as indications for reductions in IL-6 and TNF-alpha. These results imply that yoga may be implemented as a complementary intervention for populations at risk or already suffering from diseases with an inflammatory component. Beyond this, yoga practice may exert further beneficial effects by enhancing cell-mediated and mucosal immunity. It is hypothesized that longer time spans of yoga practice are required to achieve consistent effects especially on circulating inflammatory markers. Overall, this field of investigation is still young, hence the current body of evidence is small and for most immune parameters, more research is required to draw distinct conclusions.

Expectations about the effectiveness of pain- and itch-relieving medication administered via different routes.

BACKGROUND: Placebo effects on pain have been found to vary in size for different routes of medication administration (e.g. oral vs. injection). This has important implications for both clinical research and practice. To enhance our understanding of these differential placebo effects, research on the underlying expectations about multiple routes and symptoms other than pain is vital. METHODS: A cross-sectional, Internet-based survey was conducted in a representative sample of the Dutch population (n = 508). Respondents rated the expected effectiveness of pain- and itch-relieving medication in six forms, representing oral, injection and topical routes of administration. RESULTS: Injected medication was expected to be most effective for relieving pain, and topical medication for relieving itch. Furthermore, exploratory analyses showed that injections were expected to have the most rapid onset and long-lasting effects, and to be most frightening and expensive, while topical medication was expected to be the safest and the easiest to use, and oral medication was expected to have the most side effects. Higher expected effectiveness was moderately associated with expectations of more rapid onset and long-lasting effects, and better safety and ease of use. Associations of expected effectiveness with respondent characteristics (e.g. medication use and personality characteristics) were statistically small or nonsignificant. CONCLUSIONS: Expected effectiveness of medication differed depending on route of administration and targeted symptom. These findings have important implications for the design and interpretation of clinical trials and suggest that medication effects might be enhanced by prescribing medicine via the route that patients expect to be most effective for their complaint. SIGNIFICANCE: Differences in the expected effectiveness of medication depend on the route of administration (oral, injection, topical) and targeted symptom (pain, itch). These findings have important implications for clinical practice and the design and interpretation of clinical trials.

The current total economic burden of diabetes mellitus in the Netherlands.

INTRODUCTION AND AIM: Insight into the total economic burden of diabetes mellitus (DM) is essential for decision makers and payers. Currently available estimates for the Netherlands only include part of the total burden or are no longer up-to-date. Therefore, this study aimed to determine the current total economic burden of DM and its complications in the Netherlands, by including all the relevant cost components. METHODS: The study combined a systematic literature review to identify all relevant published information and a targeted review to identify relevant information in the grey literature. The identified evidence was then combined to estimate the current total economic burden. RESULTS: In 2016, there were an estimated 1.1 million DM patients in the Netherlands, of whom approximately 10% had type 1 and 90% had type 2 DM. The estimated current total economic burden of DM was € 6.8 billion in 2016. Healthcare costs (excluding costs of complications) were € 1.6 billion, direct costs of complications were € 1.3 billion and indirect costs due to productivity losses, welfare payments and complications were € 4.0 billion. CONCLUSION: DM and its complications pose a substantial economic burden to the Netherlands, which is expected to rise due to changing demographics and lifestyle. Indirect costs, such as welfare payments, accounted for a large portion of the current total economic burden of DM, while these cost components are often not included in cost estimations. Publicly available data for key cost drivers such as complications were scarce.

Placebo-like analgesia via response imagery.

BACKGROUND: Placebo effects on pain are reliably observed in the literature. A core mechanism of these effects is response expectancies. Response expectancies can be formed by instructions, prior experiences and observation of others. Whether mental imagery of a response can also induce placebo-like expectancy effects on pain has not yet been studied systematically. METHODS: In Study 1, 80 healthy participants were randomly allocated to (i) response imagery or (ii) control imagery. In Study 2, 135 healthy participants were randomly allocated to (i) response imagery with a verbal suggestion regarding its effectiveness, (ii) response imagery only, or (iii) no intervention. In both studies, expected and experienced pain during cold pressor tests were measured pre- and post-intervention, along with psychological and physiological measures. RESULTS: Participants rated pain as less intense after response imagery than after control imagery in Study 1 (p = 0.044, ηp2 = 0.054) and as less intense after response imagery (with or without verbal suggestion) than after no imagery in Study 2 (p < 0.001, ηp2 = 0.154). Adding a verbal suggestion did not affect pain (p = 0.068, ηp2 = 0.038). The effects of response imagery on experienced pain were mediated by expected pain. CONCLUSIONS: Thus, in line with research on placebo effects, the current findings indicate that response imagery can induce analgesia, via its effects on response expectancies. SIGNIFICANCE: The reported studies extend research on placebo effects by demonstrating that mental imagery of reduced pain can induce placebo-like expectancy effects on pain.

Are individual levels of pain anxiety related to negative interpretation bias? An examination using an ambiguous word priming task.

BACKGROUND: Cognitive processes like attentional and interpretation biases have been suggested to play a vital role in the onset and exacerbation of chronic pain. Research consistently supports the occurrence of interpretation bias (IB) in pain patients and healthy individuals high in pain anxiety. Nevertheless, studies on the indirect assessment of IB or the relation between IB and responses to pain are limited. The present studies examined the association between indirect assessed IB and pain anxiety, while Study 2 additionally examined IB as a mediator in the relation between pain anxiety and pain responses. METHOD: In Study 1 (N = 125) and Study 2 (N = 73), anxiety sensitivity, injury/illness sensitivity (IS) and pain catastrophizing were assessed with questionnaires. IB was indirectly derived from performance on an ambiguous word priming task. In Study 2, an experimental heat pain induction was used to assess pain responses (i.e. tolerance and subjective pain experience). RESULTS: Results showed a positive correlation between pain anxiety and IB, albeit that the strength of the observed associations differed between both studies. Furthermore, IB was inversely related to pain tolerance, and found to mediate the relation between IS and pain tolerance in Study 2. CONCLUSIONS: Current findings underscore the importance of interpretational processes in the context of physical health threat. Furthermore, the ambiguous word priming task is proposed as a suitable paradigm for further research on the indirect assessment of IB. Nevertheless, further research is warranted to deepen our understanding of IB and its contribution to the experience of (chronic) pain.

Predictors of physical and emotional recovery 6 and 12 months after surgery.

BACKGROUND: A proportion of patients do not recover fully from surgery or they develop chronic postsurgical pain. The aim of this study was to examine the incidence and predictors of unfavourable long-term outcome after surgery using a prospective cohort design. METHODS: Some 401 patients undergoing various elective surgical procedures filled in the RAND 36-item Health Survey 1.0 health-related quality-of-life questionnaire before operation and at 6 and 12 months of follow-up to assess changes in pain, physical functioning, mental health and vitality. Preoperative psychological assessment was obtained. RESULTS: Most patients showed improvement in the various aspects of health-related quality of life after surgery, but a considerable proportion (14-24 per cent) still showed deterioration at 6 and 12 months. Multivariable linear regression analysis identified acute postoperative pain, duration of the operation and preoperative physical condition as the most important predictors of long-term pain and physical functioning. Preoperative surgical fear also had a small but significant contribution. The main predictors of mental health and vitality were physical condition before surgery, surgical fear and optimism. CONCLUSION: Up to a quarter of patients experienced suboptimal recovery after surgery. Both somatic and psychological factors were associated with the long-term outcome. Optimal recovery could be promoted by effective interventions on malleable factors.

The prevalence of postoperative pain in a sample of 1490 surgical inpatients.

BACKGROUND AND OBJECTIVE: To measure the prevalence of postoperative pain, an assessment was made of 1490 surgical inpatients who were receiving postoperative pain treatment according to an acute pain protocol. METHODS: Measurements of pain (scores from 0 to 100 on a visual analogue scale) were obtained three times a day on the day before surgery and on days 0-4 postoperatively; mean pain intensity scores were calculated. Patients were classified as having no pain (score 0-5), mild pain (score 6-40), moderate pain (score 41-74) or severe pain (score 75-100). RESULTS: Moderate or severe pain was reported by 41% of the patients on day 0, 30% on days 1 and 19%, 16% and 14% on days 2, 3 and 4. The prevalence of moderate or severe pain in the abdominal surgery group was high on postoperative days 0-1 (30-55%). A high prevalence of moderate or severe pain was found during the whole of days 1-4 in the extremity surgery group (20-71%) and in the back/spinal surgery group (30-64%). CONCLUSION: We conclude that despite an acute pain protocol, postoperative pain treatment was unsatisfactory, especially after intermediate and major surgical procedures on an extremity or on the spine.

Dutch version of the Pain Vigilance and Awareness Questionnaire: validity and reliability in a pain-free population.

The current study examined validity and reliability of the Pain Vigilance and Awareness Questionnaire (PVAQ) in two samples of healthy college students. Exploratory and confirmatory factor analysis showed that a two-factor model of the PVAQ was most suitable in the present study. The first factor could be referred to as attention to pain whereas the second factor could be specified as attention to changes in pain. With regard to the convergent and divergent validity, the PVAQ was found to correlate highly with related constructs like catastrophising (PCS) and general body vigilance (BVQ). The correlation between PVAQ and pain-related fear (FPQ) was moderate, whereas correlations with unrelated constructs like trait anxiety (STAI-T) and fear of spiders (FSQ) were low. Furthermore, the PVAQ showed good internal consistency and fair test-retest reliability. Altogether, these findings suggest that the PVAQ is a valid and reliable measure of pain vigilance in healthy individuals. The results of this study can be regarded as a starting point for further validation of the PVAQ in clinical pain populations. Implications for future research and treatment interventions are discussed.

Role of alendronate and risedronate in preventing and treating osteoporosis.

Alendronate and risedronate, the two oral bisphosphonates approved in the United States for preventing and treating osteoporosis, have never been compared in direct head-to-head trials, but they appear to have similar pharmacokinetics, drug interactions, adverse effect profiles, and efficacy. Alendronate, however, can be given as a once-weekly dose, whereas risedronate is not yet available in this dosage form. On the other hand, alendronate is not approved for preventing glucocorticoid-induced osteoporosis, whereas risedronate carries this indication.

Insecticidal proteins from Bacillus thuringiensis protect corn from corn rootworms.

Field tests of corn co-expressing two new delta-endotoxins from Bacillus thuringiensis (Bt) have demonstrated protection from root damage by western corn rootworm (Diabrotica virgifera virgifera LeConte). The level of protection exceeds that provided by chemical insecticides. In the bacterium, these proteins form crystals during the sporulation phase of the growth cycle, are encoded by a single operon, and have molecular masses of 14 kDa and 44 kDa. Corn rootworm larvae fed on corn roots expressing the proteins showed histopathological symptoms in the midgut epithelium.

The effects of failure feedback and pain-related fear on pain report, pain tolerance, and pain avoidance in chronic low back pain patients.

The aim of this study was to investigate the influence of non-pain-related failure experiences and pain-related fear on pain report, pain tolerance and pain avoidance in chronic low back pain (CLBP) patients. Moreover, the mediating and moderating role of negative affectivity (trait-NA) in the relationship between failure experiences and pain was examined. Seventy-six patients were divided into high and low pain-related fear groups and within each group they were randomly assigned to the failure or success feedback condition. In the first part of the study patients completed a 'social empathy test' and experimenter 1 subsequently delivered false failure or success feedback. A second experimenter, who was blind for the condition, subsequently administered two lifting tasks in order to obtain measures of pain report, tolerance and avoidance. Failure feedback did have an effect on pain avoidance but unexpectedly, and not as hypothesized, pain avoidance was reduced instead of enhanced. With regard to pain report and pain tolerance similar patterns were found, but these were not statistically significant. The effect of failure feedback on pain avoidance was moderated by trait-NA. Only in the subgroup of patients who scored low on trait-NA did failure feedback decrease pain avoidance. State-NA did not mediate the effects of feedback. In line with previous findings, pain-related fear resulted in lower pain tolerance. Moreover, this study was the first to show that pain-related fear predicted higher pain report in CLBP patients. Pain-related fear did not predict pain avoidance when pre-lifting pain and gender were controlled for. Finally, pre-lifting pain turned out to be the strongest predictor with regard to all pain measures. The role of pain-related fear and unexpected findings with regard to feedback are discussed as well as some clinical implications.

Does failure hurt? The effects of failure feedback on pain report, pain tolerance and pain avoidance.

In this study an experiment was conducted to examine whether failure experiences have an effect on pain report, pain tolerance and pain avoidance. Furthermore, it was investigated if negative affectivity (NA) affected the impact of failure feedback on pain report, either as a mediator, in the case of negative state affect, or as a moderator when NA as a personality trait was considered. Fifty-four healthy female volunteers were included and randomly assigned to one of three conditions: (1) failure feedback; (2) success feedback; (3) neutral control task. After the manipulation, subjects were given a cold pressor task in order to obtain pain measures. Regarding the effects of failure feedback on pain report, it was found that, in comparison with success feedback, failure feedback led to increased pain report. With regard to pain tolerance, pain was tolerated for longer when preceded by success feedback than when preceded by failure feedback. Differences between failure and control conditions did not reach significance. With regard to pain avoidance, no differences between the conditions were found. The hypothesized mediating role of negative state affect was not found. Though in the hypothesized direction, no significant effect was found for NA-trait moderating the influence of failure on pain. The discussion focuses on a number of research questions that remain to be answered, and the clinical relevance of the effects of failure and success experiences on pain report and pain tolerance.

Electronic diary assessment of pain, disability and psychological adaptation in patients differing in duration of pain.

Computerized diary measurement of pain, disability and psychological adaptation was performed four times a day for 4 weeks in 80 patients with various duration of unexplained pain. Reported are (1) the temporal characteristics and stability of pain report during the 4-week measurement period, (2) the association between pain duration and pain report, disability and general psychopathology, and (3) the accordance between diary assessment versus questionnaire assessment of pain, disability and psychological adaptation. No evidence of instrument reactivity was found: pain report was stable across the 4-week period. However, pain report appeared to be highly variable both between and within days. About half the patients showed a clear increasing trend in pain during the day. Several differences were found between subgroups of patients varying in pain duration. Patients with less than 6 months of pain reported significantly less pain intensity, disability and fatigue than patients whose pain persisted for more than 6 months. Pain coping and responses to pain behaviors by the spouse also differed for the subgroups: longer pain duration was associated with increased catastrophizing and solicitous responses from the spouse. Comparison of scores obtained with diary versus questionnaire assessment indicated moderate correlations for most variables. Retrospective (questionnaire) assessment of pain intensity yielded significantly higher pain scores than diary assessment.

Immune responses to experimental stress: effects of mental effort and uncontrollability.

OBJECTIVE: Two important determinants of physiological stress responses have been identified, uncontrollability of the stressor and amount of effort involved in coping with the stressor. In the present experiment, we tried to identify the specific contributions of effort and uncontrollability to immune system responses to stress. METHODS: In a 2 x 2 design, effort and uncontrollability were manipulated independently of each other. Subjects participated in one of four experimental conditions, and their endocrine, immune, and sympathetic nervous system responses to the task were assessed. RESULTS: Effort had a stimulating effect on enumerative immunological parameters (CD8 and CD16+ cells) and on natural killer cell activity. The effect occurred immediately after the stressor and was transient. Regression models indicated that this effort effect may have been mediated by activation of the sympathetic nervous system. Uncontrollability influenced in vitro production of the cytokine interleukin-6, leading to decreased production 15 and 30 minutes after the stressor. Uncontrollability also led to an increased level of cortisol, but no evidence was found that the decrease in cytokine production was mediated by cortisol release. CONCLUSION: The results suggest that two major stressor characteristics, effort and uncontrollability, may have differential effects on the immune system.

Does carbohydrate-rich, protein-poor food prevent a deterioration of mood and cognitive performance of stress-prone subjects when subjected to a stressful task?

This study investigates whether in stress-prone subjects, carbohydrate-rich, protein-poor food (CR/PP) prevents a deterioration of mood and performance under uncontrollable laboratory stress conditions. The assumption was that in stress-prone subjects there is a higher risk of serotonin deficiency in the brain and that carbohydrates may prevent a functional shortage of central serotonin during acute stress, due to their potentiating effect on brain tryptophan. Twenty-four subjects with a high stress-proneness (HS) and 24 subjects with a low stress-proneness (LS) participated in an uncontrollable stress situation under both a CR/PP and a protein-rich, carbohydrate-poor (PR/CP) diet condition. The plasma ratio of tryptophan to the other large neutral amino acids (LNAA) (ratio Tryptophan/ summation operatorLNAA) was determined as a measure indicating the dietary effect on brain tryptophan and serotonin levels. Significant increases were found in the ratio tryptophan/ summation operatorLNAA during the CR/PP diet compared with the PR/CP diet. Experimental stress had significant effects on pulse rate, skin conductance, cortisol and mood in all subjects. During the CR/PP diet only the HS subjects did not show the stress-induced rise in depression, decline in vigour and cortisol elevation that they showed after the PR/CP diet. With respect to cognitive performance, significant dietary effects were found on reaction time. It is suggested that CR/PP food in HS subjects may increase personal control, probably under the influence of higher levels of brain tryptophan and serotonin.

Cardiovascular and endocrine responses to experimental stress: effects of mental effort and controllability.

The objective of the study was to investigate the unique and interactive effects of the controllability of a task and mental effort required by that task on cardiovascular and endocrine reactivity, when both were manipulated independently. A 2 x 2 factorial design was used, with two levels of mental effort and two levels of control. Twenty-four healthy male subjects participated in each experimental condition. Heart rate, blood pressure, catecholamine and cortisol responses were determined. High effort lead to greater increases in heart rate, blood pressure and norepinephrine levels. Uncontrollability lead to higher cortisol, blood pressure and norepinephrine responses. In addition, there was an effort x control interaction effect on the diastolic blood pressure response. In conclusion, effort has clear sympathetic effects, whereas control influences both the sympathetic nervous system and the release of cortisol. Having control seems to be most beneficial in high effort situations, at least with respect to sympathetic reactivity.

Apparent amnesia on experimental memory tests in dissociative identity disorder: an exploratory study.

Dissociative identity disorder (DID; called multiple personality disorder in DSMIII-R) is a psychiatric condition in which two or more identity states recurrently take control of the person's behavior. A characteristic feature of DID is the occurrence of apparently severe amnestic symptoms. This paper is concerned with experimental research of memory function in DID and focuses on between-identity transfer of newly learned neutral material. Previous studies on this subject are reviewed and a pilot study with four subjects is described. This study is specifically concerned with the question whether self-reported asymmetries in between-identity transfer can be replicated on experimental memory tests. A secondary aim was to examine whether, in the absence of explicit transfer, implicit transfer of information would occur. The results showed that the apparent amnestic asymmetry for explicit information was substantiated in the laboratory, although at least some leakage was present between the apparently amnestic identities. No evidence was found for better performance on implicit than on explicit memory tests in the apparently amnestic identities. In the discussion, parallels between apparent amnesia in DID and state-dependent memory are drawn, and the question of simulated amnesia is addressed.

Direction of temperature control in the thermal biofeedback treatment of vascular headache.

In order to test for the specific therapeutic effects of thermal biofeedback (TBF) for hand warming on vascular headache (HA), 70 patients with chronic vascular HA were randomly assigned to TBF for hand warming, TBF for hand cooling, TBF for stabilization of hand temperature, or biofeedback to suppress alpha in the EEG. Patients in each condition initially had high levels of expectation of therapeutic benefit and found the treatment rationales highly credible. Participants in each condition received 12 treatment sessions on a twice-per-week basis. Based on daily HA diary data gathered for 4 weeks prior to treatment and 4 weeks after treatment, HA Index was significantly (p = .003) reduced as was HA medication consumption. There were no differential reductions in HA Index or Medication Index among the four conditions. Global self-reports of improvement gathered at the end of the post-treatment monitoring period also did not differ among the four conditions. We were unable to demonstrate a specific effect of TBF for hand warming on vascular HA activity.

Diminished autonomic nervous system responsiveness in rheumatoid arthritis of recent onset.

OBJECTIVE: To investigate responsiveness of the autonomic nervous system in rheumatoid arthritis (RA) of recent onset. METHODS: 21 patients (17 women, mean age 55.7 years) and 20 healthy controls (16 women, mean age 52.7 years) were subjected to 4 tasks eliciting divergent autonomic reactions: film watching, mild physical exercise, cognitive discrimination, and the Stroop color-word interference test. Changes in heart rate, diastolic (DBP) and systolic (SBP) blood pressure, and skin conductance relative to pretask baseline values were computed and related to erythrocyte sedimentation rate, pain, mobility, and dexterity. RESULTS: Mean autonomic levels of patients were normal, as well as autonomic responses to film watching and mild physical exercise. Diminished autonomic responses were observed during cognitive discrimination and during the Stroop test. Blood pressure responses were negatively related to pain severity, but positively to impaired dexterity. CONCLUSION: Diminished autonomic nervous system response is observed in RA of recent onset, most clearly in patients with more severe pain. This suggests that it is associated with primary pathophysiological mechanisms.