Relaxation training and opioid inhibition of blood pressure response to stress

Stress and pain: modality-specific opioid mediation of stress-induced analgesia

Preclinical research has demonstrated that exposure to acute stress is associated with attenuated pain perception, so called stress-induced analgesia (SIA). Mechanisms of SIA in humans have not been reliably demonstrated. This study examined the role of the endogenous opioid system in the impact of combined interpersonal and mental stressors on evoked pain responses in 84 participants (34 women). Using a within-subject, double-blinded, counterbalanced design, participants were administered either oral placebo or the opioid antagonist naltrexone (50 mg) across two testing sessions. In each session, they experienced two evoked pain stimuli (cold pressor test [CPT], heat pain) after an extended rest period (rest condition) and after exposure to an acute stressor (a combination of public speaking and mental arithmetic challenge; stress condition). Results showed that both stress and opioid blockade produced significant changes in hormonal and cardiovascular measures, consistent with successful induction of acute stress. Stress was associated with attenuated pain perception (SIA) as indicated by significantly increased CPT tolerance. These effects were particularly pronounced in individuals experiencing the stress condition first. More importantly, SIA effects on CPT tolerance were abolished by opioid blockade. There were no significant SIA effects on heat pain responses. This study demonstrates that the endogenous opioid system may mediate effects of acute stress on pain perception, although this effect seems to be qualified by the type of evoked pain stimuli experienced.

Psychosocial factors predict opioid analgesia through endogenous opioid function

Use of opioid analgesics for management of chronic nonmalignant pain has become common, yet there are presently no well-validated predictors of optimal opioid analgesic efficacy. We examined whether psychosocial factors (eg, depressive symptoms) predicted changes in spontaneous low back pain after administration of opioid analgesics, and whether endogenous opioid (EO) function mediated these relationships. Participants with chronic low back pain but who were not chronic opioid users (N = 89) underwent assessment of low back pain intensity pre- and post-drug in 3 (counterbalanced) conditions: (1) placebo, (2) intravenous naloxone, and (3) intravenous morphine. Comparison of placebo condition changes in back pain intensity to those under naloxone and morphine provided indexes of EO function and opioid analgesic responses, respectively. Results showed that (1) most psychosocial variables were related significantly and positively to morphine analgesic responses for low back pain, (2) depressive symptoms, trait anxiety, pain catastrophizing, and pain disability were related negatively to EO function, and (3) EO function was related negatively to morphine analgesic responses for low back pain. Bootstrapped mediation analyses showed that links between morphine analgesic responses and depressive symptoms, trait anxiety, pain catastrophizing, and perceived disability were partially mediated by EO function. Results suggest that psychosocial factors predict elevated analgesic responses to opioid-based medications, and may serve as markers to identify individuals who benefit most from opioid therapy. Results also suggest that people with greater depressive symptoms, trait anxiety, pain catastrophizing, and perceived disability may have deficits in EO function, which may predict enhanced response to opioid analgesics.

A systematic review of sex differences in the placebo and the nocebo effect

Objectives

The present review investigated whether there are systematic sex differences in the placebo and the nocebo effect.

Methods

A literature search was conducted in multiple electronic databases. Studies were included if the study compared a group or condition where a placebo was administered to a natural history group or similar cohort.

Results

Eighteen studies were identified – 12 on placebo effects and 6 on nocebo effects. Chi-square tests revealed that 1) males responded more strongly to placebo treatment, and females responded more strongly to nocebo treatment, and 2) males responded with larger placebo effects induced by verbal information, and females responded with larger nocebo effects induced by conditioning procedures.

Conclusion

This review indicates that there are sex differences in the placebo and nocebo effects, probably caused by sex differences in stress, anxiety, and the endogenous opioid system.

Personalized medicine and opioid analgesic prescribing for chronic pain: opportunities and challenges

Use of opioid analgesics for pain management has increased dramatically over the past decade, with corresponding increases in negative sequelae including overdose and death. There is currently no well-validated objective means of accurately identifying patients likely to experience good analgesia with low side effects and abuse risk prior to initiating opioid therapy. This paper discusses the concept of data-based personalized prescribing of opioid analgesics as a means to achieve this goal. Strengths, weaknesses, and potential synergism of traditional randomized placebo-controlled trial (RCT) and practice-based evidence (PBE) methodologies as means to acquire the clinical data necessary to develop validated personalized analgesic-prescribing algorithms are overviewed. Several predictive factors that might be incorporated into such algorithms are briefly discussed, including genetic factors, differences in brain structure and function, differences in neurotransmitter pathways, and patient phenotypic variables such as negative affect, sex, and pain sensitivity. Currently available research is insufficient to inform development of quantitative analgesic-prescribing algorithms. However, responder subtype analyses made practical by the large numbers of chronic pain patients in proposed collaborative PBE pain registries, in conjunction with follow-up validation RCTs, may eventually permit development of clinically useful analgesic-prescribing algorithms.

PERSPECTIVE

Current research is insufficient to base opioid analgesic prescribing on patient characteristics. Collaborative PBE studies in large, diverse pain patient samples in conjunction with follow-up RCTs may permit development of quantitative analgesic-prescribing algorithms that could optimize opioid analgesic effectiveness and mitigate risks of opioid-related abuse and mortality.

Endogenous opioid function mediates the association between laboratory-evoked pain sensitivity and morphine analgesic responses

Predictors of responsiveness to opioid analgesic medications are not well understood. This study tested whether individual differences in endogenous opioid (EO) function are associated with analgesic responsiveness to morphine. In randomized, counterbalanced order over 3 sessions, 45 chronic low back pain participants and 31 healthy controls received an opioid antagonist (8 mg naloxone), morphine (0.08 mg/kg), or placebo. Participants then engaged in 2 laboratory-evoked pain tasks (ischemic and thermal). Outcomes included pain threshold, pain tolerance, and pain ratings. Indexes of EO function and morphine analgesic responsiveness were derived for each measure as the difference in pain responses between the placebo condition and naloxone or morphine condition, respectively. For all 7 pain measures across the 2 laboratory pain tasks, greater EO function was associated with significantly lower morphine analgesic responsiveness (P<0.001-P=0.02). Morphine reduced pain responses of low EO individuals to levels similar to those of high EO individuals receiving placebo. Higher placebo condition-evoked pain sensitivity was associated with significantly greater morphine analgesic responsiveness for 5 of 7 pain measures (P<0.001-P=0.02). These latter associations were significantly mediated by EO function for 4 of these 5 pain outcomes (all P values<0.05). In the laboratory-evoked pain context, opioid analgesic medications may supplement inadequate EO analgesia, with little incremental benefit in those with preexisting high EO function. Implications for personalized medicine are discussed.

Effects of estrogen and opioid blockade on blood pressure reactivity to stress in postmenopausal women

Estrogen may influence coronary heart disease risk in women through the effects of endogenous opioids on autonomic control of blood pressure. In a randomized, placebo-controlled trial, we examined the combined effects of estrogen and the opioid antagonist, naltrexone, on blood pressure responses to psychological stress in 42 postmenopausal women. After 3 months of estrogen or estrogen plus progestin (hormone replacement therapy; n = 27) or placebo replacement, participants completed a mental arithmetic task after administration of .7 mg/kg oral naltrexone or placebo. Systolic blood pressure (SBP), diastolic blood pressure, mean arterial pressure and heart rate (HR) were measured at rest and during the arithmetic stressor. Stress produced significant increases in circulatory measures regardless of estrogen condition or opioid blockade (p's < .001). Interestingly, there was an estrogen by naltrexone interaction on SBP reactivity scores [F(1,38) = 4.36, p < .05], where women on estrogen with intact opioid receptors showed the largest SBP responses to stress, compared with all other conditions. This is consistent with some studies of premenopausal women, suggesting that estrogens may alter opioid function during stress. The interaction between estrogen and endogenous opioids may explain sex differences in opioid effects on stress reactivity in younger premenopausal women.

What do plasma beta-endorphin levels reveal about endogenous opioid analgesic function?

Plasma levels of beta-endorphin (BE), an endogenous opioid analgesic, are often reported as they relate to acute and chronic pain outcomes. However, little is known about what resting plasma BE levels might reveal about functioning of the endogenous opioid antinociceptive system. This study directly examined associations between resting plasma BE and subsequent endogenous opioid analgesic responses to acute pain in 39 healthy controls and 37 individuals with chronic low back pain (LBP). Resting baseline levels of plasma BE were assessed. Next, participants received opioid blockade (8 mg naloxone i.v.) or placebo in a double-blind, randomized, crossover design. Participants then underwent two acute pain stimuli: finger pressure (FP) pain and ischaemic (ISC) forearm pain. Blockade effects (naloxone minus placebo pain ratings) were derived to index endogenous opioid analgesic function. In placebo condition analyses for both pain stimuli, higher resting BE levels were associated with subsequently greater reported pain intensity (p's < 0.05), with this effect occurring primarily in healthy controls (BE × Participant Type interactions, p's < 0.05). In blockade effect analyses across both pain tasks, higher resting plasma BE predicted less subsequent endogenous opioid analgesia (smaller blockade effects; p's < 0.05). For the ISC task, these links were significantly more prominent in LBP participants (BE × Participant Type Interactions, p's < 0.05). Results suggest that elevated resting plasma BE may be a potential biomarker for reduced endogenous opioid analgesic capacity, particularly among individuals with chronic pain. Potential clinical implications are discussed.

The relation of emotions to placebo responses

The hypothesis put forth is that expectations of treatment effects reduce negative emotions and thereby reduce symptoms, e.g. pain. Negative emotions increase pain, and it is hypothesized that placebos reduce pain by reducing negative emotions, i.e. feelings of nervousness, fear and anxiety. Placebo analgesia has been shown to be mediated via opioid activity, and relaxation increases opioid activity. The placebo acquires its relaxing effect due to verbal information that pain will be reduced, or due to associations between the placebo and the reduction in pain after effective treatment. Thus, the placebo signals that unpleasantness will be less after administration of the placebo. This involves negative reinforcement which is due to activation of a dopaminergic system that has been found to be activated during placebo analgesia and is involved in positive emotions. The nocebo effect of increased pain is, consistent with this model, because of increased fear and anxiety. The new aspect of the presented model is the hypothesis that expectations reduce negative emotions, and that negative reinforcement that involves the dopaminergic reinforcement system should be a contributor to placebo responses.

Comparison of two pain-management strategies during chest tube removal: Relaxation exercise with opioids and opioids alone

PURPOSE

The purpose of this study was to determine whether the use of a slow deep-breathing relaxation exercise, when used as an adjunct to opioid analgesia, decreases pain during chest tube removal (CTR) after coronary bypass surgery.

DESIGN

A two-group quasi-experimental pretest/posttest design was used.

SAMPLE

A convenience sample of 40 adults who had undergone coronary artery bypass graft surgery and met all inclusion criteria were recruited before CTR.

SETTING

Data were collected in the Cardiothoracic Surgical Intensive Care Units of three acute care facilities in the Midwestern United States.

METHOD

A 10-cm vertical Visual Analog Scale was used to measure pain at three points: before CTR, immediately after CTR, and 15 minutes after CTR. The experimental group received slow breathing relaxation exercises in addition to the usual opioid doses administered.

FINDINGS

Data were analyzed using analysis of variance, and multivariate analysis of covariance yielded a significant difference in pain ratings immediately after CTR and 15 minutes after CTR for the group receiving relaxation exercise as an adjunct to opioid analgesic.

CONCLUSIONS

This study supports the use of a slow deep-breathing relaxation exercise as an adjunct to the use of opioids for pain management during CTR among patients who have undergone coronary bypass surgery.

Effects of mental relaxation and slow breathing in essential hypertension

OBJECTIVES

To compare mental relaxation and slow breathing as adjunctive treatment in patients of essential hypertension by observing their effects on blood pressure and other autonomic parameters like heart rate, respiratory rate, peripheral skin temperature, electromyographic activity of the frontalis muscle and skin conductance.

METHODS

One hundred patients of essential hypertension either receiving antihypertensive drugs or unmedicated were selected randomly. Various parameters were recorded during the resting state and then during mental relaxation and slow breathing for 10 min each, separated by a quiet period of 15 min. All parameters were recorded again after mental relaxation and slow breathing. Changes in various parameters observed after mental relaxation and slow breathing were analyzed and compared.

RESULTS

Both mental relaxation and slow breathing resulted in a fall in systolic blood pressure, diastolic blood pressure, heart rate, respiratory rate and electromyographic activity with increase in peripheral skin temperature and skin conductance. Slow breathing caused a significantly higher fall in heart rate (p<0.05), respiratory rate (p<0.001), systolic blood pressure (p<0.05) and diastolic blood pressure (p<0.01). Increase in peripheral skin temperature (p<0.05) and reduction in electromyographic activity (p<0.05) occurred more with mental relaxation. No significant differences were seen between increases in skin conductance (p>0.2) observed with both the modalities.

CONCLUSIONS

Even a single session of mental relaxation or slow breathing can result in a temporary fall in blood pressure. Both the modalities increase the parasympathetic tone but have effects of different intensity on different autonomic parameters.

Improvement of balance between work stress and recovery after a body awareness program for chronic aspecific psychosomatic symptoms

OBJECTIVE

A 3-day residential body awareness program (BAP) was developed to teach people with chronic aspecific psychosomatic symptoms (CAPS) to react adequately to disturbances of the balance between a daily workload and the capacity to deal with it. The long-term effects of the program in improving the balance between work stress and recovery are presented in this study. The intervening effect of 'improved balance' on quality of life is also analysed.

METHODS

A pre-post design is used with post-measures at 2 and 12 months after the program, without controls (n = 122). Mean age is 42.5 years (S.D. = 9.0) and 60% of participants are female.

RESULTS

The results show participants become more active physically and socially, and at the same time take the opportunity to recover. There was a difference measured in changing balance for participants who are fully employed and participants who are not working or are working part-time due to health problems: the second group reintegrated into work, the first group spent more time socialising inside the family. Personal goals are realised by 85% of the participants. Realising personal goals and becoming more active is a mediating factor for increasing quality of life. The majority of the measured changes can be interpreted as clinically relevant outcomes with medium-to-large effect sizes. Spouses of the participants also confirm these effects.

DISCUSSION AND CONCLUSION

Evaluation of the BAP gives evidence to conclude that this program leads to long-term effects in CAPS. Participants react more adequately to disturbances between daily workload and the capacity to deal with this load. Two and 12 months after the 3-day program, they changed their behaviour to a more active lifestyle and increased self-management in coping with stress and psychosomatic symptoms.

PRACTICE IMPLICATIONS

By paying more attention to the balance between work stress and recovery, patient educators may be able to increase their effectiveness. Personal goal realization can be effective in guiding people by getting them out of the negative spiral.

The long-term lasting effectiveness on self-efficacy, attribution style, expression of emotions and quality of life of a body awareness program for chronic a-specific psychosomatic symptoms

OBJECTIVE

A 3-day residential body awareness program (BAP) was developed to teach people with chronic a-specific psychosomatic symptoms (CAPS) to react adequately to disturbances of the balance between a daily workload and the capacity to deal with it. The long-term effects of the program on body awareness, psychological factors, psychosomatic symptoms and quality of life for people with CAPS are presented in this study.

METHODS

A pre-post design is used with post-measures 2 and 12 months after the program, without controls (n = 122). Mean age is 42.5 (S.D. = 9.0) and 60% is female.

RESULTS

The results showed an increase of body awareness, self-efficacy, expression of emotions and quality of life. Stress-related symptoms decreased and the attribution style was found to be less depressive. Participants achieved significantly higher levels of functioning at 2 months which increased significantly more at 12 months. The majority of the measured changes can be interpreted as clinically relevant outcomes with medium-to-large effect sizes. Spouses of the participants also confirm the found effects.

DISCUSSION AND CONCLUSION

Evaluation of the BAP gives evidence to conclude that this program leads to the theoretically expected long-term effects in CAPS. Participants react more adequately to disturbances between daily workload and the capacity to deal with this load. Two and 12 months after the 3-day program, they are more capable of self-management in coping with stress and psychosomatic symptoms.

PRACTICE IMPLICATIONS

This article sheds new light on the difficulties that individuals with psychosomatic symptoms and their professional interventionists encounter when attempting to manage the chronicity of the problems. By paying more attention to learning self-management by increasing body awareness and self-efficacy, patient educators may be able to increase their effectiveness.

The short-term effects of a body awareness program: better self-management of health problems for individuals with chronic a-specific psychosomatic symptoms

A three-day residential Body Awareness Program (BAP) was developed to teach people with Chronic A-specific Psychosomatic Symptoms (CAPS) to react adequately to disturbances of the balance between a daily workload and the capacity to deal with it. The short-term effects of the program for people with CAPS are presented in this study. The design is a non-control group design with pre- and post-measures (2 months after the program). The sample for this paper was formed by 187 participants. The mean age is 42.3 (S.D. = 8.9), and 57% is female. The results showed decreased stress-related symptoms, increased quality of life, increased self-efficacy, less depressive attribution style, more expression of emotions, and a positive change of lifestyle. Most of these measured changes can be interpreted as clinically relevant outcomes with medium-to-large effect sizes. Personal pre-training goals were attained by 85% of the participants. Spouses also confirmed the found effects. Evaluation of the BAP gives enough evidence to conclude that this program leads to positive effects in CAPS. Participants react more adequately to disturbances between daily workload and the capacity to deal with this load. They are more capable of self-management in coping with stress and psychosomatic symptoms. Conclusions are drawn about the prevention by early interventions for patients with a-specific physical symptoms.

Anger management style, blood pressure reactivity, and acute pain sensitivity: evidence for "Trait x Situation" models

BACKGROUND

Anger management style is related to acute and chronic pain, but it is not clear whether anger arousal is needed for these associations to emerge or whether physiological mechanisms mediate these links.

PURPOSE

"Trait x Situation" models were examined to determine whether relationships between anger-out and pain and anger-in and pain depended on anger provocation's preceding pain induction and whether pain sensitivity variance explained by anger management style overlapped with variance in harassment-induced blood pressure reactivity.

METHODS

Healthy individuals (N = 53) underwent either mental arithmetic with harassment and then a cold pressor (MA/CP) or vice versa (CP/MA). The Spielberger Anger Expression Inventory assessed anger-out using the Anger-Out subscale (AOS) and anger-in using the Anger-In subscale (AIS).

RESULTS

AOS x Order and AIS x Order interactions for pain tolerance emerged, such that (a) AOS was related negatively to tolerance among MA/CP participants, whereas AOS and tolerance were not related in CP/MA; (b) AIS was related positively to tolerance in MA/CP, whereas AIS was related negatively to tolerance in CP/MA; and (c) tolerance variance accounted for by AOS in MA/CP overlapped substantially with tolerance variance accounted for by diastolic blood pressure reactivity.

CONCLUSIONS

Findings support the notion that anger management style affects pain and are consistent with evidence that deficient endogenous opioid functioning may be one mechanism through which anger-out is linked to both pain sensitivity and cardiovascular stress reactivity, a connection that appears most reliably when anger is provoked.

Elevated resting blood pressure and dampened emotional response

OBJECTIVE

Increased blood pressure is associated with decreased reports of aversiveness for both physical pain and psychosocial stressors. Based on these findings, higher blood pressure could be associated with altered emotional responses to a broader range of stimuli. There are at least 3 ways this could happen: a) less dire response to negative stimuli with no change in response to positive stimuli; b) more positive responses to both negative and positive stimuli; or c) dampened emotional responses to both positive and negative stimuli.

METHODS

Sixty-five normotensive volunteers had their resting blood pressure measured, then rated their emotional responses to a series of positive and negative photographs.

RESULTS

Resting systolic blood pressure was significantly and negatively correlated with subjective emotional ratings of both positive (r = -.26) and negative (r = -.35) photographs.

CONCLUSION

Results were consistent with emotion dampening for elevated resting blood pressure and may reflect homeostatic integration of neurocirculatory control and affect regulation.

Altered central nervous system processing of noxious stimuli contributes to decreased nociceptive responding in individuals at risk for hypertension

Previous evidence indicates that individuals with hypertension and those at increased risk for the disorder exhibit decreased pain perception. To test the hypothesis that attenuation of nociceptive processing in individuals at genetic risk for hypertension is related to differential central modulation of nociceptive transmission, the present study examined descending modulation, alpha-motoneuron excitability, and temporal summation of nociceptive input in young adults with and without a parental history of hypertension. Nociceptive flexion (NFR) and non-nociceptive Hoffman reflexes were assessed at rest and during performance of a mental arithmetic task. Temporal summation was assessed by examining NFR threshold in response to a series of five electrical pulses delivered at 2 Hz. Compared to participants without a parental history of hypertension, offspring of individuals with hypertension exhibited significantly higher NFR thresholds, suggesting that risk for hypertension may be associated with enhanced activation of central pain inhibition pathways.

Effects of physical exercise on anxiety, depression, and sensitivity to stress: a unifying theory

Until recently, claims for the psychological benefits of physical exercise have tended to precede supportive evidence. Acutely, emotional effects of exercise remain confusing, both positive and negative effects being reported. Results of cross-sectional and longitudinal studies are more consistent in indicating that aerobic exercise training has antidepressant and anxiolytic effects and protects against harmful consequences of stress. Details of each of these effects remain unclear. Antidepressant and anxiolytic effects have been demonstrated most clearly in subclinical disorder, and clinical applications remain to be exploited. Cross-sectional studies link exercise habits to protection from harmful effects of stress on physical and mental health, but causality is not clear. Nevertheless, the pattern of evidence suggests the theory that exercise training recruits a process which confers enduring resilience to stress. This view allows the effects of exercise to be understood in terms of existing psychobiological knowledge, and it can thereby provide the theoretical base that is needed to guide future research in this area. Clinically, exercise training continues to offer clinical psychologists a vehicle for nonspecific therapeutic social and psychological processes. It also offers a specific psychological treatment that may be particularly effective for patients for whom more conventional psychological interventions are less acceptable.

Are vacations good for your health? The 9-year mortality experience after the multiple risk factor intervention trial

OBJECTIVE

The objective of this study was to determine the risk for various causes of posttrial death associated with vacation frequency during the Multiple Risk Factor Intervention Trial (MRFIT).

METHODS

Middle-aged men at high risk for coronary heart disease (CHD) were recruited for the MRFIT. As part of the questionnaires administered during the first five annual visits, men were asked whether they had had a vacation during the past year. For trial survivors (N = 12,338), the frequency of these annual vacations during the trial were used in a prospective analysis of posttrial all-cause and cause-specific mortality during the 9-year follow-up period.

RESULTS

The relative risk (RR) associated with more annual vacations during the trial was 0.83 (95% confidence interval [CI], 0.71-0.97) for all-cause mortality during the 9-year follow-up period. For cause of death, the RRs were 0.71 (95% CI, 0.58-0.89) and 0.98 (95% CI, 0.78-1.23) for cardiovascular and noncardiovascular causes, respectively. The RR was 0.68 (95% CI, 0.53-0.88) for CHD (including acute myocardial infarction). These associations remained when statistical adjustments were made for possible confounding variables, including baseline characteristics (eg, income), MRFIT group assignment, and occurrence of a nonfatal cardiovascular event during the trial.

CONCLUSIONS

The frequency of annual vacations by middle-aged men at high risk for CHD is associated with a reduced risk of all-cause mortality and, more specifically, mortality attributed to CHD. Vacationing may be good for your health.

Role of cardiovascular reactivity to mental stress in predicting future hypertension

Hypertension (HT) has been known since times immemorial to be one of the major causes of morbidity and mortality. It contributes to atherosclerotic cardiovascular disease, increasing its risk 2-3 times and is also associated with dyslipidemia, insulin resistance, glucose intolerance and obesity (1). The age of onset of hypertension is now earlier than before, making it essential that early detection of people who could be future hypertensives is done. Therefore, cardiovascular reactivity to stress in predicting future hypertension becomes important. In this fast paced age most people are exposed to mental stress which is the most common and prevalent form of stress. Increase in blood pressure (BP) in response to emotional arousal is well known, but support for this hypothesis of reactivity in predicting future hypertension is limited. We are attempting here to put forth a review of the various endeavours done so far to support this hypothesis.

Theoretical review: altered pain regulatory systems in chronic pain

This review synthesizes the existing literature regarding the relationship between resting blood pressure and pain sensitivity, and the literature indicating possible endogenous opioid dysfunction in chronic pain. Adaptive interactions between the cardiovascular and pain regulatory systems occur in healthy individuals, with greater blood pressure associated with decreased acute pain sensitivity. Endogenous opioids appear necessary for full expression of this relationship. There is ample evidence indicating diminished endogenous opioid CSF/plasma levels in chronic pain patients, yet little is known about the functional effects of these opioid changes. A theoretical model is proposed based upon the literature reviewed suggesting progressive dysfunction in endogenous opioid systems with increasing chronic pain duration. This dysfunction is hypothesized to result in dysregulation of normally adaptive relationships between the cardiovascular and pain regulatory systems, resulting in increased chronic pain intensity and increased acute pain sensitivity among chronic pain patients. Preliminary data are consistent with the hypothesis of progressive opioid changes resulting in dysfunctional alterations in the adaptive blood pressure-pain relationship. Clinical implications of this theory are discussed.

The effects of a stress-management training program in individuals at risk in the community at large

In this study we examine the effects of a stress-management training program on individuals without serious (mental) health complaints but with an increased chance of developing them as a consequence of stress. Potential subjects were randomly selected from the community at large and, then screened for participation in the training program if some of several (mental) health risk factors could be attributed to them: past life-events, neuroticism, inassertiveness, avoidant coping style and lack of social support. The control group, which did not take part in the training program, consisted of individuals with a similar risk profile as those in the training group. The training program consisted of several stress-management techniques: changing unhealthy life-style, relaxation training, problem-solving training and social skills-training. Multivariate analyses of variance showed that the training group, as compared to the control group, reported significantly less distress, less trait anxiety, less daily hassles, more assertiveness and more satisfaction with social support at follow-up. There were, however, no significant changes found in the coping skills of either group.

Endogenous opioids inhibit ambulatory blood pressure during naturally occurring stress

OBJECTIVE

Laboratory experiments suggest that endogenous opioids inhibit blood pressure responses during psychological stress. Moreover, there seem to be considerable individual differences in the efficacy of opioid blood pressure inhibition, and these differences may be involved in the expression of risk for cardiovascular disease. To further evaluate the possible role of opioid mechanisms in cardiovascular control, the present study sought to document the effects of the long-lasting oral opioid antagonist naltrexone (ReVia, DuPont, Wilmington, DE) on ambulatory blood pressure responses during naturally occurring stress.

METHOD

Thirty male volunteers participated in a laboratory stress study using naltrexone followed by ambulatory blood pressure under placebo and during the subsequent 24-hour period. Within-subject analyses were performed on ambulatory blood pressures under placebo and naltrexone conditions.

RESULTS

Laboratory results indicate no significant group effects of naltrexone on blood pressure levels or reactivity. Ambulatory results indicate that during periods of low self-reported stress, no effect of opioid blockade was apparent. In contrast, during periods of high stress, opioid blockade increased ambulatory blood pressure.

CONCLUSIONS

These findings suggest that naltrexone-sensitive opioid mechanisms inhibit ambulatory blood pressure responses during naturally occurring stress.