The impact of panic disorder on interoception and dyspnea reports in chronic obstructive pulmonary disease

Sensory and affective aspects of the perception of respiratory resistance

Perception of airway resistance has a sensory and an affective aspect, i.e., perceived resistance and unpleasantness, respectively. The current study aimed to shed more light on the relationship of these aspects, as well as their malleability to trait-like aspects of body awareness. In a laboratory study, 71 young participants completed two respiratory resistive load discrimination tasks relying on sensory and affective evaluation, respectively, and filled out questionnaires assessing somatosensory amplification, anxiety sensitivity, somatic symptoms distress, and breath awareness. Frequentist and Bayesian statistical analysis revealed no differences in discrimination accuracy with respect to the sensory and affective aspect of perceived resistance. Psychological traits were not associated with accuracy scores. In conclusion, affective evaluation of respiratory load is as accurate as sensory evaluation. Neither sensory not affective accuracy is influenced by various aspects of body awareness.

Recent insights into respiratory modulation of brain activity offer new perspectives on cognition and emotion

Over the past six years, a rapidly growing number of studies have shown that respiration exerts a significant influence on sensory, affective, and cognitive processes. At the same time, an increasing amount of experimental evidence indicates that this influence occurs via modulation of neural oscillations and their synchronization between brain areas. In this article, we review the relevant findings and discuss whether they might inform our understanding of a variety of disorders that have been associated with abnormal patterns of respiration. We review literature on the role of respiration in chronic obstructive pulmonary disease (COPD), anxiety (panic attacks), and autism spectrum disorder (ASD), and we conclude that the new insights into respiratory modulation of neuronal activity may help understand the relationship between respiratory abnormalities and cognitive and affective deficits.

Where is emotional feeling felt in the body? An integrative review

Contemporary research on "embodied emotion" emphasizes the role of the body in emotional feeling. The evidence base on interoception, arguably the most prominent strand of embodied emotion research, places emphasis on the cardiac, respiratory and gastrointestinal systems. In turn, interoception has evidence-based links with improved emotion regulation. Despite the focus on separate bodily systems, it is unclear whether particular interoceptive locations play a greater role in emotional feeling and emotion regulation. Further, according to Gross' "process model", the sooner that regulation of an emotion occurs, the better; hence, it is additionally important to identify the first body areas to activate. These issues are investigated in a two-stage integrative review. The first stage was preliminary, giving an overview of the evidence base to highlight the distribution of measured body areas. This indicated that 86% of publications (n = 88) measured cardiac activity, 26% measured the respiratory system, and six percent the gastrointestinal system. Given the emphasis placed on all three systems in interoception theory and research on emotion, this suggests a dearth of comprehensive findings pertaining to feeling locations. The second stage investigated the core issues of where emotional feelings are felt in the body and time-related implications for regulation. This was based on ten texts, which together suggested that the head, throat and chest are the most consistently detected locations across and within numerous emotional contexts. Caution is required, however, since-among other reasons discussed-measurement was not time-restricted in these latter publications, and direct physiological measurement was found in only a minority of cases.

Interoception of breathing and its relationship with anxiety

Interoception, the perception of internal bodily states, is thought to be inextricably linked to affective qualities such as anxiety. Although interoception spans sensory to metacognitive processing, it is not clear whether anxiety is differentially related to these processing levels. Here we investigated this question in the domain of breathing, using computational modeling and high-field (7 T) fMRI to assess brain activity relating to dynamic changes in inspiratory resistance of varying predictability. Notably, the anterior insula was associated with both breathing-related prediction certainty and prediction errors, suggesting an important role in representing and updating models of the body. Individuals with low versus moderate anxiety traits showed differential anterior insula activity for prediction certainty. Multi-modal analyses of data from fMRI, computational assessments of breathing-related metacognition, and questionnaires demonstrated that anxiety-interoception links span all levels from perceptual sensitivity to metacognition, with strong effects seen at higher levels of interoceptive processes.

Acceptability of capnography-assisted respiratory therapy: a new mind-body intervention for COPD

Dyspnoea self-management is often suboptimal for patients with COPD. Many patients with COPD experience chronic dyspnoea as distressing and disabling, especially during physical activities. Breathing therapy is a behavioural intervention that targets reducing the distress and impact of dyspnoea on exertion in daily living. Using a qualitative design, we conducted interviews with 14 patients after they participated in a novel mind-body breathing therapy intervention adjunct, capnography-assisted respiratory therapy (CART), combined with outpatient pulmonary rehabilitation. Comprehensive CART consisted of patient-centred biofeedback, tailored breathing exercises, a home exercise programme and motivational interviewing counselling. We assessed participants' perceptions and reported experiences to gauge the acceptability of CART and refine CART based on feedback. Constant comparative analysis was used to identify commonalities and themes. We identified three main themes relating to the acceptability and reported benefits of CART: (1) self-regulating breathing; (2) impact on health; and (3) patient satisfaction. Our findings were used to refine and optimise CART (i.e. its intensity, timing and format) for COPD. By addressing dysfunctional breathing behaviours and dysregulated interoception, CART offers a promising new paradigm for relieving dyspnoea and related anxiety in patients with COPD.

Managing the experience of breathlessness with Tai Chi: A qualitative analysis from a randomized controlled trial in COPD

PURPOSE

Chronic obstructive pulmonary disease (COPD) is associated with dyspnea, decreased physical activity, and reduced quality-of-life. While pulmonary rehabilitation is helpful, maintenance of physical activity afterwards is problematic. We sought to explore qualitatively the multi-dimensional, biopsychosocial experience of patients with COPD who participated in Tai Chi (TC) vs. group walking to facilitate physical activity after pulmonary rehabilitation).

METHODS

We analyzed semi-structured qualitative exit interviews (N = 81) from a randomized controlled trial comparing 6-months TC with a time-matched group walking intervention and usual care control (UC). Transcripts were reviewed by at least 2 independent reviewers utilizing a social constructivist framework and theoretical sampling approach. An in-depth analysis of an exemplar subset was performed to thematic saturation and captured emergent themes within and between groups.

RESULTS

Focused analysis was conducted on 54 transcripts (N = 21 TC, N = 16 Walking, N = 17 UC). Participants were characterized by mean age 68.5 (±8.3) years, GOLD Stage = 3.0 (IQR 2.0-3.0), baseline FEV1 percent predicted 48.8% (±16.4), and 48.2% female. We identified predominant themes of breathlessness, and associated fear and embarrassment that limited physical activity across all groups. In both TC and walking, participants reported improvements in energy and endurance. Those in TC additionally shared improvements in breathing, mobility, and capacity for daily activities facilitated by body and breath awareness, emotional control and regulation of breathing, and an adaptive reframing of breathlessness.

CONCLUSION

TC promoted physical and mental wellbeing by diminishing fear and embarrassment associated with breathlessness. Results highlight the multimodal characteristics of TC that may facilitate continued physical activity and improvement in quality of life.

Anxiety sensitivity and respiratory disease outcomes among individuals with chronic obstructive pulmonary disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Depression and anxiety worsen COPD and lead to greater respiratory symptom severity and health care utilization. Fear of physical sensations of anxiety (AS-P) is known to exacerbate respiratory symptoms. The current study investigated the unique contribution of AS-P in respiratory symptom exacerbations, emergency department visits, hospitalizations, and COPD-related functional health status, controlling for medical characteristics, depression, and anxiety.

METHOD

The sample included 535 adults with COPD (M_age = 56.57; 58.1% male). Participants were recruited from a web-based panel of adults with chronic respiratory disease and completed an online battery of self-report measures.

RESULTS

Consistent with hypotheses, AS-P significantly increased the likelihood of acute symptom exacerbations by 12% and respiratory-related emergency department visits and hospitalizations by 7% during the prior 12 month period. Additionally, AS-P demonstrated a unique, large effect (f² = 0.37) on COPD-related functional health status.

CONCLUSION

Fear of physical sensations contributed to worse respiratory outcomes and health care utilization among adults with COPD. Screening for AS-P may effectively identify at-risk COPD patients, while reducing AS-P through targeted interventions may result in decreased symptom severity, functional limitations, and burden on the health care system.

Respiratory modulation of intensity ratings and psychomotor response times to acoustic startle stimuli

Respiratory interoception may play an important role in the perception of respiratory symptoms in pulmonary diseases. As the respiratory cycle affects startle eye blink responses, startle modulation may be used to assess visceral-afferent signals from the respiratory system. To ascertain the potential impact of brainstem-relayed signals on cortical processes, we investigated whether this pre-attentive respiratory modulation of startle (RMS) effect is also reflected in the modulation of higher cognitive, evaluative processing of the startle stimulus. Twenty-nine healthy volunteers received 80 acoustic startle stimuli (100 or 105 dB(A); 50 ms), which were presented at end and mid inspiration and expiration, while performing a paced breathing task (0.25 Hz). Participants first responded to the startle probes by 'as fast as possible' button pushes and then rated the perceived intensity of the stimuli. Psychomotor response time was divided into 'reaction time' (RT; from stimulus onset to home button release; represents stimulus evaluation) and 'movement time' time (MT; from home button release to target button press). Intensity judgments were higher and RTs accelerated during mid expiration. No effect of respiratory cycle phase was found on eye blink responses and MTs. We conclude that respiratory cycle phase affects higher cognitive, attentional processing of startle stimuli.

Systemic corticosteroids for the management of cancer-related breathlessness (dyspnoea) in adults

BACKGROUND

Dyspnoea is a common symptom in advanced cancer, with a prevalence of up to 70% among patients at end of life. The cause of dyspnoea is often multifactorial, and may cause considerable psychological distress and suffering. Dyspnoea is often undertreated and good symptom control is less frequently achieved in people with dyspnoea than in people with other symptoms of advanced cancer, such as pain and nausea. The exact mechanism of action of corticosteroids in managing dyspnoea is unclear, yet corticosteroids are commonly used in palliative care for a variety of non-specific indications, including pain, nausea, anorexia, fatigue and low mood, despite being associated with a wide range of adverse effects. In view of their widespread use, it is important to seek evidence of the effects of corticosteroids for the management of cancer-related dyspnoea.

OBJECTIVES

To assess the effects of systemic corticosteroids for the management of cancer-related breathlessness (dyspnoea) in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Science Citation Index Web of Science, Latin America and Caribbean Health Sciences (LILACS) and clinical trial registries, from inception to 25 January 2018.

SELECTION CRITERIA

We included randomised controlled trials that included adults aged 18 years and above. We included participants with cancer-related dyspnoea when randomised to systemic corticosteroids (at any dose) administered for the relief of cancer-related dyspnoea or any other indication, compared to placebo, standard or alternative treatment.

DATA COLLECTION AND ANALYSIS

Five review authors independently assessed trial quality and three extracted data. We used means and standard deviations for each outcome to report the mean difference (MD) with 95% confidence interval (CI). We assessed the risk of bias and quality of evidence using GRADE. We extracted primary outcomes of sensory-perceptual experience of dyspnoea (intensity of dyspnoea), affective distress (quality of dyspnoea) and symptom impact (burden of dyspnoea or impact on function) and secondary outcomes of serious adverse events, participant satisfaction with treatment and participant withdrawal from trial.

MAIN RESULTS

Two studies met the inclusion criteria, enrolling 157 participants (37 participants in one study and 120 in the other study), of whom 114 were included in the analyses. The studies compared oral dexamethasone to placebo, followed by an open-label phase in one study. One study lasted seven days, and the duration of the other study was 15 days.We were unable to conduct many of our predetermined analyses due to different agents, dosages, comparators and outcome measures, routes of drug delivery, measurement scales and time points. Subgroup analysis according to type of cancer was not possible.Primary outcomesWe included two studies (114 participants) with data at one week in the meta-analysis for change in dyspnoea intensity/dyspnoea relief from baseline. Corticosteroid therapy with dexamethasone resulted in an MD of lower dyspnoea intensity compared to placebo at one week (MD -0.85 lower dyspnoea (scale 0-10; lower score = less breathlessness), 95% CI -1.73 to 0.03; very low-quality evidence), although we were uncertain as to whether corticosteroids had an important effect on dyspnoea as results were imprecise. We downgraded the quality of evidence by three levels from high to very low due to very serious study limitations and imprecision.One study measured affective distress (quality of dyspnoea) and results were similar between groups (29 participants; very low-quality evidence). We downgraded the quality of the evidence three times for imprecision, inconsistency, and serious study limitations.Both studies assessed symptom impact (burden of dyspnoea or impact on function) (113 participants; very low-quality evidence). In one study, it was unclear whether dexamethasone had an effect on dyspnoea as results were imprecise. The second study showed more improvement for physical well-being scores at days eight and 15 in the dexamethasone group compared with the control group, but there was no evidence of a difference for FACIT social/family, emotional or functional scales. We downgraded the quality of the evidence three times for imprecision, inconsistency, and serious study limitations.Secondary outcomesDue to the lack of homogenous outcome measures and inconsistency in reporting, we could not perform quantitative analysis for any secondary outcomes. In both studies, the frequency of adverse events was similar between groups, and corticosteroids were generally well tolerated. The withdrawal rates for the two studies were 15% and 36%. Reasons for withdrawal included lost to follow-up, participant or carer (or both) refusal, and death due to disease progression. We downgraded the quality of evidence for these secondary outcomes by three levels from high to very low due to serious study limitations, inconsistency and imprecision.Neither study examined participant satisfaction with treatment.

AUTHORS' CONCLUSIONS

There are few studies assessing the effects of systemic corticosteroids on cancer-related dyspnoea in adults with cancer. We judged the evidence to be of very low quality that neither supported nor refuted corticosteroid use in this population. Further high-quality studies are needed to determine if corticosteroids are efficacious in this setting.

The midbrain periaqueductal gray as an integrative and interoceptive neural structure for breathing

The periaqueductal gray (PAG) plays a critical role in autonomic function and behavioural responses to threatening stimuli. Recent evidence has revealed the PAG's potential involvement in the perception of breathlessness, a highly threatening respiratory symptom. In this review, we outline the current evidence in animals and humans on the role of the PAG in respiratory control and in the perception of breathlessness. While recent work has unveiled dissociable brain activity within the lateral PAG during perception of breathlessness and ventrolateral PAG during conditioned anticipation in healthy humans, this is yet to be translated into diseases dominated by breathlessness symptomology, such as chronic obstructive pulmonary disease. Understanding how the sub-structures of the PAG differentially interact with interoceptive brain networks involved in the perception of breathlessness will help towards understanding discordant symptomology, and may reveal treatment targets for those debilitated by chronic and pervasive breathlessness.

Visceral-afferent signals from the cardiovascular system, but not urinary urge, affect startle eye blink

The aim of the current study was to investigate if startle methodology is suitable to reflect urinary urgency. Eighteen healthy men were tested on two separate days, each including an ingestion of fluid until 80% of the subjective urge to micturate was reached. EMG responses to acoustic startle stimuli were assessed before and after micturition, as well as in the early and late cardiac cycle phases (230 vs. 530 ms after a cardiac R-wave). Sonographic assessment confirmed bladder-filling status. Emotional arousal, stress, urge and unpleasantness ratings, as well as mean blood pressure were higher before than after micturition. Startle eye blink responses were lower during the early than during the late cardiac cycle phase, but were not affected by bladder filling status. We conclude that startle methodology is suitable for the investigation of afferent signals from the cardiovascular system, but not to reflect urinary urgency. This result may be due to different neurophysiological mechanisms underlying afferent signals from the bladder compared to other visceral organs or interference with affective states or sympathetic activation associated with bladder filling. Notwithstanding, the present research protocol of fluid intake, sonographic assessment of the bladder, and subjective reports, can be applied to examine effects of urinary urge on physiological and psychological processes.

Randomised controlled trial of cognitive behavioural therapy in COPD

Anxiety is an important comorbidity in chronic obstructive pulmonary disease (COPD). We investigated if cognitive behavioural therapy (CBT), delivered by respiratory nurses, reduced symptoms of anxiety and was cost-effective. Patients with COPD and anxiety were randomised to CBT or self-help leaflets. Anxiety, depression and quality of life were measured at baseline, 3, 6 and 12 months. A cost-effectiveness analysis was conducted from a National Health Service hospital perspective and quality-adjusted life-years estimated using the EuroQol-5D questionnaire. In total, 279 patients were recruited. Group mean change from baseline to 3 months in the Hospital Anxiety and Depression Anxiety Subscale was 3.4 (95% CI 2.62-4.17, p<0.001) for the CBT group and 1.88 (95% CI 1.19-2.55, p<0.001) in the leaflet group. The CBT group was superior to leaflets at 3 months (mean difference in the Hospital Anxiety and Depression Anxiety Subscale was 1.52, 95% CI 0.49-2.54, p=0.003). Importantly, the CBT intervention was more cost-effective than leaflets at 12 months, significantly lowering hospital admissions and attendance at emergency departments. CBT delivered by respiratory nurses is a clinically and cost-effective treatment for anxiety in patients with COPD relative to self-help leaflets.

Breathlessness catastrophizing relates to poorer quality of life in adults with cystic fibrosis

BACKGROUND

Cystic Fibrosis (CF) is the most common genetic disease affecting children and young adults in Canada. It is a multi-system disease, however lung disease is largely responsible for mortality. Treatment advances have resulted in increased life expectancy and a subsequent need to better understand psychosocial issues associated with quality of life in adults living with CF. Emerging research suggests that anxiety and depression are related to poorer health-related quality of life (HRQoL) in CF patients, but there is little research examining cognitive processes, such as breathlessness catastrophizing. The present study addresses this gap in the literature.

METHODS

Participants in this study are based on a convenience sample of patients recruited during their regular CF clinic appointments at a tertiary care center. Forty-five adults (M_age = 30.73 years) completed measures of lung function, depression, anxiety, pain, breathlessness catastrophizing, and HRQoL at one time point.

RESULTS

Results of a hierarchical multiple regression indicate that increased breathlessness catastrophizing was related to poorer HRQoL, after controlling for lung function, depression, anxiety, and pain (p < .05). Depression, pain, and breathlessness catastrophizing all emerged as significant unique predictors of HRQoL.

CONCLUSIONS

Breathlessness catastrophizing is a potential target for clinical intervention and might impact HRQoL. Further research on breathlessness catastrophizing in CF is warranted including longitudinal studies to examine the mechanisms by which breathlessness catastrophizing relates to HRQoL and treatment outcomes in CF.

Agoraphobic avoidance predicts emotional distress and increased physical concerns in chronic obstructive pulmonary disease

BACKGROUND

Anxiety and panic attacks are more common in chronic obstructive pulmonary disease (COPD) than in the overall population. Individuals with panic attacks often attempt to avoid situations perceived as at risk of eliciting bodily sensations such as dyspnea, which paradoxically may lead to anxiety-related responsivity. Although there is some evidence that COPD individuals restrict their participation in various life activities because they fear that these may trigger breathlessness, little is known about agoraphobic avoidance and its impact on cognitions and emotional distress in this population. It was thus our aim to investigate the degree of agoraphobic avoidance in COPD individuals, its clinical concomitants and consequences.

METHODS

A total of 48 patients with COPD and 48 matched controlled subjects completed measures of anxiety sensitivity, agoraphobic avoidance, anxiety and depression. Objective COPD severity was measured using forced expiratory volume in the first second.

RESULTS

Patients showed significant impairment in respiratory functioning and psychological distress. Relative to the control, the COPD group exhibited greater depression, anxiety, physical symptom concerns and avoidance (alone and accompanied), irrespective of whether they were panickers or not. Patients with high avoidance showed more intense physical concerns when compared to those with low avoidance. Importantly, the level of avoidance predicted emotional distress and increased physical concerns in COPD.

CONCLUSIONS

Physical concerns scores in COPD patients are partially explained by avoidance in this group. The results of the study provide evidence for the importance of evaluating avoidance in COPD patients and implicate targeting this behavior in therapeutic interventions.

Respiratory modulation of startle eye blink: a new approach to assess afferent signals from the respiratory system

Current approaches to assess interoception of respiratory functions cannot differentiate between the physiological basis of interoception, i.e. visceral-afferent signal processing, and the psychological process of attention focusing. Furthermore, they typically involve invasive procedures, e.g. induction of respiratory occlusions or the inhalation of CO₂-enriched air. The aim of this study was to test the capacity of startle methodology to reflect respiratory-related afferent signal processing, independent of invasive procedures. Forty-two healthy participants were tested in a spontaneous breathing and in a 0.25 Hz paced breathing condition. Acoustic startle noises of 105 dB(A) intensity (50 ms white noise) were presented with identical trial frequency at peak and on-going inspiration and expiration, based on a new pattern detection method, involving the online processing of the respiratory belt signal. The results show the highest startle magnitudes during on-going expiration compared with any other measurement points during the respiratory cycle, independent of whether breathing was spontaneous or paced. Afferent signals from slow adapting phasic pulmonary stretch receptors may be responsible for this effect. This study is the first to demonstrate startle modulation by respiration. These results offer the potential to apply startle methodology in the non-invasive testing of interoception-related aspects in respiratory psychophysiology.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Psychophysical Differences in Ventilatory Awareness and Breathlessness between Athletes and Sedentary Individuals

Purpose: Breathlessness is a complex set of symptoms that are comprised of both sensory and affective (emotional) dimensions. While ventilation is now understood to be a potential limiter to performance in highly-trained individuals, the contribution of breathlessness-anxiety in those nearing maximal ventilation during intense exercise has not yet been considered as a limiter to performance.

Methods: In this study, we compared the physiology and psychology of breathlessness in 20 endurance athletes with 20 untrained age- and sex-matched sedentary controls. Subjects completed baseline spirometry and anxiety questionnaires, an incremental exercise test to exhaustion and a steady-state hypercapnic ventilatory response test, with concurrent measures of breathlessness intensity and breathlessness-anxiety.

Results: Compared with sedentary subjects, athletes reported equivalent breathlessness intensity but greater breathlessness-anxiety at maximal exercise (athletes vs. sedentary (mean ± SD): breathlessness intensity (0–100%) 80.7 (22.7) vs. 72.5 (17.2), p = 0.21; breathlessness-anxiety (0–100%), 45.3 (36.3) vs. 22.3 (20.0), p = 0.02). Athletes operated at higher proportions of their maximal ventilatory capacity (MVV) (athletes vs. sedentary (mean ventilation ± SD; % MVV): 101.6 (27.2) vs. 73.7 (30.1), p = 0.003). In the athletes there was a positive linear correlation between ventilation and breathlessness score during the hypercapnic challenge that was not observed in the sedentary controls.

Conclusion: The results of this study indicate that whilst operating at high proportions of maximal ventilation, breathlessness-anxiety becomes increasingly prominent in athletes. Our results suggest that ventilatory perception pathways may be a target for improved athletic performance in some individuals.

Loss of Dignity in Severe Chronic Obstructive Pulmonary Disease

CONTEXT

The maintenance of dignity is an important concept in palliative care, and the loss of dignity is a significant concern among patients with advanced cancer.

OBJECTIVES

The goals of this study were to examine whether loss of dignity is also a concern for patients receiving interdisciplinary rehabilitation for Stage III or IV chronic obstructive pulmonary disease. We examined the prevalence and correlates of loss of dignity and determined whether it improves with treatment.

METHODS

Inpatients underwent a structured interview inquiry around their sense of dignity and completed measures of pulmonary, physical, and psychological function at admission (n = 195) and discharge (n = 162).

RESULTS

Loss of dignity was identified as a prominent ongoing concern for 13% of patients. It was correlated with measures of depression and anxiety sensitivity, but not with pulmonary capacity or functional performance. A robust improvement in loss of dignity was demonstrated, with 88% of those who reported a significant problem at admission no longer reporting one at discharge.

CONCLUSION

The prevalence of a problematic loss of dignity among patients with severe chronic obstructive pulmonary disease is at least as high as among those receiving palliative cancer care. Loss of dignity may represent a concern among people with medical illnesses more broadly, and not just in the context of "death with dignity" at the end of life. Furthermore, interdisciplinary care may help to restore a sense of dignity to those individuals who are able to participate in rehabilitation.

Development of a dyspnoea word cue set for studies of emotional processing in COPD

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The first cue-based task to explore recall of dyspnoea and dyspnoea-related anxiety in COPD.

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Patients’ dyspnoea and dyspnoea-anxiety ratings agreed with established measures of dyspnoea.

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Patients’ dyspnea-anxiety ratings changed in accordance with clinical improvement.

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The task was reliable and well tolerated.

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The task is suitable for FMRI use and may aid dyspnoea neuroimaging research.

Patients with chronic dyspnoea may learn to fear situations that cue dyspnoea onset. Such dyspnoea-specific cues may then cause anxiety, and worsen or trigger dyspnoea even before commencement of physical activity. We therefore developed an experimental tool to probe emotional processing of dyspnoea for use with neuroimaging in COPD. The tool consists of a computerised task comprising multiple presentations of dyspnoea-related word cues with subsequent rating of dyspnoea and dyspnoea-anxiety with a visual analogue scale. Following 3 development stages, sensitivity to clinical change was tested in 34 COPD patients undergoing pulmonary rehabilitation. We measured internal consistency, sensitivity to clinical change and convergence with established dyspnoea measures (including Dyspnoea-12). Cronbach’s alpha was 0.90 for dyspnoea and 0.94 for dyspnea-anxiety ratings. Ratings correlated with Dyspnoea-12 (dyspnoea: r = 0.51, P = 0.002; dyspnea-anxiety: r = 0.54, P = 0.001). Reductions in dyspnea-anxiety ratings following pulmonary rehabilitation correlated with reductions in Dyspnoea-12 (r = 0.51, P = 0.002). We conclude that the word-cue task is reliable, and is thus a potentially useful tool for neuroimaging dyspnoea research.

A Breathlessness Catastrophizing Scale for chronic obstructive pulmonary disease

OBJECTIVE

Catastrophizing about breathlessness may be related to disability in patients with chronic obstructive pulmonary disease (COPD), but assessment options are limited. This study reports the initial validation of a 13-item Breathlessness Catastrophizing Scale (BCS).

METHOD

Pulmonary rehabilitation inpatients completed spirometric, functional performance and questionnaire assessments at admission (N=242) and discharge (n=186).

RESULTS

The BCS comprised a unifactorial scale that demonstrated excellent internal consistency (Cronbach's alpha=.96) and correlated with measures of anxiety sensitivity, depression, and self-efficacy, but not with performance on walk and stair-climbing tests. BCS scores improved robustly with rehabilitation, approaching a medium effect size (d=.43), and demonstrated a modest association with enhanced performance in a stair-climbing test of exercise tolerance.

CONCLUSION

The BCS is a reliable measure of catastrophizing in severe COPD that has good convergent validity and sensitivity to change. Its association with functional performance requires further investigation. However, it appears that a high level of catastrophizing about breathlessness is not a barrier to functional improvement with inpatient pulmonary rehabilitation.

Cognitive behaviour therapy reduces dyspnoea ratings in patients with chronic obstructive pulmonary disease (COPD)

There is evidence that psychological factors contribute to the perception of increased difficulty of breathing in patients with chronic obstructive pulmonary disease (COPD), and increase morbidity. We tested the hypothesis that cognitive behaviour therapy (CBT) decreases ratings of perceived dyspnoea in response to resistive loading in patients with COPD. From 31 patients with COPD, 18 were randomised to four sessions of specifically targeted CBT and 13 to routine care. Prior to randomisation, participants were tested with an inspiratory external resistive load protocol (loads between 5 and 45cmH2O/L/s). Six months later, we re-measured perceived dyspnoea in response to the same inspiratory resistive loads and compared results to measurements prior to randomisation. There was a significant 17% reduction in dyspnoea ratings across the loads for the CBT group, and no reduction for the routine care group. The decrease in ratings of dyspnoea suggests that CBT to alleviate breathing discomfort may have a role in the routine treatment of people with COPD.

A pilot study: mindfulness meditation intervention in COPD

Living well with chronic obstructive pulmonary disease (COPD) requires people to manage disease-related symptoms in order to participate in activities of daily living. Mindfulness practice is an intervention that has been shown to reduce symptoms of chronic disease and improve accurate symptom assessment, both of which could result in improved disease management and increased wellness for people with COPD. A randomized controlled trial was conducted to investigate an 8-week mindful meditation intervention program tailored for the COPD population and explore the use of breathing timing parameters as a possible physiological measure of meditation uptake. Results demonstrated that those randomized to the mindful meditation intervention group (N=19) had a significant increase in respiratory rate over time as compared to those randomized to the wait-list group (N=22) (P=0.045). It was also found that the mindful meditation intervention group demonstrated a significant decrease in level of mindfulness over time as compared to the wait-list group (P=0.023). When examining participants from the mindful meditation intervention who had completed six or more classes, it was found that respiratory rate did not significantly increase in comparison to the wait-list group. Furthermore, those who completed six or more classes (N=12) demonstrated significant improvement in emotional function in comparison to the wait-list group (P=0.032) even though their level of mindfulness did not improve. This study identifies that there may be a complex relationship between breathing parameters, emotion, and mindfulness in the COPD population. The results describe good feasibility and acceptability for meditation interventions in the COPD population.

Subjective ratings of prolonged inspiratory resistive loaded breathing in males and females

Dyspnea and fear of suffocation are burdensome to patients with respiratory disease. Inspiratory resistive loads offer an experimental respiratory stimulus to quantify the discriminative domain of respiratory perception. Resistive (R) load magnitude estimation (ME) and subjective ratings were measured over sustained multiple breaths in healthy subjects. There was no significant group difference between the ME for Breath 1 and 20 for small R loads, but a significant gender difference for large R loads. Subjective responses of fear, fear of suffocation, displeasure, chest pressure, faintness, dizziness, fear of losing control, trembling, and tingling were significantly greater for females. These results demonstrate that ME of large resistive sustained loads elicits nonsignificant increases in ME in females, but a significant decrease in ME for males. The maintenance of ME in females co-occurs with increased aversive processing relative to males.

A 10-year prospective study of respiratory disease and depression and anxiety in adulthood

BACKGROUND

Several cross-sectional studies have found an association between respiratory disease and increased mood or anxiety disorders among adults. Little is known about the nature of these associations over time or the role of potential confounders in these links.

OBJECTIVES

To investigate the association between respiratory disease and incident and persistent depression or anxiety disorders 10 years later and to examine potential pathways of these associations.

METHODS

Data were drawn from the Midlife Development in the United States survey, a representative sample of adults in the United States ages 18 to 74 years. Participants (N = 2,101) were interviewed on a range of health domains at baseline at wave 1 (1994) and again at wave 2 (2005).

RESULTS

Respiratory disease was associated with increased odds of depression and anxiety disorders cross-sectionally at both time points. Respiratory disease at wave 1 was not associated with incident depression or anxiety disorders at wave 2. Respiratory disease at wave 1 was associated with increased odds of persistent depression or anxiety disorders 10 years later among those with depression or anxiety disorders at wave 1. Associations were not explained by differences in demographic characteristics, secondhand smoke exposure, cigarette smoking, or history of exposure to childhood maltreatment.

CONCLUSION

Findings shed new light on the association between respiratory disease and depression or anxiety disorders. Individuals with respiratory disease appear to have higher prevalence of concurrent depression or anxiety disorders and persistent depression or anxiety disorders compared with those without respiratory disease. However, a history of respiratory disease does not appear to confer increased risk of new onset of depression or anxiety disorders.

Dyspnea and panic among patients with newly diagnosed non-small cell lung cancer

CONTEXT

Among patients with lung cancer, dyspnea is associated with psychological distress, fatigue, and poor coping. Respiratory symptoms are also a common trigger for panic attacks in the general population. Minimal research has addressed the prevalence of panic disorder or the association of dyspnea with the risk of panic disorder in lung cancer.

OBJECTIVES

We explored the frequency of panic disorder symptoms and the association of dyspnea with the risk of panic disorder symptoms among patients with newly diagnosed non-small cell lung cancer.

METHODS

During 2006-2010, consecutive patients presenting for initial consultation at a thoracic oncology clinic completed a survey of current symptoms, including dyspnea and panic disorder symptoms. We evaluated the frequency of panic disorder symptoms. Logistic regression was used to test the association of dyspnea with the risk of panic disorder symptoms, adjusting for age, gender, disease stage, performance status, and major depression symptoms.

RESULTS

Among 624 patients (mean age=63.7; standard deviation=12.1; 52.6% female), 48.1% reported that breathing was at least somewhat difficult and 11.2% endorsed panic disorder symptoms. Dyspnea was independently associated with higher risk of panic disorder symptoms (odds ratio=2.19, 95% confidence interval=1.11-4.31, P=0.02). Younger age and major depression symptoms also were associated with higher risk (P<0.01).

CONCLUSION

Almost half of the patients with newly diagnosed non-small cell lung cancer reported dyspnea, and patients with dyspnea were more than twice as likely to endorse panic disorder symptoms relative to patients without dyspnea. Results highlight the need to differentiate panic disorder symptoms among patients who report dyspnea, particularly those who are younger or experiencing major depression symptoms.

High Thrill and adventure seeking is associated with reduced interoceptive sensitivity: evidence for an altered sex-specific homeostatic processing in high sensation seekers

OBJECTIVE

The personality trait of sensation seeking (SS) has been traditionally linked to the construct of exteroception, i.e. sensing of the outside world. Little is known about the relationship between SS and interoception, i.e. sensing originating in the body. Interoceptive sensations have strong affective and motivational components that may influence behaviors such as risk-taking in SS. This investigation examined whether interoceptive differences contribute to different behavioral characteristics in SS.

METHOD

Using an inspiratory resistive load breathing task, the response to an aversive interoceptive stimulus as a basic homeostatic process was studied in 112 subjects (n=74 females, 38 males). A linear-mixed model approach was used to examine the influence of thrill and adventure seeking (TAS) on the interoceptive response across three levels of breathing resistances (10, 20, 40 cmH₂O/L/sec).

RESULTS

High relative to low TAS individuals were less responsive in evaluating intensities of perceived choking with increasing inspiratory resistive loads. This effect was driven by male, but not female high TAS individuals and was particularly associated with reduced interoceptive sensitivity in males.

CONCLUSION

The conceptualization of SS as primarily driven by exteroceptive stimuli can be expanded to a view of an altered homeostasis in SS, specifically in males.

Effectiveness of cognitive behavioural therapy (CBT) interventions for anxiety in patients with chronic obstructive pulmonary disease (COPD) undertaken by respiratory nurses: the COPD CBT CARE study: (ISRCTN55206395)

Background

Anxiety and depression are common co-morbidities in patients with chronic obstructive pulmonary disease (COPD). Serious implications can result from psychological difficulties in COPD including reduced survival, lower quality of life, and reduced physical and social functioning, increased use of health care resources and are associated with unhealthy behaviours such as smoking. Cognitive behavioural therapy (CBT) is a psychological intervention which is recommended for the treatment of many mental health problems including anxiety and depression. Unfortunately access to trained CBT therapists is limited. The aim of this study is to test the hypothesis that CBT delivered by respiratory nurses is effective in the COPD population. In this paper the design of the Newcastle Chronic Obstructive Pulmonary Disease Cognitive Behavioural Therapy Study (Newcastle COPD CBT Care Study) is described.

Methods/Design

This is a prospective open randomised controlled trial comparing CBT with self-help leaflets. The primary outcome measure is the Hospital Anxiety & Depression Scale (HADS) – anxiety subscale. Secondary outcome measures include disease specific quality of life COPD Assessment Tool (CAT), generic quality of life (EQ5D) and HADS-depression subscale. Patients will be followed up at three, six and 12 months following randomisation.

Discussion

This is the first randomised controlled trial to evaluate the use of cognitive behavioural therapy undertaken by respiratory nurses. Recruitment has commenced and should be complete by February 2014.

Trial registration

Current Controlled Trials, ISRCTN55206395

Emotions and neural processing of respiratory sensations investigated with respiratory-related evoked potentials

OBJECTIVE

Patients with respiratory diseases such as asthma and chronic obstructive pulmonary disease frequently experience respiratory sensations, which are often perceived as unpleasant or threatening. However, the accurate perception of respiratory sensations is important for the management and treatment of these diseases. Emotions can substantially influence the perception of respiratory sensations and might affect the course of respiratory diseases, but the underlying neural mechanisms are poorly understood. The respiratory-related evoked potential (RREP) recorded from the electroencephalogram is a noninvasive technique that allowed first studies to examine the impact of emotions on the neural processing of respiratory sensations.

METHODS

In this review, we will briefly introduce the importance of the perception of respiratory sensations and the influence of emotions on respiratory perception. We then provide an overview on the technique of RREP and present a systematic review on recent findings using this technique in the context of emotions.

RESULTS AND CONCLUSIONS

The evidence currently available from studies in healthy individuals suggests that short-lasting emotional states and anxiety affect the later RREP components (N1, P2, P3) related to higher-order neural processing of respiratory sensations, but not the earlier RREP components (Nf, P1) related to first-order sensory processing. We conclude with a discussion of the implications of this work for future research that needs to focus on respiratory patient groups and the associated clinical outcomes.

The Multidimensional Assessment of Interoceptive Awareness (MAIA)

This paper describes the development of a multidimensional self-report measure of interoceptive body awareness. The systematic mixed-methods process involved reviewing the current literature, specifying a multidimensional conceptual framework, evaluating prior instruments, developing items, and analyzing focus group responses to scale items by instructors and patients of body awareness-enhancing therapies. Following refinement by cognitive testing, items were field-tested in students and instructors of mind-body approaches. Final item selection was achieved by submitting the field test data to an iterative process using multiple validation methods, including exploratory cluster and confirmatory factor analyses, comparison between known groups, and correlations with established measures of related constructs. The resulting 32-item multidimensional instrument assesses eight concepts. The psychometric properties of these final scales suggest that the Multidimensional Assessment of Interoceptive Awareness (MAIA) may serve as a starting point for research and further collaborative refinement.

The effect of anxiety on respiratory sensory gating measured by respiratory-related evoked potentials

Respiratory sensory gating is evidenced by decreased amplitudes of the respiratory-related evoked potentials (RREP) N1 peak for the second (S2) compared to the first occlusion (S1) when two paired occlusions are presented with a 500-millisecond (ms) inter-stimulus-interval during one inspiration. Because anxiety is prevalent in respiratory diseases and associated with altered respiratory perception, we tested whether anxiety can modulate individuals' respiratory neural gating mechanism. By using high-density EEG, RREPs were measured in a paired inspiratory occlusion paradigm in 11 low and 10 higher anxious individuals with normal lung function. The N1 peak gating S2/S1 ratio and the N1 S2 amplitudes were greater in higher compared to low anxious individuals (p's<0.05). In addition, higher anxiety levels were correlated with greater S2/S1 ratios (r=0.54, p<0.05) and S2 amplitudes (r=-0.49, p<0.05). The results demonstrate that anxiety is associated with reduced respiratory sensory gating which might underlie altered respiratory symptom perception in anxious individuals.

Catastrophic interpretations and anxiety sensitivity as predictors of panic-spectrum psychopathology in chronic obstructive pulmonary disease

OBJECTIVE

Panic-spectrum psychopathology (denoting panic attacks and panic disorder) is highly prevalent in chronic obstructive pulmonary disease (COPD), and the cognitive model of panic has been proposed as an explanation of this high prevalence. In the current cross-sectional study we investigated factors predicting panic-spectrum psychopathology in COPD, and hypothesized that, consistent with the cognitive model, both the catastrophic interpretation of shortness of breath and elevated anxiety sensitivity would be significant predictors when variance shared with confounding variables was controlled.

METHODS

Sixty-two participants with COPD were interviewed with the Anxiety Disorders Interview Schedule for DSM-IV, Panic Disorder section, and completed measures of interpretation of breathing difficulty, anxiety sensitivity, anxiety, depression, disease-specific quality of life, and stressful life events. Objective disease severity was measured using forced expiratory volume in the first second.

RESULTS

Direct logistic regression was performed, and worse depressive symptoms, more catastrophic interpretations of shortness of breath, higher anxiety sensitivity, higher magnitude of recent stressful life events, and worse disease severity were each found to be significant unique predictors of panic-spectrum psychopathology in COPD after shared variance was controlled.

CONCLUSIONS

The results of the study provide support for the cognitive model of panic, and also suggest a diathesis-stress explanation of the development of panic-spectrum psychopathology in COPD. The findings have implications for future preventative psychological interventions.

Neurobiology of panic and pH chemosensation in the brain

Panic disorder is a common and disabling illness for which treatments are too frequently ineffective. Greater knowledge of the underlying biology could aid the discovery of better therapies. Although panic attacks occur unpredictably, the ability to provoke them in the laboratory with challenge protocols provides an opportunity for crucial insight into the neurobiology of panic. Two of the most well-studied panic provocation challenges are CO(2) inhalation and lactate infusion. Although it remains unclear how these challenges provoke panic animal models of CO(2) and lactate action are beginning to emerge, and offer unprecedented opportunities to probe the molecules and circuits underlying panic attacks. Both CO(2) and lactate alter pH balance and may generate acidosis that can influence neuron function through a growing list of pH-sensitive receptors. These observations suggest that a key to better understanding of panic disorder may He in more knowledge of brain pH regulation and pH-sensitive receptors.

An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea

BACKGROUND

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.

PURPOSE

The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.

METHODS

An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.

RESULTS

Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.

CONCLUSIONS

Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.

An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea

BACKGROUND

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.

PURPOSE

The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.

METHODS

An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.

RESULTS

Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.

CONCLUSIONS

Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.

Negative beliefs about breathlessness increases panic for patients with chronic respiratory disease

Breathlessness is a multidimensional symptom of respiratory disease and is associated with the experience of panic. Patients with panic disorder have increased mortality, morbidity and healthcare utilisation that is unrelated to their disease severity. Our qualitative study aimed to appraise respiratory patients' experiences of breathlessness and whether their cognitions were associated with panic aetiology. The self-regulatory theory was utilised to develop the framework for the semi-structured interview schedule. Twelve individuals with respiratory disease at a U.K. cardiothoracic centre participated and their data were analysed using interpretative phenomenological analysis. Perceived control over the disease, symptoms and panic emerged as the core theme with three related belief systems; (1) Perceived consequences of panic and disease; (2) Illness and symptom coherence; and (3) Emotional adaptation. Panic symptoms were most prevalent in participants with low perceived control over symptoms and the disease, negative beliefs about the life-limiting consequences of unpredictable breathless attacks and by those using emotional coping strategies such as denial and avoidance. The experience of panic for respiratory patients can be explained through the cognitive-behavioural model of anxiety, which highlights the contributory role of catastrophic beliefs about the control and consequences of symptoms and disease as a significant contributory factor for the prevalence and maintenance of panic. The mortality and morbidity of respiratory patients is significantly affected by a co-morbid diagnosis of panic disorder and so it is critical to patients' long-term healthcare that their psychological experiences are assessed. Healthcare services must enhance patients' understanding about their disease to improve their confidence to control symptoms. Recent evidence suggests that cognitive-behavioural interventions that increase problem-solving coping will reduce catastrophic misinterpretations about the perceived consequences of breathlessness and improve emotional adaption to respiratory disease.

Mental health problems, obstructive lung disease and lung function: findings from the general population

OBJECTIVE

There is cumulative evidence for a strong association of obstructive lung disease, i.e. asthma and COPD, with poor mental health, particularly with anxiety disorders and major depression. However, studies relating mental health problems to objective measures of lung function as assessed by spirometry are lacking.

METHODS

The 12-month prevalence of specific psychopathological syndromes among 1772 adults from the general population was estimated by a structured interview. Additionally, participants underwent spirometry and were asked about obstructive lung disease in the year prior to the study. Logistic and linear regression models were used to relate obstructive lung disease and spirometrically defined airway obstruction to mental health problems.

RESULTS

Mental health problems were found in 35.7% of the participants. After adjusted for sociodemographic, clinical and life-style factors, asthma and chronic bronchitis were associated with almost all domains of mental health problems. In contrast, independent of its definition, spirometric airflow limitation was only related to generalized anxiety (odds ratios ranging from 2.3 to 2.7). A reduced ratio of forced expiratory volume in one second to forced vital capacity was associated with mental health problems in general and panic and general anxiety in particular.

CONCLUSION

Our findings suggest an association of objective measure of airflow limitation to generalized anxiety and panic. While the causal relationship between obstructive lung disease, airflow limitation and anxiety remains to be determined, clinicians should pay diagnostic attention to the significant overlap of these conditions.

The impact of anxiety on the neural processing of respiratory sensations

Previous studies demonstrated that anxiety considerably impacts the reported perceptions of respiratory sensations. A novel feature of the current study is exploring the impact of anxiety on the neural processing of respiratory sensations elicited by short inspiratory occlusions during different affective contexts. Using high-density EEG, respiratory-related evoked potentials (RREP) were recorded in 23 low and 23 matched higher anxious individuals when viewing unpleasant or neutral picture series. Low anxious individuals showed the expected pattern of reduced magnitudes of later RREP components P2 and P3 during the unpleasant compared to the neutral affective context (p<0.05 and p<0.01). In contrast, higher anxious individuals showed greater magnitudes of P2 and P3 during the unpleasant compared to the neutral affective context (p's<0.05). Moreover, higher anxiety levels were correlated with greater magnitudes for P2 (r=0.44, p<0.01) and P3 (r=0.54, p<0.001) during the unpleasant relative to the neutral affective context. Earlier components of the RREP (Nf, P1, N1) were not affected by anxiety. This study demonstrates that anxiety affects the later, higher-order neural processing of respiratory sensations, but not its earlier, first-order sensory processing. These findings might represent a neural mechanism that underlies the increased perception of respiratory sensations in anxious individuals.

A murine model of stress controllability attenuates Th2-dominant airway inflammatory responses

Epidemiological and experimental studies suggest a positive correlation between chronic respiratory inflammatory disease and the ability to cope with adverse stress. Interactions between neuroendocrine and immune systems are believed to provide insight toward the biological mechanisms of action. The utility of an experimental murine model was employed to investigate the immunological consequences of stress-controllability and ovalbumin-induced airway inflammation. Pre-conditioned uncontrollable stress exacerbated OVA-induced lung histopathological changes that were typical of Th2-predominant inflammatory response along respiratory tissues. Importantly, mice given the ability to exert control over aversive stress attenuated inflammatory responses and reduced lung pathology. This model represents a means of investigating the neuro-immune axis in defining mechanisms of stress and respiratory disease.