Association of anxiety with perception of histamine induced bronchoconstriction in patients with asthma

Anxiety in asthma: a systematic review and meta-analysis

BACKGROUND

Background: Growing evidence from observational studies indicates a high prevalence of anxiety in asthma. However, prevalence rates of coexisting anxiety symptoms and comorbid anxiety disorders vary widely across studies. We aimed to evaluate the associations between anxiety and asthma and provide more precise comorbidity estimates.

METHODS

We systematically reviewed the literature from case-controlled studies and conducted a meta-analysis to evaluate the pooled prevalence estimates and risks of anxiety symptoms and anxiety disorders in asthma individuals. Screening, data extraction, and quality assessment were undertaken following PRISMA guidelines for preferred reporting of systematic reviews and meta-analysis. A random-effects model was used to calculate pooled prevalence rates. Meta-analysis was conducted using Review Manager 5.3. Multiple databases including PubMed, ScienceDirect, PsychINFO, and PsycARTICLES were searched for publications before 1 December 2019. The review protocol was registered on PROSPERO (ref: CRD42020176028).

RESULTS

In total, 19 studies involving 106813 participants were included. The pooled prevalence of anxiety symptoms and anxiety disorders in individuals with asthma was 0.32 (95% CI 0.22-0.43) and 0.24 (95% CI 0.13-0.41), respectively. The risks of coexisting anxiety symptoms and comorbid anxiety disorders were significantly higher in asthma patients than in non-asthma controls indicated by OR 1.89 (95% CI 1.42-2.52; Z = 4.37; p < 0.001) and OR 2.08 (95% CI 1.70-2.56; Z = 6.97; p < 0.001), respectively. Anxiety symptoms and anxiety disorders occur at increased frequency among patients with asthma.

CONCLUSIONS

Our findings highlight the need for appropriate assessments for these comorbid conditions, which may help to identify a subgroup of patients who might benefit from interventions designed to reduce anxiety and enhance the quality of life.

Symptoms and perception of airway obstruction in asthmatic patients: Clinical implications for use of reliever medications

BACKGROUND

Asthma causes the unpleasant sensation of breathlessness (dyspnea) caused by airway obstruction. Patients with poor perception of airway obstruction are at risk of delay in seeking medical attention and undertreatment, which can lead to avoidable deaths. Conversely, those with heightened perception are at risk of overtreatment and iatrogenic adverse effects with reliever medications, anxiety, and unnecessary use of health care resources.

OBJECTIVE

We sought to review evidence about symptom misperception in asthmatic patients and how to identify and manage affected patients, particularly with regard to reliever medications.

METHODS

We conducted a systematic literature search for studies of perception of airway function in asthmatic patients. We searched the OVID (Medline and Medline [R] in process [PubMed]), Embase, and Adisearch/Odyssey databases, restricting our search to human studies published in English from 1990-2018, with no restrictions on age, sex, or racial origin.

RESULTS

We found that both underperception and overperception assessed during induced bronchoconstriction or bronchodilation or during changes in airway resistance were common across all age groups and that aging, disease severity, smoking, sex, ethnicity, psychologic factors, and medication are all associated with differences in perception. Importantly, airway inflammation was associated with impaired perception and a history of severe or near-fatal asthma. We also identified knowledge gaps, such as whether an individual patient's perception varies over time and the influence perception has on patients' use of reliever medication.

CONCLUSION

We found that abnormal perception of airway obstruction has important clinical implications for the management of patients with asthma.

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.

A blended psychosocial support program for partners of patients with amyotrophic lateral sclerosis and progressive muscular atrophy: protocol of a randomized controlled trial

Background

Informal caregivers of patients with Amyotrophic Lateral Sclerosis (ALS) or Progressive Muscular Atrophy (PMA) face stressful demands due to severe impairments and prospect of early death of the patients they care for. Caregivers often experience feelings of psychological distress and caregiver burden, but supportive interventions are lacking. The objective of this study is to investigate the effectiveness of a psychosocial support program aimed at enhancing feelings of control over caregiving tasks and reducing psychological distress. This support program is based on an existing program for adult partners of people with cancer and is adapted to meet the needs of ALS caregivers.

Methods

This study is a randomized controlled trial using a wait-list control design. One hundred and forty caregiver-patient dyads, recruited from a nationwide database and through the website of the Dutch ALS Center, will be either randomized to a support program or a wait-list control group. The blended intervention is based on Acceptance and Commitment Therapy and consists of 1 face-to-face contact, 6 online guided modules and 1 telephone contact. The intervention can be worked through in 8 weeks. The effectiveness and the participants’ satisfaction with the intervention will be evaluated using a mixed method design. Caregivers and patients will be asked to fill in questionnaires on 4 occasions during the study: baseline, 3 months, 6 months and 9 months. The main study outcome is the psychological distress of the caregiver assessed with the Hospital Anxiety and Depression Scale. Secondary outcomes are caregiver burden, caregiver quality of life, quality of life of the patient and psychological distress of the patient. Group differences in primary and secondary outcomes at 6 months will be compared with linear mixed model analysis. In a subgroup of caregivers we will explore experiences with the support program through semi-structured interviews. Usage of the online modules will be logged.

Discussion

The study will provide insights into the effectiveness of a blended psychosocial support program on psychological distress of caregivers of patients with ALS or PMA, as well as into indirect relations with patients’ wellbeing.

Trial registration

Netherlands Trial Registry NTR5734, registered 28 March 2016.

Breathlessness amplifies amygdala responses during affective processing

Breathlessness is an aversive symptom in many prevalent somatic and psychiatric diseases and is usually experienced as highly threatening. It is strongly associated with negative affect, but the underlying neural processes remain poorly understood. Therefore, using fMRI, the present study examined the effects of breathlessness on the neural processing of affective visual stimuli within candidate brain areas including the amygdala, insula, and anterior cingulate cortex (ACC). During scanning, 42 healthy volunteers, mean (SD) age: 29.0 (6.0) years, 14 female, were presented with affective picture series of negative, neutral, and positive valence while experiencing either no breathlessness (baseline conditions) or resistive-load induced breathlessness (breathlessness conditions). Respiratory measures and self-reports suggested successful induction of breathlessness and affective experiences. Self-reports of breathlessness intensity and unpleasantness were significantly higher during breathlessness conditions, mean (SD): 45.0 (16.6) and 32.3 (19.8), as compared to baseline conditions, mean (SD): 1.9 (3.0) and 2.9 (5.5). Compared to baseline conditions, stronger amygdala activations were observed during breathlessness conditions for both negative and positive affective picture series relative to neutral picture series, while no such effects were observed in insula and ACC. The present findings demonstrate that breathlessness amplifies amygdala responses during affective processing, suggesting an important role of the amygdala for mediating the interactions between breathlessness and affective states.

Breathlessness and the body: Neuroimaging clues for the inferential leap

Breathlessness debilitates millions of people with chronic illness. Mismatch between breathlessness severity and objective disease markers is common and poorly understood. Traditionally, sensory perception was conceptualised as a stimulus-response relationship, although this cannot explain how conditioned symptoms may occur in the absence of physiological signals from the lungs or airways. A Bayesian model is now proposed, in which the brain generates sensations based on expectations learnt from past experiences (priors), which are then checked against incoming afferent signals. In this model, psychological factors may act as moderators. They may alter priors, change the relative attention towards incoming sensory information, or alter comparisons between priors and sensations, leading to more variable interpretation of an equivalent afferent input. In the present study we conducted a supplementary analysis of previously published data (Hayen et al., 2017). We hypothesised that individual differences in psychological traits (anxiety, depression, anxiety sensitivity) would correlate with the variability of subjective perceptions of equivalent breathlessness challenges. To better understand the resulting inferential leap in the brain, we explored where these behavioural measures correlated with functional brain activity across subjects. Behaviourally, anxiety sensitivity was found to positively correlate with each subject's variability of intensity and unpleasantness during mild breathlessness, and with variability of unpleasantness during strong breathlessness. In the brain, anxiety sensitivity was found to negatively correlate with precuneus activity during anticipation, positively correlate with anterior insula activity during mild breathlessness, and negatively correlate with parietal sensorimotor areas during strong breathlessness. Our findings suggest that anxiety sensitivity may reduce the robustness of this Bayesian sensory perception system, increasing the variability of breathlessness perception and possibly susceptibility to symptom misinterpretation. These preliminary findings in healthy individuals demonstrate how differences in psychological function influence the way we experience bodily sensations, which might direct us towards better understanding of symptom mismatch in clinical populations.

Patient adherence and effective communication

BACKGROUND

Poor adherence to inhaled corticosteroid medication is a critical problem for asthma because it contributes to morbidity and mortality through poor asthma control, frequent asthma exacerbations, acute care visits, and oral corticosteroid use.

OBJECTIVE

To discuss evidence-based, time-efficient strategies that can be adopted by most practitioners to try to increase patient adherence.

METHODS

Asthma management guidelines and other key publications are used to enhance discussion.

RESULTS

Establishing patient-centered, collaborative care that permits effective patient-practitioner communication can improve adherence, thus leading to improved asthma outcomes. One critical strategy is shared decision making, in which the patient and the practitioner share relevant information, discuss risks vs benefits of various treatment options, express treatment preferences, deliberate the options, and agree on treatment. Asthma self-management education, which emphasizes self-efficacy, is also essential. The education necessary to provide those skills depends in part on consideration of the patient's health literacy. Practitioners also have at their disposal a variety of tips and techniques to improve communication and gather information not only at the patient-practitioner level but also at the practitioner-practitioner level, such as within a group practice or within a health care system.

CONCLUSION

To improve patient adherence, clinicians need to consider a variety of factors and implement strategies that directly target underlying issues. Strategies may include customizing and simplifying learning and intervention regimens, identifying barriers to adherence and addressing them, ensuring patient support structures are in place, and improving self-efficacy and health literacy.

Addressing unmet needs in understanding asthma mechanisms: From the European Asthma Research and Innovation Partnership (EARIP) Work Package (WP)2 collaborators

Asthma is a heterogeneous, complex disease with clinical phenotypes that incorporate persistent symptoms and acute exacerbations. It affects many millions of Europeans throughout their education and working lives and puts a heavy cost on European productivity. There is a wide spectrum of disease severity and control. Therapeutic advances have been slow despite greater understanding of basic mechanisms and the lack of satisfactory preventative and disease modifying management for asthma constitutes a significant unmet clinical need. Preventing, treating and ultimately curing asthma requires co-ordinated research and innovation across Europe. The European Asthma Research and Innovation Partnership (EARIP) is an FP7-funded programme which has taken a co-ordinated and integrated approach to analysing the future of asthma research and development. This report aims to identify the mechanistic areas in which investment is required to bring about significant improvements in asthma outcomes.

Interoceptive dimensions across cardiac and respiratory axes

Interoception refers to the sensing of signals concerning the internal state of the body. Individual differences in interoceptive sensitivity are proposed to account for differences in affective processing, including the expression of anxiety. The majority of investigations of interoceptive accuracy focus on cardiac signals, typically using heartbeat detection tests and self-report measures. Consequently, little is known about how different organ-specific axes of interoception relate to each other or to symptoms of anxiety. Here, we compare interoception for cardiac and respiratory signals. We demonstrate a dissociation between cardiac and respiratory measures of interoceptive accuracy (i.e. task performance), yet a positive relationship between cardiac and respiratory measures of interoceptive awareness (i.e. metacognitive insight into own interoceptive ability). Neither interoceptive accuracy nor metacognitive awareness for cardiac and respiratory measures was related to touch acuity, an exteroceptive sense. Specific measures of interoception were found to be predictive of anxiety symptoms. Poor respiratory accuracy was associated with heightened anxiety score, while good metacognitive awareness for cardiac interoception was associated with reduced anxiety. These findings highlight that detection accuracies across different sensory modalities are dissociable and future work can better delineate their relationship to affective and cognitive constructs.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

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.

Case series: the application of "third wave" cognitive behavioural therapies in difficult to treat asthma

OBJECTIVE

This paper provides for the first time cases of individual psychological therapy undertaken in tertiary, difficult to treat asthma services using "third wave" cognitive behavioural therapy (CBT) approaches.

METHODS

These cases were selected to represent common psychological presentations in difficult to treat asthma clinics, namely denial of severity and over-identification with asthma. Assessment, formulation, intervention and results are outlined.

RESULTS

Case 1 demonstrated change from severe to mild depression and anxiety, reduction in shame and improved well-being. Case 2 demonstrated improvements in well-being and psychological symptoms. Both interventions were experienced by the patients as highly satisfactory.

CONCLUSIONS

It is concluded that a psychological understanding of patients' presentations can open up new avenues for intervention. Further research into the potential utility of third wave cognitive therapies in difficult to treat asthma is warranted.

Do Panic Symptoms Affect the Quality of Life and Add to the Disability in Patients with Bronchial Asthma?

Background. Anxiety and panic are known to be associated with bronchial asthma with variety of impact on clinical presentation, treatment outcome, comorbidities, quality of life, and functional disability in patients with asthma. This study aims to explore the pattern of panic symptoms, prevalence and severity of panic disorder (PD), quality of life, and disability in them. Methods. Sixty consecutive patients of bronchial asthma were interviewed using semistructured proforma, Panic and Agoraphobia scale, WHO Quality of life (QOL) BREF scale, and WHO disability schedule II (WHODAS II). Results. Though 60% of the participants had panic symptoms, only 46.7% had diagnosable panic attacks according to DSM IV TR diagnostic criteria and 33.3% had PD. Most common symptoms were “sensations of shortness of breath or smothering,” “feeling of choking,” and “fear of dying” found in 83.3% of the participants. 73.3% of the participants had poor quality of life which was most impaired in physical and environmental domains. 55% of the participants had disability score more than a mean (18.1). Conclusion. One-third of the participants had panic disorder with significant effect on physical and environmental domains of quality of life. Patients with more severe PD and bronchial asthma had more disability.

Why aren't we doing better in asthma: time for personalised medicine?

After decades of improvement, asthma outcomes have stalled. Mortality, hospitalisations, exacerbations and symptom control remain sub-optimal. In controlled trials, most patients gain high levels of control, but in ‘real-life’ routine clinical practice most patients do not. Avoidable factors are found in most asthma deaths and hospital admissions. This perspective paper considers and contextualises the factors underlying poor asthma outcomes, and it suggests approaches that could improve the situation. Factors discussed include severe, therapy-resistant disease and the role of new and upcoming pharmacological therapies in improving outcomes. These are likely to be beneficial when targeted on patients with severe disease and discrete phenotypic characteristics, identified through biomarkers. However, for the majority of patients treated in the community, they are unlikely to be used widely, and better use of current therapy classes will be more important. Non-adherence with regular inhaled corticosteroid treatment and over-use of rescue bronchodilators are common, and many patients have poor inhaler technique. Self-management is frequently poor, particularly in those with psychosocial disadvantages and co-morbidities. Communication between clinicians and patients is sometimes poor, with failure to detect avoidable poor control and non-adherence, and failure to provide the necessary information and education to support efficient self-management. Strategies for improving monitoring and clinician–patient interactions to allow personalised treatment are considered. These strategies have the potential to allow individual patient needs to be recognised and efficient targeting of the variety of effective pharmacological and non-pharmacological interventions that we possess, which has the potential to improve both individual and population outcomes.

Breathing exercises for asthma

Educational aims

To summarise the evidence of the role of breathing control approaches in the management of asthma

To provide information on the content of evidence-based breathing exercises programmes

Summary

Asthma is a complex, multi-dimensional condition that affects patients in many ways. Having asthma is inherently stressful and psychological problems are common and associated with poor asthma outcomes. Although most patients in clinical trials can achieve high levels of control with optimised pharmacotherapy, in “real-life” practice, poor control is common, with over-reliance on rescue bronchodilator medication and ongoing symptoms and quality-of-life impairment. Many patients are interested in non-pharmacological treatments to improve asthma control, particularly breathing control exercises but, until recently, the evidence base has been inadequate. The place of breathing exercises has been controversial, partly because some proponents have made exaggerated, implausible claims of effectiveness. Recent evidence, however, has resulted in endorsement of breathing exercises as add-on treatment in asthma in systematic reviews and guidelines.

This review summarises the current evidence of effectiveness of breathing exercises programmes as an adjuvant treatment to pharmacological strategies for people with asthma. The types of breathing training programmes used and the content of effective programmes are discussed. We conclude that patients whose asthma continues to cause symptoms and quality-of-life impairment, despite adequate pharmacological treatment, or who have high bronchodilator use, should be offered access to an effective breathing training programme as a part of holistic, integrated asthma care.

Key points

Asthma is frequently poorly controlled despite effective modern medication

Psychological factors can be as important as physiological ones in affecting symptom perception and disease impact

Breathing exercises can improve patient-reported outcomes and psychological state

Breathing exercises should be offered to all asthma patients with symptoms or impaired quality of life despite standard treatment

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 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.

Cognitive behavioural intervention for adults with anxiety complications of asthma: prospective randomised trial

BACKGROUND

High levels of asthma-related fear and panic exacerbate asthma symptoms and complicate the management of asthma. Asthma-specific fear may be reduced by a cognitive behavioural intervention. We aimed to test if there is a reduction in asthma-specific fear after cognitive behavioural intervention compared with routine treatment.

METHODS

Adults with asthma registered with family doctors in Sheffield UK were screened for anxiety and 94 highly anxious patients were randomly allocated to receive either a cognitive behavioural intervention to improve self-management of their anxiety (n = 50) or routine clinical care (n = 44). Asthma-specific fear at the end of treatment and at six month follow up were the primary endpoints. Service usage in the six months prior to and six months following the intervention was monitored to allow estimation of costs. Data were analysed by intention to treat.

FINDINGS

At the end of treatment, there was a significantly greater reduction in asthma-specific fear for people in the CBT group compared with controls. At six months after treatment the reduction in asthma-specific fear in the CBT group was increased and the difference between treatment and control group was statistically significant. Service use costs were not reduced in the CBT group.

INTERPRETATION

A brief cognitive behavioural intervention was found to have efficacy in reducing asthma-specific panic fear immediately after treatment and at 6 months follow up. There was no cost advantage to cognitive behavioural treatment.

Predicting asthma treatment outcome at diagnosis: the role of symptom perception during a histamine challenge test

OBJECTIVE

In asthma, many treatment decisions are dependent upon patient perception/patient report of asthma symptoms. Discrepancies between patient perception of asthma symptoms and objective indicators of pathophysiology are widespread and can hinder asthma treatment. Early detection of problems in asthma symptom perception may be a first step to help these patients. We investigated the predictive value of symptom perception during a histamine challenge test (HCT) at asthma diagnosis for patient-rated outcome of asthma treatment 3 months later.

METHODS

In a prospective observational study, persons with asthma (N = 60) showing bronchial hyperresponsiveness in a HCT completed questions on asthma symptoms and negative affectivity (NA). The HCT was extended with an ambiguous situation suggesting asthma symptoms despite physiological recovery. Lung function (forced expiratory volume in 1 second (FEV(1))) and symptom ratings were measured during the test (after each histamine dosage), and we constructed several measures of asthma symptom perception based on FEV(1) and symptom ratings. Three months later, 30 participants completed questionnaires on asthma control and asthma-related quality of life.

RESULTS

Symptoms reported during HCT predicted worse asthma control and quality of life 3 months later. The prospective association between symptoms during HCT and asthma control remained significant when controlling for NA and baseline lung function. These effects were strongest for symptoms during ambiguous situations.

CONCLUSIONS

Higher symptom levels at the start of the HCT and during recovery may reflect a tendency to inaccurately perceive asthma symptoms in ambiguous situations. Assessing symptoms during diagnostic challenge tests can help predict problems with asthma treatment.

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.

Impact of comorbidities on asthma

Asthma is a common and serious illness with suboptimal outcomes of care. Epidemiological studies show certain comorbidities occurring more frequently than expected with asthma, with some being associated with poor control and a differential response to therapy options. This review summarizes the evidence of clinically important comorbidities, focusing on the best-explored conditions, including rhinitis and rhinosinusitis, anxiety and depression, obesity, gastroesophageal reflux, smoking and dysfunctional breathing. The evidence of epidemiological and pathophysiological associations for these comorbidities is explored, and the practical therapeutic implications are considered. Comorbidities are important for clinicians treating asthma as they may be markers of patients at risk of poor outcomes, they may point to specific effective treatment options and they are important to researchers as possible confounding factors in clinical trials.

Psychological status in uncontrolled asthma is not related to airway hyperresponsiveness

BACKGROUND

Airway hyperresponsiveness (AHR) is the characteristic functional abnormality of asthma, and previous studies have shown the potential for AHR to be influenced by psychological factors, yet the relationship between anxiety and/or depression and AHR remains unclear in patients with asthma.

OBJECTIVE

To explore the relationship between psychological status and AHR in asthma patients.

METHODS

In a cross-sectional study, 168 adult subjects were recruited with physician-diagnosed uncontrolled asthma and a positive result for AHR in methacholine (Mch) challenge test. Psychological status, asthma control, and asthma quality of life were assessed using Zung self-rating anxiety/depression scale, asthma control test (ACT), and asthma quality of life questionnaire (AQLQ), respectively. AHR severity was evaluated and quantified by the provocative concentration of Mch, which evoked a given decrease of 20% in FEV(1).

RESULTS

A total of 70.23% of recruited patients (n = 118) met the diagnostic criteria for anxiety and/or depression. There was a trend between negative psychological status and AHR in asthma patients that did not reach statistical significance, but no independent effects of negative mood states (anxiety, depression, or both) on AHR were established. Further, analyses revealed that only anxiety is associated with worse asthma control (p = 0.029), and a significant interaction effect of depression and anxiety accounted for lower asthma-related quality-of-life scores (p < 0.001).

CONCLUSIONS

AHR and psychological status are loosely related to each other even if in uncontrolled asthma.

Inaccurate perception of asthma symptoms: a cognitive-affective framework and implications for asthma treatment

Inaccurate perception of respiratory symptoms is often found in asthma patients. Typically, patients who inaccurately perceive asthma symptoms are divided into underperceivers and overperceivers. In this paper we point out that this division is problematic. We argue that little evidence exists for a trait-like stability of under- and overperception and that accuracy of respiratory symptom perception is highly variable within persons and strongly influenced by contextual information. Particularly, expectancy and affective cues appear to have a powerful influence on symptom accuracy. Based on these findings and incorporating recent work on associative learning, attention and mental representations in anxiety and symptom perception, we propose a cognitive-affective model of symptom perception in asthma. The model can act as a framework to understand both normal perception as well as under- and overperception of asthma symptoms and can guide the development of affect-related interventions to improve perceptual accuracy, asthma control and quality of life in asthma patients.

Measurement invariance of the Mini Asthma Quality of Life Questionnaire across African-American and Latino adult asthma patients

PURPOSE

This study tested the factorial and measurement invariance of the Mini Asthma Quality of Life Questionnaire (MiniAQLQ) in a sample of Latino and African-American asthmatic patients.

METHODS

We used confirmatory factor analyses (CFA) to examine data from adult outpatients diagnosed with asthma (n = 265). We proceeded by examining the original factor structure of the MiniAQLQ in the whole sample. We then determined whether the factor structure supported by the data was invariant across African-American and Latino patients by testing a series of nested models.

RESULTS

Results revealed that a three-factor structure model that combined the emotional function and symptom domains had the best fit to the whole sample (chi (2)(91) = 99.83, P = 0.08). Analysis using a MIMIC model among Latino participants indicated that survey language did not influence item functioning (chi (2)(93) = 103.29, P = 0.22). Multi-group CFA showed that both the structure and the meaning of the items were invariant across Africa-American and Latino participants. Scalar and strict measurement invariance was supported for 11 out of 15 items.

CONCLUSION

These data suggest that structure of the MiniAQLQ needs to be reassessed. Additional research needs to examine whether elimination of current items or inclusion of new items can ensure that constructs are measured without bias across different ethnic groups.

Elucidating the relationship between negative affectivity and symptoms: the role of illness-specific affective responses

BACKGROUND

More than 20 years of research confirm a positive association of trait negative affect (NA) with reports of physical symptoms. As the mechanisms underlying the association of trait NA and symptom reporting have not been identified, the meaning of the association remains unclear.

PURPOSE

We attempted to clarify the processes underlying this association by examining the relationship of trait NA and illness-specific worry to both vague, general symptoms and illness-specific symptoms. We tested the hypothesis that trait NA has both a "biasing" effect when ambiguous symptoms are interpreted as a sign of physical illness and an "accuracy" effect on the reports of illness-specific symptoms mediated by illness-specific worry.

METHOD

We examined the relationship of trait and state NA to symptoms reports in both cross-sectional and longitudinal data from inner-city adults with moderate and severe asthma.

RESULTS

Whereas high levels of trait NA were associated with reports of both asthma and nonasthma symptoms, only the relationship of trait NA to symptoms specific to asthma was mediated by asthma worry. In addition, these data showed that trait NA was not associated with the misattribution of symptoms to disease.

CONCLUSIONS

We concluded that NA motivates individuals, through asthma worry, to be more aware of illness-specific symptoms and correctly report and attribute these symptoms to asthma.

Anxiety and panic fear in adults with asthma: prevalence in primary care

Background

Patients may find it difficult to distinguish between the symptoms of anxiety and those of asthma. Findings are equivocal on whether there is a specific link between anxiety and asthma. The aims of this study were to i) to identify the prevalence of anxiety, depression and panic fear in adults with asthma compared with that of the general population ii) to investigate whether there is a specific relationship between asthma and anxiety.

Methods

An epidemiological survey of 872 adults with a diagnosis of asthma identified from six General Practices in Sheffield, England. Community postal survey using self-completion questionnaire.

Results

The response rate was 59%. People with asthma had higher mean Hospital Anxiety and Depression Scale (HADS) anxiety scores than UK norms with a higher proportion above the clinical cut-off. Mean HADS depression scores were significantly higher than UK norms and norms for a general population sample of people registered with the same practice. These effects were age-related with the relationship between asthma and psychological distress most marked over the age of 45. The prevalence of asthma-specific panic fear was 15.7%.

Conclusion

A significant minority of people have high levels of panic fear (as measured by the Asthma Symptom Checklist) associated with asthma. However, in adults with asthma there is also high prevalence of both generalised anxiety and depression (as measured by the HADS), suggesting that the link of anxiety to asthma may be part of a broader relationship between psychological distress and chronic disease rather than a specific one.

What is worse for asthma control and quality of life: depressive disorders, anxiety disorders, or both?

BACKGROUND

The high burden of asthma appears to be related to poor asthma control. Although previous studies have reported associations between depressive disorders (DDs) and anxiety disorders (ADs) and worse asthma control and quality of life, the relative impact of these disorders on asthma control and quality of life has not been explored. This study evaluated the relative impact of having a DD and/or AD on asthma control and quality of life.

METHOD

Five hundred four consecutive adults with confirmed, physician-diagnosed asthma underwent a brief, structured psychiatric interview using the Primary Care Evaluation of Mental Disorders. Asthma control and asthma-related quality of life were assessed using the Asthma Control Questionnaire (ACQ) and the Asthma Quality of Life Questionnaire (AQLQ). All patients underwent standard spirometry.

RESULTS

Thirty-one percent of patients (n = 157) met the diagnostic criteria for one or more psychiatric disorders (8% had DD only, 12% had AD only, and 11% had both). Analyses revealed independent effects for DDs on total ACQ scores (p < 0.01), and for DDs and ADs on total AQLQ scores and all four AQLQ subscales (p < 0.05). There were no interaction effects.

CONCLUSIONS

Results suggest that DDs and ADs are associated with worse asthma-related quality of life, but only DDs are associated with worse asthma control. Interestingly, having both a DD and an AD did not confer additional risk for worse asthma control or quality of life. Physicians may want to consider the differential impact of negative mood states when assessing levels of asthma control and quality of life.

Symptom perception in childhood asthma: the role of anxiety and asthma severity

This study tested the relationship of anxiety and asthma severity to symptom perception. Eighty-six children diagnosed with mild or moderate asthma had symptom perception and pulmonary function measured throughout methacholine challenge (to induce bronchoconstriction). Higher trait anxiety was associated with heightened symptom perception (controlling for pulmonary function) at baseline. Greater asthma severity was associated with blunted symptom perception (controlling for pulmonary function) at the end of methacholine challenge and with a slower rate of increase in symptom perception across methacholine challenge. These results suggest that anxiety plays a role when children's symptoms are mild, whereas medical variables such as severity play a role in perception of changes in asthma symptomatology as bronchoconstriction worsens.

Differentiation between the sensory and affective aspects of histamine-induced bronchoconstriction in asthma

Respiratory symptom perception research has focused mainly on respiratory sensations. Because dyspnea is multidimensional, affective aspects should be investigated. Patients with asthma (N=25) underwent a histamine provocation until a 20% fall in forced expiratory volume in 1s (FEV(1)). After each dose level, 6 symptoms of dyspnea intensity and 6 symptoms of dyspnea affectivity were rated. Individual perceptual sensitivity was determined by calculating the linear slope between the fall in FEV(1) and the increase in the total symptom score, and for affective and sensory symptoms separately [Bijl-Hofland, Folgering, van den Hoogen, et al. Perception of bronchoconstriction in asthma patients measured during histamine challenge test. Eur Respir J 1999;14:1049-54]. Trait anxiety, baseline state anxiety, daily asthma symptoms and catastrophizing during an asthma exacerbation were also assessed. Sensitivity was unrelated to physiological indices of disease severity (i.e., baseline FEV(1) and histamine dose level at 20% fall in FEV(1)), whereas it was positively related to trait anxiety, state anxiety, daily asthma symptoms and catastrophic thinking during an asthma exacerbation in daily life. These relationships were overall much stronger for affective than for sensory symptom slopes. In stepwise multiple regressions, state anxiety was the best predictor of the affective symptom slopes, whereas catastrophic thinking during an asthma exacerbation was the best predictor for the sensory symptom slopes. The differentiation between sensory and affective components of dyspnea adds to the understanding of respiratory symptom perception in asthma.

Rollercoaster asthma: when positive emotional stress interferes with dyspnea perception

The current study assessed how negative and positive stress is related to dyspnea perception. The participants were 25 young women with a medical diagnosis of severe asthma, and 15 matched controls. Stress was induced during repeated rollercoaster rides. Results showed that negative emotional stress and blood pressure peaked just before, and positive emotional stress and heart beat peaked immediately after rollercoaster rides. Dyspnea in women with asthma was higher just before than immediately after rollercoaster rides, even in women with asthma with a rollercoaster-evoked reduction in lung function. These results suggest that stressed and highly aroused individuals with chronic asthma tend to perceive dyspnea in terms of acquired, familiar associations between dyspnea and positive versus negative feeling states, favoring either underperception or overperception of dyspnea, depending on the emotional valence of a situation.

Current perspectives on symptom perception in asthma: a biomedical and psychological review

Symptom perception in patients with asthma is often inadequate. Patients may fail to perceive serious airway obstruction or suffer from breathlessness without objective cause. These extremes are associated with fatal asthma and excessive use of medicines, respectively. This article covers symptom perception in a multidisciplinary perspective. A presentation of current definitions and methods for studying symptom perception in asthma is followed by a summary of theories on the origin of breathlessness. Next, biomedical and psychological factors influencing symptom perception are examined. Preliminary biomedical research emphasizes neural pathway impairment, but causal factors remain inconclusive, particularly regarding the overperception of symptoms. Psychological studies suggest that the accuracy of symptom perception is influenced by (a) competition between asthmatic and nonasthmatic sensory information, (b) negative emotions, and (c) acquired response tendencies (e.g. habituation to symptoms, repression of symptoms, selective perception, and false interpretation of symptoms). These factors may favor either blunted perception or overperception. Empirical data in support of psychological factors are still insufficient. Methodological problems and procedures to improve symptom perception are discussed.

The association of anxiety with asthma among a sample of asthmatics in Ile-Ife Osun State Nigeria

BACKGROUND

The association between asthma and anxiety has been a subject of various studies in developed countries, but there has been little work done in this area in developing countries. The goal of this study is to determine whether asthmatics are more anxious than orthopaedic patients and healthy individuals.

METHOD

Fifty consecutive asthmatics were assessed. All completed a sociodemographic questionnaire, the General Health Questionnaire (GHQ--30) and the State Trait Anxiety Inventory (STAI--1 and 2). Healthy individuals (30) and orthopaedic patients (30) were also recruited as controls; they also completed the GHQ and the STAI--1 and 2.

RESULTS

No significant difference was found in the sociodemographic variables such as age, sex, occupation, and marital status. The asthmatics had a mean GHQ score of 4.2 (SD+/-4.6) while orthopaedic and healthy control groups scored 1.6 (SD+/-1.8) and 2 (SD+/- 1.8), respectively. There was a significant difference in the mean score of the index population (Asthmatics) and the comparison groups (F=7.09, DF=2/107, P=0.004). With GHQ, cutoff point of > or =5.34% of asthmatics scored above 5 while 10% and 13.3% of the orthopaedic patients and healthy controls each scored > or =5. A significant difference was obtained in the mean scores on the STAI--1 questionnaire (F=4.6, DF=2/107, P=.012) indicating state anxiety whereas there was no significant difference on the STAI-2 questionnaire (F= 1.2, DF=2/107, P=0.31).

CONCLUSION

Although asthmatics have higher anxiety compared to controls, this is not an inherent problem or trait among them.

Acquired sensitivity to relevant physiological activity in patients with chronic health problems

The hypothesis that biased symptom perception toward excessive symptoms is common when relatively normal chronic patients enter symptom-relating situations, irrespective of emotional variables, was tested in 19 women with severe asthma, 18 with somatization-like characteristics, and 18 controls. Each underwent three experimental conditions: mental stress, resting, and physical exercise. Each condition included three breathing conditions: breathing normally, normal compressed air, and 5.5% CO2-enriched compressed air. Results yielded no group differences in physiological measures, e.g. elevated CO2 in exhaled air (end-tidal partial pressure of CO2, PetCO2), or lung function. Asthma patients experienced more breathlessness, and somatization-like participants more breathlessness, miscellaneous symptoms, and subjective stress than controls. Although these differences suggested acquired biased symptom perception, as it turned out, breathlessness in asthmatics was more influenced by PetCO2 and less by subjective stress compared to controls. Likewise, breathlessness in somatization-like participants was similarly influenced by PetCO2 and subjective stress compared to controls, and miscellaneous symptoms were even more influenced by PetCO2 and less by subjective stress compared to controls. It was concluded that acquired sensitivity to physiological activity associated with habitual symptoms may account for excessive symptoms in patients with chronic health problems.

Psychological aspects of asthma

Asthma can be affected by stress, anxiety, sadness, and suggestion, as well as by environmental irritants or allergens, exercise, and infection. It also is associated with an elevated prevalence of anxiety and depressive disorders. Asthma and these psychological states and traits may mutually potentiate each other through direct psychophysiological mediation, nonadherence to medical regimen, exposure to asthma triggers, and inaccuracy of asthma symptom perception. Defensiveness is associated with inaccurate perception of airway resistance and stress-related bronchoconstriction. Asthma education programs that teach about the nature of the disease, medications, and trigger avoidance tend to reduce asthma morbidity. Other promising psychological interventions as adjuncts to medical treatment include training in symptom perception, stress management, hypnosis, yoga, and several biofeedback procedures.

Frequency and perception of cough severity

OBJECTIVE

The frequency of the common symptom of cough in children is unknown. The aim of this study was to compare cough frequency and perception of cough severity in children with and without recurrent cough.

METHODOLOGY

Eighty-four children with (C) and without (NC) recurrent cough were recruited in the same season. Cough frequency (measured with cough-meter) and subjective cough severity (measured on parent-completed and child-completed diary cards on two subjective systems), were compared between the two groups.

RESULTS

Cough frequency in C (median 65/day) was significantly higher than in NC (10/day). The correlation between daytime and night-time cough was higher in NC (rs = 0.51, P < 0.00001) than in C (rs = 0.3, P = 0.05). The C group had significantly higher coughs per score than NC, for both subjective methods.

CONCLUSIONS

Children with recurrent cough have a higher frequency and different pattern of cough than controls enrolled in the same season. Subjective perception of cough severity is dependent on the population studied.

Paradoxical breathlessness in asthma

This study tested the hypothesis that breathlessness in asthma relates linearly to airway obstruction when situational, attentional and emotional influences are held constant via random presentation of different intensities of externally applied airflow obstruction. Adolescents with stable asthma and normal controls (n = 25 + 25) with lung functions of approximately 3.5 1 forced expiratory volume in 1 s (FEV1) breathed through a device which obstructed airflow with five stimulus intensities, analogous to a mean reduction in FEV1 of 8-66%. A session consisted of 10 blocks, each with presentation of five stimulus intensities plus the baseline resistance of the apparatus. Breathlessness was continuously reported by moving a lever along a 10-point scale. The mean breathlessness was computed per stimulus intensity. Lung function and anxiety were measured before and after the test. Participants with asthma, not controls, manifested a paradoxical response: they reported significantly more breathlessness, but undifferentially. One patient against 12 controls' reported consistently more breathlessness from baseline to severe obstruction. The hypothesis was only supported for controls. Breathlessness did not correlate with severity of asthma, lung function, duration of asthma, number of exacerbations over the last six months, age, sex or anxiety. It was concluded that the meaning of airflow obstruction in patients with asthma has changed and underlies their paradoxical responses, even when situational, attentional and emotional factors are controlled.

Perception of induced bronchoconstriction in a community sample of adolescents

BACKGROUND

Poor perception of asthma symptoms has been cited as a risk factor for asthma death, yet there is no consensus as to the best way to characterize perception, and little is known about perception in normative samples. Hypoperceivers are of clinical interest because of risks of undertreatment; hyperperceivers are at risk for adverse iatrogenic effects caused by overtreatment.

OBJECTIVE

This study investigates perception of methacholine-induced bronchoconstriction in 175 adolescents.

METHODS

Breathlessness was rated after each inhalation by using the Borg scale. Perception groups were calculated on the basis of change from placebo Borg to high Borg scores (perception score at the highest methacholine dose). Subjects were called hypoperceivers if their Borg change score was greater than 1 SD below the mean for their FEV(1) group, hyperperceivers if their Borg change score was greater than 1 SD above the mean for their FEV(1) group, and accurate perceivers otherwise.

RESULTS

For subjects with an FEV(1) drop of less than 10%, accurate perceivers had a change in Borg score of 1.4 or less, and hyperperceivers had a change of greater than 1.4. For a drop in FEV(1) between 10% and 19%, hypoperceivers had a change in Borg score of less than 0.2, accurate perceivers had a change between 0.2 and 2.1, and hyperperceivers had a change of greater than 2.1. For those with an FEV(1) drop of 20% or greater, hypoperceivers had a Borg change of less than 0.2, accurate perceivers had a change between 0.2 and 2.6, and hyperperceivers had a change of greater than 2.6. No differences in age, sex, placebo Borg ratings, baseline pulmonary functions, PC(20) values, or psychologic variables were found among perception groups.

CONCLUSION

This study provides reference Borg values during methacholine challenge for 175 community adolescents.

Excessive breathlessness through emotional imagery in asthma

Breathlessness and negative emotions during asthma attacks interact in complex patterns. This study tested the influence of emotional imagery on breathlessness during voluntary breath holding. Adolescents with and without asthma (n = 36 + 36) were assigned to positive imagery, negative imagery, or no imagery. There were four trials with close to thresholds for breath holding combined with imagery. Breathlessness and quality of imagery were measured by the end of breath holding. Additional measures were lung function and anxiety. The results showed that positive and negative imagery were only influencing breathlessness in participants with asthma. Although threshold duration for the groups were not significantly different, participants with asthma reported more breathlessness. The intensity of imagery enhanced breathlessness but diminished the accuracy of symptom perception. Positive imagery diminished breathlessness in participants with asthma, but also the difference in breathlessness between 75% and 95% of threshold duration. Breathlessness did not correlate with lung function, anxiety or other variables. It was concluded that emotional imagery during asthma attacks distracts from accurate introspection or enhances breathlessness, irrespective of anxiety.

Reviewing asthma and anxiety

The main characteristic of asthma is sudden and unexpected attacks of impaired breathing. Both the attacks themselves and the prospect of attacks generate much anxiety amongst patients. Several different forms of anxiety can be identified which vary in intensity and the situations in which they appear. Anxiety disorders are more common in asthmatics and have a considerable influence on asthma management because they influence symptom perception. Excessive anxiety about asthma symptoms can affect the patient's response to an asthma attack; anxiety related to asthma triggers can reduce the patient's quality of life and anxiety related to medical treatment can influence compliance. The extent of this influence depends upon an individual's ability to cope. Behavioural therapeutic programmes for patient education offer an opportunity to reduce anxiety and to improve asthma self-management. Physicians should look carefully for anxiety when taking the patient's history, and should support the patient's participation in asthma education programs.

Perceptions of asthma by adolescents at home

OBJECTIVES

To test symptom perception in asthma under natural circumstances and to establish relationships between changes in airway obstruction as indicated by wheeze, dyspnea, general sensations, and emotional state.

DESIGN

Continuous in vivo monitoring.

METHOD

Symptom perception was tested in 30 adolescents with severe, unstable asthma. They were continuously monitored in their homes for 72 h. Symptom perception was defined as the relation between self-reported dyspnea and airway obstruction as evident from audible wheeze. Tracheal sounds were continuously recorded with wireless telemetry for wheeze assessment. Dyspnea was assessed four times per day on a Likert-type 10-point scale, as well as four times randomly after pager remote command. The subjects kept records of use of medication, daily activities, general symptoms, and mood state in a diary.

RESULTS

There were nine subjects with one or two wheeze episodes, another three subjects with three or four episodes, and one subject with almost continuous wheeze. The presence of wheeze in general related significantly to a rise (from individual baseline) in dyspnea of > 2.5 scale points. Acute wheeze was the best predictor of a rise in dyspnea, but prolonged wheeze correlated significantly with negative mood and general symptoms.

CONCLUSION

Patients with prolonged airway obstruction perceived symptoms less well and were more vulnerable to negative effects of asthma than patients with acute onset airway obstruction.

The impact of severe asthma on schoolchildren

Episodic airway obstruction and hypoxia are potentially life-threatening to children with asthma and may account for neuropsychological impairment. Moreover, living with this chronic disease may severely disrupt children's emotional functioning. The general functioning of 25 children with severe asthma aged 10-13 years was tested by a comparison with 25 matched normal controls. Testing included variables with relevance to normal daily functioning: memory, concentration, school performance, physical condition, subjective symptoms after exercise, and negative emotions. The results showed that children with asthma did not significantly deviate from controls. They reported more dyspnea after physical exercise, which could not be attributed to lung function. Differences in school performance were not significant. It was concluded that children may generally adapt well to living with asthma.