Influence of breathing therapy on complaints, anxiety and breathing pattern in patients with hyperventilation syndrome and anxiety disorders

Use of breathing retraining exercises and SSRIs in patients with hyperventilation syndrome

Hyperventilation syndrome (HVS) is a condition that is seen in almost 10% of the general adult population. It presents with difficulty breathing, often in conjunction with anxiety, dizziness and light-headedness. We report a case involving a woman in her 30s, who presented to the emergency room with a primary complaint of shortness of breath and had a prolonged expiratory phase on examination. During a follow-up office visit, she had a generalised anxiety disorder-7 (GAD-7) score of 11, consistent with moderate anxiety. The diagnosis of HVS was made, and the patient began breathing retraining exercises and a selective serotonin reuptake inhibitor (SSRI), fluoxetine. At her subsequent visit 1 month later, the patient reported significant improvement in both her shortness of breath and anxiety. Her GAD-7 score had decreased to 4, consistent with minimal anxiety. We believe that early recognition, behavioural interventions and SSRIs improved the patient's outcome.

Service failure is bound to happen: Unraveling the impact of dissatisfaction, complaint behavior and re-travel intention in travel and tourism industry

Service failure is bound to happen, but dissatisfaction has always been undermined by scholars previously. The present study investigates dissatisfaction factors in travel decision-making leading towards re-travel intention with the help of the expectancy disconfirmation theory (EDT) model. Moreover, complaint behavior mediates the relationship between dissatisfaction and re-travel intention concerning the factors involved in it. For the findings, 434 real-time responses were collected through an offline survey following the lifetime value (LTV) approach. Kaiser-Meyer-Olkin (KMO) and Bartlett's tests were conducted to test the sphericity of the variables one by one. Furthermore, structural equation modeling (SEM) was implied to test the measurement and structural models. All the hypotheses supported and accepted the proposed research questions. The findings reveal that the dissatisfaction factors, with their interaction terms (transaction-based and experience-based), help study the variable dissatisfaction and its multifaceted concept in travel and tourism literature. Moreover, complaint behavior is identified as a key mediating factor in the relationship between dissatisfaction and re-travel intention, suggesting that commuters' response to dissatisfaction, including complaints, shapes their future re-travel intentions. The theoretical implications of the study are substantial, as it advances our understanding of commuter behavior in the context of public transport travel and tourism. Practically, the findings offer actionable insights for public transport authorities and service providers. Understanding the specific dissatisfaction factors influencing re-travel intention allows for targeted interventions to improve service quality and customer experience. Recognizing the importance of effective complaint management systems can help organizations better address customer grievances and mitigate the negative effects of dissatisfaction on re-travel intention.

Remote Short Sessions of Heart Rate Variability Biofeedback Monitored With Wearable Technology: Open-Label Prospective Feasibility Study

BACKGROUND

Heart rate variability (HRV) biofeedback is often performed with structured education, laboratory-based assessments, and practice sessions. It has been shown to improve psychological and physiological function across populations. However, a means to remotely use and monitor this approach would allow for wider use of this technique. Advancements in wearable and digital technology present an opportunity for the widespread application of this approach.

OBJECTIVE

The primary aim of the study was to determine the feasibility of fully remote, self-administered short sessions of HRV-directed biofeedback in a diverse population of health care workers (HCWs). The secondary aim was to determine whether a fully remote, HRV-directed biofeedback intervention significantly alters longitudinal HRV over the intervention period, as monitored by wearable devices. The tertiary aim was to estimate the impact of this intervention on metrics of psychological well-being.

METHODS

To determine whether remotely implemented short sessions of HRV biofeedback can improve autonomic metrics and psychological well-being, we enrolled HCWs across 7 hospitals in New York City in the United States. They downloaded our study app, watched brief educational videos about HRV biofeedback, and used a well-studied HRV biofeedback program remotely through their smartphone. HRV biofeedback sessions were used for 5 minutes per day for 5 weeks. HCWs were then followed for 12 weeks after the intervention period. Psychological measures were obtained over the study period, and they wore an Apple Watch for at least 7 weeks to monitor the circadian features of HRV.

RESULTS

In total, 127 HCWs were enrolled in the study. Overall, only 21 (16.5%) were at least 50% compliant with the HRV biofeedback intervention, representing a small portion of the total sample. This demonstrates that this study design does not feasibly result in adequate rates of compliance with the intervention. Numerical improvement in psychological metrics was observed over the 17-week study period, although it did not reach statistical significance (all P>.05). Using a mixed effect cosinor model, the mean midline-estimating statistic of rhythm (MESOR) of the circadian pattern of the SD of the interbeat interval of normal sinus beats (SDNN), an HRV metric, was observed to increase over the first 4 weeks of the biofeedback intervention in HCWs who were at least 50% compliant.

CONCLUSIONS

In conclusion, we found that using brief remote HRV biofeedback sessions and monitoring its physiological effect using wearable devices, in the manner that the study was conducted, was not feasible. This is considering the low compliance rates with the study intervention. We found that remote short sessions of HRV biofeedback demonstrate potential promise in improving autonomic nervous function and warrant further study. Wearable devices can monitor the physiological effects of psychological interventions.

Breathing Practices for Stress and Anxiety Reduction: Conceptual Framework of Implementation Guidelines Based on a Systematic Review of the Published Literature

Anxiety and stress plague populations worldwide. Voluntary regulated breathing practices offer a tool to address this epidemic. We examined peer-reviewed published literature to understand effective approaches to and implementation of these practices. PubMed and ScienceDirect were searched to identify clinical trials evaluating isolated breathing-based interventions with psychometric stress/anxiety outcomes. Two independent reviewers conducted all screening and data extraction. Of 2904 unique articles, 731 abstracts, and 181 full texts screened, 58 met the inclusion criteria. Fifty-four of the studies' 72 interventions were effective. Components of effective and ineffective interventions were evaluated to develop a conceptual framework of factors associated with stress/anxiety reduction effectiveness. Effective breath practices avoided fast-only breath paces and sessions <5 min, while including human-guided training, multiple sessions, and long-term practice. Population, other breath paces, session duration ≥5 min, and group versus individual or at-home practices were not associated with effectiveness. Analysis of interventions that did not fit this framework revealed that extensive standing, interruptions, involuntary diaphragmatic obstruction, and inadequate training for highly technical practices may render otherwise promising interventions ineffective. Following this evidence-based framework can help maximize the stress/anxiety reduction benefits of breathing practices. Future research is warranted to further refine this easily accessible intervention for stress/anxiety relief.

Breathwork Interventions for Adults with Clinically Diagnosed Anxiety Disorders: A Scoping Review

Anxiety disorders are the most common group of mental disorders, but they are often underrecognized and undertreated in primary care. Dysfunctional breathing is a hallmark of anxiety disorders; however, mainstays of treatments do not tackle breathing in patients suffering anxiety. This scoping review aims to identify the nature and extent of the available research literature on the efficacy of breathwork interventions for adults with clinically diagnosed anxiety disorders using the DSM-5 classification system. Using the PRISMA extension for scoping reviews, a search of PubMed, Embase, and Scopus was conducted using terms related to anxiety disorders and breathwork interventions. Only clinical studies using breathwork (without the combination of other interventions) and performed on adult patients diagnosed with an anxiety disorder using the DSM-5 classification system were included. From 1081 articles identified across three databases, sixteen were included for the review. A range of breathwork interventions yielded significant improvements in anxiety symptoms in patients clinically diagnosed with anxiety disorders. The results around the role of hyperventilation in treatment of anxiety were contradictory in few of the examined studies. This evidence-based review supports the clinical utility of breathwork interventions and discusses effective treatment options and protocols that are feasible and accessible to patients suffering anxiety. Current gaps in knowledge for future research directions have also been identified.

Physical Therapy and Mental Health: A Scoping Review

OBJECTIVES

Coexistence of mental and physical health conditions is prevalent. To achieve optimal physical therapy outcomes, neither should be treated in isolation. This review aimed to map intersections between physical therapy and mental health.

METHODS

This was a scoping review searching MEDLINE, CINAHL, PsycInfo, Cochrane, and PEDro databases. Two independent researchers screened studies of physical therapy practice with adolescents/adults with mental health disorders or research using primary mental health outcomes in physical health conditions or clinicians' perspective. Data were extracted on study type, participants, topics, publication year, and country.

RESULTS

The search yielded 3633 studies with 135 included. Five studies included adolescents. More than one-half were published since 2015. Studies specific to participants with mental health diagnoses included schizophrenia (n = 12), depressive disorders (n = 8), eating disorders (n = 6), anxiety disorders (n = 4), bipolar disorders (n = 1), somatic disorders (n = 5), and trauma and stressor-related disorders (n = 8) or varied mental health diagnoses (n = 14). Forty-one studies had primary mental health outcomes or clinical practice approaches with a mental health emphasis with participants with physical health conditions (musculoskeletal [n = 13], neurological [n = 7], other [n = 21]). Systematic reviews or randomized controlled trials predominantly involved exercise therapy and/or physical activity. Descriptions of physical therapists as participants (n = 35) included 4 main topics: (1) mental health screening; (2) knowledge, attitudes, and experiences; (3) key practice components; and (4) research priorities.

CONCLUSION

Physical therapy intersects with people experiencing mental health disorders across a broad spectrum of diagnoses, covering a range of interventions with a small but growing evidence base.

IMPACT

Exercise and physical activity studies dominated the highest levels of evidence and future focus, although economic evaluations and consumer-driven or patient experience studies are needed. There is a contrast between the confidence and knowledge of specialized physical therapists working within mental health settings and those in general practice settings. Inspiring, integrated education is required to further improve health care outcomes following physical therapy for people with mental health disorders or symptoms.

Reducing Test Anxiety and Related Symptoms Using a Biofeedback Respiratory Practice Device: A Randomized Control Trial

Test Anxiety is a widespread psychological phenomenon. With prevalence rates of 20-40 percent of university students, it impedes adaptive functioning and life quality. Many available treatments for Test Anxiety involve the intervention of clinicians and usually a few months are required before symptom reduction is reported. The present randomized controlled trial examined a simple behavioral intervention-the use of breathing tools-as an exclusive therapy for Test Anxiety. Specifically, the efficacy of a biofeedback respiratory practice device was examined. 34 students were assigned to 3 treatment groups during their exam period: Biofeedback device group, self-directed breathing exercise group, and psychoeducation group. Self-report measures of Test Anxiety were collected pre- and post-intervention. Participants also reported additional exploratory measures such as depression and anxiety, quality of life, and their perceived adaptive functioning post-intervention. The results reveal that only participants from the biofeedback device group reported a significant reduction in Test Anxiety symptoms (p's < 0.05). Participants from the biofeedback device group also reported a decrease in depression and anxiety symptoms and an increase in psychological wellbeing (p's < 0.05), a subscale of the quality of life questionnaire. Findings support the notion that using biofeedback respiratory devices may reduce students' Test Anxiety symptoms. Indications for further research are discussed.

Efficacy of a Virtual Reality Biofeedback Game (DEEP) to Reduce Anxiety and Disruptive Classroom Behavior: Single-Case Study

BACKGROUND

Many adolescents in special education are affected by anxiety in addition to their behavioral problems. Anxiety leads to substantial long-term problems and may underlie disruptive behaviors in the classroom as a result of the individual's inability to tolerate anxiety-provoking situations. Thus, interventions in special needs schools that help adolescents cope with anxiety and, in turn, diminish disruptive classroom behaviors are needed.

OBJECTIVE

This study aimed to evaluate the effect of a virtual reality biofeedback game, DEEP, on daily levels of state-anxiety and disruptive classroom behavior in a clinical sample. In addition, the study also aimed to examine the duration of the calm or relaxed state after playing DEEP.

METHODS

A total of 8 adolescents attending a special secondary school for students with behavioral and psychiatric problems participated in a single-case experimental ABAB study. Over a 4-week period, participants completed 6 DEEP sessions. In addition, momentary assessments (ie, 3 times a day) of self-reported state-anxiety and teacher-reported classroom behavior were collected throughout all A and B phases.

RESULTS

From analyzing the individual profiles, it was found that 6 participants showed reductions in anxiety, and 5 participants showed reductions in disruptive classroom behaviors after the introduction of DEEP. On a group level, results showed a small but significant reduction of anxiety (d=-0.29) and a small, nonsignificant reduction of disruptive classroom behavior (d=-0.16) on days when participants played DEEP. Moreover, it was found that the calm or relaxed state of participants after playing DEEP lasted for about 2 hours on average.

CONCLUSIONS

This study demonstrates the potential of the game, DEEP, as an intervention for anxiety and disruptive classroom behavior in a special school setting. Future research is needed to fully optimize and personalize DEEP as an intervention for the heterogeneous special school population.

Dysfunctional breathing: what do we know?

Dysfunctional breathing (DB) is a respiratory condition characterized by irregular breathing patterns that occur either in the absence of concurrent diseases or secondary to cardiopulmonary diseases. Although the primary symptom is often dyspnea or “air hunger”, DB is also associated with nonrespiratory symptoms such as dizziness and palpitations. DB has been identified across all ages. Its prevalence among adults in primary care in the United Kingdom is approximately 9.5%. In addition, among individuals with asthma, a positive diagnosis of DB is found in a third of women and a fifth of men. Although DB has been investigated for decades, it remains poorly understood because of a paucity of high-quality clinical trials and validated outcome measures specific to this population. Accordingly, DB is often underdiagnosed or misdiagnosed, given the similarity of its associated symptoms (dyspnea, tachycardia, and dizziness) to those of other common cardiopulmonary diseases such as COPD and asthma. The high rates of misdiagnosis of DB suggest that health care professionals do not fully understand this condition and may therefore fail to provide patients with an appropriate treatment. Given the multifarious, psychophysiological nature of DB, a holistic, multidimensional assessment would seem the most appropriate way to enhance understanding and diagnostic accuracy. The present narrative review was developed as a means of summarizing the available evidence about DB, as well as improving understanding of the condition by researchers and practitioners.

Association of dysfunctional breathing with health-related quality of life: A cross-sectional study in a young population

Symptomatic hyperventilation (SH) is a pathological condition that manifests with breathlessness, dyspnea, light-headedness, anxiety, and paresthesia. However, little is known about the prevalence of SH and its association with health-related quality of life (HRQoL) in a young population. The Nijmegen questionnaire (NQ), which measures severity of SH, had not previously been cross-culturally translated into Korean. In this study, the NQ was cross-culturally translated into Korean (KNQ), using translation and back-translation methods. To examine the reliability and validity levels of the KNQ, as well as its association with HRQoL, 237 college students (21.38 ± 2.45 years) were asked to complete the KNQ, the Korean version of the general health questionnaire (K-GHQ-30) and the short form-36 (K-SF-36). The KNQ showed satisfactory reliability (Cronbach's α = 0.878). In the construct validity test, four factors (neuropsychological, respiratory, neurogastrointestinal, and neuromuscular) were extracted (% of total variance = 59.8). Using a KNQ cut-off score of 23 points, the prevalence of SH was 22.8%. Physical and mental HRQoL levels estimated by the K-GHQ-30 score and the 8 subscale scores of the K-SF-36 were lower in the SH group than in those of the non-SH group. It is concluded that the cross-culturally translated KNQ is reliable and valid, and management of SH may prevent a reduction in physical and mental HRQoL in a young population.

Automated analysis of breathing waveforms using BreathMetrics: a respiratory signal processing toolbox

Nasal inhalation is the basis of olfactory perception and drives neural activity in olfactory and limbic brain regions. Therefore, our ability to investigate the neural underpinnings of olfaction and respiration can only be as good as our ability to characterize features of respiratory behavior. However, recordings of natural breathing are inherently nonstationary, nonsinusoidal, and idiosyncratic making feature extraction difficult to automate. The absence of a freely available computational tool for characterizing respiratory behavior is a hindrance to many facets of olfactory and respiratory neuroscience. To solve this problem, we developed BreathMetrics, an open-source tool that automatically extracts the full set of features embedded in human nasal airflow recordings. Here, we rigorously validate BreathMetrics' feature estimation accuracy on multiple nasal airflow datasets, intracranial electrophysiological recordings of human olfactory cortex, and computational simulations of breathing signals. We hope this tool will allow researchers to ask new questions about how respiration relates to body, brain, and behavior.

Slow Breathing Can Be Operantly Conditioned in the Rat and May Reduce Sensitivity to Experimental Stressors

In humans, exercises involving slowed respiratory rate (SRR) counter autonomic sympathetic bias and reduce responses to stressors, including in individuals with various degrees of autonomic dysfunction. In the rat, we examined whether operant conditioning could lead to reductions in respiratory rate (RR) and performed preliminary studies to assess whether conditioned SRR was sufficient to decrease physiological and behavioral responsiveness to stressors. RR was continuously monitored during 20 2-h sessions using whole body plethysmography. SRR conditioned, but not yoked control rats, were able to turn off aversive visual stimulation (intermittent bright light) by slowing their breathing below a preset target of 80 breaths/min. SRR conditioned rats greatly increased the incidence of breaths below the target RR over training, with average resting RR decreasing from 92 to 81 breaths/min. These effects were significant as a group and vs. yoked controls. Preliminary studies in a subset of conditioned rats revealed behavioral changes suggestive of reduced reactivity to stressful and nociceptive stimuli. In these same rats, intermittent sessions without visual reinforcement and a post-training priming stressor (acute restraint) demonstrated that conditioned rats retained reduced RR vs. controls in the absence of conditioning. In conclusion, we present the first successful attempt to operantly condition reduced RR in an animal model. Although further studies are needed to clarify the physio-behavioral concomitants of slowed breathing, the developed model may aid subsequent neurophysiological inquiries on the role of slow breathing in stress reduction.

Inhalation/Exhalation ratio modulates the effect of slow breathing on heart rate variability and relaxation

Slow breathing is widely applied to improve symptoms of hyperarousal, but it is unknown whether its beneficial effects relate to the reduction in respiration rate per se, or, to a lower inhalation/exhalation (i/e) ratio. The present study examined the effects of four ventilatory patterns on heart rate variability and self-reported dimensions of relaxation. Thirty participants were instructed to breathe at 6 or 12 breaths/min, and with an i/e ratio of 0.42 or 2.33. Participants reported increased relaxation, stress reduction, mindfulness and positive energy when breathing with the low compared to the high i/e ratio. A lower compared to a higher respiration rate was associated only with an increased score on positive energy. A low i/e ratio was also associated with more power in the high frequency component of heart rate variability, but only for the slow breathing pattern. Our results show that i/e ratio is an important modulator for the autonomic and subjective effects of instructed ventilatory patterns.

Influence of visual acuity on anxiety, panic and depression disorders among young and middle age adults in the United States

BACKGROUND

Previous research, albeit limited, has demonstrated an association of visual acuity with depression and anxiety. However, these studies are limited in that they have focused on older adults, used a convenient sample, and/or used a subjective assessment of visual function. As a result, the purpose of this study was to examine the association of objectively-measured visual acuity with depression and anxiety (and panic disorder) among a national sample of young- and middle-age U.S. adults (20-39 years).

METHODS

Using data from the 2003-2004 NHANES (n=602), the presence of anxiety, depression, and panic disorders was assessed from a diagnostic interview. Visual acuity was assessed from a vision exam using the Nidek Auto Lensmeter Model (LM-990A) and expressed as LogMAR units.

RESULTS

After adjusting for age, gender, race-ethnicity, body mass index, mean arterial pressure, cotinine, diabetes, and physical activity, visual acuity was not associated with panic disorder (p=0.71) or depression disorder (p=0.20), but for every 0.1 LogMAR unit change in vision, participants had a 14% (OR=1.14; p=0.04) higher odds of having an anxiety disorder.

LIMITATIONS

The main limitation of this study was the cross-sectional design.

CONCLUSION

Young- and middle-age U.S. adults with worse visual function are at increased odds of having an anxiety disorder. Strategies to prevent and treat anxiety among those with worse visual function are needed.

The Nijmegen Questionnaire and dysfunctional breathing

The Nijmegen Questionnaire is useful to quantify and assess the normality of subjective sensations http://ow.ly/MBJj1.

Getting to grips with 'dysfunctional breathing'

Dysfunctional breathing (DB) is common, frequently unrecognised and responsible for a substantial burden of morbidity. Previously lack of clarity in the use of the term and the use of multiple terms to describe the same condition has hampered our understanding. DB can be defined as an alteration in the normal biomechanical patterns of breathing that result in intermittent or chronic symptoms. It can be subdivided into thoracic and extra thoracic forms. Thoracic DB is characterised by breathing patterns involving relatively inefficient, excessive upper chest wall activity with or without accessory muscle activity. This is frequently associated with increased residual volume, frequent sighing and an irregular pattern of respiratory effort. It may be accompanied by true hyperventilation in the minority of subjects. Extra thoracic forms include paradoxical vocal cord dysfunction and the increasingly recognised supra-glottic 'laryngomalacia' commonly seen in young sportsmen and women. While the two forms would appear to be two discreet entities they often share common factors in aetiology and respond to similar interventions. Hence both forms are considered in this review which aims to generate a more coherent approach to understanding, diagnosing and treating these conditions.

Improvements in sleep and handwriting after complementary medical intervention using acupuncture, applied kinesiology, and respiratory exercises in a nine-year-old ADHD patient on methylphenidate

The case study reports on the effect of pharmacological, complementary, and alternative medicine including acupuncture, Applied Kinesiology, and respiratory exercises in a boy with attention-deficit hyperactivity disorder (ADHD) on methylphenidate. A nine-year-old male patient was referred to treatment with a three-year diagnosis of ADHD, sleeping troubles, and dissatisfaction with methylphenidate. Examination included Applied Kinesiology, the coachman׳s test, assessment of breathing pattern disorders, and traditional chinese medicine (TCM) diagnosis. Muscle weakness related to thoracic breathing was found in the coachman׳s test. Respiratory exercises, acupuncture with permanent needles, and Applied Kinesiology treatments were given. Within the first treatment, muscle function as assessed by the coachman׳s test normalized. After two treatments, sleep behavior improved rapidly, and with further treatments, handwriting was improving. Methylphenidate continues to be given. The results were stable after 15 months. A multimodal approach to ADHD integrating pharmacological treatment and complementary and alternative medicine (CAM) including Applied Kinesiology, breathing exercises, and acupuncture.

Cross-sectional assessment of exertional dyspnea in otherwise healthy children

OBJECTIVES

Exertional dyspnea during sport at school in children with asthma or in otherwise healthy children is commonly attributed to exercise-induced asthma (EIA), but when a short-acting beta agonist (SABA) trial fails to improve symptoms the physician is often at a loose end.

DESIGN

The aims were to prospectively assess the causes of exertional dyspnea in children/adolescents with or without asthma using a cardiopulmonary exercise test while receiving a SABA and to assess the effects of standardized breathing/reassurance therapy.

RESULTS

Seventy-nine patients (12.2 ± 2.3 years, 41 girls, 49 with previously diagnosed asthma) with dyspnea unresponsive to SABA were prospectively included. Exercise test outcomes depicted normal or subnormal performance with normal ventilatory demand and capacity in 53/79 children (67%) defining a physiological response. The remaining 26 children had altered capacity (resistant EIA [n = 17, 9 with previous asthma diagnosis], vocal cord dysfunction [n = 2]) and/or increased demand (alveolar hyperventilation [n = 3], poor conditioning [n = 7]). Forty-two children who had similar characteristics than the remaining 37 children underwent the two sessions of standardized reassurance therapy. They all demonstrated an improvement that was rated "large." The degree of improvement correlated with % predicted peak V'O2 (r = -0.37, P = 0.015) and peak oxygen pulse (r = -0.45, P = 0.003), whatever the underlying dyspnea cause. It suggested a higher benefit in those with poorer conditioning condition.

CONCLUSIONS

The most frequent finding in children/adolescents with mild exertional dyspnea unresponsive to preventive SABA is a physiological response to exercise, and standardized reassurance afforded early clinical improvement, irrespective of the dyspnea cause.

Does manual therapy provide additional benefit to breathing retraining in the management of dysfunctional breathing? A randomised controlled trial

PURPOSE

Dysfunctional breathing (DB) is associated with an abnormal breathing pattern, unexplained breathlessness and significant patient morbidity. Treatment involves breathing retraining through respiratory physiotherapy. Recently, manual therapy (MT) has also been used, but no evidence exists to validate its use. This study sought to investigate whether MT produces additional benefit when compared with breathing retraining alone in patients with DB.

METHODS

Sixty subjects with primary DB were randomised into either breathing retraining (standard treatment; n = 30) or breathing retraining plus MT (intervention; n = 30) group. Both the groups received standardised respiratory physiotherapy, which included: DB education, breathing retraining, home regimen, and audio disc. Intervention group subjects additionally received MT following further assessment. Data from 57 subjects were analysed.

RESULTS

At baseline, standard treatment group subjects were statistically younger (41.7 + 13.5 versus 50.8 + 13.0 years; p = 0.001) with higher Nijmegen scores (38.6 + 9.5 versus 31.5 + 6.9; p = 0.001). However, no significant difference was found between the groups for primary outcome Nijmegen score (95% CI (-1.1, 6.6) p = 0.162), or any secondary outcomes (Hospital Anxiety & Depression Score, spirometry or exercise tolerance).

CONCLUSION

Breathing retraining is currently the mainstay of treatment for patients with DB. The results of this study suggest MT provides no additional benefit in this patient group.

IMPLICATIONS FOR REHABILITATION

Dysfunctional breathing (DB) is associated with significant patient morbidity but often goes unrecognised, leading to prolonged investigation and significant use of health care resources. Breathing retraining remains the primary management of this condition. However, physiotherapists are also using manual therapy (MT) as an adjunctive treatment for patients with DB. However, the results of this study suggest that MT provides no further benefit and cannot be recommended in the clinical management of this condition.

Adolescent girls with emotional disorders have a lower end-tidal CO2 and increased respiratory rate compared with healthy controls

Hyperventilation has been linked to emotional distress in adults. This study investigates end-tidal carbon dioxide (ETCO₂), respiratory rate (RR), and heart rate variability (HRV) in adolescent girls with emotional disorders and healthy controls. ETCO₂, RR, HRV, and ratings of emotional symptom severity were collected in adolescent female psychiatric patients with emotional disorders (n = 63) and healthy controls (n = 62). ETCO₂ and RR differed significantly between patients and controls. ETCO₂, HR, and HRV were significant independent predictors of group status, that is, clinical or healthy, while RR was not. ETCO₂ and RR were significantly related to emotional symptom severity and to HRV in the total group. ETCO₂ and RR were not affected by use of selective serotonin reuptake inhibitors. It is concluded that emotional dysregulation is related to hyperventilation in adolescent girls. Respiratory-based treatments may be relevant to investigate in future research.

Breathing exercises for dysfunctional breathing/hyperventilation syndrome in children

BACKGROUND

Dysfunctional breathing is described as chronic or recurrent changes in breathing pattern causing respiratory and non-respiratory symptoms. It is an umbrella term that encompasses hyperventilation syndrome and vocal cord dysfunction. Dysfunctional breathing affects 10% of the general population. Symptoms include dyspnoea, chest tightness, sighing and chest pain which arise secondary to alterations in respiratory pattern and rate. Little is known about dysfunctional breathing in children. Preliminary data suggest 5.3% or more of children with asthma have dysfunctional breathing and that, unlike in adults, it is associated with poorer asthma control. It is not known what proportion of the general paediatric population is affected. Breathing training is recommended as a first-line treatment for adults with dysfunctional breathing (with or without asthma) but no similar recommendations are available for the management of children. As such, breathing retraining is adapted from adult regimens based on the age and ability of the child.

OBJECTIVES

To determine whether breathing retraining in children with dysfunctional breathing has beneficial effects as measured by quality of life indices.To determine whether there are any adverse effects of breathing retraining in young people with dysfunctional breathing.

SEARCH METHODS

We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE and EMBASE. We searched the National Research Register (NRR) Archive, Health Services Research Projects in Progress (HSRProj), Current Controlled Trials register (incorporating the metaRegister of Controlled Trials and the International Standard Randomised Controlled Trial Number (ISRCTN) to identify research in progress and unpublished research. The latest search was undertaken in October 2013.

SELECTION CRITERIA

We planned to include randomised, quasi-randomised or cluster-randomised controlled trials. We excluded observational studies, case studies and studies utilising a cross-over design. The cross-over design was considered inappropriate due to the purported long-lasting effects of breathing retraining. Children up to the age of 18 years with a clinical diagnosis of dysfunctional breathing were eligible for inclusion. We planned to include children with a primary diagnosis of asthma with the intention of undertaking a subgroup analysis. Children with symptoms secondary to cardiac or metabolic disease were excluded.We considered any type of breathing retraining exercise for inclusion in this review, such as breathing control, diaphragmatic breathing, yoga breathing, Buteyko breathing, biofeedback-guided breathing modification and yawn/sigh suppression. We considered programmes where exercises were either supervised (by parents or a health professional, or both) or unsupervised. We also considered relaxation techniques and acute episode management as long as it was clear that breathing exercises were a component of the intervention.Any intervention without breathing exercises or where breathing exercises were not key to the intervention were excluded.

DATA COLLECTION AND ANALYSIS

We planned that two authors (NJB and MJ) would extract data independently using a standardised form. Any discrepancies would be resolved by consensus. Where agreement could not be reached a third review author (MLE) would have considered the paper.

MAIN RESULTS

We identified 264 potential trials and reviews from the search. Following removal of duplicates, we screened 224 papers based on title and abstract. We retrieved six full-text papers and further evaluated them but they did not meet the inclusion criteria. There were, therefore, no studies suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

The results of this systematic review cannot inform clinical practice as no suitable trials were identified for inclusion. Therefore, it is currently unknown whether these interventions offer any added value in this patient group or whether specific types of breathing exercise demonstrate superiority over others. Given that breathing exercises are frequently used to treat dysfunctional breathing/hyperventilation syndrome, there is an urgent need for well-designed clinical trials in this area. Future trials should conform to the CONSORT statement for standards of reporting and use validated outcome measures. Trial reports should also ensure full disclosure of data for all important clinical outcomes.

Negative mood and alcohol problems are related to respiratory dynamics in young adults

This study examined the relationship of negative affect and alcohol use behaviors to baseline respiration and respiratory response to emotional challenge in young adults (N = 138, 48 % women). Thoracic-to-abdominal ratio, respiratory frequency and variability, and minute volume ventilation were measured during a low-demand baseline task, and emotional challenge (viewing emotionally-valenced, emotionally-neutral, and alcohol-related pictures). Negative mood and alcohol problems principal components were generated from self-report measures of negative affect and mood, alcohol use, and use-related problems. The negative mood component was positively related to a thoracic bias when measured throughout the study (including baseline and picture exposure). There was generally greater respiratory activity in response to the picture cues, although not specifically in response to the content (emotional or alcohol-related) of the picture cues. The alcohol problems component was positively associated with respiratory reactivity to picture cues, when baseline breathing patterns were controlled. Self-report arousal data indicated that higher levels of negative mood, but not alcohol problems, were associated with greater arousal ratings overall. However, those with alcohol problems reported greater arousal to alcohol cues, compared to emotionally neutral cues. These results are consistent with theories relating negative affect and mood to breathing patterns as well as the relationship between alcohol problems and negative emotions, suggesting that the use of respiratory interventions may hold promise for treating problems involving negative affect and mood, as well as drinking problems.

Hyperventilation and exhaustion syndrome

Chronic stress is among the most common diagnoses in Sweden, most commonly in the form of exhaustion syndrome (ICD-10 classification - F43.8). The majority of patients with this syndrome also have disturbed breathing (hyperventilation). The aim of this study was to investigate the association between hyperventilation and exhaustion syndrome. Thirty patients with exhaustion syndrome and 14 healthy subjects were evaluated with the Nijmegen Symptom Questionnaire (NQ). The participants completed questionnaires about exhaustion, mental state, sleep disturbance, pain and quality of life. The evaluation was repeated 4 weeks later, after half of the patients and healthy subjects had engaged in a therapy method called 'Grounding', a physical exercise inspired by African dance. The patients reported significantly higher levels of hyperventilation as compared to the healthy subjects. All patients' average score on NQ was 26.57 ± 10.98, while that of the healthy subjects was 15.14 ± 7.89 (t = -3.48, df = 42, p < 0.001). The NQ scores correlated strongly with two measures of exhaustion (Karolinska Exhaustion Scale KES r = 0.772, p < 0.01; Shirom Melamed Burnout Measure SMBM r = 0.565, p < 0.01), mental status [Hospital Anxiety and Depression Score (HADS) depression r = 0.414, p < 0.01; HADS anxiety r = 0.627, p < 0.01], sleep disturbances (r = -0.514, p < 0.01), pain (r = -.370, p < 0.05) and poor well-being (Medical Outcomes Survey Short Form 36 questionnaire- SR Health r = -0.529, p < 0.05). In the logistic regression analysis, the variance in the scores from NQ were explained to a high degree (R(2) = 0.752) by scores in KES and HADS. The brief Grounding training contributed to a near significant reduction in hyperventilation (F = 2.521, p < 0.124) and to significant reductions in exhaustion scores and scores of depression and anxiety. The conclusion is that hyperventilation is common in exhaustion syndrome patients and that it can be reduced by systematic physical therapy such as Grounding.

Coping skills and exposure therapy in panic disorder and agoraphobia: latest advances and future directions

Although cognitive-behavioral treatments for panic disorder have demonstrated efficacy, a considerable number of patients terminate treatment prematurely or remain symtpomatic. Cognitive and biobehavioral coping skills are taught to improve exposure therapy outcomes but evidence for an additive effect is largely lacking. Current methodologies used to study the augmenting effects of coping skills test the degree to which the delivery of coping skills enhances outcomes. However, they do not assess the degree to which acquisition of coping skills and their application during exposure therapy augment outcomes. We examine the extant evidence on the role of traditional coping skills in augmenting exposure for panic disorder, discuss the limitations of existing research, and offer recommendations for methodological advances.

Medically unexplained dyspnea: partly moderated by dysfunctional (thoracic dominant) breathing pattern

BACKGROUND

Dysfunctional breathing (DB) may contribute to disproportionate dyspnea and other medically unexplained symptoms. The extent of dysfunctional breathing is often evaluated using the Nijmegen Questionnaire (NQ) or by the presence of abnormal breathing patterns. The NQ was originally devised to evaluate one form of dysfunctional breathing - hyperventilation syndrome. However, the symptoms identified by the NQ are not primarily due to hypocapnia and may be due to other causes including breathing pattern dysfunction.

OBJECTIVES

The relationships between breathing pattern abnormalities and the various categories of NQ symptoms including respiratory or dyspnea symptoms have not been investigated. This study investigates these relationships.

METHOD

62 patients with medically unexplained complaints, that seemed to be associated with tension and breathing dysfunction, were referred, or self-referred, for breathing and relaxation therapy. Dysfunctional breathing symptoms and breathing patterns were assessed at the beginning and end of treatments using the NQ for assessment of DB symptoms, and the Manual Assessment of Respiratory Motion (MARM) to quantify the extent of thoracic dominant breathing. Subscales for the NQ were created in 4 categories, tension, central neurovascular, peripheral neurovascular and dyspnea. Relationships between the NQ (sum scores and subscales) and the MARM were explored.

RESULTS

Mean NQ scores were elevated and mean MARM values for thoracic breathing were also elevated. There was a small correlation pre-treatment between MARM and NQ (r=0.26, p<0.05), but classification of subjects as normal/abnormal on both measurements agreed in 74% (p < 0.001) of patients. From the sub scores of NQ only the respiratory or 'dyspnea' items correlated with the MARM values. Dyspnea was only elevated for subjects with abnormal MARM. After treatment, both MARM and NQ returned to normal values (p< 0.0001). Changes in NQ were largest for subjects with abnormal MARM pre-treatment. There was a large interaction between the change in the NQ sub score dyspnea and initial MARM values. (p<0.001).

Relationships between measures of dysfunctional breathing in a population with concerns about their breathing

BACKGROUND

Dysfunctional breathing (DB) is implicated in physical and psychological health, however evaluation is hampered by lack of rigorous definition and clearly defined measures. Screening tools for DB include biochemical measures such as end-tidal CO(2), biomechanical measures such assessments of breathing pattern, breathing symptom questionnaires and tests of breathing function such as breath holding time.

AIM

This study investigates whether screening tools for dysfunctional breathing measure distinct or associated aspects of breathing functionality.

METHOD

84 self-referred or practitioner-referred individuals with concerns about their breathing were assessed using screening tools proposed to identify DB. Correlations between these measures were determined.

RESULTS

Significant correlations where found within categories of measures however correlations between variables in different categories were generally not significant. No measures were found to correlate with carbon dioxide levels.

CONCLUSION

DB cannot be simply defined. For practical purposes DB is probably best characterised as a multi-dimensional construct with at least 3 dimensions, biochemical, biomechanical and breathing related symptoms. Comprehensive evaluation of breathing dysfunction should include measures of breathing symptoms, breathing pattern, resting CO(2) and also include functional measures such a breath holding time and response of breathing to physical and psychological challenges including stress testing with CO(2) monitoring.

Psychophysiological reactions to two levels of voluntary hyperventilation in panic disorder

Panic disorder (PD) patients usually react with more self-reported distress to voluntary hyperventilation (HV) than do comparison groups. Less consistently PD patients manifest physiological differences such as more irregular breathing and slower normalization of lowered end-tidal pCO(2) after HV. To test whether physiological differences before, during, or after HV would be more evident after more intense HV, we designed a study in which 16 PD patients and 16 non-anxious controls hyperventilated for 3 min to 25 mmHg, and another 19 PD patients and another 17 controls to 20 mmHg. Patients reacted to HV to 20 mmHg but not to 25 mmHg with more self-reported symptoms than controls. However, at neither HV intensity were previous findings of irregular breathing and slow normalization of pCO(2) replicated. In general, differences between patients and controls in response to HV were in the cognitive-language rather than in the physiological realm.

Effects of Acupuncture As A Treatment for Hyperventilation Syndrome: A Pilot, Randomized Crossover Trial

BACKGROUND

Sustained and subtle hyperventilation can result in a wide variety of symptoms, leading to a chronic condition that has been termed hyperventilation syndrome (HVS). Treatment options include physiotherapy, in the form of breathing retraining (BR), but additional approaches aim to reduce the anxiety that is recognized as being a frequent component of this condition.

OBJECTIVES

The aim of this study was to evaluate whether acupuncture is an appropriate treatment for HVS to reduce anxiety, and whether a crossover trial is an appropriate study design to evaluate acupuncture in this condition.

DESIGN

A single-blind crossover trial was carried out comparing the effects of 4 weeks (30 minutes twice weekly) acupuncture and BR on patients with HVS.

SUBJECTS

Ten (10) patients diagnosed with HVS were recruited to the trial and randomized into two groups. Both groups received acupuncture and BR with a washout period of 1 week.

OUTCOME MEASURES

The primary outcome measure used was the Hospital Anxiety and Depression (HAD) Scale. Other outcome measures used were the Nijmegen questionnaire and Medical Research Council Dyspnea scale.

RESULTS

The results showed statistically significant treatment differences between acupuncture and breathing retraining, in favor of acupuncture. Reductions were found in the HAD A (anxiety) (p = 0.02) and Nijmegen (symptoms) (p = 0.03) scores. There was no statistical evidence of any carryover effects. However, when graphically examining individual anxiety scores, in those who received acupuncture first, there was a reduction in anxiety levels which persisted through the washout period, suggesting that there may have been some carryover effect from this treatment.

CONCLUSIONS

This study suggests that acupuncture may be beneficial in the management of HVS in terms of reducing anxiety levels and symptom severity. However, there may be some carryover effect, after acupuncture treatment, which went undetected because the small sample size. This preliminary study provides the basis for a larger, sufficiently powered and methodologically sound trial.

Cognitive behavioral psychotherapy for generalized anxiety disorder: a primer

Generalized anxiety disorder is a highly debilitating psychologic disorder associated with cognitive, affective, behavioral and physiologic forms of rigidity and dysfunction. Chronic and uncontrollable worry, a future-oriented and highly negative form of verbal thought, is its hallmark symptom. Cognitive behavioral therapy, the most well-established psychologic treatment for generalized anxiety disorder, entails techniques designed to target and reduce dysfunction in each of these mutually interrelating domains. This review serves as an introduction to cognitive behavioral therapy for generalized anxiety disorder, including conceptualization, treatment methods and evidence for efficacy. Future directions for augmenting treatment efficacy are also discussed.

Ventilatory Responses to Inhaled Carbon Dioxide, Hypoxia, and Exercise in Idiopathic Hyperventilation

Idiopathic hyperventilation (IH) is a poorly understood condition of sustained hypocapnia and controversial etiology. Although behavioral/emotional factors may contribute, it is uncertain whether chemosensitivity is altered, hyperventilation is maintained during exercise, and the associated breathlessness reflects the hyperventilation. In 39 patients with IH and 23 control subjects, we described ventilatory responses to isocapnic-hypoxia, hyperoxic-hypercapnia, and exercise; breath-hold tolerance; breathlessness; and psychologic status. Patients demonstrated hyperventilation at rest, with hypocapnia (28 +/- 3.8 mm Hg), a normal (slightly alkaline) arterial pH and [H(+)]a, and a significant base excess (-4.5 +/- 2.7 mEq/L), consistent with compensated respiratory alkalosis. Hyperventilation was sustained during exercise, despite hyperoxic-hypercapnic ventilatory responsiveness being normal and isocapnic-hypoxic ventilatory responsiveness being low relative to control (but exceeding control [2.4 +/- 1.0 vs. 1.6 +/- 0.5 L/min/%, p < 0.05] with acute restoration to normocapnia). Hyperventilation was maintained during exercise, at the resting CO(2) "setpoint." Relative to control, the breath-hold tolerance was attenuated, and dyspnea during exercise was significantly greater and not simply ascribable to the high ventilation. These observations suggest that patients with IH have a sustained hyperventilatory and dyspneic drive that, although not attributable to central chemosensitivity, may possibly have peripheral chemoreflex contributions. The nature and etiology of this chronic hyperventilatory drive remain unclear.

Hyperventilation in the vestibular clinic: use of the Nijmegen Questionnaire

The objective of the present study was to determine the prevalence of hyperventilation syndrome in patients seen for vestibular assessment and to assess the clinical utility of the Nijmegen Questionnaire in this group. The Nijmegen Questionnaire and Dizziness Handicap Inventory (DHI) were administered prospectively to a consecutive series of 100 patients identified as candidates for vestibular assessment within the University Hospital Neuro-otology practice. Twenty-three per cent of patients seen for vestibular assessment were diagnosed with hyperventilation syndrome using the Nijmegen Questionnaire. Seventeen of these (74%) would have remained undetected had the Nijmegen questionnaire not been used. No relationship was found between vestibular assessment results and either Nijmegen or DHI scores. A significant correlation was found between DHI scores and Nijmegen Questionnaire scores (rho = 0.348, P = 0.0005). In conclusion, the Nijmegen Questionnaire is a quick, easy to administer and low-impact assessment tool for hyperventilation syndrome and is a useful adjunct to the otological consultation. Diagnosed patients can then be offered breathing control exercises as part of a vestibular rehabilitation programme.

Breathing training for treating panic disorder. Useful intervention or impediment?

Breathing training (BT) is commonly used for treatment of panic disorder. We identified nine studies that reported the outcome of BT. Overall, the published studies of BT are not sufficiently compelling to allow an unequivocal judgment of whether such techniques are beneficial. This article discusses problems with the underlying rationale, study design, and techniques used in BT, and it identifies factors that may have determined therapy outcomes. The idea that hypocapnia and respiratory irregularities are underlying factors in the development of panic implies that these factors should be monitored physiologically throughout therapy. Techniques taught in BT must take account of respiration rate and tidal volume in the regulation of blood gases (pCO2). More studies are needed that are designed to measure the efficacy of BT using an adequate rationale and methodology. Claims that BT should be rejected in favor of cognitive or other forms of intervention are premature.

Breathing retraining for dysfunctional breathing in asthma: a randomised controlled trial

BACKGROUND

Functional breathing disorders may complicate asthma and impair quality of life. This study aimed to determine the effectiveness of physiotherapy based breathing retraining for patients treated for asthma in the community who have symptoms suggestive of dysfunctional breathing.

METHODS

33 adult patients aged 17-65 with diagnosed and currently treated asthma and Nijmegen questionnaire scores > or =23 were recruited to a randomised controlled trial comparing short physiotherapy breathing retraining and an asthma nurse education control. The main outcome measures were asthma specific health status (Asthma Quality of Life questionnaire) and Nijmegen questionnaire scores

RESULTS

Of the 33 who entered the study, data were available on 31 after 1 month and 28 at 6 months. The median (interquartile range) changes in overall asthma quality of life score at 1 month were 0.6 (0.05-1.12) and 0.09 (-0.25-0.26) for the breathing retraining and education groups, respectively (p=0.018), 0.42 (0.11-1.17) and 0.09 (-0.58-0.5) for the symptoms domain (p=0.042), 0.52 (0.09-1.25) and 0 (-0.45-0.45) for the activities domain (p=0.007), and 0.50 (0-1.50) and -0.25 (-0.75-0.75) for the environment domain (p=0.018). Only the change in the activities domain remained significant at 6 months (0.83 (-0.10-1.71) and -0.05 (-0.74-0.34), p=0.018), although trends to improvement were seen in the overall score (p=0.065), the symptoms domain (p=0.059), and the environment domain (p=0.065). There was a correlation between changes in quality of life scores and Nijmegen questionnaire scores at 1 month and at 6 months. The number needed to treat to produce a clinically important improvement in health status was 1.96 and 3.57 at 1 and 6 months.

CONCLUSION

Over half the patients treated for asthma in the community who have symptoms suggestive of dysfunctional breathing show a clinically relevant improvement in quality of life following a brief physiotherapy intervention. This improvement is maintained in over 25% 6 months after the intervention.

Respiratory biofeedback-assisted therapy in panic disorder

The authors describe a new methodologically improved behavioral treatment for panic patients using respiratory biofeedback from a handheld capnometry device. The treatment rationale is based on the assumption that sustained hypocapnia resulting from hyperventilation is a key mechanism in the production and maintenance of panic. The brief 4-week biofeedback therapy is aimed at voluntarily increasing self-monitored end-tidal partial pressure of carbon dioxide (PCO2) and reducing respiratory rate and instability through breathing exercises in patients' environment. Preliminary results from 4 patients indicate that the therapy was successful in reducing panic symptoms and other psychological characteristics associated with panic disorder. Physiological data obtained from home training, 24-hour ambulatory monitoring pretherapy and posttherapy, and laboratory assessment at follow-up indicate that patients started out with low resting PCO2 levels, increased those levels during therapy, and maintained those levels at posttherapy and/or follow-up. Partial dissociation between PCO2 and respiratory rate questions whether respiratory rate should be the main focus of breathing training in panic disorder.

A review of psychological factors/processes affecting anxious responding during voluntary hyperventilation and inhalations of carbon dioxide-enriched air

Despite advances in our understanding of the nature of anxiety-related responding during periods of elevated bodily arousal, it is not necessarily evident by what psychological mechanisms anxiety is produced and maintained. To address this issue, researchers have increasingly employed biological challenge procedures to examine how psychological factors affect anxious responding during elevated bodily arousal. Of the challenging procedures, hyperventilation and inhalations of carbon dioxide-enriched air have been among the most frequently employed, and a relatively large body of literature using these procedures has now accumulated. Unfortunately, existing reviews do not comprehensively examine findings from hyperventilation and inhalations of carbon dioxide studies, and only rarely the methodological issues specific to these studies. To address these issues, we review the voluntary hyperventilation and carbon dioxide-enriched air literature in order to identify the primary methodological issues/limitations of this research and address the extent to which psychological variables influence anxious responding to such challenges. Overall, we conclude challenge research is a promising paradigm to examine the influence of psychological variables in anxious responding, and that such work will likely be enhanced with greater attention to psychological process issues.

Somatizing disorders affecting the respiratory tract

Respiratory disease in childhood is common but not all children presenting to the paediatrician have an underlying organic cause for their symptoms. This article reviews the spectrum of non-organic somatization disorders that might be encountered and advises about the diagnosis and treatment of habit cough, laryngeal dysfunction and hyperventilation.

Anxiety and depression in advanced lung disease

Anxiety, panic, and depression commonly complicate chronic airflow obstruction, and probably other forms of advanced lung disease as well. Despite the recent development of many new therapeutic options, these conditions remain under-recognized and under-treated in this patient population. Under-diagnosis may result in part from the challenge of distinguishing between the somatic manifestations of psychiatric disease and the physical symptoms of severe respiratory dysfunction. Treatment relies on judicious pharmacotherapy and appropriate psychologic support. Serotonin selective reuptake inhibitors are particularly useful in the treatment of depression and panic, and may be helpful in controlling other forms of anxiety, as well. Cognitive behavioral therapy is an important adjunct in the management of anxiety. Electroconvulsive therapy should be considered for selected lung disease patients with refractory depression.

Hyperventilation syndrome: a chimera?

There is now an impressive body of research to suggest that the concept of a discrete hyperventilation syndrome is no longer tenable. The evidence for this has been carefully gathered and the scientific studies have employed innovative methodological techniques and have introduced a key psychological dimension. Both have led to a greater understanding of the respiratory correlates of anxiety, but in the process have revealed the "hyperventilation syndrome" to be a chimera. Furthermore, there is no evidence to support the view that panic attacks and hyperventilation are synonymous: on the contrary, hyperventilation rarely accompanies panic and, when it does, it is more likely to be a consequence than a cause of the panic. Finally, there is no evidence that "breathing therapy" works by normalizing pCO2; its nonspecific effects on anxiety appear to be mediated in part by slowing respiratory rate. Further research in this field might be more profitably focused on the nature of the association between anxiety disorders and organic lung disease, especially asthma.