Panic attack symptom dimensions and their relationship to illness characteristics in panic disorder

Biobehavioral approach to distinguishing panic symptoms from medical illness

Panic disorder is a common psychiatric diagnosis characterized by acute, distressing somatic symptoms that mimic medically-relevant symptoms. As a result, individuals with panic disorder overutilize personal and healthcare resources in an attempt to diagnose and treat physical symptoms that are often medically benign. A biobehavioral perspective on these symptoms is needed that integrates psychological and medical knowledge to avoid costly treatments and prolonged suffering. This narrative review examines six common somatic symptoms of panic attacks (non-cardiac chest pain, palpitations, dyspnea, dizziness, abdominal distress, and paresthesia), identified in the literature as the most severe, prevalent, or critical for differential diagnosis in somatic illness, including long COVID. We review somatic illnesses that are commonly comorbid or produce panic-like symptoms, their relevant risk factors, characteristics that assist in distinguishing them from panic, and treatment approaches that are typical for these conditions. Additionally, this review discusses key factors, including cultural considerations, to assist healthcare professionals in differentiating benign from medically relevant symptoms in panic sufferers.

The Effectiveness of a Digital App for Reduction of Clinical Symptoms in Individuals With Panic Disorder: Randomized Controlled Trial

BACKGROUND

Panic disorder is a common and important disease in clinical practice that decreases individual productivity and increases health care use. Treatments comprise medication and cognitive behavioral therapy. However, adverse medication effects and poor treatment compliance mean new therapeutic models are needed.

OBJECTIVE

We hypothesized that digital therapy for panic disorder may improve panic disorder symptoms and that treatment response would be associated with brain activity changes assessed with functional near-infrared spectroscopy (fNIRS).

METHODS

Individuals (n=50) with a history of panic attacks were recruited. Symptoms were assessed before and after the use of an app for panic disorder, which in this study was a smartphone-based app for treating the clinical symptoms of panic disorder, panic symptoms, depressive symptoms, and anxiety. The hemodynamics in the frontal cortex during the resting state were measured via fNIRS. The app had 4 parts: diary, education, quest, and serious games. The study trial was approved by the institutional review board of Chung-Ang University Hospital (1041078-202112-HR-349-01) and written informed consent was obtained from all participants.

RESULTS

The number of participants with improved panic symptoms in the app use group (20/25, 80%) was greater than that in the control group (6/21, 29%; χ21=12.3; P=.005). During treatment, the improvement in the Panic Disorder Severity Scale (PDSS) score in the app use group was greater than that in the control group (F1,44=7.03; P=.01). In the app use group, the total PDSS score declined by 42.5% (mean score 14.3, SD 6.5 at baseline and mean score 7.2, SD 3.6 after the intervention), whereas the PDSS score declined by 14.6% in the control group (mean score 12.4, SD 5.2 at baseline and mean score 9.8, SD 7.9 after the intervention). There were no significant differences in accumulated oxygenated hemoglobin (accHbO2) at baseline between the app use and control groups. During treatment, the reduction in accHbO2 in the right ventrolateral prefrontal cortex (VLPFC; F1,44=8.22; P=.006) and the right orbitofrontal cortex (OFC; F1,44=8.88; P=.005) was greater in the app use than the control group.

CONCLUSIONS

Apps for panic disorder should effectively reduce symptoms and VLPFC and OFC brain activity in patients with panic disorder. The improvement of panic disorder symptoms was positively correlated with decreased VLPFC and OFC brain activity in the resting state.

TRIAL REGISTRATION

Clinical Research Information Service KCT0007280; https://cris.nih.go.kr/cris/search/detailSearch.do?seq=21448.

Biofeedback Training to Increase P co2 in Asthma With Elevated Anxiety: A One-Stop Treatment of Both Conditions?

OBJECTIVE

Anxiety is highly prevalent in individuals with asthma. Asthma symptoms and medication can exacerbate anxiety, and vice versa. Unfortunately, treatments of comorbid anxiety and asthma are largely lacking. A problematic feature common to both conditions is hyperventilation. It adversely affects lung function and symptoms in asthma and anxiety. We examined whether a treatment to reduce hyperventilation, shown to improve asthma symptoms, also improves anxiety in asthma patients with high anxiety.

METHOD

One hundred twenty English- or Spanish-speaking adult patients with asthma were randomly assigned to either Capnometry-Assisted Respiratory Training (CART) to raise P co2 or feedback to slow respiratory rate (SLOW). Although anxiety was not an inclusion criterion, 21.7% met clinically relevant anxiety levels on the Hospital Anxiety and Depression Scale (HADS). Anxiety (HADS-A) and depression (HADS-D) scales, anxiety sensitivity (Anxiety Sensitivity Index [ASI]), and negative affect (Negative Affect Scale of the Positive Affect Negative Affect Schedule) were assessed at baseline, posttreatment, 1-month follow-up, and 6-month follow-up.

RESULTS

In this secondary analysis, asthma patients with high baseline anxiety showed greater reductions in ASI and PANAS-N in CART than in SLOW ( p values ≤ .005, Cohen d values ≥ 0.58). Furthermore, at 6-month follow-up, these patients also had lower ASI, PANAS-N, and HADS-D in CART than in SLOW ( p values ≤ .012, Cohen d values ≥ 0.54). Patients with low baseline anxiety did not have differential outcomes in CART than in SLOW.

CONCLUSIONS

For asthma patients with high anxiety, our brief training designed to raise P co2 resulted in significant and sustained reductions in anxiety sensitivity and negative affect compared with slow-breathing training. The findings lend support for P co2 as a potential physiological target for anxiety reduction in asthma.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00975273 .

Psychosocial treatment for panic disorder: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

Panic disorder is a common and disabling psychiatric condition marked by sudden onset of physiological sensations that are appraised as dangerous. A number of studies and reviews have examined the efficacy of psychosocial treatments for PD; however, there is a lack of overarching reports that discuss the strength of evidence for the different psychosocial treatments for PD. This umbrella review provides an overview of systematic reviews and meta-analyses on psychosocial treatments for PD.

METHODS

A systematic search and review of the literature was conducted according to PRISMA guidelines.

RESULTS

A total of 38 reviews (31 meta-analyses and 7 systematic reviews) were included in the umbrella review. Most of the 38 reviews were focused on the use of CBT, both in-person and internet-based, to treat PD among adults, generally finding it to be an efficacious treatment compared to control conditions. A limited number of the 38 reviews included other age ranges or examined other forms of psychosocial treatments. The methodological quality of most included reviews was rated as critically low according to the AMSTAR-2 rating system.

CONCLUSIONS

Future reviews should focus on improving their methodological quality. Although the included reviews supported CBT as an efficacious treatment for reducing panic symptoms among adults, future research could focus on how CBT compares to other psychosocial treatments and the efficacy of CBT for PD among other populations (e.g., children and adolescents) and among diverse cultural groups.

Validity and Reliability of the Self-administered Psycho-TherApy-SystemS (SELFPASS) Item Pool for the Daily Mood Tracking of Depressive Symptoms: Cross-sectional Web-Based Survey

BACKGROUND

e-Mental health apps targeting depression have gained increased attention in mental health care. Daily self-assessment is an essential part of e-mental health apps. The Self-administered Psycho-TherApy-SystemS (SELFPASS) app is a self-management app to manage depressive and comorbid anxiety symptoms of patients with a depression diagnosis. A self-developed item pool with 40 depression items and 12 anxiety items is included to provide symptom-specific suggestions for interventions. However, the psychometric properties of the item pool have not yet been evaluated.

OBJECTIVE

The aim of this study is to investigate the validity and reliability of the SELFPASS item pool.

METHODS

A weblink with the SELFPASS item pool and validated mood assessment scales was distributed to healthy subjects and patients who had received a diagnosis of a depressive disorder within the last year. Two scores were derived from the SELFPASS item pool: SELFPASS depression (SP-D) and SELFPASS anxiety (SP-A). Reliability was examined using Cronbach α. Construct validity was assessed through Pearson correlations with the Patient Health Questionnaire-9 (PHQ-9), the General Anxiety Disorder Scale-7 (GAD-7), and the WHO-5-Wellbeing-Scale (WHO-5). Logistic regression analysis was performed as an indicator for concurrent criterion validity of SP-D and SP-A. Factor analysis was performed to provide information about the underlying factor structure of the item pool. Item-scale correlations were calculated in order to determine item quality.

RESULTS

A total of 284 participants were included, with 192 (67.6%) healthy subjects and 92 (32.4%) patients. Cronbach α was set to .94 for SP-D and α=.88 for SP-A. We found significant positive correlations between SP-D and PHQ-9 scores (r=0.87; P<.001) and between SP-A and GAD-7 scores (r=0.80; P<.001), and negative correlations between SP-D and WHO-5 scores (r=-0.80; P<.001) and between SP-A and WHO-5 scores (r=-0.69; P<.001). Increasing scores of SP-D and SP-A led to increased odds of belonging to the patient group (SP-D: odds ratio 1.03, 95% CI 1.01-1.05; P<.001; SP-A: 1.05, 1.05-1.01; P=.01). The item pool yielded 2 factors: one that consisted of mood-related items and another with somatic-related items.

CONCLUSIONS

The SELFPASS item pool showed good psychometric properties in terms of reliability, construct, and criterion validity. The item pool is an appropriate source for daily mood tracking in future e-mental health apps among patients with depression. Our study provides general recommendations for future developments as well as recommendations within the item pool.

Habituation or Normalization? Experiential and Respiratory Recovery From Voluntary Hyperventilation in Treated Versus Untreated Patients With Panic Disorder

Psychophysiological theories postulate respiratory dysregulation as a mechanism contributing to panic disorder (PD). Additionally, symptomatic and respiratory recovery from voluntary hyperventilation (HVT-recovery) have been shown to lag in PD and it is unclear if HVT-recovery normalizes with treatment. Thirty-seven panic disorder patients were randomized to hypoventilation therapy (TX, n = 20) or waitlist control (WL, n = 17) (Meuret et al., 2008). In a secondary analysis, their HVT-recovery was analyzed at pre- and post-TX/WL, compared to 29 healthy controls (HC). HVT included three phases: 5-min baseline, 3-min hyperventilation, and 8-min recovery. HVT-elicited symptom severity and anxiety were rated following each phase, and end-tidal PCO₂ and respiratory rate (RR) were recorded throughout. Treatment, compared to WL, was highly effective in reducing PD pathology (d=2.21, Meuret et al., 2008). At pre-TX/WL, PD demonstrated delayed HVT-recovery PCO₂ and higher RR. Treated patients demonstrated normalization of HVT-recovery for PCO₂ and RR; however, improvements of HVT-recovery for symptom severity and anxiety did not differ between TX and WL. Results replicate pretreatment HVT respiratory recovery abnormalities in PD and further demonstrate normalization, comparable to HC, following successful treatment. The results provide support for respiratory dysregulation as a feature of PD and demonstrate the utility of HVT respiratory recovery as treatment outcome measure for respiration-based PD therapy.

Panic disorder respiratory subtype: psychopathology and challenge tests - an update

Panic disorder (PD) pathophysiology is very heterogeneous, and the discrimination of distinct subtypes could be very useful. A subtype based on respiratory symptoms is known to constitute a specific subgroup. However, evidence to support the respiratory subtype (RS) as a distinct subgroup of PD with a well-defined phenotype remains controversial. Studies have focused on characterization of the RS based on symptoms and response to CO2. In this line, we described clinical and biological aspects focused on symptomatology and CO2 challenge tests in PD RS. The main symptoms that characterize RS are dyspnea (shortness of breath) and a choking sensation. Moreover, patients with the RS tended to be more responsive to CO2 challenge tests, which triggered more panic attacks in this subgroup. Future studies should focus on discriminating respiratory-related clusters and exploring psychophysiological and neuroimaging outcomes in order to provide robust evidence to confirm RS as a distinct subtype of PD.

Anxiety Disorders and Medical Comorbidity: Treatment Implications

Anxiety disorders are debilitating psychological disorders characterized by a wide range of cognitive and somatic symptoms. Anxiety sufferers have a higher lifetime prevalence of various medical problems. Chronic medical conditions furthermore increase the likelihood of psychiatric disorders and overall dysfunction. Lifetime rates of cardiovascular, respiratory, gastrointestinal, and other medical problems are disproportionately high in anxiety and panic/fear sufferers. The heightened comorbidity is not surprising as many symptoms of anxiety and panic/fear mimic symptoms of medical conditions. Panic disorder specifically is strongly linked to medical conditions due to its salient somatic symptoms, such as dyspnea, dizziness, numbness, chest pain, and heart palpitations, all of which can signal danger and deterioration for chronic disease sufferers. This chapter identifies shared correlates of medical illness and anxiety disorders and evidence for misinterpretation of symptoms as medically relevant and offers an analysis of implications for treatment of both types of conditions. We will concentrate on medical conditions with high associations for anxiety and panic by aspects of symptomatology, specifically neurological disorders (fibromyalgia, epilepsy, cerebral palsy), diabetes, gastrointestinal illness (irritable bowel syndrome, gastroesophageal reflux disease), and cardiovascular and respiratory illnesses (asthma).

PTSD symptoms are differentially associated with general distress and physiological arousal: Implications for the conceptualization and measurement of PTSD

BACKGROUND

The primary purpose of this study was to examine the place of posttraumatic stress disorder (PTSD) vis-à-vis the external dimensions of general distress and physiological arousal.

METHODS

Using data collected from veterans of the wars in Iraq and Afghanistan (N = 1350), latent variable covariance structure modeling was employed to compare correlations of PTSD symptom clusters and individual PTSD symptoms with general distress and physiological arousal.

RESULTS

Each PTSD symptom cluster, and 17 of 20 individual PTSD symptoms were more strongly associated with general distress than with physiological arousal. However, moderate to strong associations were also found between physiological arousal and both PTSD clusters and symptoms.

LIMITATIONS

Findings are based on self-reported data elicited from a single sample of veterans with substantial PTSD symptoms. Replication, particularly by clinician interview, is necessary. Generalizability to other traumatized populations is unknown.

CONCLUSIONS

Results offer support, with caveats, for viewing PTSD as a distress disorder. Findings are not consistent with the position that PTSD is a hybrid disorder with some features reflecting hyperarousal and others indicative of general distress. Results have implications for the conceptualization and measurement of PTSD.

Differential diagnosis of late-type reactions to injected local anaesthetics: Inflammation at the injection site is the only indicator of allergic hypersensitivity

BACKGROUND

Anaphylaxis-like reactions developing within a few minutes are the most frequent complications of subcutaneous or submucosal injections of local anaesthetics (LAs), and topically applied LAs are potential contact allergens. In addition, injected LAs have been reported to induce delayed reactions, including local inflammation at the injection site, and various general symptoms.

OBJECTIVES

To assess the frequency and symptoms of late-type hypersensitivity occurring several hours after LA injections.

METHODS

We retrospectively evaluated clinical data and test results from all patients referred to our allergy clinic in a period of 20 years for diagnostic work-up of LA-associated late-type reactions.

RESULTS

Of 202 patients reporting symptoms with onset at least 1 hour after LA injection, 40 had cutaneous inflammation confined to the injection site, and 162 reported various systemic symptoms. LA hypersensitivity could be excluded in all patients with systemic complaints by means of skin testing and subsequent subcutaneous provocation. In 8 of the 40 patients (20%) with local inflammatory reactions, late-type allergic LA hypersensitivity was confirmed.

CONCLUSIONS

Late-type LA allergy commonly causes inflammatory skin reactions confined to the injection site. Conversely, LAs are highly unlikely to trigger delayed systemic symptoms such as urticarial or exanthematous skin eruptions.

Toward a personalized therapy for panic disorder: preliminary considerations from a work in progress

Although several treatment options for panic disorder (PD) are available, the best intervention for each individual patient remains uncertain and the use of a more personalized therapeutic approach in PD is required. In clinical practice, clinicians combine general scientific information and personal experience in the decision-making process to choose a tailored treatment for each patient. In this sense, clinicians already use a somehow personalized medicine strategy. However, the influence of their interpretative personal models may lead to bias related to personal convictions, not sufficiently grounded on scientific evidence. Hence, an effort to give some advice based on the science of personalized medicine could have positive effects on clinicians' decisions. Based on a narrative review of meta-analyses, systematic reviews, and experimental studies, we proposed a first-step attempt of evidence-based personalized therapy for PD. We focused on some phenomenological profiles, encompassing symptoms during/outside panic attacks, related patterns of physiological functions, and some aspects of physical health, which might be worth considering when developing treatment plans for patients with PD. We considered respiratory, cardiac, vestibular, and derealization/depersonalization profiles, with related implications for treatment. Given the extensiveness of the topic, we considered only medications and some somatic interventions. Our proposal should be considered neither exhaustive nor conclusive, as it is meant as a very preliminary step toward a future, robust evidence-based personalized therapy for PD. Clearly much more work is needed to achieve this goal, and recent technological advances, such as wearable devices, big data platforms, and the application of machine learning techniques, may help obtain reliable findings. We believe that combining the efforts of different research groups in this work in progress can lead to largely shared conclusions in the near future.

Twenty Years' Experience with Anaphylaxis-Like Reactions to Local Anesthetics: Genuine Allergy is Rare

BACKGROUND

Anaphylaxis-like reactions occur within minutes after the application of local anesthetics (LA), most commonly during dental interventions. Impressive symptoms including respiratory distress or loss of consciousness frequently give rise to a suspicion of allergy and may prompt patients and treating physicians to refuse future LA injections.

OBJECTIVE

Nonallergic mechanisms are responsible for the majority of LA-induced immediate-type reactions. In view of the preponderance of nonallergic reactions, the question arises whether genuine LA allergy may be missed during routine testing procedures.

METHODS

We retrospectively evaluated clinical data and test results from patients referred to our allergy clinic within the past 20 years for diagnostic workup of LA-induced immediate-type reactions.

RESULTS

Of 402 evaluated patients, 29 had an episode of acute urticaria within 30 minutes after LA injections, and the remaining 373 had a history of mainly subjective cutaneous, respiratory, cardiovascular, and neurological complaints. Of the patients reporting urticaria with or without angioedema, 14 were diagnosed with a spontaneous episode of urticaria, 13 had allergic or nonallergic reactions to other agents, and 2 had IgE-mediated LA allergy. LA allergy was definitely excluded by 771 subcutaneous provocation tests with skin test negative LA, thereby demonstrating the high predictive value of negative intradermal testing.

CONCLUSIONS

Skin testing and provocative LA challenge are useful to exclude LA allergy, and this testing procedure seems to be appropriate to identify the extremely rare cases with IgE-mediated LA allergy.

Hypoventilation Therapy Alleviates Panic by Repeated Induction of Dyspnea

BACKGROUND

Previous research has shown that hypoventilation therapy reduces panic symptoms in part by increasing basal partial pressure of carbon dioxide (PCO₂) levels. We tested an additional pathway by which hypoventilation therapy could exert its therapeutic effects: through repeated interoceptive exposure to sensations of dyspnea.

METHODS

A total of 35 patients with panic disorder were trained to perform exercises to raise their end-tidal PCO₂ levels using a portable capnometry device. Anxiety, dyspnea, end-tidal PCO₂, and respiratory rate were assessed during each exercise across 4 weeks of training. Mixed-model analysis examined whether within-exercise levels of dyspnea were predictive of reduction of panicogenic cognitions.

RESULTS

As expected, within-exercise anxiety and respiratory rate decreased over time. Unexpectedly, PCO₂ dropped significantly from the beginning to the end of exercise, with these drops becoming progressively smaller across weeks. Dyspnea increased and remained consistently above basal levels across weeks. As hypothesized, greater dyspnea was related to significantly lower panicogenic cognitions over time even after controlling for anxiety and PCO₂. Additional exploratory analyses showed that within-exercise increases in dyspnea were related to within-exercise increases in anxiety but were not related to within-exercise increases in PCO₂.

CONCLUSIONS

In support of the interoceptive exposure model, we found that greater dyspnea during hypoventilation exercises resulted in lower panicogenic cognitions even after the effect of PCO₂ was taken into account. The findings offer an additional important target in panic treatment.

Panic Disorder Comorbidity with Medical Conditions and Treatment Implications

Panic disorder (PD) is unique among the anxiety disorders in that panic symptoms are primarily of a physical nature. Consequently, comorbidity with medical illness is significant. This review examines the association between PD and medical illness. We identify shared pathophysiological and psychological correlates and illustrate how physiological activation in panic sufferers underlies their symptom experience in the context of the fight-or-flight response and beyond a situation-specific response pattern. We then review evidence for bodily symptom perception accuracy in PD. Prevalence of comorbidity for PD and medical illness is presented, with a focus on respiratory and cardiovascular illness, irritable bowel syndrome, and diabetes, followed by an outline for potential pathways of a bidirectional association. We conclude by illustrating commonalities in mediating mechanistic pathways and moderating risk factors across medical illnesses, and we discuss implications for diagnosis and treatment of both types of conditions.

Understanding the Connection Between Posttraumatic Stress Symptoms and Respiratory Problems: Contributions of Anxiety Sensitivity

Respiratory problems and posttraumatic stress disorder (PTSD) are the signature health consequences associated with the September 11, 2001 (9/11), World Trade Center disaster and frequently co-occur. The reasons for this comorbidity, however, remain unknown. Anxiety sensitivity is a transdiagnostic trait that is associated with both PTSD and respiratory symptoms. The present study explored whether anxiety sensitivity could explain the experience of respiratory symptoms in trauma-exposed smokers with PTSD symptoms. Participants (N = 135; M_age = 49.18 years, SD = 10.01) were 9/11-exposed daily smokers. Cross-sectional self-report measures were used to assess PTSD symptoms, anxiety sensitivity, and respiratory symptoms. After controlling for covariates and PTSD symptoms, anxiety sensitivity accounted for significant additional variance in respiratory symptoms (ΔR² = .04 to .08). This effect was specific to the somatic concerns dimension (β = .29, p = .020); somatic concerns contributed significantly to accounting for the overlap between PTSD and respiratory symptoms, b = 0.03, 95% CI [0.01, 0.07]. These findings suggest that the somatic dimension of anxiety sensitivity is important in understanding respiratory symptoms in individuals with PTSD symptoms. These findings also suggest that it may be critical to address anxiety sensitivity when treating patients with comorbid respiratory problems and PTSD.

A System Computational Model of Implicit Emotional Learning

Nowadays, the experimental study of emotional learning is commonly based on classical conditioning paradigms and models, which have been thoroughly investigated in the last century. Unluckily, models based on classical conditioning are unable to explain or predict important psychophysiological phenomena, such as the failure of the extinction of emotional responses in certain circumstances (for instance, those observed in evaluative conditioning, in post-traumatic stress disorders and in panic attacks). In this manuscript, starting from the experimental results available from the literature, a computational model of implicit emotional learning based both on prediction errors computation and on statistical inference is developed. The model quantitatively predicts (a) the occurrence of evaluative conditioning, (b) the dynamics and the resistance-to-extinction of the traumatic emotional responses, (c) the mathematical relation between classical conditioning and unconditioned stimulus revaluation. Moreover, we discuss how the derived computational model can lead to the development of new animal models for resistant-to-extinction emotional reactions and novel methodologies of emotions modulation.

Does 'fear of dying' indicate a more severe presentation of panic disorder?

Research suggests a relationship between the presence of fearful cognitions and panic disorder (PD) severity. With little existing evidence addressing the clinical significance of individual panic-cognitions, the current study examined presentation and impairment differences among 331 outpatients with PD according to whether they experience "fear of dying" (FOD) during panic attacks. Patients reporting FOD (n=153) were compared to patients denying FOD (n=178) on variables indicating PD severity (e.g., number of symptoms) and psychiatric impairment (e.g., hospitalizations). PD patients with FOD reported a greater number of panic symptoms, agoraphobia diagnoses, and were more likely to be seeking treatment primarily for PD. We found no clinical impairment or comorbidity differences between groups. Results suggest that panic attacks with FOD are related to a more acute presentation of PD. Such results substantiate past research connecting cognitive distress and PD severity and further suggest that FOD may be particularly relevant to this relationship.

Panic and comorbid depression and their associations with stress reactivity, interoceptive awareness and interoceptive accuracy of various bioparameters

BACKGROUND

While current theories on perception of interoceptive signals suggest impaired interoceptive processing in psychiatric disorders such as panic disorder or depression, heart-rate (HR) interoceptive accuracy (IAc) of panic patients under resting conditions is superior to that of healthy controls. Thus, in this study, we chose to assess further physiological parameters and comorbid depression in order to get information on how these potentially conflicting findings are linked together.

DESIGN

We used a quasi-experimental laboratory design which included multi-parametric physiological data collection of 40 panic subjects and 53 matched no-panic controls, as well as experimental induction of stress and relaxation over a time-course.

METHODS

Stress reactivity, interoceptive awareness (IAw; from the Body Perception Questionnaire (BPQ)) and IAc (as correlation between self-estimation and physiological data) were major outcome variables. Self-estimation of bioparametrical change was measured via numeric rating scales.

RESULT

Panic subjects had stronger HR-reaction and more accurate HR-interoception. Concurrently, though, their IAc of skin conductance level, pulse amplitude and breathing amplitude was significantly lower than that of the control group. Interestingly, comorbid depression was found to be associated with increased IAw but attenuated IAc.

LIMITATIONS

Demand characteristics and a categorical approach to panic confine the results.

CONCLUSION

The potentially conflicting findings coalesce, as panic was associated with an increase of the ability to perceive the fear-related parameter and a simultaneous decrease of the ability to perceive other parameters. The superordinate integration of afferent signals might be impaired.

IDENTIFYING PANIC DISORDER SUBTYPES USING FACTOR MIXTURE MODELING

BACKGROUND

The clinical presentation of panic disorder (PD) is known to be highly heterogeneous, complicating research on its etiology, neurobiological pathways, and treatment. None of the attempts to identify PD subtypes have been independently reproduced, rendering the current literature inconclusive.

METHODS

Using a data-driven, case-centered approach (factor mixture modeling) on a broad range of anxiety symptoms assessed with the Beck anxiety inventory, the present study identifies PD disorder subtypes in a large (n = 658), well-documented mixed-population sample from the Netherlands Study of Depression and Anxiety (NESDA), with subtypes being validated and detailed using a variety of clinical characteristics.

RESULTS

A three-class, one-factor model proved superior to all other possible models (Bayesian information criterion = 13,200; Lo-Mendel-Rubin = 0.0295; bootstrapped likelihood ratio test ≤ 0.0001), with the first class, a cognitive-autonomic subtype, accounting for 29.8%, the second class, the autonomic subtype, for 29.9%, and a third class, the aspecific subtype, for 40.3% of the population. The cognitive-autonomic and autonomic subtypes showed significant differences compared to the aspecific subtype (e.g., comorbidity and suicide attempts) but on severity differed between themselves only.

CONCLUSION

Three qualitatively different PD subtypes were identified: a severe cognitive-autonomic subtype, a moderate autonomic subtype, and a mild aspecific subtype. Qualitative and quantitative differences were related to severity and clinical properties such as comorbidity, suicide attempts, sleep, and sense of mastery.

Dimensional structure of bodily panic attack symptoms and their specific connections to panic cognitions, anxiety sensitivity and claustrophobic fears

BACKGROUND

Previous studies of the dimensional structure of panic attack symptoms have mostly identified a respiratory and a vestibular/mixed somatic dimension. Evidence for additional dimensions such as a cardiac dimension and the allocation of several of the panic attack symptom criteria is less consistent. Clarifying the dimensional structure of the panic attack symptoms should help to specify the relationship of potential risk factors like anxiety sensitivity and fear of suffocation to the experience of panic attacks and the development of panic disorder.

METHOD

In an outpatient multicentre study 350 panic patients with agoraphobia rated the intensity of each of the ten DSM-IV bodily symptoms during a typical panic attack. The factor structure of these data was investigated with nonlinear confirmatory factor analysis (CFA). The identified bodily symptom dimensions were related to panic cognitions, anxiety sensitivity and fear of suffocation by means of nonlinear structural equation modelling (SEM).

RESULTS

CFA indicated a respiratory, a vestibular/mixed somatic and a cardiac dimension of the bodily symptom criteria. These three factors were differentially associated with specific panic cognitions, different anxiety sensitivity facets and suffocation fear.

CONCLUSIONS

Taking into account the dimensional structure of panic attack symptoms may help to increase the specificity of the associations between the experience of panic attack symptoms and various panic related constructs.

A longitudinal examination of anxiety disorders and physical health conditions in a nationally representative sample of U.S. older adults

BACKGROUND

There has been growing interest in the relation between anxiety disorders and physical conditions in the general adult population. However, little is known about the nature of this association in older adults. Understanding the complex relationship between these disorders can help to inform prevention and treatment strategies unique to this rapidly growing segment of the population.

METHODS

A total of 10,409 U.S. adults aged 55+ participated in Wave 1 (2001-2002) and Wave 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Lifetime and past-year DSM-IV anxiety, mood, and substance use disorders, and lifetime personality disorders, were assessed in both waves. Participants self-reported on whether they had been diagnosed by a healthcare professional with a broad range of physical health conditions; this study focuses on cardiovascular disease, gastrointestinal disease, and arthritis. Multivariable logistic regressions adjusted for sociodemographics, comorbid mental disorders, and number of physical health conditions assessed: (1) the relation between past-year physical conditions at Wave 1 and incident past-year anxiety disorders at Wave 2 and; (2) the relation between individual lifetime anxiety disorders at Wave 1 and incident physical conditions at Wave 2. A second set of adjusted multinomial logistic regressions examined Wave 1 sociodemographic and physical and mental health risk factors associated with incident physical condition alone, anxiety disorder alone, and comorbid anxiety and physical condition at Wave 2.

RESULTS

Past-year arthritis at Wave 1 was significantly associated with increased odds of incident generalized anxiety disorder at Wave 2. Further, any lifetime anxiety disorder and posttraumatic stress disorder at Wave 1 were significantly associated with increased odds of incident gastrointestinal disease at Wave 2. Differential sociodemographic and physical and mental health predictors were significantly associated with increased odds of incident comorbid anxiety disorder and physical conditions.

CONCLUSION

Results of the current study elucidate the longitudinal bidirectional relationships between anxiety disorders and physical health conditions in a large, nationally representative sample of older adults. These results have important implications for identifying at risk older adults, which will not only impact this growing segment of the population directly, but will also potentially lessen burden on the healthcare system as a whole.

Etiology, triggers and neurochemical circuits associated with unexpected, expected, and laboratory-induced panic attacks

Panic disorder (PD) is a severe anxiety disorder that is characterized by recurrent panic attacks (PA), which can be unexpected (uPA, i.e., no clear identifiable trigger) or expected (ePA). Panic typically involves an abrupt feeling of catastrophic fear or distress accompanied by physiological symptoms such as palpitations, racing heart, thermal sensations, and sweating. Recurrent uPA and ePA can also lead to agoraphobia, where subjects with PD avoid situations that were associated with PA. Here we will review recent developments in our understanding of PD, which includes discussions on: symptoms and signs associated with uPA and ePAs; Diagnosis of PD and the new DSM-V; biological etiology such as heritability and gene×environment and gene×hormonal development interactions; comparisons between laboratory and naturally occurring uPAs and ePAs; neurochemical systems that are associated with clinical PAs (e.g. gene associations; targets for triggering or treating PAs), adaptive fear and panic response concepts in the context of new NIH RDoc approach; and finally strengths and weaknesses of translational animal models of adaptive and pathological panic states.

The phenomenology of the first panic attack in clinical and community-based samples

The purpose of the study was to contrast first panic attacks (PAs) of patients with panic disorder (PD) with vs. without agoraphobia and to explore differences between first PAs leading to the development of PD and those that remain isolated. Data were drawn from a community survey (N=2259 including 88 isolated PAs and 75 PD cases). An additional sample of 234 PD patients was recruited in a clinical setting. A standardized interview assessed the symptoms of the first PA, context of its occurrence and subsequent coping attempts. Persons who developed PD reported more severe first PAs, more medical service utilization and exposure-limiting coping attempts than those with isolated PAs. The context of the first PA did not differ between PD and isolated PAs. PD with agoraphobia was specifically associated with greater symptom severity and occurrence of first attacks in public. Future research should validate these findings using a longitudinal approach.

"But it might be a heart attack": intolerance of uncertainty and panic disorder symptoms

Panic disorder models describe interactions between feared anxiety-related physical sensations (i.e., anxiety sensitivity; AS) and catastrophic interpretations therein. Intolerance of uncertainty (IU) has been implicated as necessary for catastrophic interpretations in community samples. The current study examined relationships between IU, AS, and panic disorder symptoms in a clinical sample. Participants had a principal diagnosis of panic disorder, with or without agoraphobia (n=132; 66% women). IU was expected to account for significant variance in panic symptoms controlling for AS. AS was expected to mediate the relationship between IU and panic symptoms, whereas IU was expected to moderate the relationship between AS and panic symptoms. Hierarchical linear regressions indicated that IU accounted for significant unique variance in panic symptoms relative to AS, with comparable part correlations. Mediation and moderation models were also tested and suggested direct and indirect effects of IU on panic symptoms through AS; however, an interaction effect was not supported. The current cross-sectional evidence supports a role for IU in panic symptoms, independent of AS.

Panic symptom clusters differentially predict suicide ideation and attempt

Increasingly strong evidence links anxiety disorders in general and panic attacks in particular to suicidality. The underlying causes and specifics of this relation, however, remain unclear. The present article sought to begin addressing this question by clarifying the association between panic symptoms and suicidality. Data were sampled from the NESARC epidemiological data set from the US and analyzed as four independently, randomly selected subsets of 1000 individuals using structural equation modeling analyses and replicating results across samples. Evidence is presented for four symptom clusters (cognitive symptoms, respiratory distress, symptoms of alpha and beta adrenergic activation) and the differential association of each with suicidal ideation and attempts. Symptoms of alpha adrenergic activation predicted prior suicide attempt whereas cognitive symptoms predicted prior suicidal ideation. These findings were independent of comorbid major depressive disorder. It is suggested that assessment of suicide risk in the community includes the presentation of cognitive symptoms and symptoms related to alpha adrenergic activation.

Phosphate levels as a possible state marker in panic disorder: preliminary study of a feasible laboratory measure for routine clinical practice

OBJECTIVE

Low serum phosphate level is considered one of the metabolic adaptations to the respiratory alkalosis induced by hyperventilation associated with panic disorder. The aim of this study was to assess phosphatemia as a possible state marker for panic disorder.

METHODS

Sixteen panic disorder patients underwent clinical assessment with a semi-structured interview, a set of rating scales and the self-rated State and Trait Anxiety Inventory (STAI), as well as extraction of venous blood samples at baseline and after 12 weeks of pharmacological treatment. Ten healthy volunteers of similar sex, age and educational level filled out the STAI and gave blood samples at baseline and 12 weeks later.

RESULTS

The median (25th-75th percentiles) of phosphate levels (mg/dl) was 2.68 (2.22-3.18) among patients and 4.13 (3.74-4.70) among healthy volunteers respectively (P < 0.001). Seven (44%) patients and no healthy volunteers presented low serum phosphate (<2.50 mg/dl) at baseline; this patient abnormality was corrected in all cases after successful treatment. At baseline, the age-adjusted correlation between phosphate levels and state-anxiety was -0.66 (P < 0.001) among all 26 participants and -0.51 (P = 0.05) among the 16 panic disorder patients.

CONCLUSIONS

Measurement of phosphate levels could be easily introduced into clinical practice as a possible marker for chronic hyperventilation in panic disorder, although further investigations with larger sample sizes are necessary to characterize panic disorder patients with low versus normal phosphate levels.

Gender effect on the relationship between stress hormones and panic-agoraphobic spectrum dimensions in healthy subjects

INTRODUCTION

Alterations of the hypothalamic-pituitary-adrenal (HPA) axis and of its peripheral indices have been reported in both normal and pathological anxiety with controversial findings. The aim of the present study was to investigate the possible correlations between serum cortisol and dehydroepiandrosterone-sulfate (DHEA-S) levels and DHEA-S/cortisol ratio, and panic-agoraphobic spectrum dimensions in a sample of healthy subjects.

METHODS

Forty-two healthy subjects of both sexes, with no current or lifetime psychiatric disorders, were assessed by means of the Structured Clinical Interview for DSM-IV (SCID-I/P) and the so-called Panic Agoraphobic Spectrum-Self Report lifetime version (PAS-SR).

RESULTS

Significant, negative correlations were found between cortisol levels and the total score of the separation sensitivity, panic-like symptoms, and medication/substance sensitivity PAS-SR domains. The PAS-SR total and the panic-like symptoms domain scores were positively related to the DHEAS/cortisol ratio. When the sample was divided in women and men, these correlations were present in women only.

DISCUSSION

These findings, while indicating the presence of significant relationships between panic-agoraphobic traits and some indices of HPA axis functioning in healthy women, would suggest this as one of the factors explaining the greater vulnerability of women to cross the line between normal and pathological anxiety.

CONCLUSIONS

Further studies are needed to explore gender differences in the relationships between HPA axis alterations and the panic-agoraphobic spectrum dimensions.

Patient Health Questionnaire: Greek language validation and subscale factor structure

This study aimed to assess the reliability, validity, and factor structure of the Greek translation of the Patient Health Questionnaire (PHQ) in a sample of Cypriot, Greek-speaking university students. This is the first study to examine PHQ psychometric properties in Greek and to investigate the factor structure of the PHQ subscales. A total of 520 participants (73.9% women; M(Age) = 21.57; SD, 4.94) completed the PHQ and assessment tools used for convergent validity analysis. Patient Health Questionnaire was translated and culturally adapted according to international standards. Overall, PHQ subscales in Greek language demonstrated good internal consistency (mean Cronbach α = .75, P < .001) and convergent validity with the following: Alcohol Use Disorders Identification Test, Beck Depression Inventory, Psychiatric Diagnostic Screening Questionnaire (panic disorder, somatization, bulimia, and binge eating), and Anxiety Sensitivity Index (overall mean, r = 0.52; P < .001). The relation between the PHQ subscale diagnoses and functional impairment, as assessed by the 12-item Health Survey 12, was comparable with the original validation results for all subscales except alcohol. The depression, alcohol, and anxiety subscales exhibited single-factor structures. Subscales assessing eating disorders, panic disorder, and somatization difficulties exhibited 2-, 3-, and 4-factor structures, respectively. Overall, PHQ subscales demonstrated good psychometric properties, with the exception of the subscale examining problematic alcohol use. Overall, PHQ demonstrates good reliability, validity, and appropriate factor structure in a Greek-speaking college population. Psychometric research is needed on the Greek PHQ in primary care settings.

Depersonalization disorder and anxiety: a special relationship?

A significant association between anxiety and depersonalization has been found in healthy controls and psychiatric patients irrespective of underlying conditions. Although patients with depersonalization disorder (DPD) often have a history of severe anxiety symptoms, clinical observations suggest that the relation between anxiety and depersonalization is complex and poorly understood. Using relevant rating scales, levels of anxiety and depersonalization were assessed in 291 consecutive DPD cases. 'High' and 'low' depersonalization groups, were compared according to anxiety severity. Correlation and multivariate regression analyses were also used to assessed the contribution of anxiety to the phenomenology and natural course of depersonalization. A low but significant association between depersonalization and anxiety (as measured by Beck's Anxiety Inventory) was only apparent in those patients with low intensity depersonalization, but not in those with severe depersonalization. Levels of anxiety did not seem to make specific contributions to the clinical features of depersonalization itself, although DPD patients with high anxiety seem characterised by additional non-specific perceptual symptoms. The presence of a 'statistical dissociation' between depersonalization and anxiety adds further evidence in favour of depersonalization disorder being an independent condition and suggests that its association with anxiety has been overemphasized.

Predictors of response among patients with panic disorder treated with medications in a naturalistic follow-up: the role of adult separation anxiety

BACKGROUND

Efficacy of treatments for panic disorder is well established, but not all patients respond. Adult separation anxiety has been found to predict poorer response to CBT, but its effect on response to medication has not been previously explored.

STUDY AIM

The aim of this study is to investigate if panic-agoraphobic spectrum factors, including 'separation anxiety' factor predict treatment outcome in patients with panic disorder.

STUDY SAMPLE

Participants who met criteria for PD (n=57) completed baseline assessment and 12 months follow-up. Patients were administered the Panic Agoraphobic Spectrum Self-Report (PAS-SR, Lifetime and Last-Month Versions), and the Panic Disorder Severity Scale (PDSS). We examined patients who met the following criteria at baseline: 1) PDSS total score>7; 2) no current Axis I comorbidity with major depression; 3) no lifetime or current bipolar disorder. All patients were treated with evidence-based psychopharmacological treatment for panic disorder during the 12-month observation period.

RESULTS

Twenty eight patients (48.1%) achieved remission during the follow-up period. In a logistic regression model, controlling for baseline severity, gender and age, only the last-month PAS-SR 'separation anxiety' factor was associated with a lower likelihood of remission.

CONCLUSIONS

Signs and symptoms of separation anxiety in adulthood, as assessed with the PAS-SR Last Month version, are predictors of poor treatment outcome in patients with PD. We submit that the assessment of panic-agoraphobic spectrum features, including adult separation anxiety, should become routine of clinical assessment of patients with PD. It is likely that a better psychopathological characterization of patients may inform treatment selection, and result in better treatment outcome.

Prevalence and correlates of respiratory and non-respiratory panic attacks in the general population

BACKGROUND

Panic attacks are heterogeneous with regards to symptom profile. Subtypes of panic attacks have been proposed, of which the most investigated is respiratory panic attacks (RPA). Limited information exists about RPA in the general population.

METHOD

The prevalence and correlates of RPA and non-respiratory panic attacks (NRPA) were examined in a subsample (n=8.796) of individuals participating in a cross-sectional survey of the adult general population of six European countries. Panic attacks, mental disorders, and chronic physical conditions were assessed with the Composite International Diagnostic Interview (CIDI) 3.0. Data on use of health services and disability were obtained.

RESULTS

The lifetime prevalence of RPA was 6.77 and the 12-month prevalence was 2.26. No robust associations of RPA with sociodemographic characteristics, mental disorders or physical conditions were found as compared to NRPA. RPA were associated with increased use of health services but similar disability in comparison to NRPA.

LIMITATIONS

Few direct data are available on the validity of the CIDI to assess RPA. Other definitions of RPA exist in the literature.

CONCLUSIONS

Our findings suggest that there are very few differences between RPA and NRPA and do not support the need of subtyping panic attacks in current classification systems.

Respiratory and cognitive mediators of treatment change in panic disorder: evidence for intervention specificity

OBJECTIVE

There are numerous theories of panic disorder, each proposing a unique pathway of change leading to treatment success. However, little is known about whether improvements in proposed mediators are indeed associated with treatment outcomes and whether these mediators are specific to particular treatment modalities. Our purpose in this study was to analyze pathways of change in theoretically distinct interventions using longitudinal, moderated mediation analyses.

METHOD

Forty-one patients with panic disorder and agoraphobia were randomly assigned to receive 4 weeks of training aimed at altering either respiration (capnometry-assisted respiratory training) or panic-related cognitions (cognitive training). Changes in respiration (PCO₂, respiration rate), symptom appraisal, and a modality-nonspecific mediator (perceived control) were considered as possible mediators.

RESULTS

The reductions in panic symptom severity and panic-related cognitions and the improvements in perceived control were significant and comparable in both treatment groups. Capnometry-assisted respiratory training, but not cognitive training, led to corrections from initially hypocapnic to normocapnic levels. Moderated mediation and temporal analyses suggested that in capnometry-assisted respiratory training, PCO₂ unidirectionally mediated and preceded changes in symptom appraisal and perceived control and was unidirectionally associated with changes in panic symptom severity. In cognitive training, reductions in symptom appraisal were bidirectionally associated with perceived control and panic symptom severity. In addition, perceived control was bidirectionally related to panic symptom severity in both treatment conditions.

CONCLUSION

The findings suggest that reductions in panic symptom severity can be achieved through different pathways, consistent with the underlying models.

Catastrophic Appraisal and Perceived Control as Moderators of Treatment Response in Panic Disorder

The purpose of this study was to examine the moderating effects of cognitive risk factors in two mechanistically-distinct interventions. Forty-one patients with panic disorder and agoraphobia were randomly assigned to receive training aimed at altering respiration (Capnometry-assisted respiratory training, CART) or symptom appraisal (cognitive skill training, CT). Using a mixed effects regression model, we assessed whether reductions in panic symptom severity (PDSS) were moderated by the variables of interest. While improvement in PDSS did not differ among treatment modalities, moderating effects emerged. Individuals with greater initial levels of misappraisal showed smaller reduction in PDSS when receiving CT, but larger reduction when receiving CART. Greater lack of perceived control was predictive of worse outcome in CART, but better outcome in CT. Better homework compliance was related to greater reductions in PDSS irrespective of condition. The findings illustrate the complexity of moderating influences within and between distinct interventions.

Panic disorder respiratory subtype: psychopathology, laboratory challenge tests, and response to treatment

OBJECTIVE

Our objective is to summarize the new findings concerning the respiratory subtype (RS) of panic disorder (PD) since its first description.

METHODS

Two searches were made in the Institute for Scientific Information Web of Science: with the keywords "panic disorder" and "respiratory symptoms," and all articles that cited Briggs and colleagues' 1993 article "Subtyping of Panic Disorder by Symptom Profile" (Br J Psychiatry 1993;163:201-9). Altogether, 133 articles were reviewed.

RESULTS

We describe and discuss RS epidemiology, genetics, psychopathology, demographic features, clinical features, correlations with the respiratory system, traumatic suffocation history, provocative tests, and nocturnal panic. Compared to patients with the nonrespiratory subtype (non-RS), the RS patients had higher familial history of PD, lower comorbidity with depression, longer duration of illness, lower neuroticism scores, and higher scores in severity scales, such as the Panic and Agoraphobia Scale, Panic-Agoraphobia Spectrum scale and the Clinical Global Impression scale. Tests to induce panic attacks, such as those with CO(2), hyperventilation, and caffeine, produce panic attacks in a higher proportion of RS patients than non-RS patients. Differences in the subtypes' improvement with the pharmacologic treatment were found. There are also some controversial findings regarding the RS, including the age of onset of PD, and alcohol and tobacco use in RS patients.

CONCLUSIONS

Some characteristics, such as the increased sensitivity to CO(2) and the higher familial history of PD, clearly distinguish the RS from the non-RS. Nevertheless, there are also controversial findings. More studies are needed to determine the validity of the RS subtype.

The psychophysiology of blood-injection-injury phobia: looking beyond the diphasic response paradigm

Blood-injection-injury (BII) phobia is an anxiety disorder that may be accompanied by vasovagal fainting during confrontation with the feared stimuli. The underlying pattern of autonomic regulation has been characterized as a diphasic response, with initial increases in heart rate and blood pressure that are typical of a fight-flight response, and subsequent drops in blood pressure and/or heart rate that may precipitate vasovagal fainting. Tensing skeletal muscles of the arms, legs, and trunk (applied tension) has been proposed as a technique to cope with this dysregulation. This review critically examines the empirical basis for the diphasic response and its treatment by applied tension in BII phobia. An alternative perspective on the psychophysiology of BII phobia and vasovagal fainting is offered by focusing on hypocapnia that leads to cerebral blood flow reductions, a perspective supported by research on neurocardiogenic and orthostatically-induced syncope. The evidence may indicate a role for respiration-focused coping techniques in BII phobia.

Hyperventilation in panic disorder and asthma: empirical evidence and clinical strategies

Sustained or spontaneous hyperventilation has been associated with a variety of physical symptoms and has been linked to a number of organic illnesses and mental disorders. Theories of panic disorder hold that hyperventilation either produces feared symptoms of hypocapnia or protects against feared suffocation symptoms of hypercapnia. Although the evidence for both theories is inconclusive, findings from observational, experimental, and therapeutic studies suggest an important role of low carbon dioxide (CO2) levels in this disorder. Similarly, hypocapnia and associated hyperpnia are linked to bronchoconstriction, symptom exacerbation, and lower quality of life in patients with asthma. Raising CO2 levels by means of therapeutic capnometry has proven beneficial effects in both disorders, and the reversing of hyperventilation has emerged as a potent mediator for reductions in panic symptom severity and treatment success.

Do symptom interpretations mediate the relationship between panic attack symptoms and agoraphobic avoidance?

BACKGROUND

There is little consensus as to whether agoraphobic avoidance in panic disorder is characterized by a prominence of particular symptoms and interpretations of those symptoms.

AIMS

We sought to clarify the relationship between symptoms and agoraphobic avoidance and to establish whether catastrophic interpretations of symptoms mediate any such relationships.

METHOD

The Symptom Checklist 90-Revised, Agoraphobic Cognitions Questionnaire and Mobility Inventory were administered to 117 patients with panic disorder who were attending an outpatient anxiety disorders clinic.

RESULTS

Medium to large associations were found between most symptoms and agoraphobic avoidance and between particular symptoms and the corresponding symptom interpretation items. Some interpretations of symptoms were found to mediate relationships between symptoms and agoraphobic avoidance.

CONCLUSIONS

These findings suggest that the catastrophic misinterpretation model of panic disorder can to some extent be invoked to explain the extent of agoraphobic avoidance, but that there may also be other pathways leading from symptoms to agoraphobia.

Differences in mortality in acute coronary syndrome symptom clusters

BACKGROUND

The timely and accurate identification of symptoms of acute coronary syndrome (ACS) is a challenge for patients and clinicians. It is unknown whether response times and clinical outcomes differ with specific symptoms. We sought to identify which ACS symptoms are related-symptom clusters-and to determine if sample characteristics, response times, and outcomes differ among symptom cluster groups.

METHODS

In a multisite randomized clinical trial, 3522 patients with known cardiovascular disease were followed up for 2 years. During follow-up, 331 (11%) had a confirmed ACS event. In this group, 8 presenting symptoms were analyzed using cluster analysis. Differences in symptom cluster group characteristics, delay times, and outcomes were examined.

RESULTS

The sample was predominantly male (67%), older (mean 67.8, S.D. 11.6 years), and white (90%). Four symptom clusters were identified: Classic ACS characterized by chest pain; Pain Symptoms (neck, throat, jaw, back, shoulder, arm pain); Stress Symptoms (shortness of breath, sweating, nausea, indigestion, dread, anxiety); and Diffuse Symptoms, with a low frequency of most symptoms. Those in the Diffuse Symptoms cluster tended to be older (P = .08) and the Pain Symptoms group was most likely to have a history of angina (P = .01). After adjusting for differences, the Diffuse Symptoms cluster demonstrated higher mortality at 2 years (17%) than the other 3 clusters (2%-5%, P < .001), although prehospital delay time did not differ significantly.

CONCLUSION

Most ACS symptoms occur in groups or clusters. Uncharacteristic symptom patterns may delay diagnosis and treatment by clinicians even when patients seek care rapidly. Knowledge of common symptom patterns may facilitate rapid identification of ACS.

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

The prevalence of panic disorder (PD) in patients with chronic obstructive pulmonary disease (COPD) is significantly higher than that in the general population. Comorbid anxiety disorders in COPD are associated with a number of worse outcomes, however little is known about the mechanisms by which PD affects patients with COPD. We hypothesized that patients with COPD and PD would have greater dyspnea severity, but not greater somatosensory sensitivity, to dyspneic stimuli. We studied 10 patients with COPD and PD, 9 patients with COPD without PD, and 9 healthy, matched controls. Participants were administered the Anxiety Sensitivity Index-3. We tested interoceptive sensitivity using a respiratory load detection protocol and dyspnea ratings in response to inspiratory resistive loads. Participants with COPD and PD had higher anxiety sensitivity scores and reported greater dyspnea in response to resistive loads. However no group differences were found in resistive load detection threshold. Anxiety sensitivity scores accounted for a significant amount of the variance in the group difference in dyspnea ratings. Patients with COPD and PD do not show heightened interoceptive sensitivity, but report greater dyspnea to inspiratory resistive loads. Emotional responses to dyspneic sensations may account for higher dyspnea ratings in patients with PD and COPD.

Subtypes of panic attacks: a critical review of the empirical literature

BACKGROUND

Panic disorder is a heterogeneous disorder, comprising a variety of somatic, physiological, and cognitive symptoms during repeated panic attacks. As a result, considerable data have examined whether panic attacks may be classified into distinct diagnostic or functional subtypes. The aim of this study is to evaluate the existing literature regarding the validity of panic attack subtypes.

METHODS

This review focuses on data published since 2000, with the publication of DSM-IV-TR, augmented by replicated data published since 1980, with the publication of DSM-III and subsequently DSM-IV. Published reports evaluating empirical evidence for the validity of panic attack subtypes are reviewed.

RESULTS

Five sets of panic symptoms (respiratory, nocturnal, nonfearful, cognitive, and vestibular) have been shown to cluster together at varying degrees of consistency. However, none of these potential subtypes have been associated with sufficient and reliable external validation criteria indicative of functional differences. This apparent lack of findings may be related to methodological inconsistencies or limitations across the reviewed studies.

CONCLUSIONS

Although at present the data do not warrant the utility of subtyping, further research aimed at patent gaps in the literature, including clearer operationalization of symptom subtypes, greater use of biological challenge paradigms and physiological and other more objective measures of fear and anxiety, and exploration of subtyping based on biological factors such as genetics, may support the future designation of panic attack subtypes and their ultimate clinical utility.

Caffeine challenge in patients with panic disorder: baseline differences between those who panic and those who do not

A proportion of patients with panic disorder (PD) display an increased sensitivity to the anxiogenic/panicogenic properties of caffeine. The aim of this study is to identify probable baseline differences between PD patients who panic and those who do not, after caffeine administration. In a randomized, double-blind, cross-over experiment performed in two occasions 3-7 days apart, 200 and 400 mg of caffeine, respectively, were administered in a coffee form to 23 patients with PD with or without Agoraphobia. Evaluations included the State-Trait Anxiety Inventory, the DSM-IV 'panic attack' symptoms (visual analogue scale form), the Symptom Checklist-90-Revised (SCL-90-R), as well as breath-holding (BH) duration, heartbeat perception accuracy and heart rate. Only those patients who did not present a panic attack after both challenges ('no panic group', N=14, 66.7%), and those who presented a panic attack after at least one challenge ('panic group', n=7, 33.3%) were included in the analysis. The panickers, compared to the non-panickers, presented at baseline: significantly higher total score of the SCL-90-R; significantly higher scores on all the SCL-90-R clusters of symptoms, except that of 'paranoid ideation'; significantly lower BH duration. The present preliminary findings indicate that PD patients who panic after a 200 mg or a 400 mg caffeine challenge, compared to the PD patients who do not panic after both of these challenges, may present at baseline significantly higher non-specific general psychopathology--as reflected in the SCL-90-R--and significantly shorter BH duration.

Changes in respiration mediate changes in fear of bodily sensations in panic disorder

The purpose of the study was to examine whether changes in pCO(2) mediate changes in fear of bodily sensation (as indexed by anxiety sensitivity) in a bio-behavioral treatment for panic disorder that targets changes in end-tidal pCO(2). Thirty-five panic patients underwent 4 weeks of capnometry-assisted breathing training targeting respiratory dysregulation. Longitudinal mediation analyses of the changes in fear of bodily symptoms over time demonstrated that pCO(2), but not respiration rate, was a partial mediator of the changes in anxiety sensitivity. Results were supported by cross lag panel analyses, which indicated that earlier pCO(2) levels predicted later levels of anxiety sensitivity, but not vice versa. PCO(2) changes also led to changes in respiration rate, questioning the importance of respiration rate in breathing training. The results provide little support for changes in fear of bodily sensations leading to changes in respiration, but rather suggest that breathing training targeting pCO(2) reduced fear of bodily sensations in panic disorder.

[Panic attacks simulate presence of somatic illnesses]

INTRODUCTION

Panic attacks are characterized with sudden attacks of anxiety with numerous somatic symptoms, such as palpitations, tachycardia, tachypnea, nausea, vertigo. The objective of this study was to analyze symptoms of panic attacks in patients with panic disorder, especially, to determine the specific relationship of somatic and neurological symptoms of panic attacks in boundaries of somatic systems.

MATERIAL AND METHODS

The study sample consisted of 97 patients with primary diagnosis of panic disorder, without any acute, severe and unstable somatic illness. The presence and frequency of symptoms of panic attacks were estimated by the Panic Disorder Questionnaire.

RESULTS

The study results indicate that the most frequent symptoms of panic attacks were cardiological signs (heart pounding or racing) and trembling, followed by unsteady and fainting feeling symptoms, sweating, respiratory symptoms and gastroenterological symptoms. The results of correlation analyses indicate that symptoms of panic attacks classified into cardiovascular, gastro-enterological, respiratory and neurootological systems show statistically significant correlations.

CONCLUSION

The results of analyses of symptoms of panic attacks point to their intercorrelation. This specific association of the symptoms, if they are examined on their own in the patients, could lead to false clinical manifestation of some somatic illness. Therefore, it is necessary to analyze adequately and make the proper differential diagnosis of patients with panic disorder.

The structure of lifetime panic-agoraphobic spectrum

The heterogeneity of the clinical presentation of panic disorder (PD) has prompted researchers to describe different subtypes of PD, on the basis of the observed predominant symptoms constellation. Starting from a dimensional approach to panic disorder, an instrument to assess lifetime panic-agoraphobic spectrum (PAS) available in interview or self-report form (SCI-PAS, PAS-SR) was developed which proved to have sound psychometric properties and the ability to predict delayed response to treatment in patients with mood disorders. However, the structure of the instrument was defined a priori and an examination of its empirical structure is still lacking. Aim of the present report is to analyse the factor structure of the PAS taking advantage of a large database of subjects with panic disorders (N=630) assessed in the framework of different studies. Using a classical exploratory factor analysis based on a tetrachoric correlation matrix and oblique rotation, 10 factors were extracted, accounting overall for 66.3% of the variance of the questionnaire: panic symptoms, agoraphobia, claustrophobia, separation anxiety, fear of losing control, drug sensitivity and phobia, medical reassurance, rescue object, loss sensitivity, reassurance from family members. The first two factors comprise the DSM-IV criteria for panic disorder and agoraphobia. The other factors had received limited empirical support to date. We submit that these symptoms profiles might be clinically relevant for tailoring drug treatments or psychotherapeutic approaches to specific needs. Future perspectives might include the use of these factors to select homogeneous subgroups of patients for brain-imaging studies and to contribute to elucidating the causes and pathophysiology of panic disorder at molecular level.

The association between bodily anxiety symptom dimensions and the scales of the Revised NEO Personality Inventory and the Temperament and Character Inventory

The association between anxiety disorders and different measures of personality has been extensively studied to further the understanding of etiology, course, and treatment, and to possibly prevent the development of anxiety disorders. We have proposed a hierarchical model of bodily anxiety symptoms with 1 second-order severity factor and 5 first-order factors: cardio-respiratory, gastro-intestinal, autonomic, vertigo, and tension. The aim of this study was to investigate whether personality traits were differentially related to distinct symptom subdimensions or exclusively related to the general severity factor. Structural equation modeling of data on 120 patients with a primary diagnosis of social phobia and 207 patients with a primary diagnosis of panic disorder was used to examine the association between anxiety symptom dimensions and the scales of the Temperament and Character Inventory and of the Revised NEO Personality Inventory. When both sets of personality measures were simultaneously modeled as predictors, the Revised NEO Personality Inventory scales, neuroticism and extraversion, remained significantly associated with the severity factor, whereas the association between the Temperament and Character Inventory dimensions, harm avoidance and novelty seeking, and the severity factor became nonsignificant. Harm avoidance was negatively associated with the vertigo first-order factor, whereas neuroticism was negatively associated with the cardio-respiratory first-order factor, indicating that personality factors may be differentially related to specific anxiety subdimensions.