Evaluation of diagnostic criteria for panic attack using item response theory: findings from the National Comorbidity Survey in USA

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.

Select panicogenic drugs and stimuli induce consistent increases in tail skin flushes and decreases in core body temperature

Panic attacks (PAs) are episodes of intense fear or discomfort that are accompanied by a variety of both psychological and somatic symptoms. Panic induction in preclinical models (e.g. rats) has largely been assayed through flight and avoidance behavioral tests and cardiorespiratory activity. Yet, the literature pertaining to PAs shows that thermal sensations (hot flushes/heat sensations and chills) are also a common symptom during PAs in humans. Considering that temperature alterations are objectively measurable in rodents, we hypothesized that select panicogenic drugs and stimuli induce consistent changes in thermoregulation related to hot flushes and chills. Specifically, we challenged male rats with intraperitoneal injections of the GABAergic inverse agonist FG-7142; the α2 adrenoceptor antagonist yohimbine; the serotonin agonist D-fenfluramine, and 20% CO2 (an interoceptive homeostatic challenge). We assayed core body temperature and tail skin temperature using implanted radiotelemetry probes and tail thermistors/thermal imaging camera, respectively, and found that all challenges elicited rapid, high-amplitude (~7-9°C) increase in tail skin temperature and delayed decreases (~1-3°C) in core body temperature. We propose that thermal sensations such as these may be an additional indicator of a panic response in rodents and humans, as these panicogenic compounds or stimuli are known to precipitate PAs in persons with panic disorder.

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.

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.

Clinical symptoms associated with suicidality in patients with panic disorder

BACKGROUND

Patients with panic disorder have higher rates of suicide than the general population. Among panic disorder subjects, early onset, female gender, alcohol abuse, and mood disorder increase the risk of suicidality. However, less is known about the unique relationships between discrete DSM-IV panic symptoms and higher suicidality. Therefore, in the current study we examined the panic symptom profile that is associated with higher suicidality in a sample of outpatients with panic disorder.

METHODS

This cross-sectional study included 427 patients diagnosed with current panic disorder on the basis of the DSM-IV-TR. In order to assess the contribution of the clinical variables, a univariate logistic regression was carried out examining the relationships between the demographic variables, suicidality from the suicide module of the Korean version of the MINI International Neuropsychiatric Interview Plus, and DSM-IV panic symptoms. Additionally, a multivariate logistic regression was performed to identify specific panic symptoms that were significant risk factors for suicidality among patients with current panic disorder.

RESULTS

We found that 74 (17.33%) panic disorder patients experienced high suicidality. Univariate analyses showed that high suicidality was significantly associated with a younger age (OR = 13.66; 95% CI 2.68-69.70), comorbid depressive disorders (OR = 4.57; 95% CI 2.57-8.11), and the following panic symptoms: palpitations (OR = 2.20; 95% CI 0.90-5.35), trembling (OR = 0.61; 95% CI 0.362-1.18), nausea or abdominal distress (OR = 1.77; 95% CI 0.96-3.27), fear of losing control or going crazy (OR = 2.18; 95% CI 1.12-4.23), and paresthesia (OR = 1.57; 95% CI 0.83-2.98). Multivariate logistic regression analyses demonstrated that specific panic symptoms, such as palpitations (adjusted OR = 2.69; 95% CI 1.08-6.73) and fear of losing control or going crazy (adjusted OR = 2.28; 95% CI 1.21-4.31), were related to suicidality after controlling for confounding factors.

CONCLUSION

Some panic symptoms (e.g. palpitations and fear of losing control or going crazy) are associated with a risk of suicidality among patients with panic disorder. A priori identification of high-risk suicidal subjects could lead to effective treatment strategies for panic disorder.

An IRT Analysis of the Symptoms of Major Depressive Disorder

This study examines the psychometric properties of a major depressive episode using a large sample (N = 2,907) of outpatients with mood and anxiety disorders. A two-parameter logistic model yielded item threshold and discrimination parameters. A two-group confirmatory factor analysis was used to evaluate gender bias. Item thresholds fell along a continuum with the core features of depressed mood and anhedonia, along with fatigue, endorsed at lower levels of depression, and change in appetite and suicidal ideation endorsed at more severe levels. Item discriminations were highest for depressed mood and anhedonia, and lowest for change in appetite and suicidal ideation. The data indicate that the symptoms of depression assess a range of severity, with varying precision in discriminating depression. No gender differences were observed. Three exploratory symptom sets were compared with the full symptom set for depression, offering quantitative evidence that can be used to modify the psychiatric classification system.

Mild to severe social fears: ranking types of feared social situations using item response theory

Social anxiety disorder is one of the most common mental disorders, and is associated with long term impairment, distress and vulnerability to secondary disorders. Certain types of social fears are more common than others, with public speaking fears typically the most prevalent in epidemiological surveys. The distinction between performance- and interaction-based fears has been the focus of long-standing debate in the literature, with evidence performance-based fears may reflect more mild presentations of social anxiety. This study aims to explicitly test whether different types of social fears differ in underlying social anxiety severity using item response theory techniques. Different types of social fears were assessed using items from three different structured diagnostic interviews in four different epidemiological surveys in the United States (n=2261, n=5411) and Australia (n=1845, n=1497); and ranked using 2-parameter logistic item response theory models. Overall, patterns of underlying severity indicated by different fears were consistent across the four samples with items functioning across a range of social anxiety. Public performance fears and speaking at meetings/classes indicated the lowest levels of social anxiety, with increasing severity indicated by situations such as being assertive or attending parties. Fears of using public bathrooms or eating, drinking or writing in public reflected the highest levels of social anxiety. Understanding differences in the underlying severity of different types of social fears has important implications for the underlying structure of social anxiety, and may also enhance the delivery of social anxiety treatment at a population level.

Panic symptom profiles in social anxiety disorder: a person-centered data-analytic approach

Panic attacks (PAs) are prevalent among individuals with social anxiety disorder (SAD), but the clinical utility of panic symptom profiles is unclear. The aims of the present investigation were to empirically define panic symptom profiles in a treatment-seeking sample of individuals with SAD (N = 280) and to assess the associations of observed panic symptom profiles with clinical features of SAD. Results of a latent class analysis revealed four distinct panic symptom profiles: low panic symptoms, high typical SAD-related panic, high cardiac sensations and paresthesias, and moderate panic. Comparisons of external validators across latent classes indicated that the classes were differentially associated with clinical features of SAD. The present findings suggest that individuals with SAD experience distinct patterns of panic symptoms that may be clinically useful in conducting diagnostic assessments and determining treatment targets.

Assessing DSM-IV symptoms of panic attack in the general population: an item response analysis

BACKGROUND

Unexpected panic attacks may represent a non-specific risk factor for future depression and anxiety disorders. The examination of panic symptoms and associated latent severity levels may lead to improvements in the identification, prevention, and treatment of panic attacks and subsequent psychopathology for 'at risk' individuals in the general population.

METHODS

The current study utilised item response theory to assess the DSM-IV symptoms of panic in relation to the latent severity level of the panic attack construct in a sample of 5913 respondents from the National Epidemiologic Survey on Alcohol and Related conditions. Additionally, differential item functioning (DIF) was assessed to determine if each symptom of panic targets the same level of latent severity between different sociodemographic groups (male/female, young/old).

RESULTS

Symptoms indexing 'choking', 'fear of dying', and 'tingling/numbness' are some of the more severe symptoms of panic whilst 'heart racing', 'short of breath', 'tremble/shake', 'dizzy/faint', and 'perspire' are some of the least severe symptoms. Significant levels of DIF were detected in the 'perspire' symptom between males and females and the 'fear of dying' symptom between young and old respondents.

LIMITATIONS

The current study was limited to examining cross-sectional data from respondents who had experienced at least one panic attack across their lifetime.

CONCLUSIONS

The findings of the current study provide additional information regarding panic symptoms in the general population that may enable researchers and clinicians to further refine the detection of 'at-risk' individuals who experience threshold and sub-threshold levels of panic.

Evaluation of the DSM-IV and ICD-10 criteria for depressive disorders in a community population in Japan using item response theory

The DSM-IV and ICD-10 are both operational diagnostic systems that classify known psychological disorders according to the number of criteria symptoms. Certain discrepancies between the criteria exist and may lead to some inconsistencies in psychiatric research. The purpose of this study was to investigate these differences in the assessment of depression with item response theory (IRT) analyses. The World Mental Health-Japan (WMHJ) Survey is an epidemiological survey of the general population in Japan. We analyzed data from the WMHJ completed by 353 respondents who had either depressive mood or diminished interest. A two-parameter logistic model was used to evaluate the characteristics of the symptoms of the DSM-IV and ICD-10. IRT analyses revealed that the symptoms about psychomotor activity, worthlessness and self-reproach were more informative and suggestive of greater severity, while the symptoms about dietary habits were less informative. IRT analyses also revealed that the ICD-10 seems more sensitive to the mild range of the depression spectrum compared to the DSM-IV. Although there were some variations in severity among respondents, most of the respondents diagnosed with a severe or moderate depressive episode according to the ICD-10 were also diagnosed with a major depressive episode according to the DSM-IV.

ADHD in a representative sample of the Brazilian population: estimated prevalence and comparative adequacy of criteria between adolescents and adults according to the item response theory

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a clinically significant disorder in adulthood, but current diagnostic criteria and instruments do not seem to adequately capture the complexity of the disorder in this developmental phase. Accordingly, there are limited data on the proportion of adults affected by the disorder, specially in developing countries.

METHOD

We assessed a representative household sample of the Brazilian population for ADHD with the Adult ADHD Self-report Scale (ASRS) Screener, and evaluated the instrument according to the Rasch model of item response theory.

RESULTS

The sample was comprised by 3007 individuals, and the overal prevalence of positive screeners for ADHD was 5.8% [95% confidence interval (CI), 4.8-7.0]. Rasch analyses revealed the misfitt of the overall sample to expectations of the model. The evaluation of the sample stratified by age revealed that data for adolescents showed a signficant fittnes to the model expectations, while items completed by adults were not adequated.

CONCLUSIONS

The lack of fitness to the model for adult respondents challenges the possibility of a linear transformation of the ordinal data into interval measures and the utilization of parametric analyses of data. This result suggests that diagnostic criteria and instruments for adult ADHD must take into account a developmental perspective. Moreover, it calls for further evaluation of currently employed research methods in light of modern theories of psychometrics.

Electroencephalogram abnormalities in panic disorder patients: a study of symptom characteristics and pathology

Background

Since the 1980s, a high EEG abnormality rate has been reported for patients with panic disorder. However, how the EEG abnormalities of panic disorder patients are related to the clinical features and pathology of these patients has yet to be clarified. In this study we investigated whether or not EEG abnormalities are related to the 13 symptoms in the DSM-IV criteria for a diagnosis of panic attacks.

Methods

Subjects were 70 patients diagnosed with panic disorder.

Logistic regression analysis was performed with EEG findings as dependent variables and age, sex and with or without the 13 symptoms as independent variables.

Results

(1)EEG findings for panic disorder patients with EEG abnormalities: Of the 17 patients, 13 had repeated slow waves in the θ-band; the most prevalent EEG abnormality found in this study. Paroxysmal abnormality interpreted as epileptiform was found in only two cases. (2)Nausea or abdominal distress (37.7% vs 82.45%, OR-12.5), derealization or depersonalization (7.5% vs 47.1%, OR = 13.9,) and paresthesias (43.4% vs 64.7%, OR = 7.9,) were extracted by multivariate analysis as factors related to EEG abnormalities.

Conclusion

Of the 70 patients studied, 17 had EEG abnormalities. Among these 17 cases, "repeated slow waves in the θ-band" was the most common abnormality. The factors identified as being related to EEG abnormalities are nausea or abdominal distress, derealization or depersonalization, and paresthesias. The study indicated that physiological predispositions are closely related to panic attacks.

Panic disorder: a review of DSM-IV panic disorder and proposals for DSM-V

This review covers the literature since the publication of DSM-IV on the diagnostic criteria for panic attacks (PAs) and panic disorder (PD). Specific recommendations are made based on the evidence available. In particular, slight changes are proposed for the wording of the diagnostic criteria for PAs to ease the differentiation between panic and surrounding anxiety; simplification and clarification of the operationalization of types of PAs (expected vs. unexpected) is proposed; and consideration is given to the value of PAs as a specifier for all DSM diagnoses and to the cultural validity of certain symptom profiles. In addition, slight changes are proposed for the wording of the diagnostic criteria to increase clarity and parsimony of the criteria. Finally, based on the available evidence, no changes are proposed with regard to the developmental expression of PAs or PD. This review presents a number of options and preliminary recommendations to be considered for DSM-V.

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.

Non-fearful vs. fearful panic attacks: a general population study from the National Comorbidity Survey

BACKGROUND

Non-fearful panic attacks constitute a subgroup of panic attacks without the experience of subjective fear. However, previous studies were mostly carried out under medical settings and with small samples. The present study aims to clarify and expand the previous findings including the prevalence and characteristics of non-fearful panic attacks by using the National Comorbidity Survey (NCS) database.

METHODS

From the 8098 original respondents in the NCS, subjects who met the DSM-III-R diagnostic criteria for a lifetime panic attack were selected. Of these, individuals with non-fearful panic attacks were identified and comparisons with subjects with fearful panic attacks were conducted.

RESULTS

30% of panic attacks occur without fears of dying or going crazy. Although these non-fearful panic attacks do not differ from their fearful counterparts in terms of age, age of onset or frequency of attacks, they are less often associated with some symptoms including shortness of breath, trembling, smothering and depersonalization, lead less often to anticipatory anxiety, and lead to less treatment with medication. Although they lead equally to panic disorder diagnosis and cause as much functional impairment, the non-fearful ones are less often associated with diagnoses of agoraphobia, as well as many other Axis I disorders such as major depressive disorder, simple phobia and substance-related disorders.

LIMITATIONS

Recall bias and response bias may have distorted estimated relationships.

CONCLUSIONS

Although milder in terms of symptomatology and some comorbidity, clinicians need to pay appropriate attention to non-fearful subtypes of panic attacks which appear to be equally dysfunctional.

Carbon dioxide-induced emotion and respiratory symptoms in healthy volunteers

A number of evidences have established that panic and respiration are closely related. Clinical studies indicated that respiratory sensations constitute a discrete cluster of panic symptoms and play a major role in the pathophysiology of panic. The aim of the present study was to explore the phenomenology of an experimental model of panic in healthy volunteers based on the hypothesis that: (1) we can isolate discrete clusters of panic symptoms, (2) respiratory symptoms represent a distinct cluster of panic symptoms, and (3) respiratory symptoms are the best predictor of the subjective feeling of panic, as defined in the DSM IV criteria.Sixty-four healthy volunteers received a double inhalation of four mixtures containing 0, 9, 17.5 and 35% CO(2,) respectively, in a double-blind, cross-over, random design. An electronic visual analog scale and the Panic Symptom List (PSL) were used to assess subjective 'fear/discomfort' and panic symptoms, respectively. Statistical analyses consisted of Spearman's correlations, a principal component factor analysis of the 13 PSL symptoms, and linear regressions analyses.The factor analysis extracted three clusters of panic symptoms: respiratory, cognitive, and neurovegetative (r(2)=0.65). Respiratory symptoms were highly related to subjective feeling of fear/discomfort specifically in the CO(2)-enriched condition. Moreover, the respiratory component was the most important predictor of the subjective feeling of 'fear/discomfort' (beta=0.54).The discrete clusters of symptoms observed in this study were similar to those elicited in panic attacks naturally occurring in patients affected by panic disorder. Consistent with the idea that respiration plays a crucial role in the pathophysiology of panic, we found that respiratory symptoms were the best predictors the subjective state defined in the DSM IV criteria for panic.