Physiological and symptom responses to hyperventilation: A comparison of frequent and infrequent panickers

Ten subjects with panic disorder and ten subjects with infrequent panic attacks were assessed during 2 min of voluntary hyperventilation using four measures of physiological arousal (heart rate, upper trapezious EMG, skin conductance, and digital skin temperature). Immediately following hyperventilation, subjects were asked to rate their degree of distress on 13 panic symptoms, derived from DSM-III criteria for panic disorder. Results indicated that frequent panickers had significant overall elevations in trapezious EMG, relative to infrequent panickers, and demonstrated a slight increase in muscle tension following hyperventilation. In contrast, infrequent panickers showed a trend toward greater vasodilation preceding and during hyperventilation, with subsequent vasoconstriction upon resumption of normal breathing. Increases in skin conductance and heart rate were noted for both samples during hyperventilation, as reported in prior research. Symptom distress ratings indicated that the infrequent panickers reported significantly greater distress from dizziness and trembling in response to overbreathing, contrary to prediction. Implications of these findings are discussed in light of current accounts of cognitive and physiological factors in the etiology of panic attacks and panic disorder.This research was supported by Biomedical Research Support Grant #507RR07147, National Institutes of Health.     

The role of anxiety sensitivity and lack of emotional approach coping in depressive symptom severity among a non-clinical sample of uncued panickers

Panic attacks and depression frequently co-occur, and the presence of this co-morbidity is often associated with worse outcomes compared with each disorder alone. Despite this, not everyone who experiences panic attacks also suffers from depression, suggesting that individual difference factors may play a role in this co-morbidity. The purpose of this study was to provide a preliminary investigation of two such individual difference factors, examining the role of anxiety sensitivity and lack of emotional approach coping in depressive symptom severity among a non-clinical sample of uncued panickers. A sample of 79 college students reporting the occurrence of uncued panic attacks within the past year completed a series of questionnaires assessing the lower-order factors of anxiety sensitivity, emotional approach coping, panic attack frequency, panic-related disability, panic symptom severity and depressive symptom severity. Participants with more severe depressive symptoms reported greater anxiety sensitivity, panic attack frequency, panic symptom severity, panic-related disability and lack of emotional approach coping. The particular anxiety sensitivity dimension of fear of cognitive dyscontrol and lack of emotional approach coping emerged as the best predictors of depressive symptom severity. Findings are discussed in terms of their implications for the improved understanding of this co-morbidity, as well as its treatment.     

Increased cardiac awareness in panic disorder.

We investigated cardiac perception in panic disorder with both self-report and objective measures. In Study 1, 120 patients with panic disorder, 86 infrequent panickers, and 38 patients with other anxiety disorders reported greater cardiac and gastrointestinal awareness than 62 normal control subjects. Subjects with panic attacks reported greater cardiac awareness, but not gastrointestinal awareness, than those with other anxiety disorders. Studies 2 and 3 included a test of heart rate perception in which subjects silently counted their heart-beats without taking their pulse. In Study 2, 65 panic disorder patients showed better performance than 50 infrequent panickers, 27 patients with simple phobias, and 46 normal control subjects. No group differences were found in ability to estimate time intervals. In Study 3, 13 patients with panic disorder and 15 with generalized anxiety disorder showed better heart rate perception than 16 depressed patients.     

The catastrophic misinterpretation of physiological distress.

Cognitive theories of panic disorder suggest that the catastrophic misinterpretation of bodily sensations is the trigger for a panic attack. A challenge to cognitive theories is the suggestion that dyspnea (shortness of breath) is central to the development of panic and that negative cognitions are by-products of panic. To examine these seemingly contradictory theoretical perspectives, the present study investigated panic symptomatology in a sample of patients with chronic shortness of breath (i.e. pulmonary patients). Past studies have shown an increased prevalence of panic in pulmonary patients, a finding that may be useful in elucidating panic etiology. The current sample of pulmonary patients (N = 28) confirmed previous reports of high prevalence rates of panic in this population. Based on self-report of panic symptomatology, a total of nine patients (32%) met DSM-IV criteria that were consistent with panic disorder. Multivariate comparison of participants with and without panic symptomatology revealed that panickers had significantly higher levels of anxiety, depression and agoraphobic cognitions. However, these groups showed no significant differences on physiological measures of pulmonary functioning. The authors conclude that dyspnea alone is inadequate in predicting panic development. High levels of panic symptomatology in pulmonary samples may reflect increased opportunities for these patients to misinterpret bodily sensations and, in particular, their pulmonary symptoms.     

Role of cognitive appraisal in panic-related avoidance

The present study examined several dimensions of panic cognitions to test whether panic appraisals predict phobicity among panic sufferers. Thirty-five patients meeting DSM-III-R criteria for panic disorder with minimal or no phobic avoidance were compared to 40 patients meeting DSM-III-R criteria for panic disorder with agoraphobia (severe). The two groups looked strikingly similar on measures of panic symptoms, panic frequency and panic severity. As expected, patients diagnosed as having panic disorder with agoraphobia reported significantly more depression and phobic avoidance than patients with PD. Striking differences emerged on each of the following panic appraisal dimensions: (a) anticipated panic, (b) perceived consequences of panic, and (c) perceived self-efficacy in coping with panic. In each case, patients with panic disorder and agoraphobia reported significantly more dysfunctional panic appraisals than patients with panic disorder and no avoidance. Of those panic appraisal dimensions studied, anticipated panic emerged as the most potent correlate of agoraphobic avoidance. These findings support the hypothesis that cognitive appraisal factors may play an important role in the genesis or maintenance of phobic avoidance among panic patients.     

Delineating generalized anxiety: A preliminary investigation

The present study examined the nature of generalized anxiety, which was defined as the constellation of symptoms listed as diagnostic criteria for generalized anxiety disorder in DSM-III-R. Generalized anxiety was assessed by means of a questionnaire that was especially constructed for this study. Although multidimensional scaling of symptoms reported by a clinically anxious sample produced orthogonal anxiety and panic dimensions, many symptoms were common to both dimensions. Whereas worry was found to be the cardinal feature of generalized anxiety, respiratory symptoms were found to associate closely with panic. These dimensions were replicated in a student sample. It is argued that while generalized anxiety symptoms constitute a unique dimension in the field of anxiety disorders, both panic and generalized anxiety may be linked with a basic anxiety response system. The findings also indicated that worry associated more closely with generalized anxiety than did apprehensive expectations. The heuristic value of the findings are discussed in light of the issue relating to an anxiety-panic continuum.     

Situations and specific coping strategies associated with clinical and nonclinical panic attacks.

The present paper reports the results of further comparisons between clinical and nonclinical panickers. Both panic disorder patients and nonclinical panickers reported a variety of situational contexts associated with panic attacks, and differed markedly in their attempts to cope with panic. Nonclinical panickers tended to use more 'positive' coping strategies in response to panic. Conversely, one of the most commonly used and subjectively effective coping strategies reported by panic disorder patients was to escape the situation.     

The hyperventilation provocation test in panic disorder.

Forty-eight patients with DSM-III-R Panic Disorder underwent a hyperventilation provocation Test (HVPT). Twenty-four patients rated the symptoms induced during the HVPT as similar to those occurring during panic attacks in daily life. Contrary to the classical hyperventilation model of panic, no differences were found in respiratory physiology between recognizers and non-recognizers before and during voluntary hyperventilation. Moreover, recognizers and non-recognizers reported comparable levels of panic and hyperventilation symptoms and state anxiety during panic attacks in daily life. Ten of the recognizers also had a panic attack during the HVPT, independent of any differential CO2 alterations. Compared to non-panickers, panickers obtained higher scores for agoraphobia and depression. On the basis of these results, it is concluded that recognizers or panickers do not show a tendency towards hyperventilation, but that reports of severe panic and hyperventilation symptoms are more closely related to the level of anxiety. These results are more consistent with the cognitive model of panic, which emphasizes the patient's tendency to interpret somatic symptoms catastrophically.     

The role of safety cues in mediating the response to inhalations of CO2 in agoraphobics

Eighteen subjects meeting DSM-III-R criteria for panic disorder with agoraphobia were randomly allocated to either a safety or non-safety condition and underwent 15 min inhalations of 5.5% CO2 in air. In the safety condition, both a senior and junior experimenter were present, the junior experimenter was presented as a professional, and subjects were in personal contact with the senior experimenter throughout the procedure. In the non-safety condition, the senior experimenter left on a bogus emergency, the junior experimenter was introduced as a "student" and was dressed casually, and subjects were alone in the experimental room throughout the procedure. Despite these dramatic manipulations, there was no significant difference between groups on either the number of subjects experiencing a panic attack or on pre-inhalation safety scores. However, a median-split analysis on safety scores indicated that those subjects who perceived themselves to be less safe before the inhalation were more likely to experience a panic attack.     

Smoking and Non-Clinical Panic Attacks: An Initial Empirical Test of Panic-Relevant Cognitive Processes

The present study evaluated panic-relevant cognitive processes in a sample of persons ( n = 70) who met criteria for either: (a) a positive panic attack history and regular smoking (smoking at least 10 cigarettes per day for S 12 months); (2) a positive panic attack history but no history of smoking; or (3) regular smoking history alone (smoking at least 10 cigarettes per day for S 12 months). As hypothesized, participants in group (a) demonstrated significantly greater bodily vigilance and anxiety sensitivity Mental Incapacitation Concerns compared with persons in either groups (b) or (c). Effects involving other dimensions of anxiety sensitivity, suffocation fear and trait anxiety did not discriminate between panickers as a function of smoking status. The observed effects could not be attributed to self-reported physical health status or history of medical problems. The implication of the present findings for understanding the potential role of smoking in panic pathology is discussed.     

Preference between onset predictable and unpredictable administrations of 20% carbon-dioxide-enriched air: implications for better understanding the etiology and treatment of panic disorder

Predictability of aversive events impacts the development and maintenance of anxiety, particularly panic disorder. Although animal studies typically have found a preference for signaled (predictable) over unsignaled (unpredictable) aversive events, results of research with human participants have been less clear. Using a panic-relevant paradigm, the authors examined predictability preference with humans as a function of anxiety sensitivity and gender during repeated administrations of 20% carbon-dioxide-enriched air. Participants preferred predictable administrations, with high-anxiety individuals showing greater preference than low-anxiety individuals and women showing greater preference than men. In addition to providing information to better understand human predictability preference for panic-related events, results also may aid in determining the applicability of predictability to the cognitive-behavioral treatment of panic disorder.     

Book Reviews

Panic attacks and depression frequently co‐occur, and the presence of this co‐morbidity is often associated with worse outcomes compared with each disorder alone. Despite this, not everyone who experiences panic attacks also suffers from depression, suggesting that individual difference factors may play a role in this co‐morbidity. The purpose of this study was to provide a preliminary investigation of two such individual difference factors, examining the role of anxiety sensitivity and lack of emotional approach coping in depressive symptom severity among a non‐clinical sample of uncued panickers. A sample of 79 college students reporting the occurrence of uncued panic attacks within the past year completed a series of questionnaires assessing the lower‐order factors of anxiety sensitivity, emotional approach coping, panic attack frequency, panic‐related disability, panic symptom severity and depressive symptom severity. Participants with more severe depressive symptoms reported greater anxiety sensitivity, panic attack frequency, panic symptom severity, panic‐related disability and lack of emotional approach coping. The particular anxiety sensitivity dimension of fear of cognitive dyscontrol and lack of emotional approach coping emerged as the best predictors of depressive symptom severity. Findings are discussed in terms of their implications for the improved understanding of this co‐morbidity, as well as its treatment.     

Borderline psychopathology in the first-degree relatives of borderline and axis II comparison probands

The purpose of this study was to assess the prevalence of each of the nine DSM criteria for borderline personality disorder and the prevalence of the disorder itself in the first-degree relatives of borderline probands and Axis II comparison subjects. Four hundred and forty-five inpatients were interviewed about familial borderline psychopathology using the Revised Family History Questionnaire--a semistructured interview of demonstrated reliability. Of these 445 subjects, 341 met both DIB-R and DSM-III-R criteria for BPD and 104 met DSM-III-R criteria for another type of personality disorder (and neither criteria set for BPD). The psychopathology of 1,580 first-degree relatives of borderline probands and 472 relatives of Axis II comparison subjects was assessed. Both DSM-III-R and DSM-IV BPD were found to be more common among the relatives of borderline than Axis II comparison probands. However, five of the criteria for BPD (inappropriate anger, affective instability, paranoia/dissociation, general impulsivity, and intense, unstable relationships) and all four sectors of borderline psychopathology (affect, cognition, impulsivity, and interpersonal relationships) were found to be both more common and discriminating than the BPD diagnosis itself. Taken together, the results of this study suggest that the subsyndromal phenomenology of BPD may be more common than the borderline diagnosis itself.     

Development and validation of the penn state worry questionnaire

The present report describes the development of the Penn State Worry Questionnaire to measure the trait of worry. The 16-item instrument emerged from factor analysis of a large number of items and was found to possess high internal consistency and good test-retest reliability. The questionnaire correlates predictably with several psychological measures reasonably related to worry, and does not correlate with other measures more remote to the construct. Responses to the questionnaire are not influenced by social desirability. The measure was found to significantly discriminate college samples (a) who met all, some, or none of the DSM-III-R diagnostic criteria for generalized anxiety disorder and (b) who met criteria for GAD vs posttraumatic stress disorder. Among 34 GAD-diagnosed clinical subjects, the worry questionnaire was found not to correlate with other measures of anxiety or depression, indicating that it is tapping an independent construct with severely anxious individuals, and coping desensitization plus cognitive therapy was found to produce significantly greater reductions in the measure than did a nondirective therapy condition.     

Sex differences in response to a panicogenic challenge procedure: an experimental evaluation of panic vulnerability in a non-clinical sample

Epidemiological studies show that women are twice as likely as men to develop panic disorder (PD) during their lifetimes. Data from retrospective studies also suggest that women are more distressed by panic and other negative emotional states than men, and that this tendency may precede the development of PD. The present prospective study sought to expand this work by evaluating sex differences in the predisposition to panic in individuals without PD or other forms of psychopathology. Participants (N=96; 52 women) were exposed to 12 panicogenic inhalations of 20% CO2-enriched air while physiological (e.g., heart rate, electrodermal response, Frontalis EMG) and self-report (e.g., subject distress, fear, frequency and severity of DSM-IV panic symptoms) response domains were monitored. As expected, magnitude of autonomic responding failed to reliably discriminate between women and men. Yet, women reported more fear and panic immediately following the challenge procedure relative to men, and this sex difference persisted when assessed again 30 min post-challenge. Implications of these results are discussed broadly in the context of biopsychosocial accounts of sex differences in the clinical presentation of PD.     

Development of personality disorder symptoms and the risk for partner violence

In a community sample (N = 543) followed over 20 years, the authors studied associations among childhood family violence exposure, personality disorder (PD) symptoms, and adult partner violence. PD symptoms (DSM-III-R Clusters A, B, and C) in early adulthood partially mediated the effect of earlier childhood risks on the odds of perpetrating partner violence. The authors tested whether stability of PD symptoms from adolescence to the early 20s differs for individuals who later perpetrated partner violence. Cluster A ("Odd/Eccentric") symptoms declined less with age among partner violent versus nonviolent men and women. Cluster B ("Dramatic/Erratic") symptoms were more stable through late adolescence in partner violent men, compared with nonviolent men and violent women. Cluster C ("Anxious") symptoms were most stable among partner violent men.     

A Study of Panic Attacks in University Students of Iran

This study examined the parameters of panic, fear, and avoidance among university students in Iran. Data were collected from 347 students using Farsi translations of the Panic Attack Questionnaire, Beck Depression Inventory, Taylor Manifest Anxiety Scale, State-Trait Anxiety Inventory, and Anxiety Sensitivity Index. Thirty-eight percent of participants reported panic attacks in the past year and 21.4% reported panic attacks in the past 4 weeks when prompted by a broad definition of panic. Men and those with unexpected panic reported greater panic severity whereas women with panic attacks reported greater situational fear and avoidance. Panickers who satisfied DSM-III-R panic disorder (PD) criteria reported greater lifestyle restriction and general psychopathology. The findings provide tentative support for cross-cultural similarity in panic phenomenology and the validity of DSM-III-R PD criteria among university students in Iran. The results are discussed by reference to nonclinical panic research and general themes of Iranian culture.     

An Empirical Evaluation of the Diagnostic Criteria for Premenstrual Dysphoric Disorder: Problems with Sex Specificity and Validity

Premenstrual dysphoric disorder is a psychiatric disorder that reportedly affects between 3 to 8% of women. Although not an official diagnosis in the current Diagnostic and Statistical Manual of Mental Disorders, premenstrual dysphoric disorder has received increasing attention in the clinical literature, and considerable debate exists regarding the validity of this proposed condition. This study examined the prevalence of premenstrual dysphoric disorder in a sample of women and men and assessed the construct validity of the disorder. Twenty percent of women met the criteria for provisional diagnosis of premenstrual dysphoric disorder using Diagnostic and Statistical Manual criteria. In addition, 4% of men met these criteria when given sex-neutral assessment forms. Self-reported psychological distress and impaired interpersonal functioning did not predict women's likelihood of meeting the criteria for premenstrual dysphoric disorder. Results cast doubt on the sex-specificity of the diagnostic criteria of premenstrual dysphoric disorder and the construct validity of the disorder. Limitations of this study are discussed.     

Avoidant coping in panic disorder: a yohimbine biological challenge study

Few studies have addressed whether the use of avoidance-oriented coping strategies is related to the development of panic in patients with panic disorder(PD). Self-report, clinician-rated, and physiological data were collected from 42 individuals who participated in a yohimbine biological challenge study, performed under double-blind, placebo-controlled conditions. Participants included 20 healthy controls and 22 currently symptomatic patients who met DSM-IV-TR diagnostic criteria for PD. Consistent with prediction, patients with PD who had higher perceived efficacy of avoidance-oriented strategies in reducing anxiety-related thoughts reported increased severity in panic symptoms during the yohimbine challenge condition as compared to the placebo. Further, patients with PD who had more fear of cognitive dyscontrol, cardiovascular symptoms, and publicly observable anxiety also reported increased severity in panic symptoms during the challenge. Healthy controls who had more fear of cardiovascular symptoms similarly reported increased severity in panic symptoms during the challenge. No effects were found for heart rate response to the challenge agent. These results provide support for the role of avoidance-oriented coping strategies and fear of anxiety-related symptoms as risk and maintenance factors in the development of panic symptoms, particularly within a biological challenge model.