Differences in reported symptom profile between panic disorder and other DSM-III-R anxiety disorders.

Previous research has indicated that reports of panic attacks are associated with a different set of symptoms to reports of generalized anxiety. The present two studies attempted to extend these findings to specific (situational) fears. In Study 1, 55 subjects with panic disorder were compared on their symptom profile during their panic attacks to 65 subjects with other anxiety disorders [simple phobia, social phobia and obsessive-compulsive disorder (OCD)] during response to their feared cue. The results indicated that, compared to subjects with other anxiety disorders, subjects with panic disorder were more likely to report parasthesias, dizziness, faintness, unreality, dyspnea, fear of dying and fear of going crazy/losing control. In Study 2, 90 subjects meeting diagnostic criteria for both panic disorder and another anxiety disorder (simple phobia, social phobia or OCD) were compared on the symptoms experienced during their unexpected panic attacks and their situationally-triggered fears respectively. Combining the symptoms found in Study 1 to differ between the groups into a linear combination, there was a significant interaction found between the type of fear reaction (panic attack vs cued fear response) and symptom group. Taken together, these findings suggest that reports of unexpected panic attacks associated with panic disorder are characterized by a different symptom profile to reports of specific fear reactions that are part of a phobic disorder or OCD.     

Emotional processing and panic

In this paper Rachman's concept of emotional processing was extended and a model highlighting the psychological operations underpinning processing was specified. Using this model, the aim was to investigate, by means of a questionnaire, whether patients with panic disorder (n=50) have more emotional processing difficulties than two samples of healthy controls (London, n=406; Aberdeen, n=125). The panic disorder group did have significantly more emotional processing difficulties than the control groups, showing a marked tendency to control feelings of anger, unhappiness and anxiety. Three emotional processing dimensions distinguished the panic from the control groups: greater control of emotional experiences ('smothering' or 'bottling up' emotions), greater awareness of feelings and more difficulties in labelling emotions. The authors hypothesise that emotional processing deficits act as a vulnerability factor for developing panic attacks.     

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.     

Animal phobias versus claustrophobias: Exteroceptive versus interoceptive cues

The overall purpose of this investigation was to examine heterogeneity among specific phobias. In particular, the goals were to compare features of fear responding between individuals fearful of claustrophobic situations and individuals fearful of spiders/snakes, and to compare their response to hyperventilation challenges. By so doing, specific predictions were tested in relation to a conceptual model of exteroceptive and interoceptive fear cues. Using a nonclinical sample, 19 subjects with spider/snake phobias, 18 nonphobies, and 9 subjects with claustrophobias were exposed on two separate occasions to a live tarantula or python, a small closet, and a hyperventilation challenge. Dependent measures included subjective anxiety, panic attacks, physical symptoms, cognitive symptoms (or, fear of symptoms) and heart rate. In addition, subjects completed a standardized self-report scale that measures fear of bodily symptoms of arousal. It was found that subjects with claustrophobia reported more physical symptoms and cognitive symptoms than did subjects with snake/spider phobias, in response to their fear-relevant stimulus. In addition, claustrophobic subjects were more fearful of hyperventilation challenges and reported more fear of bodily symptoms, than did snake/spider phobic subjects. Finally, subjects with claustrophobia were as fearful of hyperventilation as they were of their fear-relevant stimulus. Theoretical and empirical implications of these findings are discussed.     

Panic disorder in the families of patients with normal coronary arteries and non-fear panic disorder.

Patients with non-fear panic disorder (NFPD) meet DSM-III-R criteria for panic disorder, but do not report subjective fear or anxiety. Although apparently common in medical settings, this controversial group is in need of further diagnostic validation. This study assessed family history of panic disorder in patients with chest pain and normal coronary arteries (CP/NCA) and either NFPD, panic disorder with fear, or no panic. It was hypothesized that the two panic disorder groups would have similar, elevated rates of panic disorder in their first-degree relatives, compared to patients without panic. The results support the hypothesis; about 17% of the first-degree relatives of both NFPD and panic disorder patients were diagnosable with panic disorder according to proband interviews, whereas only 4.6% of the first-degree relatives of patients without panic were so diagnosable. These results support the diagnostic validity of NFPD in CP/NCA patients, because such patients had a family history of panic disorder similar to patients with a more classical panic disorder presentation. The lack of fear symptoms and behavior in NFPD may cause panic disorder to be overlooked as a potential cause of somatic symptoms in patients with no medical explanation for their condition.     

The anxiety disorder spectrum: Fear imagery,physiological reactivity,and differential diagnosis∗

Abstract

This review considers recent research assessing psychophysiological reactivity to fear imagery in anxiety disorder patients. As in animal subjects, fear cues prompt in humans a state of defensive motivation in which autonomic and somatic survival reflexes are markedly enhanced. Thus, a startle stimulus presented in a fear context yields a stronger (potentiated) reflex, providing a quantitative measure of fearful arousal. This fear potentiation is further exaggerated in specific or social phobia individuals when viewing pictures or imagining the phobic object. Paradoxically, fear imagery studies with more severe anxiety disorder patients – panic disorder with agoraphobia, generalized anxiety disorder, or anxious patients with comorbid depression – show a blunted, less robust fear potentiated response. Furthermore, this reflex blunting appears to systematically be more pronounced over the anxiety disorder spectrum, coincident with lengthier chronicity, worsening clinician-based judgments of severity and prognosis, and increased questionnaire-based indices of negative affectivity, suggesting that normal defensive reactivity may be compromised by an experience of long-term stress.     

Effects of aerobic exercise on anxiety sensitivity

Anxiety sensitivity is a known precursor to panic attacks and panic disorder, and involves the misinterpretation of anxiety-related sensations. Aerobic exercise has been shown to reduce generalized anxiety, and may also reduce anxiety sensitivity through exposure to feared physiological sensations. Accordingly, 54 participants with elevated anxiety sensitivity scores completed six 20-min treadmill exercise sessions at either a high-intensity aerobic ( n = 29 ) or low-intensity ( n = 25 ) level. Self-ratings of anxiety sensitivity, fear of physiological sensations associated with anxiety, and generalized anxiety were obtained at pre-treatment, post-treatment, and one-week follow-up. Results indicated that both high- and low-intensity exercise reduced anxiety sensitivity. However, high-intensity exercise caused more rapid reductions in a global measure of anxiety sensitivity and produced more treatment responders than low-intensity exercise. Only high-intensity exercise reduced fear of anxiety-related bodily sensations. The implications of these findings are discussed.     

Anxiety sensitivity and panic attacks in a nonclinical population

In the present study, we administered the Anxiety Sensitivity Index (ASI) and a modified version of the Panic Attack Questionnaire (PAQ) to 425 college students to determine whether high anxiety sensitivity ('fear of fear') occurs in the absence of a history of unpredictable ('spontaneous') panic attacks, or whether such attacks are a necessary precursor to high anxiety sensitivity. Based on their ASI scores, subjects were assigned to either the high, medium, or low anxiety sensitivity groups. High anxiety sensitivity subjects more frequently reported both a personal and family history of panic than did subjects in the other groups. Nevertheless, two-thirds of the high anxiety sensitivity subjects had never experienced an unpredictable panic attack. This suggests that the fear of anxiety can be acquired in ways other than through personal experience with panic.     

Panic symptoms in asthma and panic disorder: a preliminary test of the dyspnea-fear theory.

Ley's (Behaviour Research and Therapy, 27, 549-554, 1989) dyspnea-fear theory was tested on three groups of subjects: 10 with panic disorder, 24 with asthma, and 12 who were nonanxious and nonasthmatic, using measures of pulmonary function, muscle tension; and self-report measures of generalized anxiety, dyspnea, and psychopathology. Results are supportive of dyspnea-fear theory for asthmatics but not for individuals with panic disorder. Differences between groups on panic/fear measures were explained by a combination of general anxiety and dyspnea. Within-group regression analyses showed that only generalized anxiety symptoms contributed significantly to scores on the Asthma Symptom Checklist scale of panic/fear within the panic disorder group; while only dyspnea contributed to panic/fear among asthmatics. Additional results show that panic disorder subjects performed normally on pulmonary function tests but reported respiratory symptoms as severe as did asthmatics. Compared with normal subjects, both patient groups displayed lower correlations between self-rated symptoms of bronchoconstriction and objective pulmonary measures. Panic disorder subjects showed a negative relationship between pulmonary function and hyperventilation symptoms, suggesting a heightened sensitivity to, and discomfort with, sensations associated with normal pulmonary function. Asthmatics displayed a significant relationship between degree of airway obstruction and both trapezius surface EMG and ratings of hyperventilation symptoms.     

The effects of voluntary hyperventilation on patients with chest pain without coronary artery disease

The present investigation was designed to examine panic symptom experience in patients with chest pain of nonorganic etiology, using a hyperventilation provocation procedure. Given the recent focus on panic disorder in patients with nonorganic chest pain, we assessed three indices of physiological arousal, subjective anxiety, and endorsement of DSM-III-R panic symptomatology in response to 3 min of voluntary hyperventilation. Subjects included 23 patients with nonorganic chest pain (CP sample) and matched normal controls (NC sample). The results indicate that hyperventilation produced significant increases in skin conductance, heart rate, and upper trapezious EMG in both CP and NC samples. Despite equivalent levels of physiological arousal and subjective anxiety, the CP sample endorsed a greater number of DSM-III-R panic symptoms relative to the NC sample. Examination of post-hyperventilation symptoms indicated that a greater percentage of the CP sample reported palpitations, nausea, and chest pain when compared with normals. Comparison of CP patients with and without Panic Disorder revealed no significant differences on any measure. The results suggests that hyperventilation plays a role in symptom experience in patients with nonorganic chest pain, although anxiety does not appear central in moderating this effect.     

Physiological hyperarousal: construct validity of a central aspect of the tripartite model of depression and anxiety.

Physiological hyperarousal (PH) is an understudied component of the tripartite model of depression and anxiety. This study contributes to the literature on PH, the tripartite model, and anxiety and its disorders, using data from psychotherapy outpatients (n = 2,448), air force cadets (n = 1,335), and undergraduates (n = 284). Psychometrics and exploratory and confirmatory factor analyses showed that PH is a reliable, cohesive, discriminable, and valid construct. Compared with subjective anxiety, PH was more associated to panic versus mood disordered status, and to panic versus generalized anxiety disordered status. As hypothesized, an aspect of anxiety sensitivity (i.e., fear of body sensations) was particularly related to subjective anxiety in the presence of PH. Results support the PH construct as replicable, valid, and clinically important and support the utility of the tripartite and related models for understanding the relation of depressive and anxious syndromes.     

Panic-Related fears in persons reporting a family history of panic disorder

Abstract We administered the Body Sensations Questionnaire, Health Hardiness Index, Panic Attack Questionnaire, and the Symptom Checklist 90-R to college students (n=71) who either reported or did not report a family history of panic disorder. Participants who reported a family history of panic disorder reported significantly less perceived control over their health status, a greater fear of bodily arousal, and greater frequency of unexpected panic attacks compared to participants without such a history, although no significant group differences were detected for Symptom Checklist-90-R scales that measure negative emotional experiences. After controlling for personal history of panic, differences between the positive family history group remained only for the control over health measure. We discuss the results as preliminary evidence that certain cognitive responses are overrepresented in self-classified first-degree relatives of persons with panic disorder.     

Provocation of panic: three elements of the panic reaction in four anxiety disorders

Subjects with agoraphobia (N = 25), panic disorder (N = 25), social phobia (N = 19) or generalized anxiety disorder (N = 10) and controls with no psychiatric history (N = 16) underwent two provocation tests, voluntary hyperventilation and inhalation of 5% CO2 in air, and three experimental control conditions. They were measured on three elements of the panic reaction: somatic symptoms, psychic anxiety and fears of impending doom, and on a standard YES/NO measure of panic attack. The provocation conditions produced increased somatic symptoms and psychic anxiety across all groups relative to the control conditions. The agoraphobic and panic disorder groups showed a significantly greater increase in fears of impending doom from control to provocation conditions than the social phobic and GAD patients. This difference was not observed on measures of somatic symptoms or psychic anxiety. The present results provide some support for the theory that panic attacks result from the catastrophic misinterpretation of anxious symptoms, in this case produced by the two provocation tests.     

Responses to false physiological feedback in individuals with panic attacks and elevated anxiety sensitivity

Participants with elevated anxiety sensitivity and a history of panic attacks were compared to a low anxiety comparison group with respect to physiological and subjective reactivity to false heart-rate feedback and reactivity to a priming procedure. Whereas accurate heart-rate feedback elicited minimal responses, participants across groups showed significant physiological and subjective responses to false feedback. High risk and low risk participants did not differ in heart-rate responses to false feedback, though panic attack frequency did predict physiological and subjective reactions to false feedback in the high risk group. Self-reported nonspecific anxiety was significantly higher in high risk female participants than in low risk female participants, while males did not different in general subjective anxiety. However, high risk participants reported more panic-specific symptoms during the false feedback task than low risk participants, regardless of the sex of the participant. Therefore, although the experimental paradigm appeared to trigger nonspecific anxiety in high risk female participants, panic attack symptoms in reaction to the task were specific to risk group, not sex, and consistent with hypotheses. Surprisingly, the priming procedure did not influence physiological or subjective responses to false feedback in either group. These results raise additional questions regarding the process and impact of interoception in individuals with panic attacks, and suggest that false perception of internal changes may contribute to risk for panic disorder when exposed to believable cues.     

Social phobia features across the DSM-III-R anxiety disorders

One hundred sixty subjects meeting DSM-III-R criteria for the five major anxiety disorders were compared on the extent to which they reported features characteristic of social phobia. The results indicated that many patients in the anxiety disorder categories experience some degree of social anxiety. The differences between subjects with a primary diagnosis of social phobia and subjects with other anxiety disorders appear to be chiefly quantitative on this feature. Compared to the other anxiety disorders, social phobics report fear and avoidance in response to a greater number of social situations and report greater interference in their lives due to social phobic concerns. Among the anxiety disorders, generalized anxiety disorder appears to be associated with the greatest degree of social anxiety, and simple phobia with the least.     

Selective processing of threat cues in panic disorder

A computerized Stroop color-naming paradigm was used to investigate attentional biases for selectively processing threat information in panic-disordered patients. Subjects named the colors of neutral words (e.g. TYPICAL), fear words (e.g. PANIC), bodily sensation words (e.g. HEARTBEAT), and catastrophe words (e.g. HEART ATTACK). To control for familiarity with threat concepts, we used clinicians who treat panic disorder as normal control subjects. In contrast to normal controls, panic patients exhibited greater Stroop interference for all threat words, especially those associated with catastrophe. Stroop interference waned during the course of the experiment, thereby indicating habituation to the semantic content of the cues. These findings suggest that panic disorder, like other anxiety disorders, is associated with an attentional bias for processing threatening information.     

Social anxiety and fear of bodily sensations in panic disorder and agoraphobia: A matched comparison

This study tests the hypothesis that social anxiety and fear of bodily sensations are associated with the development of agoraphobic avoidance behavior in panic disorder patients. Twenty patients with panic disorder were compared to 20 patients with panic disorder with agoraphobia, matched by sex and duration of disorder. The two groups did not differ on measures of fear and frequency of assertive social responses. However, the agoraphobics scored higher on measures of interpersonal sensitivity, depression, feelings of inadequacy, and hostility. They also reported higher fear of bodily sensations. Although definitive conclusions need to be postponed until prospective studies have been conducted, there is evidence suggesting that the development of agoraphobia in panic patients is associated with hypersensitivity to bodily sensations and interpersonal situations.This research was supported by Grant 560-268-009 of the Dutch Organization for Scientific Research.     

Nonclinical panic in college students: an investigation of prevalence and symptomatology

This article presents data on the prevalence and symptomatology of panic attacks and panic disorder (PD) in a large nonclinical sample (n = 2,375) of college students. Results showed that approximately 12% of the sample had experienced at least one unexpected panic attack and that 2.36% met DSM-III-R criteria for panic disorder. Although there were no sex differences in overall panic attack prevalence, men reported significantly more panic-related worry than women, and women reported a higher panic frequency than men. Compared to subjects who met DSM-III-R criteria for PD, infrequent panickers presented with fewer panic symptoms, fewer panic episodes, less panic-related worry, lower anxiety sensitivity, and less panic-related avoidance. Moreover, compared with PD subjects, the infrequent panickers were much less likely to report fears of dying, going insane, and derealization during a panic attack. The findings provide preliminary support for the role of anxious apprehension as a psychological vulnerability factor in the pathogenesis of panic disorder.