CHAPTER 3
Panic, Agoraphobia, and Generalized Anxiety Disorder
F. Dudley McGlynn Todd A. Smitherman Jacinda C. Hammel
Description of the Disorders or Problems
Panic attacks are sudden periods of extreme biological and cognitive fearfulness that typically peak within 10 minutes then gradually subside. According to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, revised text (DSM-IV-TR; American Psychiatric Association [APA], 2000), the symptoms of panic attacks include at least four of the following: tachycardia or palpitations, sweating, trembling/shaking, shortness of breath or smothering, sensations of choking, chest pain or discomfort, nausea or stomach distress, feeling dizzy or faint, derealization or depersonalization, fear of losing control or of going crazy, fear of dying, numbing or tingling sensations, and chills or hot flushes. Panic disorder (PD), in turn, is characterized by presence of recurring, unexpected panic attacks. Formally the attacks must be accompanied by a month or longer of continuing concern about having additional attacks, by worry about implications of such attacks or their consequences, or by an adaptively significant change in behavior as a result of the attacks.
The core feature of agoraphobia is anxiety about being in places or situations from which escape might be difficult, impossible, or embarras-sing, or in which help might not be available, in the event of panic. Thus, agoraphobia involves fear of experiencing panic in one or more situations, not fear of the situations themselves. Common panic situations include public places, public transportation, and crowded areas. Usually the fear of panic eventuates in avoidance of the troublesome situations.
Of those who present agoraphobia clinically, 95% or so also merit a diagnosis of panic disorder (APA, 2000). Of those who present panic dis-order clinically, the majority also show agoraphobia. The diagnosis of panic disorder with agoraphobia (PDA) is used when the individual meets the diagnostic criteria for both disorders. Unless otherwise stated, PDA is of interest here.
Epidemiological studies estimate that lifetime prevalence of PDA is between 1.5% and 3.5%; one-year prevalence rates range from 1% to 2% (APA, 2000). Comorbidity figures for Axis I diagnoses among patients who have PDA according to DSM-III-R (APA, 1987) have ranged from 51% to 91% of patients (Beck & Zebb, 1994). Comorbidity patterns for PDA and PD are much the same; comorbid diagnoses include specific phobia and social phobia, dysthymia and major depression, and alcohol use/dependence. Major depression is more often comorbid with PDA than with PD alone (Starcevic, Uhlenhuth, Kellner, & Pathak, 1993).
Mixed panic and agoraphobia cohorts have typically been used in studies of Axis II comorbidity. Rates of personality-disorder diagnoses among these patients have been 25% to 60% (Beck & Zebb, 1994). Cluster C is overrepresented among comorbid Axis II designations. Some evidence suggests that rates of both Axis I and Axis II comorbidity increase as agoraphobia worsens and as patients’ lives become increasingly constrained.
Since the late 1980s theorists concerned with PDA have arranged biological and psychological factors into multielement etiologic models (see McNally, 1994). The model proposed by Barlow (1988, 2002) is a satisfactory exemplar. The development of PDA begins when biological and/or psychological diatheses combine with life stress to produce unusual bodily sensations that are benign but detectable. The bodily sensations, in turn, become cues for fearful catastrophizing. Next the fearful catastrophizing prompts increased attention to such sensations along with behavioral avoidance of events or situations wherein the sensations are expected to occur.
While the various etiologic models of PDA are similar to one another, important disagreements exist at virtually every theoretical choice point. There is disagreement, for example, about the physiological under-pinnings of the focal sensations, about how focal sensations become cues for fearful catastrophizing, and about how fear-motivated avoidance is established (Barlow, 2002; McNally, 1994). It is doubtless true that multielement models afford the best hope for explaining PDA satisfactorily but much work remains.
Generalized anxiety disorder (GAD) is characterized by uncontrol-lable, excessive worry accompanied by chronic anxiety. For at least 6 months, worry about a number of life events or activities is accompanied more days than not by at least three of six symptoms: restlessness, fatigue, impaired concentration, irritability, muscle tension, and sleep disturbance (APA, 2000). The focus of worry is not associated with another disorder such as worry about contamination (obsessivecompulsive disorder), worry about experiencing a panic attack (panic disorder), or worry that one's physical ailments signify a life-threatening illness (hypochondriasis).
The most recent large-scale epidemiological study, the National Comorbidity Survey, obtained a lifetime prevalence rate for GAD of 5.1% and a current prevalence rate for GAD of 1.6%, using DSM-III-R criteria (Wittchen, Zhao, Kessler, & Eaton, 1994). Also utilizing DSM-III-R criteria, the Epidemiologic Catchment Area study estimated a one-year prevalence rate of 3.8% for GAD (Blazer, Hughes, George, Swartz, & Boyer, 1991). As with PDA, there is high comorbidity of GAD with mood disorders and other anxiety disorders. Approximately 75% of individuals with a principal DSM-III-R diagnosis of GAD had a comorbid anxiety or mood disorder (Brawman-Mintzer et al., 1993; Brown & Barlow, 1992; Massion, Warshaw, & Keller, 1993). Utilizing DSM-IV criteria, Brown, Campbell, Lehman, Grisham, and Mancill (2001) reported significant comorbidity with posttraumatic stress disorder (23%), PD (19%), PDA (16%), social phobia (13%), and obsessive-compulsive disorder (12%). Beyond anxiety and mood disorders, there is significant comorbidity of GAD with health care utilization for physical complaints and with alcohol and drug-related problems (cf. Ballenger et al., 2001; Brown, Campbell, et al., 2001; Wittchen et al.). Indeed, 82% of individuals with GAD in the National Comorbidity Survey reported significant impairment in lifestyle and physical functioning (Wittchen et al. ).
Compared to PDA there are few etiologic modes of GAD that are well developed. However, some consensus is beginning to emerge regarding the general diathesis-stress etiology and regarding the role of worry in GAD (see Barlow, 2002; Borkovec & Roemer, 1995). According to that consensus, generalized biological and psychological vulnerabilities combine to form a pervasive diathesis for the development of emotional disorders. The biological domain entails a genetic vulnerability for negative affect that predisposes people to anxiety and related emotional disorders (such as depression). The psychological domain entails the effects of early experiences of uncontrollability and unpredictability usually vis-à-vis actions of caregivers. The consensus seems to be that both biological and psychological vulnerabilities are necessary to the genesis of GAD and other emotional disorders.
At the next level, the emerging consensus holds that the above vulnerabilities magnify responses to negative life events so that individu-als with GAD become overly sensitive to even minor stresses and relatively likely to think of stressful events as unrealistically probable, unpredictable, and uncontrollable. Worry enters the picture as a means of coping with catastrophic images and with the aversive affect that cognitive catastrophizing would otherwise engender. Worry then becomes chronic because it is negatively reinforced in at least two ways: worry about improbable events is usually followed by the absence of such events, and worry forestalls the (aversive) affective correlates of the imaging that worry displaces (see Borkovec & Roemer, 1995). Worry is maladaptive in the long run; by forestalling emotional imaging it forestalls emotional processing, and by suppressing sympathetic arousal it contributes to autonomic inflexibility. Thinking of stressful events as unpredictable and uncontrollable is maladaptive also because it fosters negative self-evaluation and slows the development of realistic problem-solving skills.
Range of Assessment Strategies Available
Assessment of Panic Disorder with Agoraphobia
In assessing PDA, the clinician thinks in terms of four major domains of assessment: situational antecedents, interoceptive anxiety, panic-related cognitions, and agoraphobic avoidance. In principle, self-report, behavioral, and physiological assessment methods can be used to specify problems and monitor progress during treatment. Since most physiologi-cal assessment tools are not readily available to clinicians in private practice, a narrative about psychophysiological assessment is withheld here. Readers who are interested in psychophysiological assessment of PDA, including ambulatory psychophysiological recording, can consult Papillo, Murphy, and Gorman (1988) and Barlow (2002), among other sources. Instrumentation for recording heartbeats is straightforward to use and readily available, thus heart-rate recording as part of anxiety-disorder assessment is becoming more common. Yartz and Hawk (2001) have provided an excellent clinical guide for heart-rate measurement. Clinicians should, however, review information about basic physiology such as that provided by Papillo and colleagues before interpreting heartbeat records.
Self-Report Strategies
Self-report methods afford the only means available for understanding panic phenomenologically. Such understanding is important given contemporary attention to cognitive models of anxiety and, in particular, to catastrophic misappraisals of bodily sensations in PDA (e.g., Barlow, 2002). Self-report methods are also practical and cost efficient. Self-report methods can be broken down into structured interviews, questionnaires, self-monitoring, and situational fear ratings.
Structured Interviews
When assessing for PDA and other anxiety disorders, the structured or semistructured interview of choice is the Anxiety Disorders Interview Schedule for DSM-IV: Lifetime Version (ADIS-IV-L; Di Nardo, Brown, & Barlow, 1994). The ADIS-IV-L assists in determining both lifetime and current PDA diagnoses. In addition, the ADIS-IV-L provides information about the history of the anxiety problems, about maladaptive thinking, about situational antecedents to PDA symptoms, and about the symptoms themselves. The ADIS-IV-L is composed of modules specific to each of the anxiety disorders; it also provides interview data about depression, psychosis, drug abuse, and organic symptoms. The ADIS-IV-L can be administered in its entirety, or modules may be selected that are germane to the presenting problems and referral questions.
The ADIS-IV-L and its prior editions were developed so as to keep pace with the diagnostic nomenclature as it evolved. Over the years, the ADIS has demonstrated good psychometric properties. There have been reports of good interrater reliabilities, particularly for those disorders with frequent behavioral markers. For example, Brown, Di Nardo, Lehman, and Campbell (2001) reported interrater reliabilities of DSM-IV diagnoses based on the ADIS-IV-L among 362 patients selected randomly from among those who presented to their anxiety disorders specialty clinic. For 83 patients who received at least one PDA principal diagnosis, the kappa coefficient was .77. There have also been favorable reports regarding the various issues of validity (Barlow, 2002).
Questionnaires
The narrative here provides an overview along with some details. More complete and helpful information is available in an excellent sourcebook by Antony, Orsillo, and Roemer (2001). Several questionnaires have been developed to assess aspects of PDA, including interoceptive anxiety, panic-related cognitions, and agoraphobic avoidance. Interoceptive anxiety can be assessed by administration of the Anxiety Sensitivity Index (Reiss, Peterson, Gursky, & McNally, 1986). The 16-item Anxiety Sensitivity Index is a popular and well-researched questionnaire that quantifies a construct known as anxiety sensitivity, the tendency of a person to evidence catastrophic thinking in the presence of certain bodily sensations (Reiss & McNally, 1985). While the matter is controversial, the Anxiety Sensitivity Index appears to have one higher-order factor and three lower-order factors, the latter reflecting physical concerns, social concerns, and concern over loss of cognitive capacity (Zinbarg, Barlow, & Brown, 1997). The Anxiety Sensitivity Index has been shown to have strong psychometric properties (Peterson & Reiss, 1993) and has been shown to afford prediction concerning variables such as response to challenge and response to treatment (see Taylor, 1999). Recently, the Anxiety Sensitivity Index was revised and lengthened to 36 items, in an effort to more thoroughly measure the dimensions of anxiety sensitivity. Research with the revised index has demonstrated strong internal consistency and is ongoing (Taylor & Cox, 1998).
The 18-item Body Sensations Questionnaire (Chambless, Caputo, Bright, & Gallagher, 1984) is available for assessing the bodily sensations present when the client is anxious or fearful. The Body Sensations Questionnaire was developed in conjunction with the 15-item Agoraphobic Cognitions Questionnaire (Chambless et al.), which is used for assessing the prominence of various panic-related cognitions, particu-larly those related to the themes of physical/bodily concern and loss of control. Both scales have been found to have satisfactory internal consis-tency and test-retest stability. Both have also shown good discriminant and construct validity, and sensitivity to effects from treatment (Chambless et al.; Chambless & Gracely, 1989).
The above questionnaires are among the most common and well-researched tools for assessing feared bodily sensations and panic-related cognitions. Additional instruments exist for assessing fear when in situations that are often avoided. The 27-item Albany Panic and Phobia Questionnaire (Rapee, Craske, & Barlow, 1995), for example, contains an agoraphobia subscale, an interoceptive subscale, and a social phobia subscale. It has shown adequate internal consistency and test-retest stability; its agoraphobia and interoceptive subscales have been shown to distinguish between those with PDA, those with other anxiety disorders, and those without a diagnosis (Rapee et al.). Antony (2001) and Bou-chard, Pelletier, Gauthier, Côté, and Laberge (1997) have provided comprehensive reviews of several other questionnaires sometimes used to assess PDA.
Self-Monitoring
Self-monitoring entails self-recording certain features of the behavior(s) of interest, for example, the location, intensity, and duration of panic...
