Panic Disorder
Symptoms
Panic disorder is an anxiety disorder characterized by repeated attacks of sudden and severe rush of fear or intense discomfort (panic attacks) that usually last for 10–20 minutes. The following is a list of DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision) symptoms of a panic attack.
At least four of these symptoms are necessary for a diagnosis of panic attack.
Palpitations, fast heart rate, or pounding heart
Chest pain or discomfort
Sweating
Trembling or shaking
Sensation of shortness of breath or smothering
Dizziness, lightheadedness, or faintness
Fear of dying
Fear of losing control or going crazy
Feeling of choking
Feelings of depersonalization or unreality
Nausea or gastrointestinal (GI) distress
Numbness or tingling in the hands, feet, or face
Chills or hot flashes.
A diagnosis of panic disorder requires both of the following:
1. Recurrent panic attacks, with at least two of them being uncued and unexpected, and
1. At least 1 month of one of the following:
persistent concern about having more attacks
worry about the implications of a panic attack or its consequences
(going crazy, losing control, or having a heart attack)
significant change in behavior related to the attacks
Panic attacks must also not be due to the effects of a substance (medication or drug of abuse) or a general medical condition. Finally, panic attacks must not be better accounted for by another Axis I disorder, such as social anxiety, specific phobia, GAD, PTSD, or obsessive–compulsive disorder. Panic disorder may occur with or without agoraphobia (fear of open spaces).
… I will briefly mention the main distinction between panic disorder and social anxiety disorder, since these two conditions are the most likely to be confused with each other. In social anxiety disorder, panic attacks happen only in the context of social situations (they are always cued) and the main object of fear is potential embarrassment or humiliation in the eyes of others. In panic disorder, at least some of the attacks are un-cued and unexpected and the main object of fear is the attack itself.
Etiology
There are currently two major theories of etiology of panic attacks – one states that panic attacks are a result of psychological processes with physiological symptoms as consequence, while the other considers panic attacks to be due to underlying physiological disturbances with psychological symptoms developing as a result of unexplained physiological states. Moynihan and Gevirtz (2001) provide a review of the two theories.
Psychologically based theory, whose proponents include David Clark and David Barlow, considers panic to be due to a person’s misinterpretation of certain body sensations as catastrophic and dangerous. According to this theory, a panic attack results from an overreaction to a normal physiological sensation, such as increased heart rate, which is misinterpreted as being indicative of an imminent heart attack. The exaggerated anxiety response leads to physiological symptoms of panic and more catastrophic thinking. Once such misinterpretation takes place, the person becomes fearful of and hyper-attuned to similar physiological sensations (anticipatory anxiety), which makes future panic attacks more likely.
Physiologically based theories, whose proponents include Donald Klein and Ronald Ley, consider panic to be qualitatively different from anxiety and fear, with disordered breathing being at the heart of panic etiology. Specifically, Ley’s hyperventilation theory proposes that overbreathing (see Chapter 8 on breathing) is responsible for the physiological symptoms of panic, and these symptoms subsequently produce fear and anticipatory anxiety. Several studies have shown that patients with panic disorder show low levels of end-tidal pCO2 at baseline, indicating chronic overbreathing (e.g., Salkovskis et al., 1986; Moynihan and Gevirtz, 2001; Wilhelm et al., 2001; Meuret et al., 2008).
Klein’s suffocation false alarm theory proposes that people with panic disorder are hypersensitive to rising levels of CO2. These patients perceive rising levels of CO2 at abnormally low thresholds, leading to sensations of breathlessness, suffocation, and air hunger. These sensations trigger panic attacks, with overbreathing as one of the symptoms. In addition, because of the increased sensitivity to rising levels of CO2, people with panic disorder learn to continuously keep CO2 levels low through chronic baseline overbreathing. Several studies have shown that patients with panic disorder are hypersensitive to high levels of inhaled CO2 (e.g., Nardi et al., 2006; Freire et al., 2008). Meuret et al. (2011), showed that people with panic disorder show low levels of CO2 at baseline and during panic attacks, but higher levels of CO2 right before the panic attacks begins.
Chronic overbreathing leads to compensatory physiological changes to stabilize the pH, which then evoke further overbreathing in stressful situations and may trigger panic. Hypersensitivity to rising levels of CO2 further exacerbates overbreathing response during and after a panic attack because of the person’s attempt to bring down CO2 levels. Please see Chapter 8 on breathing for a full description of the physiology and symptoms of overbreathing, as well as the physiology of compensatory physiological changes in response to chronic overbreathing.
Based on the fact that both the psychological and the physiological theories of panic have empirical support, Ronald Ley proposed that there may be two distinct and one mixed subtypes of panic disorder:
1. Respiratory subtype is characterized by prominent physiological sensations such as shortness of breath, heart palpitations, feelings of unreality, and feelings of terror. This type of panic is characterized by majority spontaneous (out-of-the-blue) panic attacks, which result from physiological changes caused by breathing disturbances.
2. Cognitive subtype is characterized by the experience of apprehensive anxiety rather than terror. Respiratory and related symptoms such as shortness of breath and heart palpitations are less likely, with fewer physiological symptoms of panic endorsed overall. This type of panic is characterized by a majority of situationally cued panic attacks. 3. Anticipatory subtype falls between the respiratory and cognitive subtypes. This type of panic may originate as respiratory, but with repeated occurrences develops into anticipatory fear of the physiological sensations, through Pavlovian conditioning. Anticipatory panickers share some symptoms of the cognitive panickers, such as anxious or ruminative thoughts, and some symptoms of the respiratory panickers, such as presence of respiratory and other physiological symptoms, but to a lesser extent than the primarily respiratory panickers. Anticipatory panickers experience both unexpected and situationally cued panic attacks.
A 2001 study by Moynihan and Gevirtz provided support for this theory by showing that patients with panic disorder fitting the description of respiratory-type panic have lower baseline levels of CO2 compared with patients with panic disorder fitting the description of cognitive-type panic and nonpanic controls. Moreover, those fitting the description of cognitive-type panic had baseline CO2 levels similar to nonpanic controls. Respiratory panickers also had lower levels of CO2 during recovery after both psychological and physical stressors, compared with the cognitive panickers and nonpanic controls. In addition, multiple studies by Alicia Meuret, Thomas Ritz, Walton Roth, Frank Wilhelm and their colleagues have demonstrated the significance of respiratory dysfunction, as indicated by low levels of end-tidal pCO2, in panic disorder (e.g., Wilhelm et al., 2001; Meuret et al., 2009; Meuret and Ritz, 2010).
It should also be noted that not all studies have confirmed the presence of respiratory dysfunction in patients with panic disorder. For example, a 2009 study by Monique Pfaltz and colleagues found no difference in the respiratory patterns of patients with panic disorder and healthy controls. However, this study did not differentiate between respiratory and cognitive or anticipatory subtypes, which may be the reason for the lack of findings.
Assessment
An assessment of panic disorder starts with an initial evaluation (see Chapter 4). An accurate diagnosis of panic disorder is important, given the similarity of symptoms but significant differences in the treatment of panic disorder and several other anxiety disorders (such as social anxiety, GAD, and specific phobia).
The following is a list of panic-specific questions that you may add to the standard initial evaluation:
1. Symptoms of panic: recently ever
o Palpitations, fast heart rate, or pounding heart __________ __________
o Chest pain or discomfort __________ __________
o Sweating __________ __________
o Trembling or shaking __________ __________
o Sensation of shortness of breath or smothering __________ __________
o Dizziness, lightheadedness, or faintness __________ __________
o Fear of dying __________ __________
o Fear of losing control or going crazy __________ __________
o Feeling of choking __________ __________
o Feelings of depersonalization or unreality __________ __________
o Nausea or GI distress __________ __________
o Numbness or tingling in the hands, feet, or face __________ __________
o Chills or hot flashes __________ __________
2.
3. 2. Frequency, intensity, and duration of panic symptoms, currently and worst ever.________________________________________________________________
4. 3. What is the main worry with respect to the panic attack and its outcome?________________________________________________________________
5. 4. Is there anticipatory anxiety?________________________________________________________________ •
6. If so, what is its frequency, intensity, and duration?________________________________________________________________
7. 5. Triggers for panic: •
o Environmental________________________________________________________________
o • Cognitive________________________________________________________________
o • Physiological/interoceptive________________________________________________________________
6. Symptoms of agoraphobia • List of difficult situations________________________________________________________________
Are they avoided or endured with distress?________________________________________________________________
7. Coping strategies (including medication and use of other substances)________________________________________________________________
8. Results of medical workup (important to rule out any cardiac issues and asthma)________________________________________________________________
Biofeedback Assessment
A standard psychophysiological stress and relaxation profiles (Chapter 5 and Chapter 6) are recommended for panic disorder in order to get an overall picture of psychophysiological functioning. Given the prominence of respiratory dysfunction in panic, it is important to follow the stress and relaxation profiles with a breathing assessment (see Chapter 8). Since the specific area of dysregulation lies in the levels of pCO2, using a capnometer during the assessment is particularly helpful.
Treatment
Standard treatment for panic disorder typically includes medication and/or psychotherapy. The succeeding sections briefly review the available treatments.
Medication
Two types of medication are commonly used in the treatment of panic disorder: antidepressants and benzodiazepines.
Selective serotonin reuptake inhibitors (SSRIs), such as paroxetine (Paxil, GlaxoSmithKline, Brentford, Middlesex, UK), sertraline (Zoloft, Pfizer, New York), and fluoxetine (Prozac, Eli Lilly, Indianapolis, IN), and the serotonin–norepinephrine reuptake inhibitor (SNRI) venlafaxine (Effexor , Wyeth, Madison, NJ), are prescribed as a daily medication for the reduction in the frequency and intensity of panic attacks.
Benzodiazepines, such as clonazepam (Klonopin, Genentech, Inc., San Francisco, CA), alprazolam (Xanax, Pfizer), and lorazepam (Ativan, Biovail Pharmaceuticals, Inc., North Bridgewater, NJ) are often prescribed to be used on an “as-needed” basis, alone or in combination with the antidepressants.
Psychotherapy
Cognitive–behavioral therapy (CBT) is the most commonly used and empirically validated psychotherapy for panic disorder. For example, David Barlow’s Panic Control Therapy (PCT) includes psychoeducation, cognitive restructuring, breathing skills, interoceptive exposure, and situational exposure as the main components of the treatment. The main goal of PCT is to identify and correct maladaptive thoughts and behaviors that contribute to anxiety and panic.
Biofeedback Treatment
There is a significant amount of evidence demonstrating that end-tidal pCO2 breathing training for panic disorder is an efficacious treatment. Yucha and Montgomery (2008), using The Applied Psychophysiology and Biofeedback/International Society for Neurofeedback and Research (AAPB/ISNR) Task Force guidelines for determining treatment efficacy, classify biofeedback treatment for anxiety as efficacious (level 4), although the guidelines do not differentiate between specific types of anxiety disorders. A recent study by Meuret et al. (2008) demonstrated the effectiveness of end-tidal pCO2 biofeedback in significantly reducing the frequency and severity of panic attacks, with 68% of patients being panic free at 12 months follow-up and 96% of patients described as “much improved” or “very much improved” at 12 months follow-up. Another remarkable finding of this study was 100% therapy session attendance, which is quite rare in psychological treatment research. This study built on the results of two previous studies by the same group, which have also demonstrated the effectiveness of end-tidal pCO2 biofeedback in improving symptoms of panic (Meuret et al., 2001, 2004). Interestingly, these studies have shown end-tidal pCO2 biofeedback to be equally effective for panickers with and without predominant respiratory symptoms. Moreover, a 2009 study by Meuret and colleagues demonstrated that end-tidal pCO2 training for patients with panic disorder decreases fear of bodily sensations, a hallmark characteristic of panic disorder.
There have been some concerns raised in the literature regarding the effectiveness of breathing training in panic disorder, and it has at times been dismissed as a “false safety signal” not beneficial to treatment. However, such conclusions disregard important physiological facts about breathing training. Earlier studies on breathing training in panic disorder have been conducted without the use of capnometry to measure end-tidal pCO2 levels and without consideration for potential overbreathing during training. In the absence of a capnometer or, at the very least, attention paid to potential overbreathing, many breathing techniques can and do easily result in overbreathing. Traditional breathing training techniques do not take into consideration the importance of both rate and tidal volume of each breath in maintaining proper levels of CO2. Deep breathing training can result in overbreathing due to a larger tidal volume of each breath. Just slowing down the breath is not sufficient to prevent overbreathing, since many people also increase their tidal volume to compensate for the slower breathing rate. To date, every study that has used CO2 biofeedback in breathing training for panic disorder has shown positive results.
In addition, there is a significant amount of evidence that heart rate variability (HRV) in people with panic disorder is lower than in panic-free controls (e.g., Klein et al., 1995; McCraty et al., 2001; Martinez et al., 2010; Petrowski et al., 2010; Diveky et al., 2012). To date, however, no studies have looked at the effectiveness of HRV biofeedback in reducing symptoms of panic disorder.
Based on this research, the primary focus of biofeedback training will be on breathing. You might consider including HRV resonance frequency breathing into the breathing training you will be doing.
Biofeedback Protocol
1. (1–2 sessions) Psychological evaluation (see Chapter 4).
2. (1–2 sessions) Psychophysiological stress and relaxation assessments (see Chapter 5 and Chapter 6).
3. (1 session) Breathing assessment (see Chapter 8).
4. (1 session) Discussion of assessment results, treatment planning, and client education.