Table of Contents

Panic Disorder

Primer

Panic disorder is a condition where there are recurrent unexpected panic attacks, in the absence of triggers. It is marked by persistent concern about additional panic attacks and/or maladaptive change in behaviour related to the attacks.

Epidemiology
Prognosis
Note: The prevalence of panic attacks (not disorder) is 11.2% in adults, and can occur in the context of anxiety disorders, other mental disorders, and medical conditions. Panic attacks in and of themselves are not pathological, and do not require treatment.
Comorbidity
Risk Factors
Cultural

Diagnostic Criteria

Criterion A

Recurrent unexpected panic attacks. A panic attack is an abrupt surge of intense fear or intense discomfort that reaches a peak within minutes, and during which time at least 4 of the following symptoms occur (Note: The abrupt surge can occur from a calm state or an anxious state):

  1. Sweating
  2. Trembling or shaking
  3. Unsteady, dizziness, light-headed, or faint
  4. Derealization (feelings of unreality) or depersonalization (being detached from one self)
  5. Excessive/accelerated heart rate, palpitations, or pounding heart
  6. Nausea or abdominal distress
  7. Tingling, numbness, parathesesias
  8. Shortness of breath
  9. Fear of losing control or “going crazy”
  10. Fear of dying
  11. Choking feelings
  12. Chest pain or discomfort
  13. Chills or heat sensations
Note: Culture-specific symptoms (e.g. - tinnitus, neck soreness, headache, uncontrollable screaming or crying) may be seen. Such symptoms should not count as one of the four required symptoms.

Panic Attack Definition

  • A panic attack is a single, discrete episode of intense fear and discomfort.
  • A panic attack can be expected or unexpected, but in order to diagnose panic disorder, there must be at least one unexpected panic attack!
  • A panic attack must peak abruptly (rapid onset of under 10 minutes), and must be accompanied by a cluster of physical symptoms.
  • A typical panic attack is relatively short and lasts no more than 15 minutes.

Mnemonic

The mnemonic STUDENTS FEAR the 3 C's can be used to remember the panic disorder criteria:

  • S - Sweating
  • T - Trembling
  • U - Unsteadiness, dizziness
  • D - Depersonalization, derealization
  • E - Excessive heart rate, palpitations
  • N - Nausea
  • T - Tingling
  • S - Shortness of breath
  • FEAR of dying
  • FEAR of losing control
  • FEAR of going crazy
  • C - Chest pain
  • C - Chills
  • C - Choking
Criterion B

At least 1 of the attacks has been followed by at least 1 month of at least 1 of the following:

  1. Persistent concern or worry about additional panic attacks or their consequences (e.g. - losing control, having a heart attack, “going crazy”).
  2. A significant maladaptive change in behavior-related to the attacks (e.g. - behaviors designed to avoid having panic attacks, such as avoidance of exercise or unfamiliar situations).
Criterion C

The disturbance is not attributable to the physiological effects of a substance (e.g. - a drug of abuse, a medication) or another medical condition (e.g. - hyperthyroidism, cardiopulmonary disorders).

Criterion D

The disturbance is not better explained by another mental disorder:

Signs and Symptoms

Asking 'Do you experience panic attacks?' is too vague!

A 'panic attack' means different things to different people, and they may not actually be experiencing panic attacks. It is more important to explore whether a cluster of physical symptoms occurs and the chronology of the symptoms. It is also helpful to identify if there are specific triggers that lead to symptoms.

A true panic attack occurs only during a discrete period of time, must peak abruptly, and is accompanied by physical symptoms. Chronic anxiety on the other hand fluctuates over a period of hours to days.

Screening and Rating Scales

Panic Disorder Scales

Name Rater Description Download
Panic Disorder Severity Scale (PDSS) Clinician The PDSS is a 7 question scale to grade panic disorder severity. Download

Pathophysiology

Learning Theory

Differential Diagnosis

  • Other specified anxiety disorder or unspecified anxiety disorder
    • Panic disorder should not be diagnosed if full-symptom (i.e. - unexpected) panic attacks have never been experienced. In the case of only limited-symptom unexpected panic attacks, the diagnosis of “other specified anxiety disorder or unspecified anxiety disorder diagnosis” should be considered.
  • Anxiety disorder due to another medical condition
    • Panic disorder should not be diagnosed if the panic attacks are thought to be a direct physiological result of another medical condition.
    • Features such as onset after age 45 years or the presence of atypical symptoms during a panic attack (e.g. - vertigo, loss of consciousness, loss of bladder or bowel control, slurred speech, amnesia) suggest the possibility that an other medical condition or a substance may be causing the panic attack symptoms.
    • Examples of medical conditions that can cause panic attacks include hyperthyroidism, hyperparathyroidism, pheochromocytoma, vestibular dysfunctions, seizure disorders, and cardiopulmonary conditions (e.g. - arrhythmias, atrial fibrillation, flutter, palpitations, dyspnea, syncope, supraventricular tachycardia, asthma, and chronic obstructive pulmonary disease [COPD])
  • Acute coronary syndrome or myocardial infarction (MI)[26]
    • This is especially important for women, who commonly present with atypical features of MI compared with men, and their symptoms may be dismissed as a “panic attack.”
  • Endocrinopathies
    • Cushing disease, diabetes mellitus (check for hypoglycemia), thyroid disease, parathyroid disease (hyperparathyroidism, pseudo-hyperparathyroidism), pancreatic tumours, and pituitary disease may cause symptoms similar to panic attacks.
    • Pheochromocytomas should be considered on the differential in rare cases, especially if the patient is not responding to conventional treatments.[27][28]
      • The classic triad of pheochromocytoma symptoms includes headache, excessive sweating, and palpitations. Around 15%-20% of patients with a pheochromocytoma patients may be normotensive.
    • Panic disorder should not be diagnosed if the panic attacks are judged to be a direct physiological consequence of a substance. Intoxication with central nervous system stimulants (e.g. - cocaine, amphetamines, caffeine) or cannabis and withdrawal from central nervous system depressants (e.g. - alcohol, barbiturates) can precipitate a panic attack. However, if panic attacks continue to occur out side of the context of substance use (e.g. - long after the effects of intoxication or withdrawal have ended), a diagnosis of panic disorder should be considered. Since panic disorder may precede substance use in some individuals and may be associated with increased substance use (i.e. - self medication), a detailed history should be taken to see if the individual had panic attacks prior to excessive substance use. If this is the case, a diagnosis of panic disorder should be considered in addition to a diagnosis of substance use disorder.
  • Other mental disorders with panic attacks as an associated feature (e.g. - other anxiety disorders and psychotic disorders)
    • Panic attacks that occur as a symptom of other anxiety disorders are expected. For example, panic attacks can be triggered by:
    • In each of these above cases, the individual would not meet criteria for panic disorder. Remember always that panic disorder is characterized by recurrent unexpected panic attacks, and the unexpected nature of the panic attacks is a defining feature of the disorder. If the panic attacks typically only occur in response to specific triggers, then only the relevant anxiety disorder is assigned. However, if the individual experiences unexpected panic attacks as well and then begins to show persistent concern and worry or begins making behavioural change because of the attacks, then an additional diagnosis of panic disorder may be considered.

Investigations

Physical Exam

Treatment

Psychotherapy

Psychotherapy Tip

It is often helpful to explain to patients that having panic disorder is like having a car with an oversensitive alarm system: every car has an alarm system that activates when a window is smashed, but sometimes the alarm system can be hypersensitive, and even a small bump or breeze can activate it.

Pharmacotherapy

Pharmacotherapy for Panic Disorder (and Agoraphobia)

Katzman, M. A. et al. (2014). Canadian clinical practice guidelines for the management of anxiety, posttraumatic stress and obsessive-compulsive disorders. BMC psychiatry, 14(1), 1-83.
1st line Citalopram, escitalopram,[41] fluoxetine, fluvoxamine, paroxetine, paroxetine CR, sertraline, venlafaxine XR
2nd line Alprazolam, clomipramine, clonazepam, diazepam, imipramine,[42] lorazepam, mirtazapine, reboxetine
3rd line Bupropion SR, divalproex, duloxetine, gabapentin, levetiracetam, milnacipran, moclobemide, olanzapine, phenelzine, quetiapine, risperidone, tranylcypromine
Adjunctive therapy Second-line: alprazolam ODT, clonazepam
Third-line: aripiprazole, divalproex, olanzapine, pindolol, risperidone
Not recommended Buspirone, propranolol, tiagabine, trazodone

Guidelines

Panic Disorder Guidelines

Guideline Location Year PDF Website
Canadian Clinical Practice Guidelines for the Management of Anxiety, Posttraumatic Stress and Obsessive-Compulsive Disorders Canada 2014 - Link
National Institute for Health and Care Excellence (NICE) UK 2011, 2019 - Link
American Psychiatric Association (APA) USA 2009 - Guideline (2009)
Quick Reference Guide
Royal Australian and New Zealand
College of Psychiatrists (RANZCP)
AUS, NZ 2018 - Link

Resources

1) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
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14) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
15) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
16) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
18) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
19) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
20) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
21) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
22) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
23) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
24) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.