Anxiety Disorders: MCCQE1 Preparation Guide

Introduction

Anxiety disorders are among the most common psychiatric conditions encountered in Canadian clinical practice. For MCCQE1 preparation, understanding the nuances of these disorders is critical, as they frequently appear in both the Multiple Choice Question (MCQ) and Clinical Decision Making (CDM) components.

As a future Canadian physician, you must approach anxiety through the CanMEDS framework:

• Medical Expert: Diagnosing based on DSM-5-TR criteria and ruling out organic causes.
• Communicator: Validating patient distress and explaining the bio-psycho-social model.
• Health Advocate: Recognizing the impact of social determinants (e.g., housing, income) on mental health in the Canadian context.

Classification of Anxiety Disorders

The DSM-5-TR categorizes anxiety disorders based on the specific object or situation that induces fear/anxiety. The most high-yield conditions for the MCCQE1 are:

1. Generalized Anxiety Disorder (GAD)
2. Panic Disorder
3. Social Anxiety Disorder (Social Phobia)
4. Specific Phobia
5. Agoraphobia

Clinical Presentation and Diagnosis

Differential Diagnosis: Medical vs. Psychiatric

For the MCCQE1, you must demonstrate the ability to rule out organic causes before diagnosing a primary psychiatric disorder. This is a critical safety competency.

Approach to the Anxious Patient (MCCQE1 Focus)

Management: Canadian Guidelines

Management should follow the Canadian Psychiatric Association (CPA) and CanMAT clinical practice guidelines.

1. Non-Pharmacological (First-Line)

• Psychoeducation: Explain the “fight or flight” response. Eliminate caffeine and alcohol.
• CBT (Cognitive Behavioural Therapy): The gold standard psychotherapy for anxiety disorders.
  • Mechanism: Challenges cognitive distortions and uses exposure techniques.
  • Access: In Canada, access can be limited. Mention online resources (e.g., BounceBack program) or self-help guides.

2. Pharmacotherapy

First-Line Agents

• SSRIs (Selective Serotonin Reuptake Inhibitors): Escitalopram, Sertraline, Paroxetine, Citalopram.
• SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors): Venlafaxine XR, Duloxetine.

Second-Line / Adjunctive

• Pregabalin: Approved in Canada for GAD.
• Benzodiazepines (e.g., Lorazepam, Clonazepam):
  • MCCQE1 Caution: Use only for short-term bridging (2-4 weeks) until SSRIs take effect, or for severe agitation.
  • Avoid in patients with history of substance use disorder.
  • Avoid in the elderly (Fall risk - Beers Criteria).
• Buspirone: Second-line for GAD. Not effective for Panic Disorder.

3. Monitoring

• Monitor for suicidal ideation after initiating antidepressants (especially in patients <25 years).
• Assess for Serotonin Syndrome if mixing serotonergic agents.

// Serotonin Syndrome Triad
1. Neuromuscular excitation (Hyperreflexia, clonus, rigidity)
2. Autonomic stimulation (Hyperthermia, tachycardia)
3. Altered mental status (Agitation, confusion)

Key Points to Remember for MCCQE1

• Thyroid: Always check TSH in new-onset anxiety.
• Substance Withdrawal: Alcohol withdrawal can mimic severe panic/anxiety (tremors, autonomic hyperactivity).
• Avoidance: The hallmark of phobias and agoraphobia is avoidance.
• Duration: Generally, symptoms must last ≥ 6 months for a formal diagnosis (except Panic Disorder which requires 1 month of worry following an attack).
• Elderly: New-onset anxiety in the elderly is organic until proven otherwise.
• Treatment: SSRI/SNRI + CBT is the most effective combination.

Sample Question

Scenario

A 24-year-old female presents to the emergency department complaining of “heart palpitations” and shortness of breath that started abruptly 30 minutes ago while she was studying at the library. She reports feeling lightheaded and fears she is “going crazy.” She has had two similar episodes in the past month. Her past medical history is unremarkable. She does not smoke or use illicit drugs but drinks 3 cups of coffee daily. Vital signs are: BP 128/78 mmHg, HR 104 bpm, RR 22/min, Temp 37.0°C. Physical examination, including cardiac auscultation, is normal. An ECG shows sinus tachycardia but is otherwise normal. TSH and electrolytes are within normal limits.

Which one of the following is the most appropriate long-term pharmacologic management for this patient?

Options

• A. Alprazolam
• B. Propranolol
• C. Sertraline
• D. Quetiapine
• E. Bupropion

Explanation

The correct answer is:

• C. Sertraline

Explanation: This patient presents with recurrent, unexpected panic attacks and worry about future attacks (implied by presenting to ED), consistent with Panic Disorder.

• Sertraline (SSRI) is a first-line pharmacologic treatment for Panic Disorder according to Canadian guidelines (CPA/CanMAT). SSRIs and SNRIs are preferred for long-term management due to their efficacy and safety profile compared to benzodiazepines.
• Alprazolam (A) is a benzodiazepine. While effective for acute symptom relief, it is not recommended for long-term monotherapy due to risks of dependence, tolerance, and withdrawal. It may be used temporarily as a “bridge.”
• Propranolol (B) is a beta-blocker. It is sometimes used for performance-only social anxiety (e.g., stage fright) to control autonomic symptoms but is not a first-line treatment for Panic Disorder.
• Quetiapine (D) is an atypical antipsychotic. It is not a first-line treatment for uncomplicated Panic Disorder.
• Bupropion (E) is an antidepressant acting on norepinephrine and dopamine. It can actually be anxiogenic (cause anxiety) and is not indicated for Panic Disorder; it is primarily used for Depression and Smoking Cessation.

Study Checklist

• Review DSM-5 criteria for GAD, Panic Disorder, and Social Anxiety Disorder.
• Memorize the “WATCHERS” and “STUDENTS FEAR the 3 Cs” mnemonics.
• Practice ruling out organic causes (Thyroid, Cardiac, Substances).
• Review the mechanism of action and side effects of SSRIs and Benzodiazepines.
• Understand the “Stepped Care” model in the Canadian healthcare system.

References

1. American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.).
2. 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. [CanMAT Guidelines]
3. Public Health Agency of Canada. (2015). Mood and Anxiety Disorders in Canada.
4. Medical Council of Canada. (2023). MCCQE Part I Objectives: Mental Health.
5. Toronto Notes. (2024). Psychiatry Chapter.