USMLE Step 2 CK: Psychiatry – Anxiety, Somatoform Disorders, Panic, GAD, OCD, Illness Anxiety

What This Is and Why It Matters for USMLE

Anxiety and Somatoform Disorders are high-yield topics for Step 1, Step 2 CK, and Step 3. They are frequently tested in basic science, clinical, and ethics/management contexts. Familiarize yourself with these conditions to accurately diagnose and manage patients.

High-Yield Facts (What You Must Memorize)

Pathophysiology (Step 1)

• Hyperarousal and hypervigilance in anxiety disorders
• Fear of anxiety in GAD
• Repetitive thoughts and compulsions in OCD
• Excessive worry about health in Illness Anxiety

Classic Presentation and Physical Exam Findings (Step 2 CK)

• Panic attacks: sudden onset, peak within 10 minutes, and resolution within 30 minutes
• GAD: excessive worry, restlessness, fatigue, and difficulty concentrating
• OCD: repetitive thoughts, compulsions, and avoidance behaviors
• Illness Anxiety: excessive worry about health, fear of illness, and hypochondriasis

Diagnostic Approach (labs, imaging)

• Lab tests: rule out underlying medical conditions (e.g., thyroid dysfunction, anemia)
• Imaging: rule out underlying medical conditions (e.g., cardiac disease, neurological disorders)

First-Line Treatment and Management (Step 2 CK, Step 3)

• Anxiety disorders: SSRIs (e.g., fluoxetine, sertraline), CBT (e.g., exposure and response prevention)
• GAD: SSRIs (e.g., fluoxetine, sertraline), benzodiazepines (e.g., alprazolam)
• OCD: SSRIs (e.g., fluoxetine, sertraline), clomipramine
• Illness Anxiety: CBT (e.g., cognitive restructuring), SSRIs (e.g., fluoxetine, sertraline)

Red Flags, Complications, and Follow-up

• Red flags: suicidal ideation, self-injury, or substance abuse
• Complications: social isolation, relationship problems, or decreased quality of life
• Follow-up: regular monitoring of symptoms, treatment response, and side effects

Clinical Pearls & Buzzwords

• Anxiety disorders: hyperarousal, hypervigilance
• GAD: excessive worry, restlessness
• OCD: repetitive thoughts, compulsions
• Illness Anxiety: excessive worry about health, hypochondriasis

Step-by-Step Clinical Reasoning

1. Identify the syndrome or presentation.
2. Generate a differential (most likely and must-not-miss).
3. Order appropriate initial tests (e.g., lab tests, imaging).
4. Interpret results.
5. Initiate treatment and monitoring.

Missing a life-threatening complication (e.g., suicidal ideation) can be a critical mistake.

Common Mistakes & Exam Traps

• The mistake: Failing to consider underlying medical conditions.
• Why it happens: Misunderstanding or rushing through the exam.
• How to avoid it: Take your time, consider the patient's medical history and physical exam findings.

• Exam board insight: The examiners want to test your ability to think critically and consider multiple possibilities.

• The mistake: Failing to recognize the difference between anxiety disorders and other conditions (e.g., depression).

• Why it happens: Misunderstanding or misreading the patient's presentation.
• How to avoid it: Pay attention to the patient's symptoms and history, and use a differential diagnosis approach.
• Exam board insight: The examiners want to test your ability to accurately diagnose and manage patients.

How It’s Tested on USMLE

Step 1:

• Basic science vignette: e.g., molecular mechanism of anxiety disorders, pharmacology of SSRIs.
• Focus on pathophysiology, pharmacology, and pathology.

Step 2 CK:

• Clinical vignette: e.g., "A 45-year-old with chest pain and anxiety."
• Focus on diagnosis and next step in management.

Step 3:

• Similar to Step 2 CK, plus prognosis, risk factors, and occasionally CCS management.

CCS (Step 3) Relevance (If Applicable)

• Initial orders: e.g., lab tests (e.g., CBC, electrolytes), imaging (e.g., chest X-ray).
• Monitoring and follow-up: e.g., regular monitoring of symptoms, treatment response, and side effects.
• Common mistakes: e.g., not ordering indicated tests, delaying treatment.

Practice Questions (3-5 single-best-answer)

Question 1:

A 30-year-old woman presents with panic attacks, excessive worry, and restlessness. Which of the following is the most likely diagnosis? A) Panic disorder B) Generalized anxiety disorder C) Obsessive-compulsive disorder D) Post-traumatic stress disorder

Answer:

A) Panic disorder

Explanation:

The patient's symptoms of panic attacks, excessive worry, and restlessness are characteristic of panic disorder. The other options are not as likely given the patient's presentation.

Question 2:

A 40-year-old man presents with repetitive thoughts and compulsions. Which of the following is the most likely diagnosis? A) Obsessive-compulsive disorder B) Generalized anxiety disorder C) Panic disorder D) Post-traumatic stress disorder

Answer:

A) Obsessive-compulsive disorder

Explanation:

The patient's symptoms of repetitive thoughts and compulsions are characteristic of obsessive-compulsive disorder. The other options are not as likely given the patient's presentation.

Question 3:

A 50-year-old woman presents with excessive worry about health and fear of illness. Which of the following is the most likely diagnosis? A) Illness anxiety disorder B) Generalized anxiety disorder C) Panic disorder D) Post-traumatic stress disorder

Answer:

A) Illness anxiety disorder

Explanation:

The patient's symptoms of excessive worry about health and fear of illness are characteristic of illness anxiety disorder. The other options are not as likely given the patient's presentation.

Quick Reference Card (60-Second Summary)

• Anxiety disorders: SSRIs (e.g., fluoxetine, sertraline), CBT (e.g., exposure and response prevention)
• GAD: SSRIs (e.g., fluoxetine, sertraline), benzodiazepines (e.g., alprazolam)
• OCD: SSRIs (e.g., fluoxetine, sertraline), clomipramine
• Illness Anxiety: CBT (e.g., cognitive restructuring), SSRIs (e.g., fluoxetine, sertraline)

If You Get Stuck on Test Day

• Eliminate obviously wrong answers: Use the process of elimination to narrow down the options.
• Use the "next best step" hierarchy: Start with the least invasive and most specific option.
• For Step 3 CCS: Order basic labs (e.g., CBC, electrolytes), imaging (e.g., chest X-ray), and IV access when unsure.

Related USMLE Topics

• Depression: Connects to anxiety disorders, treatment options (e.g., SSRIs, CBT), and side effects.
• Post-traumatic stress disorder (PTSD): Connects to anxiety disorders, treatment options (e.g., SSRIs, CBT), and side effects.
• Substance abuse: Connects to anxiety disorders, treatment options (e.g., SSRIs, CBT), and side effects.