USMLE Guide: Psychiatry of Anxiety Disorders

Introduction

This guide provides a comprehensive overview of the psychiatry of anxiety disorders, focusing on key concepts that are important for the United States Medical Licensing Examination (USMLE). Anxiety disorders are a group of mental health conditions characterized by excessive fear, worry, and distress. Understanding the classification, clinical features, diagnosis, and treatment of these disorders is essential for medical students preparing for the USMLE.

Classification of Anxiety Disorders

Anxiety disorders are classified into several subtypes, including:

1. Generalized Anxiety Disorder (GAD): Characterized by excessive worry and anxiety about various aspects of life, often accompanied by physical symptoms.
2. Panic Disorder: Involves recurrent panic attacks, which are sudden episodes of intense fear and discomfort.
3. Social Anxiety Disorder (SAD): Marked by excessive fear and avoidance of social situations due to concerns about embarrassment or humiliation.
4. Specific Phobias: Irrational fears of specific objects or situations, leading to avoidance behaviors.
5. Obsessive-Compulsive Disorder (OCD): Involves recurrent obsessions (intrusive thoughts) and/or compulsions (repetitive behaviors) causing distress or impairment.
6. Post-Traumatic Stress Disorder (PTSD): Develops after exposure to a traumatic event, leading to symptoms like flashbacks, nightmares, and hypervigilance.

Clinical Features

Each anxiety disorder has distinct clinical features, which can aid in diagnosis. These features include:

• Generalized Anxiety Disorder: Excessive worry, restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbances.
• Panic Disorder: Sudden panic attacks with symptoms like palpitations, sweating, trembling, shortness of breath, chest pain, nausea, and fear of losing control or dying.
• Social Anxiety Disorder: Fear of social situations, avoidance of social interactions, intense self-consciousness, blushing, trembling, sweating, and difficulty speaking.
• Specific Phobias: Irrational fear and avoidance of specific objects or situations (e.g., heights, spiders, flying) causing significant distress or impairment.
• Obsessive-Compulsive Disorder: Intrusive thoughts (obsessions) and repetitive behaviors (compulsions) aimed at reducing anxiety or preventing a feared event.
• Post-Traumatic Stress Disorder: Flashbacks, nightmares, intrusive thoughts, hypervigilance, exaggerated startle response, emotional numbness, and avoidance of trauma-related stimuli.

Diagnosis

Diagnosing anxiety disorders involves a comprehensive evaluation, which includes:

1. Clinical Interview: Assessing the patient's symptoms, duration, intensity, and impact on daily functioning.
2. Diagnostic Criteria: Referencing diagnostic manuals like the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) for specific criteria of each anxiety disorder.
3. Psychological and Physical Examination: Ruling out other medical or psychiatric conditions that may mimic anxiety disorders.
4. Screening Tools: Utilizing standardized questionnaires (e.g., GAD-7, PHQ-9) to assess symptom severity and monitor treatment response.

Treatment

Treatment of anxiety disorders typically involves a combination of psychotherapy and pharmacotherapy:

1. Psychotherapy: Cognitive-Behavioral Therapy (CBT) is the first-line treatment for most anxiety disorders. It involves identifying and challenging maladaptive thoughts and behaviors, gradually exposing patients to feared situations, and teaching coping strategies.
2. Medications: Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) are commonly prescribed antidepressants for anxiety disorders. Benzodiazepines may be used for short-term relief but are generally avoided for long-term use due to the risk of dependence.
3. Other Interventions: Relaxation techniques, stress management, and lifestyle modifications (e.g., regular exercise, healthy sleep habits) can complement therapy and medication.

Conclusion

Understanding the psychiatry of anxiety disorders is crucial for medical students preparing for the USMLE. Familiarity with the classification, clinical features, diagnosis, and treatment of these disorders will help in accurately identifying and managing patients with anxiety disorders.