Anxiety (Generalized Anxiety Disorder): High-Yield USMLE Review

Generalized anxiety disorder (GAD) is defined by excessive, hard-to-control worry about multiple events or activities occurring more days than not for at least 6 months. It is one of the most common conditions disclosed in primary care and is a frequent exam trap, because attributing new physical symptoms to a known 'anxiety' history can mask life-threatening organic disease.

Presentation

• Excessive anxiety and worry about multiple events or activities, present more days than not, for ≥6 months
• At least three associated symptoms: restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance
• Somatic complaints such as palpitations and chest tightness, sometimes with sinus tachycardia and mildly elevated blood pressure on exam

Diagnosis

• Clinical diagnosis: GAD requires excessive worry more days than not for ≥6 months plus ≥3 associated symptoms (restlessness, fatigue, concentration difficulty, irritability, muscle tension, sleep disturbance)
• Rule out organic mimics before attributing symptoms to anxiety—consider hyperthyroidism (check TSH), pheochromocytoma, pulmonary embolism, arrhythmia, and medication/substance effects
• ECG when a cardiac component is prominent; sinus tachycardia with nonspecific changes may be seen but does not exclude serious disease
• Screen for substance-related causes—anxiety is an early feature of alcohol withdrawal (6–24 hours after last drink)

Management

• Psychotherapy: cognitive behavioral therapy (CBT)
• SSRIs are first-line pharmacotherapy for most anxiety disorders; SNRIs and buspirone are alternatives
• Benzodiazepines for short-term use only, given the risk of dependence
• Always ask about a history of mania before starting an antidepressant, since antidepressant monotherapy in bipolar disorder can trigger mania

High-yield

• SSRIs are first-line for depression AND most anxiety disorders—know side effects: sexual dysfunction, GI upset, serotonin syndrome
• GAD requires excessive worry more days than not for ≥6 months with ≥3 associated symptoms
• Buspirone is an anxiety-specific option; benzodiazepines are short-term only due to dependence risk
• Psychiatric symptoms require medical evaluation—rule out organic causes before attributing symptoms to a primary psychiatric illness
• Anxiety, tremor, insomnia, tachycardia, and hypertension appearing 6–24 hours after the last drink point to alcohol withdrawal, not primary anxiety

Pitfalls

• Attribution error: in a patient with a known 'anxiety' history, abnormal vital signs (tachycardia, hypertension) or new symptoms may be reflexively blamed on anxiety while hyperthyroidism, pheochromocytoma, PE, arrhythmia, or substance effect are missed—evaluate abnormalities objectively regardless of psychiatric history
• Anchoring on the anxiety diagnosis plus premature closure compounds the error and delays workup of dangerous organic disease
• Using benzodiazepines as long-term therapy instead of SSRIs/SNRIs/buspirone, ignoring the risk of dependence
• Starting an antidepressant without first screening for prior mania/hypomania, risking a manic switch in unrecognized bipolar disorder
• Confusing OCD with an anxiety disorder—in DSM-5 OCD is now classified separately under Obsessive-Compulsive and Related Disorders, though it remains high-yield