A 32-year-old woman from Delhi presents to the psychiatry outpatient clinic with a 6-month history of sudden, unpredictable episodes of intense fear accompanied by palpitations, sweating, trembling, and a sense of impending doom. Each episode lasts 15–20 minutes and occurs 2–3 times per week without an obvious trigger. Between episodes, she worries constantly about having another attack and has started avoiding crowded places and public transport. She denies any medical illness, substance use, or recent stressors. Vital signs are normal, and physical examination is unremarkable. What is the most likely diagnosis?

Explanation

## Diagnosis: Panic Disorder with Agoraphobia ### Clinical Presentation This patient presents with the cardinal features of panic disorder: - **Recurrent, unexpected panic attacks** (sudden onset, 15–20 minutes duration) - **Autonomic symptoms**: palpitations, sweating, trembling - **Cognitive symptoms**: sense of impending doom - **Anticipatory anxiety** between episodes (worry about future attacks) - **Agoraphobic avoidance**: crowding, public transport (secondary to fear of having an attack in inescapable situations) ### Key Point: **Panic disorder is defined by recurrent, unexpected panic attacks followed by at least 1 month of persistent worry about having another attack or behavioural changes to avoid triggering situations.** [cite:DSM-5 Diagnostic Criteria] ### High-Yield: The presence of **agoraphobic avoidance** (avoiding places/situations from which escape might be difficult) elevates this to **panic disorder with agoraphobia** — a more severe specifier with worse prognosis and greater functional impairment. ### Pathophysiology ```mermaid flowchart TD A[Panic Disorder Pathophysiology]:::outcome --> B[Amygdala hyperactivity]:::outcome B --> C[Locus coeruleus dysregulation]:::outcome C --> D[Noradrenergic hyperactivity]:::outcome D --> E[Autonomic surge]:::action E --> F[Panic attack symptoms]:::outcome A --> G[Prefrontal cortex hypoactivity]:::outcome G --> H[Impaired threat appraisal]:::outcome H --> F F --> I[Catastrophic misinterpretation]:::decision I -->|"Fear of fear"| J[Anticipatory anxiety]:::outcome J --> K[Avoidance behavior]:::action ``` ### Differential Diagnosis | Feature | Panic Disorder | GAD | Specific Phobia | Social Anxiety | |---------|---|---|---|---| | **Onset** | Sudden, unexpected | Gradual, chronic | Triggered by specific object/situation | Triggered by social scrutiny | | **Duration** | 5–20 min | Persistent (≥6 mo) | Brief (seconds to minutes) | Variable, context-dependent | | **Trigger** | None (unexpected) | Multiple worries | Specific (e.g., heights, spiders) | Social/performance situations | | **Avoidance** | Agoraphobic (places) | Minimal | Specific stimulus | Social situations | | **Autonomic surge** | Intense, acute | Mild, chronic | Minimal unless exposed | Mild to moderate | ### Clinical Pearl: **"Fear of fear"** is pathognomonic for panic disorder — the patient becomes anxious about the possibility of having another panic attack, creating a vicious cycle of anticipatory anxiety and avoidance. This distinguishes it from specific phobia (fear of the object itself) and GAD (worry about multiple life domains). ### Treatment Implications - **First-line pharmacotherapy**: SSRIs (sertraline, paroxetine) or SNRIs (venlafaxine) - **First-line psychotherapy**: Cognitive-behavioural therapy (CBT) with interoceptive exposure - **Benzodiazepines**: Short-term use only (risk of dependence); not recommended as monotherapy