Panic Disorder
Recurrent, unpredictable episodes of overwhelming terror and physical symptoms, followed by persistent fear of future attacks.
Emergency Management: Severe acute panic presenting to the ED requires ruling out acute coronary syndrome or PE, followed by reassurance and potentially a short-acting benzodiazepine (e.g., Lorazepam 1 mg PO/IV) for acute symptom relief.
Panic disorder is an anxiety disorder characterized by recurrent, unexpected panic attacks. A panic attack is an abrupt surge of intense fear or intense discomfort that reaches a peak within minutes. The condition involves persistent concern about having additional attacks, worry about the implications of the attacks, or a significant maladaptive change in behavior related to the attacks.
Detailed Overview
The disorder significantly impairs quality of life. Patients often visit emergency departments repeatedly believing they are experiencing a myocardial infarction or life-threatening illness. The core psychological feature is 'fear of fear'—the anticipatory anxiety of the next attack. Over time, many patients develop agoraphobia (fear of places where escape might be difficult if an attack occurs), drastically restricting their daily activities. The neurobiology involves hyperactivity of the amygdala and locus coeruleus, with dysregulation of GABAergic, serotonergic, and noradrenergic systems.
Epidemiology & Demographics
Lifetime prevalence is approximately 2-3% in the US. It is roughly twice as common in women as in men. The typical age of onset is late adolescence or early adulthood (median age 20-24), though it can occur in children or older adults.
Etiological Mechanism
A complex interplay of genetic vulnerability and environmental stressors. Heritability is estimated at around 40%. Psychosocial stressors, such as major life transitions or a history of physical or sexual abuse in childhood, frequently precipitate the onset. Carbon dioxide hypersensitivity is a known biological trigger in susceptible individuals.
Primary Causes
No single cause. Arises from a hypersensitive fear network in the brain (amygdala, medial prefrontal cortex) that misinterprets somatic sensations as catastrophic threats. Suffocation false alarm theory suggests hypersensitive brainstem CO2 receptors trigger sudden hyperventilation and panic.
The pathophysiologic mechanism centers on the 'fear network' of the brain. An innocuous somatic trigger (e.g., mild tachycardia) is perceived by the interoceptive cortex and relayed to the amygdala. The amygdala initiates a massive, disproportionate sympathetic nervous system response via the locus coeruleus (releasing norepinephrine). This causes the profound physical symptoms. The prefrontal cortex fails to exhibit normal top-down inhibitory control over the amygdala, allowing the panic response to escalate rapidly.
Diagnostic Criteria & Guidelines
DSM-5 criteria require: Recurrent, unexpected panic attacks comprising ≥4 of 13 specific symptoms (palpitations, sweating, trembling, shortness of breath, choking feeling, chest pain, nausea, dizziness, chills/heat, paresthesias, derealization, fear of losing control, fear of dying). AND at least one of the attacks has been followed by ≥1 month of persistent concern about additional attacks or a significant maladaptive change in behavior.
Cognitive Behavioral Therapy (CBT) encompassing psychoeducation, cognitive restructuring, and interoceptive exposure is highly effective. First-line pharmacotherapy includes SSRIs (e.g., Sertraline 25 mg daily titrated up to 100-200 mg/day, or Escitalopram 5 mg daily titrated to 10-20 mg/day) or SNRIs (e.g., Venlafaxine XR 37.5 mg daily titrated to 150-225 mg/day). Note: Start at half the usual depression dose to avoid activation syndrome.
Second-Line & Adjunctive Therapy
Tricyclic antidepressants (e.g., Imipramine). Benzodiazepines (e.g., Clonazepam 0.25-0.5 mg BID or Alprazolam 0.5 mg TID) can be used for short-term acute stabilization while waiting for SSRIs to take effect (usually 4-6 weeks), but long-term use is discouraged due to tolerance and dependence.
Surgical & Procedural Management
None.
Patient Counseling & Advice
Educate the patient that panic attacks, while intensely uncomfortable and terrifying, are not physically dangerous or life-threatening. Explain the 'fight or flight' response. Emphasize that SSRIs take 4-6 weeks to work and might cause a slight increase in anxiety during the first week. Warn against self-medicating with alcohol.
Follow-Up & Monitoring Schedule
Review patient every 1-2 weeks initially to monitor tolerability of SSRIs and assess suicide risk. Once stable, review every 1-3 months. Maintenance therapy is recommended for at least 12-24 months after symptom remission.
Preventive Strategies
Early intervention with CBT for individuals experiencing subclinical panic attacks can prevent progression to full panic disorder and agoraphobia.
Highly treatable. With adequate CBT and pharmacotherapy, 70-90% of patients experience significant improvement or complete remission. However, relapse can occur, especially if medications are discontinued abruptly or without concurrent CBT.