Definition and Overview
Panic disorder is an anxiety disorder characterized by unpredictable, repetitive panic attacks, followed by one or more of the following symptoms that persist for more than a month: persistent worry about having another panic attack (anticipatory anxiety), worry about the consequences of the attack (heart attack, fear of going crazy), or changing behavior to avoid the attack.
A panic attack is a state in which extreme fear or discomfort reaches its peak within a few minutes and is accompanied by four or more of 13 symptoms, including heart palpitations, sweating, tremors, shortness of breath, chest pain, nausea, dizziness, cold and hot sensations, depersonalization and unreality, and fear of dying or going crazy. At least 4 of these 13 symptoms occur together.
According to a large-scale epidemiological study in the United States, the lifetime prevalence of panic disorder is approximately 4.7%, and it occurs approximately twice as often in women than in men. The domestic prevalence rate is also reported to be at a similar level.
Causes and Mechanisms
neurobiological mechanism
The core mechanism of panic disorder is the hypersensitivity of the brain's fear circuit, especially the amygdala. When the amygdala sends out a danger signal even though there is no real threat, the sympathetic nervous system is activated through the hypothalamus, resulting in a 'fight-or-flight response'. This response causes increased heart rate, increased blood pressure, hyperventilation, and increased muscle tension, which are the physical symptoms of a panic attack.
Increased norepinephrine release from the locus coeruleus and serotonin dysregulation are also involved in the occurrence of attacks.
Autonomic dysfunction
In patients with panic disorder, a decrease in heart rate variability (HRV), that is, a decrease in parasympathetic nerve activity and a state of sympathetic nerve dominance, is consistently confirmed. Studies have shown that this is an underlying condition that not only occurs during attacks but also persists between attacks.
Psychological and environmental factors
- Childhood abuse, traumatic events
- history of separation anxiety
- Chronic stress and lack of sleep
- Hyperventilation after excessive caffeine intake or excessive exercise
- It is necessary to distinguish it from organic causes such as hyperthyroidism and hypoglycemia.
symptoms
panic attack
Panic attacks peak within 10 minutes and usually subside within 20 to 30 minutes. Four or more of the following symptoms appear suddenly.
- Heart palpitations or rapid pulse
- sweating
- Trembling or shivering
- Feeling suffocated or hyperventilating
- Chest pain or chest discomfort
- Nausea or abdominal discomfort
- Feeling dizzy, unsteady, or about to pass out
- Sensation of cold or heat
- Numbness or paresthesia
- Derealization (the surroundings feel unfamiliar) or depersonalization (feeling detached from oneself)
- Fear of losing control or going crazy
- fear of dying
Anticipatory anxiety and avoidance behavior
After a panic attack, fear of another attack arises, and avoidance of places where an attack is likely to occur (subway, elevator, crowds, etc.) occurs. In some cases, this develops into agoraphobia, which narrows the scope of life activities.
diagnosis
clinical diagnosis
Diagnosis of panic disorder is made through clinical evaluation according to DSM-5 or ICD-11 diagnostic criteria. Check for repetitive panic attacks, anticipatory anxiety, and avoidance behavior.
Organic causes that must be differentiated from panic disorder include hyperthyroidism, hypoglycemia, arrhythmia, and pheochromocytoma. To rule them out, basic blood tests, electrocardiogram, and thyroid function tests are needed.
Heart rate variability analysis
Quantitatively evaluate the sympathetic-parasympathetic balance in patients with panic disorder. HRV decline patterns are used to establish treatment directions for autonomic nerve-based panic disorder.
treatment
Cognitive Behavioral Therapy (CBT)
It has the strongest evidence as a first-line non-pharmacological treatment for panic disorder. Correcting misperceptions of panic symptoms (cognitive restructuring), gradual exposure to bodily sensations, and breathing control training are key components.
Interoceptive exposure is a technique that desensitizes the fear response by having the patient intentionally experience panic-like physical sensations through hyperventilation, rapid rotation, etc.
Studies have shown that panic attacks disappear or are significantly reduced in about 70-90% of patients after CBT treatment.
medication
- SSRIs (selective serotonin reuptake inhibitors): Escitalopram, paroxetine, and sertraline are the first-line drugs. It takes 2 to 4 weeks for the effect to occur, so continuous use is important.
- SNRI: Venlafaxine has also been reported to be effective in treating panic disorder.
- Benzodiazepines: Useful in controlling acute symptoms, but long-term use is not recommended due to dependence.
There is evidence that the combination of CBT and drug treatment is more effective than treatment alone.
autonomic nerve control treatment
If sympathetic nerve hyperactivation and vagal dysfunction are confirmed, autonomic nerve control through stellate ganglion blockade and transcranial magnetic stimulation (TMS) can be used as adjunctive treatment to reduce the frequency and intensity of panic attacks. Breathing training and biofeedback aimed at activating the vagus nerve are also effective.
life management
- Regular aerobic exercise helps lower anxiety and restore autonomic balance.
- Caffeine, alcohol, and smoking can trigger or worsen panic attacks by stimulating the sympathetic nervous system.
- If you practice abdominal breathing training regularly every day, your ability to cope with an attack will improve.
- Sufficient sleep (7-8 hours a day) is essential for autonomic recovery and reducing anxiety levels.
- Avoiding activities out of fear of having a panic attack actually strengthens the fear. It is important to maintain daily activities step by step while consulting with a specialist.