Carbon dioxide induced panic attack in panic disorder in Japan

Area of Science:

• Psychiatry
• Neuroscience
• Physiology

Background:

• Panic disorder is a debilitating condition characterized by sudden episodes of intense fear.
• The role of physiological challenges, such as carbon dioxide (CO2) inhalation, in triggering panic attacks is an area of ongoing research.

Purpose of the Study:

• To investigate the psychological and biochemical responses to CO2 inhalation in individuals with panic disorder.
• To examine physiological markers of sympathetic nervous system activity during induced panic.

Main Methods:

• A controlled study involving 13 patients diagnosed with panic disorder and 15 healthy controls.
• Participants underwent a 20-minute inhalation challenge with 5% CO2 in 95% O2.
• Measurements included the Acute Panic Inventory (API), heart rate, breathing rate, systolic blood pressure, and cortisol levels.

Main Results:

• CO2 inhalation induced panic attacks in 38% of panic disorder patients, with no panic observed in controls.
• Panic disorder patients exhibited significantly increased API scores, heart rate, and breathing rate post-CO2 inhalation compared to controls.
• Elevated heart rate, systolic blood pressure, and cortisol levels were observed in panic disorder patients even before CO2 exposure.

Conclusions:

• Patients with panic disorder demonstrate significant behavioral, physiological, and biochemical hypersensitivity to CO2.
• Findings support the involvement of an overactive sympathetic nervous system in panic attacks.
• Results are consistent with interoceptive conditioning models of panic disorder.