What research says about panic and carbon dioxide hypersensitivity

Posted On August 5, 2019

In the last post, I summarized Dr. Klein’s intriguing theory1 about what causes a panic attack. Simply put, over-sensitivity to carbon dioxide (CO2) leads to respiratory irregularities that create a ‘hair trigger’ for the next panic attack in at-risk individuals.  This faulty alarm system unleashes an intense fear response greatly out of proportion to any real threat.

The key to any scientific theory is that it is testable. In other words, the theory can be proven true or false based on carefully collected and analyzed data.  A group of researchers2 followed Klein’s theory by proposing a simple, elegant hypothesis: if the respiratory irregularities of panic breathing could be corrected or normalized, the patient should then experience less frequent or severe panic attacks.

To test this theory, researchers measured each patient’s CO2 level and respiratory rate using a respiratory monitor. This same monitor provided patients real-time visual feedback about their CO2 levels. The experiment included using a series of audio tones that guided patients how to alter their breathing patterns – raising and holding their CO2 levels within the normal range. The breathing exercises took place at home twice daily for 17-minutes and lasted for 28 days.

What did the results show?  One year after the 28-day treatment, 68% of patients were panic attack free and 93% had clinically significant symptom reductions. Some of these patients had been suffering from panic attacks for over ten years.  These are striking findings for a novel treatment that addresses a chronic behavioral health condition that greatly impairs quality of life.

Palo Alto Health Sciences used these findings to develop Freespira, giving panic sufferers the opportunity to access the treatment conveniently and affordably.

In the next blog, I’ll discuss a follow up study that measured the benefits of Freespira in multiple anxiety disorder clinics.

  1. Klein DF. False suffocation alarms, spontaneous panics, and related conditions. An integrative hypothesis. Arch Gen Psychiatry 1993;50:306–17. [PubMed: 8466392]
  2. Meuret AE, Wilhelm FH & Roth WT, Feedback of End-tidal pCO2 as a Therapeutic Approach for Panic Disorder, Journal of Psychiatric Research, 42:560-568, 2008.



From time to time, Palo Alto Health Sciences (Freespira) will share articles or blog posts from guest authors. Some of the information presented may not be consistent with the science-based and clinically-proven method behind Freespira. In such cases, we share the article or blog post for general informational purposes only, without any endorsement or recommendation.