The "suffocation alarm" theory of panic attacks: a critical commentary.

In 1993 Klein proposed a "false suffocation alarm" theory of panic attacks, claiming that many spontaneous panic attacks are due to a "suffocation monitor" in the brain erroneously signaling a lack of useful air, and triggering an evolved "suffocation alarm system". He proposed that carbon dioxide acts as a panic stimulus because rising arterial CO2 suggests suffocation may be imminent." The present paper provides a critical analysis of Klein's theory and concludes that there is neither empirical evidence nor compelling argument to support the assumptions or the proposed neurological mechanism of a "suffocation alarm", true or false, or a CO2 "suffocation monitor." Data relevant to the role of breathing in the phenomenon of panic can be parsimoniously subsumed within the domain of dyspnea.