Evoking analogue subtypes of panic attacks in a nonclinical population using carbon dioxide-enriched air

The increasing recognition that panic attacks are heterogeneous phenomena necessitates better and more objective criteria to define and examine what constitutes a panic attack. The central aim of the present study was to classify subtypes of panic attacks (i.e. prototypic, cognitive, and non-fearful) in a nonclinical sample (N=96) based on the concordance/discordance between subjective and physiological responding to multiple inhalations of 20 and 13% CO2-enriched air. Results show that a substantial proportion of this nonclinical sample (55.2%) responded to the CO2 challenge in a manner consistent with clinical and research definitions of different subtypes of panic attacks. The implications of this dimensional approach for discriminating subtypes of panic in the laboratory are discussed as a means to better understand the phenomenology and nature of panic attacks.