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

The increasing recognition that panic attacks are heterogeneous phenomena n ecessitates better and more objective criteria to define and examine what c onstitutes a panic attack. The central aim of the present study was to clas sify subtypes of panic attacks (i.e. prototypic, cognitive, and non-fearful ) in a nonclinical sample (N = 96) based on the concordance/discordance bet ween subjective and physiological responding to multiple inhalations of 20 and 13% CO2-enriched air. Results show that a substantial proportion of thi s nonclinical sample (55.2%) responded to the CO2 challenge in a manner con sistent with clinical and research definitions of different subtypes of pan ic attacks. The implications of this dimensional approach for discriminatin g subtypes of panic in the laboratory are discussed as a means to better un derstand the phenomenology and nature of panic attacks. (C) 2000 Elsevier S cience Ltd. All rights reserved.