EXTINCTION OF PANICOGENIC EFFECTS OF A 35-PERCENT CO2 CHALLENGE IN PATIENTS WITH PANIC DISORDER

Inhalations of high concentrations of carbon dioxide (GO,) reliably pr oduce panic attacks in patients with panic disorder The present study evaluated whether cognitive-behavioral treatment (CBT) for panic disor der would extinguish COL-induced panic and whether changes in panic an d arousal-related cognitions were associated with the induction of pan ic. Patients with panic disorder (N = 54) were assigned to 1 of 3 expe rimental conditions: CBT with respiratory training (CBT-R), CBT withou t respiratory training (CBT), or delayed treatment. Participants recei ved 5 repeated vital-capacity inhalations of 35% CO2/65% O-2 prior to and following either 12 treatment sessions or a 12-week waiting period . During pretreatment assessments, 74% of patients experienced a panic attack during at least 1 inhalation. At posttreatment, only 20% of tr eated participants (CBT-R = 19%, CBT = 22%), compared with 64% of untr eated participants, panicked. Forty-four percent of treated participan ts , compared with 0% of untreated participants, reported no anxiety d uring all posttreatment inhalations. Anxiety sensitivity as well as pa nic appraisals regarding the likelihood of panic and self-efficacy wit h coping with panic were significantly related to fearful responding t o the CO2, challenge.