Instructional set does not alter outcome of respiratory challenges in panic disorder.

In an attempt to reproduce the findings of Rapee et al (1986) that instructional set could alter the anxiogenic effects of carbon dioxide inhalation, 45 patients with panic disorder received two sets of instructions and then underwent a series of respiratory challenges (room air hyperventilation, 5% and 7% CO2 inhalation). The instructions failed to alter the anxiogenic response to any of the interventions.