Hypercarbia versus hypocarbia in panic disorder

In order to compare the panicogenic effects of hypercarbia and hypocarbia in panic disorder (PD), 12 PD patients and 11 healthy controls underwent a 35% CO2 challenge as well as a hyperventilation provocation test in a random cross-over design. Both anxiety and anxiety symptoms proved to be significantly higher during the 35% CO2 challenge in PD patients as compared to the response during 35% CO2 in normals and during hyperventilation in both patients and normals. The results suggest that PD patients are specifically hypersensitive to an increase in pCO2.