Cortisol response during different anxiogenic challenges in panic disorder patients.

The present study assessed the relation of cortisol response to anxiogenic reactivity during intravenous lactate infusion and oral fenfluramine in 12 panic disorder (PD) patients who responded positively to both challenges and in eight non-reactive control subjects. There was no significant cortisol response difference between the PD patients and the controls during lactate infusion, but there was s significant difference at 120 min during the fenfluramine challenge. These findings are consistent with the possibility that these challenges stimulate different neurobiologic mechanisms and that fenfluramine-precipitated anxiety is more akin to anticipatory or generalized anxiety than to true panic anxiety.