Alpha 2-adrenergic receptor sensitivity in panic disorder: II. Cortisol response to clonidine stimulation in panic disorder.

The cortisol responses to acute administration of saline and of clonidine (Clon), 150 micrograms IV, were examined in 12 patients with panic disorder and agoraphobia, before and after 32 days of alprazolam therapy (2.5 mg/day), and in 12 normal controls. The responses in the Clon test corrected for the responses to saline differed in the two groups, and in patients were not changed by the therapy even though significant symptomatological improvement was achieved. The results suggest that presynaptic alpha 2- or postsynaptic alpha 1-beta-adrenoceptor sensitivity is impaired in panic disorder.