CLINICAL SIMILARITY AND BIOLOGICAL DIVERSITY IN THE RESPONSE TO ALPRAZOLAM IN PATIENTS WITH PANIC DISORDER AND GENERALIZED ANXIETY DISORDER

Thirty-six patients with panic disorder (PD) and 35 patients with gene ralized anxiety disorder (GAD) participated in an open alprazolam trea tment phase that preceded controlled withdrawal from alprazolam. Clini cal ratings, blood pressure and heart rate were obtained along with pl asma measurements of cortisol, ACTH, growth hormone and catecholamines . A similar clinical response profile was evident in both groups with rapid onset of improvement within the first week. The two diagnostic g roups differed in their biological response to alprazolam. PD patients had a significant reduction in blood pressure, plasma cortisol and a trend toward significant reduction in plasma epinephrine, which were n ot seen in the GAD patients. GAD patients showed a significant reducti on in plasma norepinephrine. These findings provide further evidence t hat PD and GAD are biologically distinct syndromes.