Blunted growth hormone response to peripheral infusion of human growth hormone-releasing factor in patients with panic disorder.

Patients with panic disorder (N = 11) and age- and sex-matched normal control subjects (N = 11) were challenged with human growth hormone-releasing factor (GH-RF) (1 microgram/kg i.v.) or placebo in random order. The control subjects had significantly increased plasma growth hormone (GH) levels after GH-RF infusion whereas panic disorder patients did not. At 15 and 30 minutes after GH-RF infusion, GH concentrations were significantly higher in the control subjects than in the patients. These findings with GH-RF extend findings from earlier reports that patients with panic disorder show blunted GH response to phobic stimulation and clonidine.