Growth hormone response to intravenous clonidine in social phobia: comparison to patients with panic disorder and healthy volunteers.

The growth hormone (GH) response to intravenous administration of clonidine hydrochloride (2 micrograms/kg) was assessed in 16 patients with DSM-III-R social phobia, 13 patients with DSM-III-R panic disorder, and 31 healthy controls. Compared to the healthy volunteers, both social phobic and panic-disorder patients had significantly blunted GH increments after clonidine. The social phobic patients demonstrated a similar degree of GH "blunting" to clonidine as did the patients with panic disorder.