Epinephrine infusions in panic disorder: a double-blind placebo-controlled study.

Twenty-four subjects with Panic Disorder were infused with epinephrine in physiological doses or placebo according to a double-blind design. The panic rate in the epinephrine group (67%) was higher than in the placebo group (25%). Placebo panic occurred early during the procedure and was apparently associated with anticipation anxiety and stress-provoking situational factors. Panickers were characterized by a greater increase in heart rate as well as a drop in pCO2. Fear of bodily sensations was only weakly associated with state anxiety levels at point of panic. It is concluded that cognitive factors may not be important in epinephrine-induced panic.