Fear of anxiety and behavioral responses to pentagastrin infusion among socially phobic and normal subjects
The relationship between fear of anxiety and response to a biological challenge in 14 socially phobic and 13 normal control subjects was investigated in a randomized double-blind trial. Subjects received either a placebo or pentagastrin infusion on each of two separate study days while they engaged in a conversation role-play with a member of the opposite sex. Subjects were unaware of the timing and onset of the infusion. Pentagastrin was selected for the challenge because of its demonstrated anxiogenic effect (Abelson & Nesse, 1990) and its behavioral effects (e.g., symptoms), which are similar to those reported by socially phobic individuals in anxiety-provoking, social situations. Responses to the infusions were assessed by self- and observer ratings of anxiety during the role-play and by a questionnaire measure of the frequency of negative thoughts. Contrary to the hypothesis, fear of anxiety, as assessed by modified, composited versions of the Body Sensations Questionnaire (BSQ) and Agoraphobic Cognitions Questionnaire (ACQ) (Chambless, Caputo, Bright & Gallagher, 1984), did not predict a heightened anxiogenic response to the sensations induced by the pentagastrin. However, the unmodified ACQ subscale comprising thoughts of social and behavioral disaster from loss of control tended to predict anxiety in response to the pentagastrin infusion, above that contributed by baseline state anxiety. As expected, normal and socially phobic subjects became more anxious in response to the pentagastrin than to the placebo infusion. Contrary to the hypothesis, the socially phobic subjects responded to the pentagastrin infusion with no more anxiety than the control subjects. These results may be a consequence of using a dose of pentagastrin that was too high for the purposes of this study, causing extreme physical responses which were described by the socially phobic subjects as atypical.