PREDICTABILITY, CONTROLLABILITY, AND FEAR OF SYMPTOMS OF ANXIETY IN EPINEPHRINE-INDUCED PANIC

Background: Psychological manipulations (supplied information, safety cues) may influence panic rates during pharmacologic challenge tests i n subjects with panic disorder (PD). Psychological panic models assume that fear of stress-related bodily sensations is central to the etiol ogy of PD. Methods: Prior to infusion of epinephrine, 50 subjects with PD were randomly assigned to one out of four experimental conditions: with or without extensive information and with or without external co ntrol, according to a 2 x 2 design. The panic rate was hypothesized to be lower in subgroups possessing extensive information and/or control . Fear of bodily sensations was used as a predictor. Results: Thirty-f our out of 50 patients (68%) panicked during the infusion. Subjects wh o received extensive information were marginally less likely to panic, but manipulation of control did not influence panic rates. Panickers did not differ from nonpanickers in measures of fear of fear Anxiety s ensitivity best predicted baseline anxiety and cognitive symptom score s, but was not associated with other outcome measures in panickers. On ly baseline partial pressure of CO2 discriminated between panickers an d nonpanickers. Conclusions: Manipulating external safety cues appears to be of limited value in modulating responses to epinephrine challen ge. Together with our finding that fear of anxiety symptoms does not p redict panic rates, these data argue against ''fear of fear'' as a key mechanism in epinephrine-induced panic. (C) 1998 Society of Biologica l Psychiatry.