Agoraphobic avoidance and panic frequency as predictors of laboratory induced panic reactions

This study examined the importance of agoraphobic avoidance and frequency of panic as predictors of psychological and physiological responses of panic sufferers to a laboratory based provocation procedure. Psychophysiologic comparisons were made between 22 panic disorder patients and 15 controls, at baseline and across three periods of carbon dioxide gas inhalations (1, 3, 5%; balance oxygen). Subjective measures of anxiety, frightening cognitions and body sensations were obtained across the phases. Physiological measures of minute ventilation, breathing rate, tidal volume, end tidal CO₂ and heart rate were also obtained. Between group comparisons revealed significant differences between the groups on the subjective measures with no significant differences occurring on the physiological measures. Within group analyses revealed that pre-session questionnaire measures of agoraphobia avoidance and panic frequency predicted the degree of anxiety, frightening sensations and cognitions during baseline and 5% CO₂ inhalation. The results indicated that both self-reported agoraphobic avoidance and panic frequency are strong clinical predictors of psychological reactions of panic sufferers during laboratory provocation.