THE EFFECTS OF CAFFEINE ON PANIC PATIENTS - RESPONSE COMPONENTS OF ANXIETY

Using a double-blind placebo design, the present investigation explored the effects of caffeine on specific response components of anxiety with 21 Panic Disorder (PD) patients and 18 matched normal controls (NC). Three physiological measures (blood pressure, skin conductance, and heart rate), subjective anxiety, and panic symptom ratings were taken: preceding caffeine and 45 min. following intake of caffeine (250 mg.) or placebo. Four PD patients reported panic during the procedure, with 3 requesting termination prior to completion. Data from the 18 PD patients and NC subjects who completed the procedure indicated that the effects of caffeine on physiological arousal were small and, with the exception of skin conductance, equivalent for the PD and NC samples. In contrast, between-group and between-condition effects were observed on subjective anxiety and panic symptom reports. Although PD patients in both Caffeine and Placebo conditions endorsed a significant number of panic symptoms and reported greater symptom severity relative to the NC sample, only the PD/Caffeine sample reported a significant increase in subjective anxiety. Results are discussed in light of current theories of panic, particularly emotional hypersensitivity to somatic sensations and biological models. Emphasis is placed upon the lack of covariation between panic symptom reports and subjective anxiety in the PD/Placebo sample, with implications for understanding maintaining factors in panic.