PHYSIOLOGICAL AND SUBJECTIVE ANXIETY RESPONSES TO CAFFEINE AND STRESS IN NONCLINICAL PANIC

Physiological and subjective anxiety responses to the combination of caffeine and film, cold presser, and mental arithmetic stressors were examined in 24 healthy females with and without nonclinical panic. Caffeine (3.3 mg/kg) and placebo were administered in a within-subject, double-blind, counterbalanced design on two consecutive days. Repeated measurements of blood pressure, cardiac interbeat interval, skin conductance, and subjective anxiety were obtained during a predrug resting baseline, a postdrug resting baseline, stressor tasks, and a recovery baseline. Panic subjects in the caffeine/placebo drug order exhibited a significantly greater anxiety response on the caffeine day, which combined additively with increases produced by stress. Caffeine and stress also produced additive increases in physiological arousal, although no significant group differences were observed.