- Exposure to panic symptoms (interoceptive exposure) is often included as part of treatment for panic disorder (PD), although little is known about the relative effects of particular symptom induction exercises. This study describes responses of individuals with PD and nonclinical controls to 13 standard symptom induction exercises and 3 control exercises. Generally, individuals with PD responded more strongly to symptom induction exercises than did controls. The exercises producing the most fear included spinning, hyperventilation, breathing through a straw, and using a tongue depressor. This study also reports findings regarding specific symptoms triggered by each exercise, the percentage of participants reporting fear during each exercise, and predictors of fear.