Psychological and physiological predictors of response to carbon dioxide challenge in individuals with panic disorder

Past studies in nonclinical samples have found that suffocation fear, but n ot a behavioral index of carbon dioxide (CO2) sensitivity (i.e.. breath-hol ding duration), predicts anxious response to CO2 challenge. These associati ons were examined in individuals with panic disorder while adding more sens itive indices of CO2 sensitivity. Consistent with the earlier studies, the authors found that suffocation fear predicted anxious responding to CO2 cha llenge but breath-holding duration did not. However, highly precise measure s of CO2 sensitivity. not included in earlier studies, did predict anxious challenge responding. These findings support the predictive value and possi ble etiological relevance of both specific psychological variables and phys iological CO2 sensitivity in panic vulnerability. Further work is still nee ded to determine whether the findings are specific to panic disorder.