Biological sex and panic-relevant anxious reactivity to abrupt increases in bodily arousal as a function of biological challenge intensity

An emerging pattern of results from panic-relevant biological challenge studies suggests women respond with greater subjective anxiety than men, but only to relatively abrupt and intense challenge procedures. The current investigation examined the relation between biological sex and self-reported anxious reactivity following biological challenges of varying durations and intensity. Participants were 285 (152 females; Mage = 21.38; SD = 5.92) nonclinical adults who completed one of three protocols: a 3-min voluntary hyperventilation challenge (VH), a 5-min 10% carbon dioxide-enriched air (CO2) challenge, or a 25-s 20% CO2 challenge. As predicted, results indicated that the 20% CO2 challenge elicited greater self-reported anxiety than the VH and 10% CO2 challenges. Moreover, women endorsed greater anxious reactivity than men, but only following the 20% CO2 challenge. Results are discussed in terms of processes likely to account for sex differences in anxious reactivity following relatively abrupt and intense biological challenges.

► Biological challenges of heightened intensity lead to greatest levels of anxiety.
► Women endorse greater anxiety than men following 20% CO2 biological challenges.
► Sex differences in anxiety do not emerge following challenges of limited intensity.