Objective: PTSD is often associated with heightened physiological reactivity during fear conditioning procedures, but results vary across studies. The present study examined whether anxiety sensitivity (AS), or the fear of arousal-related sensations, strengthens the relationship between PTSD symptoms and skin conductance responses (SCR) during fear conditioning and extinction. Because gonadal hormones implicated in fear learning processes fluctuate across the menstrual cycle, the stability of these relationships in women was examined in two distinct menstrual cycle phases. Method: Thirty-two trauma-exposed women with (n=16) and without PTSD (n=16) completed the Clinician-Administered PTSD Scale, Anxiety Sensitivity Inventory, and a fear conditioning and extinction paradigm during the mid-luteal (mLP) and early-follicular (eFP) menstrual cycle phases. Results: In the mLP, stronger SCR to stimuli paired with shock (CS+) during fear acquisition significantly predicted greater PTSD symptoms only when AS was high and after removing an outlier. This appeared driven by effects on Numbing and Hyperarousal symptom clusters. Other hypothesized interactions between AS and CS responses were not significant. However, in the eFP, differential SCR between the CS+ and CS- during extinction predicted significantly greater PTSD symptoms, and there was a trend for this effect being stronger as AS increased. Conclusions: Results offer preliminary evidence that high AS contributes to a stronger relationship between physiological responses during fear acquisition and PTSD symptoms, at least among women in the mLP. Further research investigating the impact of individual differences in traits such as AS on the relationship between conditioned fear responses and PTSD symptoms is warranted.
