An evaluation of sex differences in psychological and physiological responses to experimentally-induced pain: a path analytic description

Abstract

A cold pressor task (CPT) was used with 203 college students (112 women and 91 men) in a study of sex differences in pain response. Physiological measures were taken before and after pain induction, and sex-differentiating personality traits were assessed with the Personal Attributes Questionnaire (PAQ). The Pain Catastrophizing Scale (PCS) was given with standard instructions prior to the CPT, and it was re-administered after the CPT with modified instructions to assess catastrophic thinking during the CPT. Hypotheses were formulated into an explanatory model that was evaluated by path analysis. Pain induction elevated blood pressures and cortisol levels for both sexes, but systolic blood pressure reactivity and cortisol response were greater in men, even with sex differences in CPT tolerance times controlled statistically. Post-CPT PCS scores were positively related to pain ratings and negatively related to tolerance, but baseline PCS scores did not predict tolerance or pain ratings. Pre-PCS scores were not well correlated with post-PCS scores (r=0.46) and underestimated post-PCS scores, particularly for women. The Sex difference on the post-CPT PCS was largely attributable to the PAQ personality trait of Emotional Vulnerability. The differential results obtained from assessing catastrophizing before and after the CPT emphasized the importance of specifying the context in which catastrophizing is assessed (both timing and instructions). Theoretical considerations in the construct of catastrophizing are also highlighted, including, but not limited to, the confounding of variables such as pain intensity and unpleasantness.