Not small men: Sex-specific determinants of cortisol reactivity to psychosocial stress following trauma.

Trauma impacts a vast percentage of the global population, with women disproportionally affected by trauma-related disorders-a disparity not explained by exposure alone. Identifying mechanisms associated with this inequity is critical to advancing preventative and responsive treatment. Blunted cortisol reactivity to psychosocial stress represents one possible mechanism, though the influence of sex and specific dimensions of trauma on this condition are underinvestigated. This study examined the roles of sex, developmental timing of trauma, trauma subtype, and subjective trauma impact on cortisol reactivity. Adults (N = 59, n = 37 female) participated in the Trier Social Stress Test, completed trauma measures, and provided salivary cortisol samples. Multiple regression analyses were performed to investigate correlates of blunted cortisol reactivity in the full sample and in sex-disaggregated data to account for unique endocrinological milieus. Women who endorsed childhood trauma demonstrated blunted cortisol reactivity, B = -8.72, p = .004, f ² = .39; notably, this association held only when participants endorsed the childhood traumatic event as their most stressful lifetime event. Considering the lack of clarity regarding the conditions under which blunted cortisol reactivity develops, these findings provide insight into factors that may confer risk for these psychophysiological changes. The observed salience of sex-disaggregated analysis has important implications for future research. Despite decades of study, the pathways linking trauma, cortisol dysregulation, and pathology remain elusive; accounting for sex differences may contribute to resolving this quandary. Unraveling these mechanisms could inform prospective risk assessment, prevention efforts, and focused clinical trials.