Autonomic Dysregulation Mediates the Association Between Childhood Trauma and Pain Severity: Evidence from a Mediation Model

<b>Background:</b> Childhood trauma is increasingly recognized as a key risk factor for autonomic nervous system (ANS) dysregulation and chronic pain. However, the mechanisms underlying this association remain insufficiently explored, particularly within integrated healthcare frameworks. <b>Objective:</b> This study examined whether autonomic reactivity mediates the relationship between childhood trauma and pain severity while accounting for age and gender. <b>Methods:</b> A total of 124 participants-64 with formally documented interpersonal trauma and 60 without-completed validated measures of childhood trauma (CTQ), cumulative trauma (LEC-17), autonomic reactivity (BPQ), and pain severity (BPI). Group comparisons, correlation analyses, and hierarchical regressions were used to assess associations among variables. A mediation model was used to test whether autonomic reactivity explained the trauma-pain relationship. <b>Results:</b> Trauma-exposed participants showed significantly higher autonomic reactivity than those without, while pain severity did not differ significantly between groups (<i>p</i> < 0.001). Childhood physical and emotional abuse was strongly associated with autonomic reactivity and moderately associated with pain severity but not directly linked to pain. Mediation analysis supported a full mediation, with childhood trauma predicting pain severity indirectly via autonomic reactivity (β = 0.220, 95% CI [0.087-0.422], <i>p</i> = 0.009). A preliminary gender effect on the trauma-ANS pathway was observed but was not sustained in weighted models correcting for sample imbalance. <b>Conclusions:</b> Autonomic dysregulation was found to mediate the link between childhood trauma and pain vulnerability. Incorporating autonomic assessment into trauma-informed, integrated healthcare could inform early detection and tailored interventions, with preliminary evidence suggesting generalizability across gender.