Dual Mechanistic Role of Sense of Coherence in the Trauma–Fibromyalgia Relationship: Mediation and Moderation Findings from a 2,099-Participant Cohort

Background: The biopsychosocial model positions fibromyalgia (FM) as the result of altered pain modulation shaped by trauma, psychological vulnerability, and structural stressors. The Sense of Coherence (SOC) may be a key resilience factor explaining differences in symptom severity after similar hardships. Objectives: To evaluate whether SOC mediates and/or moderates associations between trauma-related adver-sity and symptom burden in FM, and whether comorbidities, medication use, healthcare factors, or treatment engagement modify these relationships. Methods: In this cross-sectional study, 2,099 women with FM completed an online survey assessing adversity, psychosocial factors, core symptoms, healthcare support, treatment engagement, and medication use. A theo-ry-driven SOC composite followed Antonovsky’s model (comprehensibility, manageability, meaningfulness). Linear regression evaluated adversity–symptom associations, SOC mediation, and moderation by SOC and medication classes. Results: Higher adversity predicted lower SOC (e.g., cumulative abuse: B=−0.25), and lower SOC predicted higher symptom burden (e.g., Fibromyalgia Impact Questionnaire (FIQ): B=−6.77), producing robust indirect effects (cognitive symptoms: 0.22; FIQ: 1.69). SOC also moderated the effects of adversity on fatigue and global impact, weakening associations at higher SOC. Comorbidities showed modest influence: hypertension had minor indirect effects (ab=0.27), scheduled consultation produced small interactions (cognition β=−0.38 to −0.46; fatigue β=0.36), and stroke showed the only clinically meaningful moderation (β≈4.9–5.2), all far smaller than SOC effects. Conclusions: SOC plays a central mechanistic role linking trauma to FM symptoms, acting as both a pathway and resilience factor. Strengthening SOC may reduce symptom burden and improve outcomes.