Dissociative symptoms in fibromyalgia: A systematic review and meta-analysis

Background and aims Fibromyalgia (FM) is a chronic pain condition frequently associated with psychological distress and impaired stress regulation. Emerging evidence suggests that dissociative symptoms (DS), both psychoform and somatoform, may play a role in FM severity and clinical heterogeneity. This systematic review aimed to synthesize current evidence on the presence, severity, and clinical correlates of dissociative symptoms in FM and to quantitatively estimate their magnitude compared to control groups. Method The review was conducted according to PRISMA guidelines. PubMed, Scopus, and Web of Science were searched up to November 25, 2025. Quantitative observational studies assessing dissociative symptoms in adults with FM were included. A multilevel random-effects meta-analysis was performed on case–control studies to estimate pooled effect sizes. Results Thirteen studies were included, mostly cross-sectional. FM patients consistently showed significantly higher levels of dissociative symptoms than healthy controls or patients with other rheumatologic conditions. Both psychoform and somatoform dissociation were elevated and clinically relevant. Dissociation was associated with greater pain intensity, psychological distress, functional impairment, and trauma exposure. Meta-analytic results indicated a medium-to-high pooled effect size for dissociation in FM (adjusted d ≈ 0.76), remaining significant after correction for publication bias. Discussion Findings support dissociation as a relevant transdiagnostic dimension in FM, potentially linked to trauma-related stress dysregulation and altered pain processing. Conclusion Dissociative symptoms are prevalent and clinically meaningful in FM. Their systematic assessment may inform personalized, mechanism-based interventions.