Traumatic experiences and central sensitization across the nociplastic pain spectrum

Central sensitization (CS) has been considered a precursor of different nociplastic pain (NP) conditions and it has been considered a core pathophysiological mechanism involved in the maintenance of these syndromes. Clinical frameworks and empirical evidence have suggested that traumatic experiences (TEs) might play a role in the development of CS and they could represent relevant factors reinforcing clinical manifestations characterizing NP conditions. Nevertheless, there are no studies that have empirically tested whether TEs might be involved in CS features across the NP spectrum and how TEs together with CS could affect the quality of physical and mental health among these conditions. The current study enrolled a sample of 464 participants, including treatment-seeking patients with chronic migraine (CM; N = 97), fibromyalgia (FM; N = 130) and comorbid FM-CM (N = 91) together with a healthy control (HC; N = 141) group. TEs, CS and quality of physical and mental health were assessed by self-report instruments. ANCOVA, MANCOVA and moderated mediational models were conducted. Patients with FM-CM showed the highest levels of traumatization (F_{(3, 459)} = 6.15; p < .01), especially compared to CM (d = .40) and HC (d = .56). TEs were significantly associated to CS symptoms across the NP spectrum (a: b = .31; p < .05), independently of condition. Furthermore, TEs indirectly affected the quality of physical and mental health (-.19 ≤ ab ≤ -.06; [-.30 - -.01]) of patients with NP conditions through CS (b: -.66 ≤ b≤ -.55; p < .001). This is the first study that has supported a key role of TEs in core pathophysiological mechanisms of NP syndromes, especially those characterized by complex and severe manifestations. These data support the systematic inclusion of evidence-based psychotherapeutic strategies for trauma-related reactions in the treatment of NP conditions.