Central sensitivity in fibromyalgia: testing a model to explain the role of psychological factors on functioning and quality of life.

Central sensitivity (CS) is defined as an increased responsiveness of nociceptive neurons in the central nervous system to normal or subthreshold inputs. CS has recently been linked to the psychological burden associated with chronic pain, such as fibromyalgia (FM). The primary objective of this study is to investigate the impact of specific psychological constructs on CS in patients with FM. In Study 1, we explore the influence of temperament, personality, childhood trauma, defence mechanisms, and mental pain on CS. In Study 2, our goal is to test the role of the best predictors of CS in influencing quality of life (QoL) and FM functioning through a path analysis model. A total of 510 women with FM participated online, completing a self-administered protocol. Data collection took place between April and June of 2023. In Study 1, higher levels of low sensory threshold (β=0.210), traumatic experiences of physical threat (β=0.141), neurotic defences (β=0.124), and mental pain (β=0.241) emerged as the strongest predictors of increased CS. In Study 2, the presented model demonstrated a satisfactory fit (chi2=27.200; df=10; p=0.002; GFI=0.984; NFI=0.949; CFI=0.967; RMSEA=0.061 [95% CI 0.034-0.090]) with large and medium effect sizes on physical (-0.576) and psychological (-0.190) QoL. The study underscores the pivotal role of psychological dimensions in influencing CS levels and their relationships with QoL in patients with FM.