This study aimed to examine the relationship between cognitive factors (cognitive fusion and catastrophizing) and functional limitation experienced by patients with fibromyalgia across different levels of pain severity (i.e., moderation).
The sample comprised 226 women with fibromyalgia. Their mean age was 56.91 years (standard deviation = 8.94; range = 30 to 78 years).
Pain severity, cognitive fusion, and all components of catastrophizing (i.e., rumination, magnification, and helplessness) contributed to greater fibromyalgia impact on functioning in the multivariate analyses (all P < 0.001). A moderation effect was also found in the relationship between cognitive fusion and fibromyalgia impact on functioning (B = -0.12, t = -2.42, P = 0.016, 95% confidence interval: -0.22 to -0.02) and between magnification and fibromyalgia impact (B = -0.37, t = -2.21, P = 0.028, 95% confidence interval: -0.69 to -0.04). This moderation was not observed for rumination and helplessness.
The results suggest that in interventions to improve functioning in people with fibromyalgia, some maladaptive forms of thought management (i.e., cognitive fusion and magnification) preferably should be challenged at milder levels of pain severity. According to our findings, cognitive fusion and magnification might have less room to impact functioning at higher levels of pain severity; therefore, rumination and helplessness, which had comparable associations with functioning irrespective of pain levels, would be preferable targets in psychological interventions in patients with fibromyalgia experiencing more severe pain levels.