Self-Regulatory Fatigue: A Missing Link in Understanding Fibromyalgia and Other Chronic MultiSymptom Illnesses

Objective: Patients with chronic multisymptom illnesses such as fibromyalgia syndrome (FMS) are experiencing a multitude of physical and mental challenges. Facing such challenges may drain capacity to self-regulate, and research suggests patients with these illnesses may experience self-regulatory fatigue (SRF). This study sought to examine whether SRF can be associated with quality of life (QoL) in patients with FMS. Methods: Patients (N = 258) diagnosed with FMS completed self-report measures related to demographics, SRF (Self-Regulatory Fatigue 18 [SRF-18]), anxiety (Generalized Anxiety Disorder questionnaire [GAD-7]), depression (Patient Health Questionnaire [PHQ-9]), physical fatigue (Multidimensional Fatigue Inventory [MFI]), symptoms related to FMS (Fibromyalgia Impact Questionnaire [FIQ]), and QoL (36-Item Short-Form Health Survey [SF-36]). Results: Hierarchical regressions showed higher SRF to be associated with lower QoL in terms of lower overall physical QoL, with subscales related to physical functioning, role limitations—physical, bodily pain, and general health (all P's > 0.001), as well as lower overall mental QoL, with subscales related to vitality, social functioning, role limitations—emotional, and mental health (all P's > 0.001). Including traditional predictors such as anxiety, depression, physical fatigue, and FMS-related symptoms as covariates in the analyses reduced the link between SRF and QoL somewhat, but the associations remained generally strong, particularly for SRF and mental QoL. Conclusion: This is the first study to show higher SRF relating to lower QoL for patients with FMS. Results suggest that SRF is distinct from anxiety, depression, and fatigue, and predicts QoL above and beyond these traditional factors in the area of chronic multisymptom illnesses such as FMS. SRF may be a “missing link” in understanding the complex nature of chronic multisymptom illnesses.