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Intensity/Poor Sleep Quality and Impairment in Women with Severe Fibromyalgia (n = 115) Predictor variables B ß t R2 F Model 1 Pain intensity (MPQ-SF) Poor Model 3a Pain intensity (MPQ-SF) Poor sleep quality (PSQI) Psychopathology (SCL-90-R) Pain intensity (MPQ-SF) X Psychopathology Low Medium High Poor sleep quality Impairment Moderation by Psychopathology High Medium Low. Moderating Role of Psychopathology in the Relationship between Poor Sleep Quality and Impairment Psychopathology as a Moderator of the Relationship Between Physical Symptoms and Impairment in Fibromyalgia Patients 219 is no previous research focused on the pathways examined in the present study. Joustra et al. (2018) observed that FM patients with short or long sleep duration reported higher somatization than those with moderate sleep duration, but that study examined a different sleep parameter and did not include other psychopathological dimensions. The relationships between pain, sleep, and psychopathology are complex and interactive. Several reviews indicate that there is a bi-directional link between pain and sleep, but sleep impairment is a stronger predictor of pain than conversely (Finan et al., 2013). Previous research demonstrated that in FM subjective sleep quality and objective sleep effi ciency mediate the impact of pain on anxiety and depression (Díaz-Piedra et al., 2014), and that insomnia symptoms are strongly associated with risk of FM (Skarpsno et al., 2019). Pain alters sleep, but sleep disruption also interferes with the functioning of the descending pathways of paininhibition and generates a hypoactivity of the HPA axis responsible for regulating the response to stress, leading to an intensifi cation of sensitivity to painful stimuli (Choy, 2015). Sleep also has an important relationship with emotions and psychopathology, there is evidence that psychological/physiological component of emotional experiences and attentional processes are mediators of sleep-pain relationship (Whibley et al., 2019). Perhaps due to all these complexes interaccions when the sleep quality is very poor, the presence of added psychopathology (as expression of dysfunctional strategies to process information and regulate emotions) leads to a greater disability. Although the lack of a widely accepted conceptual proposal on the mediation/moderation paths between these factors makes it diffi cult to draw defi nitive conclusions. This study suggests that the characterization of the psychopathological profi le in the FM patient is crucial to a better understanding of the clinical status and to establish the best therapeutic approach. This is in line with the growing emphasis on the tailored-treatment in FM. For example, the European League Against Rheumatism recommends for the management of FM individualized strategies focused on main FM symptoms, psychological characteristics, and disability degree (Macfarlane et al., 2017). Several reviews showed that the cognitive-behavioural therapy (CBT) (Bernardy et al., 2018) and the mindfulness/ acceptance-based interventions (MABIs) (Haugmark et al., 2019) are superior to control treatments in improving FM, however, research on the effi cacy of these interventions adapted to the clinical profi les of FM is scarce. Some reports show promising results incorporating strategies aimed at insomnia in CBT (Lami et al., 2018) and MABI (Miró et al., 2017), but none of these therapies has been customized to address insomnia and psychopathology. This study has some limitations. The transversal nature of the research prevents establishing causal relationships. Possible psychopathology was evaluated via SCL-90-R, although the application of other standardized norms of this instrument or the use of another alternative self-report could have yielded different results. The assessment of experiential avoidance (VázquezMorejón et al., 2019) would have been of interest considering its close link with psychopathology. To examine pain and sleep no objective measures were used that would have complemented the self-report data. The participants were women with FM so the fi ndings may not be generalizable to men with FM. A nonprobability sampling method was used which may lead to

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