Psychological Well-Being, Negative Affectivity, and Functional Impairment in Fibromyalgia

among undergraduate students (18.7%) and their relatives (81.2%). The latter were recruited by the ‘snowball’ technique. Participation was voluntary, anonymous, and unpaid. Cases and controls did not significantly differ in employment or marital status. A significantly higher rate of controls completed at least high-school if compared to cases ( 2 = 14.177, p ! 0.05). The local ethical committee approved the study. All the participants provided written informed consent, completed a form collecting socio-demographic information and the scales below. Psychological well-being was measured by the 18-item version of the PWB [8, 11] , a self-administered inventory measuring 6 constructs: (1) Autonomy: independence and self-determination; (2) Environmental Mastery: ability to manage one’s life; (3) Personal Growth: being open to new experiences; (4) Positive Relations with others: having satisfying relationships; (5) Purpose in Life: believing that one’s life is meaningful; (6) Self-Acceptance: having a positive attitude towards oneself and past life. Negative affectivity was measured via the Hospital Anxiety and Depression Scale [18–20] , a 14-item self-administered rating scale counting 2 subscales (i.e. depression, anxiety). Functional impairment was assesses by the Daily Living and Functioning Skills subscale of the Behavior and Symptom Identification Scale [21–24] . Item 4 of the EQ-5D was used to measure perceived intensity of pain [25, 26] . Controlling for educational level, cases showed significantly higher scores on depression, functional impairment, and pain than controls. Results from the stepwise regression analyses ( table 1 ) indicated that Purpose in Life and Positive Relationships significantly predicted functional impairment in FM, beyond several potential confounds (see footnote in table 1 ). Disability, in turn, as well as anxiety, predicted depression, and Self-Acceptance predicted anxiety. Interestingly, a different pattern of predictors was found among controls. While Autonomy predicted functional impairment, both Environmental Mastery and Purpose in Life predicted depression. Unfortunately, results from this study cannot be compared with previous research [17, 27] since the available studies included patients with a different diagnosis [27] , did not control for negative affectivity [17] or for socio-demographic variables [27] , or did not explore significant predictors of disability [27] . Taken together, findings from this study are consistent with psychological research suggesting that goal-engagement and environmental mastery play a major role in determining psychological adjustment in general population samples [28–30] . However, our findings suggest that in FM patients other psychological processes and/or relationships among the variables here considered seem to come into play. In particular, 3 PWB processes appear to be related to depression in FM females, but all these relationships seem mediated by disability and anxiety. Thus, having a sense of directedness and intentionality as well as warm and Fibromyalgia (FM) is a stress-related functional somatic syndrome consisting of musculoskeletal pain and tenderness, and additional symptoms such as fatigue and difficulty concentrating [1] . Susceptibility to FM seems based on a genetic predisposition interacting with unfavorable environmental and developmental factors, leading to further sensitization of the stress response system. Factors such as ill-being, often assessed as negative affectivity, may follow, increasing the risk of unhealthy and dysfunctional lifestyles [2–6] . Psychological factors able to buffer the stress, and hence to reduce disability and negative affectivity in FM are, however, not clear enough. In this regard, research on eudaimonic well-being can provide interesting developments. The term ‘eudaimonic’ roots in Aristotle’s philosophy, and identifies well-being in the actualization of human potentials and virtue. It is opposed to hedonic well-being based on the pursuit of pleasure and happiness [7–9] . In Ryff ’s approach, eudaimonic well-being, measured via the Scales of Psychological Well-Being (PWB) [10] , posits on the extent to which people feel they are in control of their lives, feel that what they do is meaningful, and have good relationships with others [7, 10] . Although the literature suggests that PWB may buffer the effect of stress in chronic illness [11–16] , to our knowledge only Schleicher et al. [17] studied PWB in FM. They found lower PWB in FM than in rheumatoid arthritis or in healthy subjects, and observed that a lower PWB was associated with higher disability and fatigue, and with a smaller social network in FM. However, since Schleicher et al. [17] did not measure negative affectivity, at least 2 main related issues remain unclear, and constitute the aims of this study: (1) whether PWB predicts not only disability but also negative affectivity, and (2) whether the association of PWB with disability remains when ill-being and other potential confounds are controlled. Cases were 48 FM females consecutively presenting at the Pain Treatment Centre or at the Rheumatological Clinic of the Santa Chiara Hospital (Pisa, Italy) over a 9-month period. Mean duration of pain was 71.8 months (SD = 88.4 months). Controls were 48 women matched for age with cases (mean 44.25 8 10.01 years for cases; mean 45.27 8 9.89 years for controls), and recruited Received: July 30, 2010 Accepted after revision: October 12, 2010 Published online: May 4, 2011