1074 Brighter Outlook, Better Sleep, Balanced Health: Examining How Sleep Connects Optimism to Less Pain, Stress, and Depression in Fibromyalgia

Introduction Depression is prevalent in fibromyalgia (FM), a chronic condition characterized by fatigue, widespread pain, and disrupted sleep. While poor sleep exacerbates stress, pain, and psychopathology, maintaining a sense of optimism – conceptualized as a stable positive attitude about the future and tendency to anticipate favorable outcomes – may mitigate such negative effects. We hypothesized that greater optimism, and less pessimism, would be related to less depression, and that these associations would be serially mediated by sleep disturbances and, subsequently, by stress and pain, in parallel. Methods Adult respondents with fibromyalgia (N=406; Mean age=47.8, SD=12.95; 95% female, N=398), were recruited nationally (U.S.) through FM advocacy groups, support organizations, and social media. Participants completed validated measures of optimism/pessimism, sleep quality, perceived stress and depression, and pain. We conducted Pearsons product moment correlation analyses, and serial mediation analyses (PROCESS Model 81) assessing the indirect effects of sleep disturbance (M₁), stress (M₂), and pain (M₃), on the associations between optimism/pessimism and depression (in separate models), controlling for demographics. Results At the bivariate level, optimism was inversely related to all other variables which, themselves, were positively related. At the multivariate level, greater optimism and less pessimism were associated with less sleep disturbance and, in turn, less stress and pain and, finally, less depression (all p-values < .01). Specific indirect effects linking optimism/pessimism to depression also occurred via sleep disturbance and stress, but not pain. Conclusion Our findings highlight sleep disturbance as a central mechanism connecting cognitive-emotional outlook to psychosomatic outcomes in fibromyalgia. Optimists often use active, problem-focused coping (e.g., approach-oriented) and more adaptive cognitive styles (e.g., positive reframing, acceptance), supporting healthier behaviors and positive emotions. In contrast, pessimists often use avoidant or emotion-focused coping, which can exacerbate rumination and disrupt relationships, thereby contributing to a maladaptive cycle of sleep dysfunction, heightened stress and pain, and worsening psychological symptoms. Providers should consider strategies to bolster optimism and reduce pessimism (e.g., cognitive behavioral therapy [CBT]; Best Possible Self exercise), while also addressing sleep and depression directly (e.g., CBT for Insomnia; pharmacotherapy), to improve mental and physical health in patients with fibromyalgia. Support (if any)