Optimism outweighs neuroticism and anxiety sensitivity to predict insomnia symptoms in women after surgery for breast cancer

Purpose Insomnia symptoms are common among women who have undergone surgery for breast cancer. Personality traits are also believed to have an impact on sleep. However, there are no reports to address the effects of personality traits on sleep in women with breast cancer. This study examined the separate and competing roles of neuroticism, anxiety sensitivity, and optimism in predicting post-surgery insomnia symptoms. Methods Women with breast cancer ( n = 749) were enrolled the week prior to surgery and required to complete a demographic questionnaire, the Chinese version of Neuroticism subscale of NEO-Five Factor Inventory (CV-N-NEO-FFI), Anxiety Sensitivity Index-3 (CV-ASI-3), and Life Orientation Test-Revised (CV-LOT-R). Four weeks post-surgery, the Chinese version of Insomnia Severity Index (CV-ISI) was administered to evaluate insomnia symptoms. Results Neuroticism ( β = 0.317, p < 0.001), anxiety sensitivity ( β = 0.220, p < 0.001), and optimism ( β = − 0.332, p < 0.001) could predict post-surgery insomnia symptoms. When putting them together into one stepwise regression, optimism ( β = − 0.215, p < 0.001) became the statistically most important predictor for insomnia symptoms. Optimism suppressed the predictions of insomnia symptoms provided by neuroticism ( β = 0.114, p < 0.001) and anxiety sensitivity ( β = 0.079, p < 0.001). Conclusion Neuroticism and anxiety sensitivity positively predicted insomnia, but optimism negatively predicted insomnia. In particular, optimism plays a more important role in post-surgery insomnia symptoms in women with breast cancer compared to neuroticism and anxiety sensitivity. Sleep intervention in women with breast cancer should focus on enhancing their optimism level.