Effects of Rumination and Worry on Sleep.

Recent research suggests that the stress-sleep relationship is mediated by pre-sleep arousal (PSA) and that cognitive arousal has a stronger mediating effect than somatic arousal; however, this has not been directly tested. Using multilevel moderated mediation, we compared the effects of cognitive arousal and somatic arousal within the stress-sleep relationship. We also assessed whether two forms of repetitive negative thought-rumination and worry-are similarly involved in the stress-sleep relationship. Data was collected from 178 participants across the United States via an online platform. Participants completed baseline self-report surveys examining rumination tendencies and worry tendencies. Over the course of 2 weeks, participants completed daily questionnaires assessing daily stress, PSA, and sleep quality. Results indicated that indirect effects from stress to sleep quality via PSA were statistically significant at low and high levels of rumination and worry, and people at high levels of rumination and worry had stronger relationships between stress and PSA. Across all models, cognitive arousal consistently accounted for more of the variance in the stress-sleep relationship as compared to somatic arousal. Implications for the cognitive behavioral treatment of insomnia are discussed.