Self-Focused Rumination as a Potential Cognitive Risk Factor in Stress-Related Disturbed Sleep

Research to date in the insomnia literature has primarily focused on maintaining factors of sleep disturbance, with few studies examining potential predisposing factors of protracted insomnia. Predisposing factors may potentiate sleep disturbances and subsequently increase the window of vulnerability for the development of more concerning issues regarding sleep health. Greater empirical attention towards the putative risk factors related to insomnia could lead to the identification of individuals at risk of developing chronic sleep disturbances and inform preventative treatment. The current study investigates self-focused rumination as a potential cognitive risk factor in the development of insomnia. An at-risk population (i.e., young adults) responded to questionnaires examining tendencies to engage in repetitive negative thinking (i.e., rumination, worry, and general negative repetitive thinking), psychological symptoms, insomnia severity, and other sleep-related constructs at two different time points one-week apart. Collectively, the results determine that (1) self-focused rumination was significantly associated with insomnia severity, however, this effect dissipated after controlling for other types of repetitive negative thinking. (2) Symptom-focused rumination was the sole significant predictor of insomnia severity above and beyond self-focused rumination, worry, general negative repetitive thinking), and baseline subjective insomnia severity in self-defined poor sleepers. In self-defined good sleepers, general negative repetitive thinking uniquely predicted subjective insomnia severity. (3) Self-focused rumination was not a significant moderator of the stress-sleep relationship. (4) There exists a counter association between subjective insomnia severity and self focused rumination, with insomnia significantly predicting self-focused rumination one-week later. The findings provide initial support for repetitive negative thinking as a cognitive risk factor to insomnia through a stress-specific pathway. While theoretical processes underlying a transdiagnostic approach to negative repetitive thinking remain untested, the results suggest there is clinical significance in ruminative content from a disorder-specific perspective. Limitations and future directions with respect to conducting a more methodologically sound and intimate study using ecological momentary assessments to evaluate the relationship between stress, sleep, and cognitions are provided.