Neuroticism, rumination, negative affect, and sleep: Examining between- and within-person associations

Neuroticism is strongly implicated in the development of sleep impairment and sleep disorders such as insomnia. However, it is unclear if neuroticism is a direct predictor of sleep, and/or if it moderates associations between related psychological processes (e.g., rumination and negative affect, or NA) and sleep in daily life. We investigated: 1) neuroticism as a between-person predictor of reported sleep, 2) daily fluctuations in rumination and NA as predictors of reported sleep, and 3) neuroticism as a between-person moderator of the relationships in aim 2. A sample of racially and ethnically diverse adults (N = 242; 62% African-American, 24% Hispanic/Latina/o) completed a baseline assessment of neuroticism and then completed two weeks of daily reports, including bedtime assessments of daily rumination and NA and waking assessments of prior night's sleep. Individuals with higher neuroticism reported more impaired average sleep, but this relationship became non-significant after accounting for daily rumination and NA. Days with greater NA than one's individual average predicted more impaired sleep, regardless of average levels of NA, daily rumination, and neuroticism. Results suggest the importance of investigating both between- and within-person associations linking neuroticism, rumination, NA, and sleep and may help inform more targeted intervention efforts for improving sleep.