title: Rumination predicts longer sleep onset latency after an acute psychosocial stressor.
abstract: OBJECTIVE
  Rumination has been linked to self-reported sleep quality. However, whether rumination is related to an objective sleep parameter has not been tested. This study examined whether rumination predicts sleep onset latency (SOL) on the night after an acute psychosocial stressor. We hypothesized that those who ruminate (assessed with both trait and stressor-specific measures) would have longer SOL (assessed with objective and subjective methods).
  
  
  METHODS
  Seventy participants delivered a 5-minute speech in front of an evaluative panel during an afternoon laboratory session. Trait rumination was assessed before the stressor. Stressor-specific rumination was captured with the frequency of task-related thoughts participants experienced during a 10-minute rest period after the stressor. Participants wore actigraphs on their wrists on the night after the laboratory session to measure objective sleep onset latency (SOL-O). Subjective sleep onset latency was estimated by participants on the subsequent morning.
  
  
  RESULTS
  Consistent with hypotheses, trait and stressor-specific rumination predicted longer SOL-O and subjective sleep onset latency, respectively. In addition, trait and stressor-specific rumination interacted to predict longer SOL-O. SOL-O was longest among those who engaged in more stressor-specific rumination and had greater trait rumination scores. Neither rumination measure was related to sleep duration or wakefulness after sleep onset.
  
  
  CONCLUSIONS
  The findings from this study are consistent with previous research linking rumination to subjective sleep quality. The results also suggest that post-stressor ruminative thought may predict delayed sleep onset for those with a propensity for rumination.
authors.affiliation: Department of Psychology and Social Behavior, 3340 Social Ecology II, University of California, Irvine, Irvine, CA 92697-7085, USA. p.m.zoccola@uci.edu
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Zoccola
authors.forename: Sally S
authors.initials: SS
authors.lastname: Dickerson
authors.forename: Suman
authors.initials: S
authors.lastname: Lam
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003625:Data Collection / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000706:statistics & numerical data; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000503:physiopathology; D013060:Speech; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology; D011795:Surveys and Questionnaires; D013850:Thinking / Q000502:physiology; D014851:Wakefulness / Q000502:physiology