title: A seven day actigraphy-based study of rumination and sleep disturbance among young adults with depressive symptoms.
abstract: OBJECTIVE
  Trait ruminators exhibit significantly higher levels of sleep disturbance than those without this cognitive vulnerability. However, support for the sleep disruptive effects of state rumination, especially in the pre-sleep period, is rare, and hindered by methodological drawbacks such as self-report and single night assays of sleep. Finally, despite the pervasiveness of the ruminative response style among individuals with depression, the association between rumination and sleep disturbance has not been explored in this population. The present study employed a week-long daily sampling approach to examine the effects of naturally occurring pre-sleep rumination on self-reported and actigraphy-based sleep among individuals with high depressive symptomatology.
  
  
  METHODS
  Forty-two university students (19.6±3.2 yo;73.8% female), all of whom reported at least moderate levels of depressive symptoms, completed a short questionnaire after waking each morning for seven days. On this questionnaire, they self-reported sleep indices from the previous night and levels of engagement in pre-sleep rumination. Sleep was also monitored throughout this period via wrist actigraphy. Hierarchical-linear-modeling was used to examine the association between nightly rumination and sleep.
  
  
  RESULTS
  Nightly variations in pre-sleep rumination were predictive of significantly longer actigraphy- and diary-based sleep onset latency (SOL). Notably, a 1 SD increase on the pre-sleep rumination scale was associated with an approximately 7 minute increase in actigraphy-based SOL, even after controlling for baseline sleep disturbance and depressive symptoms.
  
  
  CONCLUSIONS
  These data offer compelling evidence for the impact of pre-sleep rumination on sleep onset, providing insight into one potential mechanism that triggers sleep disturbance among individuals with depressive symptoms.
authors.affiliation: Sleep Disorders & Research Center, Henry Ford Hospital, Detroit, MI, United States. Electronic address: vvenugo1@hfhs.org.
authors.forename: Vivek
authors.initials: V
authors.lastname: Pillai
authors.affiliation: Mandel School of Applied Social Sciences, Case Western Reserve University, Cleveland, OH, United States.
authors.forename: Lindsey A
authors.initials: LA
authors.lastname: Steenburg
authors.affiliation: Department of Psychology, Kent State University, Kent, OH, United States.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Ciesla
authors.affiliation: Sleep Disorders & Research Center, Henry Ford Hospital, Detroit, MI, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Roth
authors.affiliation: Sleep Disorders & Research Center, Henry Ford Hospital, Detroit, MI, United States.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Drake
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D003866:Depressive Disorder / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D057566:Self Report; D012890:Sleep; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Actigraphy; Daily sampling; Depression; Rumination; Sleep