title: 24-HOUR ACTIVITY RHYTHM AND SLEEP DISTURBANCES IN DEPRESSION AND ANXIETY: A POPULATION-BASED STUDY OF MIDDLE-AGED AND OLDER PERSONS.
abstract: BACKGROUND
  Disturbed circadian rhythms have been associated with depression and anxiety, but it is unclear if disturbances in the 24-hr activity rhythm and sleep are independently and specifically related to these disorders.
  
  
  METHODS
  In 1,714 middle-aged and elderly participants of the Rotterdam Study, we collected actigraphy recordings of at least 96 hr (138 ± 14 hr, mean ± standard deviation). Activity rhythms were quantified calculating the fragmentation of the rhythm, stability of the rhythm over days, and timing of the rhythm. Total sleep time, sleep onset latency, and wake after sleep onset were also estimated with actigraphy. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale, persons with clinically relevant depressive symptoms were interviewed to diagnose DSM-IV-depressive disorder. Anxiety disorders were determined with the Munich version of the Composite International Diagnostic Interview.
  
  
  RESULTS
  More fragmented rhythms were associated with clinically relevant depressive symptoms (odds ratio (OR): 1.27, 95% confidence interval (CI): 1.04;1.54) and anxiety disorders (OR: 1.39, 95% CI: 1.14;1.70) after covariate adjustment. Less stable rhythms, longer sleep onset latency, and more wake after sleep onset were related to clinically relevant depressive symptoms or anxiety disorders only if not adjusted for covariates and other activity rhythm and sleep indicators.
  
  
  CONCLUSIONS
  Our study in middle-aged and elderly persons suggests that fragmentation of the 24-hr activity rhythm is associated with depression and anxiety. Moreover, this association also largely accounts for the effect of disturbed sleep on these psychiatric disorders.
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Annemarie I
authors.initials: AI
authors.lastname: Luik
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Lisette A
authors.initials: LA
authors.lastname: Zuurbier
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Neşe
authors.initials: N
authors.lastname: Direk
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Sleep and Cognition, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, The Netherlands.|Departments of Integrative Neurophysiology and Medical Psychology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University and Medical Center, Amsterdam, The Netherlands.
authors.forename: Eus J W
authors.initials: EJ
authors.lastname: Van Someren
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.|Department of Child and Adolescent Psychiatry, Erasmus University Medical Center, Rotterdam, The Netherlands.|Department of Psychiatry, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Henning
authors.initials: H
authors.lastname: Tiemeier
mesh_terms: D056044:Actigraphy; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000503:physiopathology*; D001008:Anxiety Disorders / Q000503:physiopathology*; D002940:Circadian Rhythm; D003863:Depression / Q000503:physiopathology*; D003866:Depressive Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012107:Research Design; D012890:Sleep; D012893:Sleep Wake Disorders / Q000503:physiopathology*
keywords: actigraphy; aging; circadian rhythm; epidemiology; mood disorders