title: CHRONOTYPE ASSOCIATIONS WITH DEPRESSION AND ANXIETY DISORDERS IN A LARGE COHORT STUDY.
abstract: BACKGROUND
  The chronotype, being a morning or an evening type, can influence an individual's psychological health. Studies have shown a link between depressed mood and being an evening type; however, most studies have used symptom scales and not diagnostic criteria, and confounding factors such as sleep patterns and somatic health factors have often not been considered. This study aims to examine the association between chronotype and depressive (major depressive disorder (MDD), dysthymia) and anxiety (generalized anxiety disorder, panic disorder, agoraphobia, and social phobia) disorders diagnosed using clinical interviews, while taking into account relevant sociodemographic, clinical, somatic health, and sleep parameters.
  
  
  METHODS
  Data from a large cohort, the Netherlands Study of Depression and Anxiety were used (n = 1,944), which included 676 currently depressed and/or anxious patients, 831 remitted patients, and 437 healthy controls. Chronotype was assessed using the Munich Chronotype Questionnaire.
  
  
  RESULTS
  Our results showed that current depressive and/or anxiety disorders were associated with a late chronotype (β = .10, P = .004) even when adjusting for sociodemographic, somatic health, and sleep-related factors (β = .09, P = .03). When examining each type of disorder separately, MDD only, but not dysthymia or specific anxiety disorders, was associated with the late chronotype. The late chronotype also reported significant diurnal mood variation (worse mood in the morning).
  
  
  CONCLUSIONS
  Our findings show a clear association between MDD and late chronotype (being an evening type), after controlling for a range of pertinent factors. A late chronotype is therefore associated with a current status of MDD and deserves the relevant clinical attention when considering treatments.
authors.affiliation: Department of Clinical Psychology, Institute of Psychology, Leiden University, Leiden, The Netherlands.
authors.forename: Niki
authors.initials: N
authors.lastname: Antypa
authors.affiliation: Department of Psychiatry, EMGO Institute for Health and Care Research and Neuroscience Campus Amsterdam, The Netherlands.
authors.forename: Nicole
authors.initials: N
authors.lastname: Vogelzangs
authors.affiliation: Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Ybe
authors.initials: Y
authors.lastname: Meesters
authors.affiliation: Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Robert
authors.initials: R
authors.lastname: Schoevers
authors.affiliation: Department of Psychiatry, EMGO Institute for Health and Care Research and Neuroscience Campus Amsterdam, The Netherlands.
authors.forename: Brenda W J H
authors.initials: BW
authors.lastname: Penninx
mesh_terms: D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis / Q000523:psychology*; D002940:Circadian Rhythm; D015331:Cohort Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: MDD; NESDA; anxiety; diurnal mood variation; evening type; morning type