title: Eveningness relates to burnout and seasonal sleep and mood problems among young adults.
abstract: OBJECTIVE
  Diurnal preference towards eveningness among adults has been associated with unhealthy habits and a range of health hazards, such as sleeping problems and higher odds for depression. We wanted to analyse whether diurnal preference towards eveningness is associated with more severe symptoms regarding sleep problems and mental disorders among young adults.
  
  
  METHODS
  Our sample consists of 469 young adults, aged 18-29 years, from the Mental Health in Early Adulthood Study in Finland (MEAF) conducted in 2003-2005. Chronotype was based on the assessment of one question that was asked first in 2000-2001 and the second time in 2003-2005. Those 73 participants who changed their chronotype were excluded from the main analysis, but separate analyses were performed with this group.
  
  
  RESULTS
  Concerning sleep, E-types reported higher dependency on alarm clocks (p < 0.001), and E-types and I-types had more problems in feeling refreshed after waking up (p < 0.0001 and p < 0.05 respectively) than M-types. Regarding mental health, E-types and I-types had lower odds for any lifetime DSM-IV Axis I disorder (p < 0.05 and p < 0.01 respectively) than M-types.
  
  
  CONCLUSIONS
  Our results are in line with previous findings that those with the diurnal preference towards eveningness have more frequently three or more lifetime mental disorders, more sleeping problems, more seasonal variation in mood and behaviour, and more burnout compared with those with the diurnal preference towards morningness.
authors.affiliation: a Ilona Merikanto, Department of Mental Health and Substance Abuse Services , National Institute for Health and Welfare , Helsinki , Finland , Department of Biosciences , University of Helsinki , Helsinki , Finland.
authors.forename: Ilona
authors.initials: I
authors.lastname: Merikanto
authors.affiliation: b Jaana Suvisaari, Department of Mental Health and Substance Abuse Services , National Institute for Health and Welfare , Helsinki , Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Suvisaari
authors.affiliation: c Tuuli Lahti, Department of Mental Health and Substance Abuse Services , National Institute for Health and Welfare , Helsinki , Finland , Department of Behavioural Sciences and Philosophy , University of Turku , Turku , Finland.
authors.forename: Tuuli
authors.initials: T
authors.lastname: Lahti
authors.affiliation: d Timo Partonen, Department of Mental Health and Substance Abuse Services , National Institute for Health and Welfare , Helsinki , Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Partonen
mesh_terms: D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D016574:Seasonal Affective Disorder / Q000453:epidemiology / Q000503:physiopathology*; D012621:Seasons; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000503:physiopathology*; D013315:Stress, Psychological / Q000453:epidemiology / Q000503:physiopathology*; D055815:Young Adult
keywords: Circadian; DSM-IV Axis I disorder; Mid-point sleep; SAD; Structured interview; Survey; population