title: Chronotype and seasonality: morningness is associated with lower seasonal mood and behavior changes in the Old Order Amish.
abstract: BACKGROUND
  Several studies documented that lower scores on the Morningness-Eveningness Questionnaire (MEQ) are associated with a higher global seasonality of mood (GSS). As for the Modern Man artificial lighting predominantly extends evening activity and exposure to light, and as evening bright light phase is known to delay circadian rhythms, this chronic exposure could potentially lead to both lower Morningness as well as higher GSS. The aim of the study was to investigate if the MEQ-GSS relationship holds in the Old Order Amish of Lancaster County, PA, a population that does not use network electrical light.
  
  
  METHODS
  489 Old Order Amish adults (47.6% women), with average (SD) age of 49.7 (14.2) years, completed both the Seasonal Pattern Assessment Questionnaire (SPAQ) for the assessment of GSS, and MEQ. Associations between GSS scores and MEQ scores were analyzed using linear models, accounting for age, gender and relatedness by including the relationship matrix in the model as a random effect.
  
  
  RESULTS
  GSS was inversely associated with MEQ scores (p=0.006, adjusted).
  
  
  CONCLUSIONS
  include a potential recall bias associated with self-report questionnaires and no actual light exposure measurements.
  
  
  CONCLUSIONS
  We confirmed the previously reported inverse association between MEQ scores and lower seasonality of mood, for the first time in a population that does not use home network electrical lighting. This result suggests that the association is not a byproduct of exposure to network electric light, and calls for additional research to investigate mechanisms by which Morningness is negatively associated with seasonality.
authors.affiliation: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; Saint Elizabeths Hospital, Psychiatry Residency Training Program, Washington, D.C., USA.
authors.forename: Layan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: California Pacific Medical Center Research Institute, San Francisco, CA, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Evans
authors.affiliation: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; Saint Elizabeths Hospital, Psychiatry Residency Training Program, Washington, D.C., USA.
authors.forename: Uttam K
authors.initials: UK
authors.lastname: Raheja
authors.affiliation: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Stephens
authors.affiliation: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; Saint Elizabeths Hospital, Psychiatry Residency Training Program, Washington, D.C., USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Stiller
authors.affiliation: Division of Child and Adolescent Psychiatry & University of Maryland Child and Adolescent Mental Health Innovations Center, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Reeves
authors.affiliation: Department of Ophthalmology & Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Johnson
authors.affiliation: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Ryan
authors.affiliation: Division of Child and Adolescent Psychiatry & University of Maryland Child and Adolescent Mental Health Innovations Center, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Weizel
authors.affiliation: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Dipika
authors.initials: D
authors.lastname: Vaswani
authors.affiliation: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Hassan
authors.initials: H
authors.lastname: McLain
authors.affiliation: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Shuldiner
authors.affiliation: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Braxton D
authors.initials: BD
authors.lastname: Mitchell
authors.affiliation: Phoenix Epidemiology and Clinical Research Branch, NIDDK, National Institutes of Health, Phoenix, AZ, USA.
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Hsueh
authors.affiliation: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Soren
authors.initials: S
authors.lastname: Snitker
authors.affiliation: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; VISN 5 Capitol Health Care Network Mental Illness Research Education and Clinical Center (MIRECC), Baltimore, MD, USA; VISN 19 MIRECC, Denver, CO, USA. Electronic address: teopostolache@gmail.com.
authors.forename: Teodor T
authors.initials: TT
authors.lastname: Postolache
mesh_terms: D000328:Adult; D000339:Affect; D061365:Amish; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D016574:Seasonal Affective Disorder / Q000453:epidemiology* / Q000523:psychology*; D012621:Seasons; D057566:Self Report; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Amish; Global Seasonality Score (GSS); Morningness–Eveningness Questionnaire (MEQ); Seasonal Affective Disorder; Seasonal Pattern Assessment Questionnaire (SPAQ)