title: Indoors illumination and seasonal changes in mood and behavior are associated with the health-related quality of life.
abstract: OBJECTIVE
  Seasonal changes in mood and behavior are common in a general population, being of relevance to public health. We wanted to analyze whether the HRQoL is associated with the seasonal changes in mood and behavior. Because the shortage of exposure to daylight or artificial bright light has been linked to the occurrence of the seasonal changes, we wanted to know whether illumination indoors contributes to the HRQoL.
  
  
  METHODS
  Of the sample of 7979 individuals, being representative of the Finnish general population aged 30 and over, 88% were interviewed face to face, and 84% participated in the health status examination after which the self-report assessment of the HRQoL and the seasonal changes in mood and behavior took place. The illumination levels experienced indoors were asked during the interview and the 12-item General Health Questionnaire (GHQ-12) was filled in before the health examination.
  
  
  RESULTS
  The HRQoL was influenced by both the seasonal changes in mood and behavior (P < 0.001) and the illumination experienced indoors (P < 0.001). Greater seasonal changes (P < 0.001) and poor illumination indoors (P = 0.0035) were associated with more severe mental ill-being.
  
  
  CONCLUSIONS
  The routinely emerging seasonal changes in mood and behavior are associated with the HRQoL and mental well-being. Better illumination indoors might alleviate the season-bound symptoms and thereby enhance the HRQoL and mental well-being.
authors.affiliation: National Public Health Institute, Department of Mental Health and Alcohol Research, Helsinki, Finland. sharon.grimaldi-toriz@ktl.fi
authors.forename: Sharon
authors.initials: S
authors.lastname: Grimaldi
authors.forename: Timo
authors.initials: T
authors.lastname: Partonen
authors.forename: Samuli I
authors.initials: SI
authors.lastname: Saarni
authors.forename: Arpo
authors.initials: A
authors.lastname: Aromaa
authors.forename: Jouko
authors.initials: J
authors.lastname: Lönnqvist
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000339:Affect; D000368:Aged; D000369:Aged, 80 and over; D001519:Behavior; D003863:Depression / Q000453:epidemiology / Q000209:etiology; D005260:Female; D005387:Finland; D006801:Humans; D008029:Lighting; D008297:Male; D008875:Middle Aged; D011581:Psychological Tests; D011788:Quality of Life / Q000523:psychology*; D012044:Regression Analysis; D012621:Seasons; D011795:Surveys and Questionnaires