title: Seasonal and meteorological associations with depressive symptoms in older adults: A geo-epidemiological study.
abstract: BACKGROUND
  Given increased social and physiological vulnerabilities, older adults may be particularly susceptible to environmental influences on mood. Whereas the impact of season on mood is well described for adults, studies rarely extend to elders or include objective weather data. We investigated the impact of seasonality and meteorological factors on risk of current depressive symptoms in older adults.
  
  
  METHODS
  We used data on 8027 participants from the first wave of The Irish Longitudinal Study of Ageing, a population-representative cohort of adults aged 50+. Depressive symptoms were recorded using the Centre for Epidemiological Studies Depression Scale. Season was defined according to the World Meteorological Organisation. Data on climate over the preceding thirty years, and temperature and rain over the preceding month, were provided by the Irish Meteorological Service and linked using Geographic Information Systems techniques to participant's geo-coded locations at a resolution of one kilometre.
  
  
  RESULTS
  The highest levels of depressive symptoms were reported in winter and the lowest in spring (mean 6.56 [CI95% 6.09, 7.04] vs. 5.81 [CI95%: 5.40, 6.22]). In fully adjusted linear regression models, participants living in areas with higher levels of rainfall in the preceding and/or current calendar month had greater depressive symptoms (0.04 SE 0.02; p=0.039 per 10mm additional rainfall per month) while those living in areas with sunnier climates had fewer depressive symptoms (-2.67 SE 0.88; p=0.003 for every additional hour of average annual daily sunshine).
  
  
  CONCLUSIONS
  This was a cross-sectional analysis thus causality cannot be inferred; monthly rain and temperature averages were available only on a calendar month basis while monthly local levels of sunshine data were not available.
  
  
  CONCLUSIONS
  Environmental cues may influence mood in older adults and thus have relevance for the recognition and treatment of depression in this age group.
authors.affiliation: The Irish Longitudinal Study on Ageing (TILDA), Trinity College Dublin, Ireland. Electronic address: oharesh@tcd.ie.
authors.forename: Celia
authors.initials: C
authors.lastname: O'Hare
authors.affiliation: Lancaster University Management School, LA1 4YX, United Kingdom.
authors.forename: Vincent
authors.initials: V
authors.lastname: O'Sullivan
authors.affiliation: New Zealand Climate Change Research Institute, School of Geography Environment and Earth Sciences, Victoria University, Wellington 6012, New Zealand.
authors.forename: Stephen
authors.initials: S
authors.lastname: Flood
authors.affiliation: The Irish Longitudinal Study on Ageing (TILDA), Trinity College Dublin, Ireland.
authors.forename: Rose Anne
authors.initials: RA
authors.lastname: Kenny
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D062306:Geography, Medical; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016574:Seasonal Affective Disorder / Q000453:epidemiology / Q000209:etiology*; D012621:Seasons; D013472:Sunlight; D013696:Temperature; D014887:Weather
keywords: Climate; Depression; Geographic Information Systems; Older age/aged; Season