title: Local daily temperatures, thermal seasons, and suicide rates in Finland from 1974 to 2010.
abstract: OBJECTIVE
  Suicide peaks in late spring and October are still seen in Finland among many countries. Weather factors have been suggested as explanations for these peaks, although with inconsistent results. Since the exact timing of these peaks varies each year, the length of daylight and changes in it seem inadequate as an explanation. We hypothesized that ambient temperature and the timing of thermal seasons might associate with suicide rate.
  
  
  METHODS
  Suicide rates from three areas across Finland (N = 10,802) were analyzed with Poisson regression in six different models against variables calculated from the local ambient daily temperature, diurnal temperature range, and the duration from the onset of thermal seasons. Separate models for men and women were constructed.
  
  
  RESULTS
  The temperature change over 5 days associated with the suicide rate of men in Helsinki region, or in other words, the lower the suicide rate was, the higher the temperature decrease had been. For women, the results were more inconsistent.
  
  
  CONCLUSIONS
  Our study is in line with some earlier studies which imply that impairment of thermoregulation might exist among suicide victims.
authors.affiliation: Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Mannerheimintie 166, P.O. Box 30, 00271, Helsinki, Finland, laura.hiltunen@thl.fi.
authors.forename: Laura
authors.initials: L
authors.lastname: Hiltunen
authors.forename: Jari
authors.initials: J
authors.lastname: Haukka
authors.forename: Reija
authors.initials: R
authors.lastname: Ruuhela
authors.forename: Kirsi
authors.initials: K
authors.lastname: Suominen
authors.forename: Timo
authors.initials: T
authors.lastname: Partonen
mesh_terms: D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D016012:Poisson Distribution; D018570:Risk Assessment; D012621:Seasons; D012737:Sex Factors; D013405:Suicide / Q000706:statistics & numerical data*; D013696:Temperature; D013997:Time Factors