title: Association of geomagnetic disturbances and suicides in Japan, 1999-2010.
abstract: OBJECTIVE
  Previous studies have shown a positive relationship between geomagnetic disturbances and an increased incidence of suicide. The Japanese suicide rate is the ninth highest in the world, but there have been no reports examining the relationship between geomagnetic disturbance and the number of suicides, and, therefore, this paper examines this relationship.
  
  
  METHODS
  The number of Japanese suicides per month from January 1999 to December 2010 was obtained, and it was found that a total of 262,596 males and 102,539 females committed suicide during this period. To adjust the other factors which affect the number of suicides, a multiple linear regression analysis with backward elimination was carried out, with the monthly number of suicides as the response variable and the monthly mean K index value, monthly mean number of sunspots, monthly mean unemployment rate, proportion of elderly people (%), monthly mean air pressure (hPa), monthly mean air temperature (°C), monthly mean humidity (%), and monthly mean day length (h) as the explanatory variables.
  
  
  RESULTS
  In the multiple linear regression analysis for males, the monthly mean K index value was associated with the monthly number of suicides, but in females, the monthly mean K index value was not associated with the monthly number of suicides.
  
  
  CONCLUSIONS
  In this study, we generated a hypothesis that geomagnetic disturbances may trigger male suicides.
authors.affiliation: Translational Research Center, Kyoto University Hospital, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
authors.forename: Harue
authors.initials: H
authors.lastname: Tada
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishimura
authors.forename: Eiji
authors.initials: E
authors.lastname: Nakatani
authors.forename: Kazuki
authors.initials: K
authors.lastname: Matsuda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Teramukai
authors.forename: Masanori
authors.initials: M
authors.lastname: Fukushima
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D060526:Magnetic Fields / Q000009:adverse effects*; D008297:Male; D012621:Seasons; D013405:Suicide / Q000706:statistics & numerical data*