title: Trace lithium is inversely associated with male suicide after adjustment of climatic factors.
abstract: BACKGROUND
  Previously, we showed the inverse association between lithium in drinking water and male suicide in Kyushu Island. The narrow variation in meteorological factors of Kyushu Island and a considerable amount of evidence regarding the role of the factors on suicide provoked the necessities of adjusting the association by the wide variation in sunshine, temperature, rain fall, and snow fall.
  
  
  METHODS
  To keep the wide variation in meteorological factors, we combined the data of Kyushu (the southernmost city is Itoman, 26°) and Hokkaido (the northernmost city is Wakkanai, 45°). Multiple regression analyses were used to predict suicide SMRs (total, male and female) by lithium levels in drinking water and meteorological factors.
  
  
  RESULTS
  After adjustment of meteorological factors, lithium levels were significantly and inversely associated with male suicide SMRs, but not with total or female suicide SMRs, across the 153 cities of Hokkaido and Kyushu Islands. Moreover, annual total sunshine and annual mean temperature were significantly and inversely associated with male suicide SMRs whereas annual total rainfall was significantly and directly associated with male suicide SMRs.
  
  
  CONCLUSIONS
  The limitations of the present study include the lack of data relevant to lithium levels in food and the proportion of the population who drank tap water and their consumption habits.
  
  
  CONCLUSIONS
  The present findings suggest that trace lithium is inversely associated with male but not female suicide after adjustment of meteorological factors.
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan; Advanced Emergency Medical Service Center, Oita University Faculty of Medicine, Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Shiotsuki
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan. Electronic address: terao@oita-u.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Terao
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Ishii
authors.affiliation: Department of Public Health, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Shouhei
authors.initials: S
authors.lastname: Takeuchi
authors.affiliation: Department of Public Health, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kuroda
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kohno
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Mizokami
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Hatano
authors.affiliation: Advanced Emergency Medical Service Center, Oita University Faculty of Medicine, Japan.
authors.forename: Sanshi
authors.initials: S
authors.lastname: Tanabe
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Yufu, Japan; Advanced Emergency Medical Service Center, Oita University Faculty of Medicine, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanehisa
authors.affiliation: Department of Psychology, Hiroshima International University, Hiroshima, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Iwata
authors.affiliation: Department of Public Health, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Matusda
mesh_terms: D002980:Climate; D060766:Drinking Water / Q000737:chemistry*; D005260:Female; D006801:Humans; D008094:Lithium / Q000032:analysis*; D008297:Male; D012621:Seasons; D012737:Sex Factors; D013405:Suicide / Q000706:statistics & numerical data*; D013696:Temperature
chemical_list: D060766:Drinking Water; D008094:Lithium
keywords: Lithium; Rainfall; Suicide; Sunshine; Temperature