title: Lithium Levels in Tap Water and the Mental Health Problems of Adolescents: An Individual-Level Cross-Sectional Survey.
abstract: OBJECTIVE
  We investigated the association between lithium level in tap water and mental health problems, including depressive symptoms, anxiety, and aggressive and suicidal behaviors, in a general population of adolescents using a large individual-level dataset.
  
  
  METHODS
  A school-based, cross-sectional survey was conducted in Kochi Prefecture in Japan between 2008 and 2009. Students in 24 public junior high schools were asked to anonymously complete a self-report questionnaire. The main outcome measures were mental health problems, including those on the 12-item General Health Questionnaire, interpersonal violence, bullying, destructive behavior, self-harm, and suicidal ideation. Samples were collected from sources that supplied drinking water to schools, and lithium levels were measured using atomic absorption spectrophotometry. The associations of lithium levels with mental health problems were examined using a generalized linear mixed model with schools as the fixed effect. Potential confounding factors were also added into the model.
  
  
  RESULTS
  A total of 3,040 students among 3,311 students responded to the self-report questionnaire (response rate, 91.8%). The mean lithium concentration in tap water was 0.48 μg/L (SD = 0.52; range, 0.01 to 2.10; skewness = 2.01; kurtosis = 4.04), and it was relatively low compared with previous studies. In multivariable regression analysis, lithium level in tap water had an inverse association with depressive symptoms (P = .02) and interpersonal violence (P = .02) but not with suicidal behaviors (suicidal ideation, P = .82; self-harm, P = .46).
  
  
  CONCLUSIONS
  Lithium level in tap water was inversely associated with depressive symptoms and interpersonal violence among a general population of adolescents and may have antidepressive and antiaggressive effects.
authors.affiliation: Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Ando
authors.affiliation: Office for Mental Health Support, Division for Counseling and Support, University of Tokyo, Tokyo, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Koike
authors.affiliation: Department of Neuropsychiatry, Kochi Medical School, Kochi, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Shimodera
authors.affiliation: Department of Neuropsychiatry, Kochi Medical School, Kochi, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Fujito
authors.affiliation: Department of Neuropsychiatry, Kochi Medical School, Kochi, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Sawada
authors.affiliation: Department of Neuropsychiatry, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Terao
authors.affiliation: Department of Cognitive-Behavioral Medicine, Kyoto University School of Public Health, Kyoto, Japan.
authors.forename: Toshi A
authors.initials: TA
authors.lastname: Furukawa
authors.affiliation: Department of Health Education, Graduate School of Education and Office for Mental Health Support, University of Tokyo, Tokyo, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Department of Neuropsychiatry, Aizu Medical Center, Fukushima Medical University, Fukushima, Japan.
authors.forename: Shimpei
authors.initials: S
authors.lastname: Inoue
authors.affiliation: Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Asukai
authors.affiliation: Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okazaki
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan. nishida-at@igakuken.or.jp.|Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nishida
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000453:epidemiology / Q000517:prevention & control; D060766:Drinking Water / Q000737:chemistry*; D005260:Female; D006306:Health Surveys; D006801:Humans; D007564:Japan; D016014:Linear Models; D018020:Lithium Compounds / Q000032:analysis* / Q000627:therapeutic use; D008297:Male; D001523:Mental Disorders / Q000517:prevention & control*; D059020:Suicidal Ideation; D011795:Surveys and Questionnaires; D014754:Violence / Q000517:prevention & control / Q000523:psychology; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000032:analysis*
chemical_list: D060766:Drinking Water; D018020:Lithium Compounds; D014874:Water Pollutants, Chemical