title: Folate intake and depressive symptoms in Japanese workers considering SES and job stress factors: J-HOPE study.
abstract: BACKGROUND
  Recently socioeconomic status (SES) and job stress index received more attention to affect mental health. Folate intake has been implicated to have negative association with depression. However, few studies were published for the evidence association together with the consideration of SES and job stress factors. The current study is a part of the Japanese study of Health, Occupation and Psychosocial factors related Equity (J-HOPE study) that focused on the association of social stratification and health and our objective was to clarify the association between folate intake and depressive symptoms in Japanese general workers.
  
  
  METHODS
  Subjects were 2266 workers in a Japanese nationwide company. SES and job stress factors were assessed by self-administered questionnaire. Folate intake was estimated by a validated, brief, self-administered diet history questionnaire. Depressive symptoms were measured by Kessler's K6 questionnaire. "Individuals with depressive symptoms" was defined as K6≥9 (in K6 score of 0-24 scoring system). Multiple logistic regression and linear regression model were used to evaluate the association between folate and depressive symptoms.
  
  
  RESULTS
  Several SES factors (proportion of management positions, years of continuous employment, and annual household income) and folate intake were found to be significantly lower in the subjects with depressive symptom (SES factors: p < 0.001; folate intake: P = 0.001). There was an inverse, independent linear association between K6 score and folate intake after adjusting for age, sex, job stress scores (job strains, worksite supports), and SES factors (p = 0.010). The impact of folate intake on the prevalence of depressive symptom by a multiple logistic model was (ORs[95% CI]: 0.813 [0.664-0.994]; P =0.044).
  
  
  CONCLUSIONS
  Our cross-sectional study suggested an inverse, independent relation of energy-adjusted folate intake with depression score and prevalence of depressive symptoms in Japanese workers, together with the consideration of SES and job stress factors.
authors.affiliation: Division of Clinical Epidemiology, Department of Clinical Research and Informatics, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan. miyaki-keio@umin.net
authors.forename: Koichi
authors.initials: K
authors.lastname: Miyaki
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Song
authors.forename: Nay Chi
authors.initials: NC
authors.lastname: Htun
authors.forename: Akizumi
authors.initials: A
authors.lastname: Tsutsumi
authors.forename: Hideki
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Norito
authors.initials: N
authors.lastname: Kawakami
authors.forename: Masaya
authors.initials: M
authors.lastname: Takahashi
authors.forename: Akihito
authors.initials: A
authors.lastname: Shimazu
authors.forename: Akiomi
authors.initials: A
authors.lastname: Inoue
authors.forename: Sumiko
authors.initials: S
authors.lastname: Kurioka
authors.forename: Takuro
authors.initials: T
authors.lastname: Shimbo
mesh_terms: D000328:Adult; D044466:Asian People / Q000523:psychology; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D004032:Diet; D004651:Employment / Q000523:psychology*; D005260:Female; D005492:Folic Acid; D006306:Health Surveys; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012923:Social Class; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D011795:Surveys and Questionnaires; D017132:Workplace / Q000523:psychology
chemical_list: D005492:Folic Acid