title: Vitamin B12, folate, and homocysteine in depression: the Rotterdam Study.
abstract: OBJECTIVE
  The associations of vitamin B(12), folate, and homocysteine with depression were examined in a population-based study.
  
  
  METHODS
  The authors screened 3,884 elderly people for depressive symptoms. Subjects with positive screening results had psychiatric workups. Folate, vitamin B(12), and homocysteine blood levels were compared in 278 persons with depressive symptoms, including 112 with depressive disorders, and 416 randomly selected reference subjects. Adjustments were made for age, gender, cardiovascular disease, and functional disability.
  
  
  RESULTS
  Hyperhomocysteinemia, vitamin B(12) deficiency, and to a lesser extent, folate deficiency were all related to depressive disorders. For folate deficiency and hyperhomocysteinemia, the association with depressive disorders was substantially reduced after adjustment for functional disability and cardiovascular disease, but for vitamin B(12) this appeared independent.
  
  
  CONCLUSIONS
  The association of vitamin B(12) and folate with depressive disorders may have different underlying mechanisms. Vitamin B(12) may be causally related to depression, whereas the relation with folate is due to physical comorbidity.
authors.affiliation: Department of Epidemiology and Biostatistics, Erasmus Medical Centre, PO Box 1738, 3000 DR Rotterdam, The Netherlands.
authors.forename: Henning
authors.initials: H
authors.lastname: Tiemeier
authors.forename: H Ruud
authors.initials: HR
authors.lastname: van Tuijl
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: John
authors.initials: J
authors.lastname: Meijer
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Kiliaan
authors.forename: Monique M B
authors.initials: MM
authors.lastname: Breteler
mesh_terms: D000368:Aged; D002851:Chromatography, High Pressure Liquid; D003866:Depressive Disorder / Q000150:complications*; D005260:Female; D005494:Folic Acid Deficiency / Q000150:complications*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D014806:Vitamin B 12 Deficiency / Q000150:complications*