Folate, vitamin B12, homocysteine, and the MTHFR 677C->T polymorphism in anxiety and depression: the Hordaland Homocysteine Study.
BACKGROUND
An association between depression and folate status has been demonstrated in clinical studies, whereas data are sparse on the relationship between depression and other components of 1-carbon metabolism such as vitamin B12, homocysteine, and the methylenetetrahydrofolate reductase 677C-->T polymorphism. The relationship between anxiety and these components is less well known. This study examined the associations between folate, total homocysteine, vitamin B12, and the methylenetetrahydrofolate reductase 677C-->T polymorphism, and anxiety and depression in a large population-based study.


METHODS
Anxiety and depression, measured by the Hospital Anxiety and Depression Scale, were assessed in 5948 subjects aged 46 to 49 years (mean, 47.4 years) and 70 to 74 years (mean, 71.9 years) from the Hordaland Homocysteine Study cohort. By means of logistic regression models, anxiety and depression scores were examined in relation to the factors listed above.


RESULTS
Overall, hyperhomocysteinemia (plasma total homocysteine level > or =15.0 micro mol/L [> or =2.02 mg/dL]) (odds ratio, 1.90; 95% confidence interval, 1.11-3.25) and T/T methylenetetrahydrofolate reductase genotype (odds ratio, 1.69; 95% confidence interval, 1.09-2.62), but not low plasma folate or vitamin B12 levels, were significantly related to depression without comorbid anxiety disorder. Plasma folate level was inversely associated with depression only in the subgroup of middle-aged women. None of the investigated parameters showed a significant relationship to anxiety.


CONCLUSIONS
Our results provide further evidence of a role of impaired 1-carbon metabolism in depression.
Bjelland
Ingvar
I
Department of Public Health and Primary Health Care, Locus for Homocysteine and Related Vitamins, University of Bergen, Norway. ingvar.bjelland@uib.no
Tell
Grethe S
GS
Vollset
Stein Emil
SE
Refsum
Helga
H
Ueland
Per Magne
PM
D000368:Aged; D001008:Anxiety Disorders / Q000097:blood* / Q000235:genetics* / Q000378:metabolism; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000097:blood* / Q000235:genetics* / Q000378:metabolism; D005492:Folic Acid / Q000097:blood*; D005838:Genotype; D006710:Homocysteine / Q000097:blood* / Q000378:metabolism*; D006801:Humans; D016015:Logistic Models; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D009664:Norway; D016017:Odds Ratio; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D010555:Personality Inventory; D011110:Polymorphism, Genetic; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood*
D006710:Homocysteine; D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12