Background: Results of studies of the association between blood concentrations of homocysteine and depression in general populations and among psychiatric patients are inconsistent.
Objective: The objective was to study the association between depression and serum concentrations of total homocysteine (tHcy).
Design: A cross-sectional study of a sample of 924 men aged 46-64 y was conducted as a part of the Kuopio Ischaemic Heart Disease Risk Factor Study. Those who had a history of psychiatric disorder (6.0%) were excluded. Depressive symptoms were assessed with the 18-item Human Population Laboratory Depression Scale. Those who scored > or =5 at baseline or at the 4-y follow-up were considered to have a tendency toward depression.
Results: The participants were ranked according to their blood tHcy concentration and divided into tertiles. Those in the upper tertile for serum tHcy had a more than twofold (odds ratio: 2.30; 95% CI: 1.35, 3.90; P=0.002) higher risk of being depressed than did those in the lowest tertile for serum tHcy. The results remained significant after adjustment for the month of study, history of ischemic heart disease, smoking habits, alcohol consumption, marital status, education, and socioeconomic status in adulthood (odds ratio: 2.23; 95% CI: 1.30, 3.83; P=0.004).
Conclusion: High serum concentrations of tHcy may be associated with depression in middle-aged men.