Taking folate supplements may help suppress depression suggests a new study, which found that people with high blood levels of homocysteine, thought to be broken down by the B vitamin, were more likely to suffer from the condition.
The researchers at the University of Bergen in Norway also found that depression occurred more commonly in people with the T/T methylenetetrahydrofolate reductase genotype, or those carrying a form of the gene that encodes a protein involved in processing folate. This is associated with poorer metabolism of the nutrient.
The team took blood samples from almost 6,000 people between aged 46 to 49, and examined them for depression and anxiety. Those with high levels of homocysteine in their blood were almost twice as likely to be depressed, compared to people with the lowest blood levels of homocysteine.
Plasma folate levels did not appear to differ between people with and without depression, except for the subgroup of middle-aged women, said the researchers. This implies that the folate in the blood is not being efficiently transferred to the cells, in some people, shows the study.
Writing in the Archives of General Psychiatry, the authors conclude: "Our results provide further evidence of a role of impaired 1-carbon metabolism in depression."
Previous research has linked folate deficiency and low folate status to depression, persistent depressive symptoms, and poor antidepressant response. A recent study, by a Norwegian/US team, suggested that folate supplements may be important following a depressive episode, when the nutrient is used up.