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as 90%. However, at least in the U.S., FDA-required folate supplementation of grain
products since 1998 and higher public awareness of the need for B-vitamin consumption
and supplementation have reduced the relevance of these studies.
- EFFICACY: DEPRESSION: Folate is a promising monotherapy and adjunctive treatment for
depression. Supplementation of folate deficiencies is recommended by five sources and
only disavowed by one, and adjunctive treatment of depression with folate is a promising
practice, especially for women, even if blood serum folate levels are not low. Two
(implicitly, three) of the sources counsel supplementation even in the absence of folate
deficiency.
According to Fugh-Berman and Cott, folate deficiency is one of the most common
nutritional deficiencies in the world and has often been associated with
neuropsychiatric disorders. This deficiency may be an understudied risk factor for
depression, especially since studies have shown that folate deficiency can significantly
reduce the efficacy of prescribed antidepressants.
Fugh-Berman and Cott recommend folate supplementation as an adjunctive
treatment for depression based principally on a study by Fava et al.(1997),^2 which
examined the relationships between levels of folate, vitamin B12, and homocysteine
and response to fluoxetine (Prozac) (20 mg per day for 8 weeks) treatment in 213
outpatients with major depressive disorder. Response to treatment was determined by
the percentage change in score on the HAM-D depression scare. Subjects with low
folate levels were more likely to have melancholic depression and were significantly
less likely to respond to fluoxetine. The researchers concluded that there was a link
between low folate levels and poorer response to antidepressant treatment. They
suggested that folate levels be considered in the evaluation of depressed people who do
not respond to antidepressant treatment.
Relying on the scholarly work of Bottiglieri,^3 Brown et al. note that low levels of folate
(B9) and other B vitamins (B6 and B12) are associated with depression and with
genetic precursors of depression. They posit that folate deficiency is likely to suppress
