Evidence for...Folic Acid for depression

Folate for depressive disorders: systematic review and meta-analysis of randomized controlled trials.
Taylor MJ et al.
J Psychopharmacol. 2004;18:251-6.
Evidence was reviewed from 3 randomised controlled trials (247 participants) on the effectiveness, adverse effects and acceptability of folate in the treatment of patients with a diagnosis of depressive disorder. In the 2 studies that assessed the use of folate in addition to other treatment, adding folate reduced Hamilton Depression Rating Scale scores on average by a further 2.65 points, while the remaining study found no statistically significant difference when folate alone was compared with trazodone. Folate was well tolerated.


Enhancement of the antidepressant action of fluoxetine by folic acid: a randomised, placebo controlled trial.
Coppen A and Bailey J.
J Affect Disord. 2000;60:121-30.
127 patients with major depression were randomly assigned to receive either 500 microg folic acid or a placebo in addition to 20 mg fluoxetine daily. At 10 weeks, the overall response rate (>50% decrease from baseline in Hamilton Depression Rating Scale score) was 82% for folate plus fluoxetine group vs 62% for the placebo and fluoxetine group; an analysis of these data according to gender found that the difference was 94% vs 61% in the women, respectively, while there was no difference in the men.


Folate and unipolar depression.
Morris DW et al.
J Altern Complement Med. 2008;14:277-85.
This review of the literature on the clinical utility of folate augmentation for patients with major depressive disorder concluded that depressed patients with both low and normal folate levels may benefit from augmentation of antidepressant medication with a folate supplement either initially, at the onset of treatment, or later in cases of treatment resistance.