Does Folic acid during pregnancy have any beneficial effects on the mood state of the mother, during pregnancy, immediately post-partum or later. This study published in the European Journal of Clinical Nutrition implies that it does, but that we have to wait almost 2 years to identify the impact – that seems a very long time to me, and does not indicate that this should be considered a sensible supplementation if post-partum depression management is your goal. Single nutrient therapies, whilst attractive from an intervention study perspective, fail time and again to modify complex disorders. Humans have the annoying reality of multiple points of impact; nutritional supplementation needs to be considered as a therapeutic intervention in line with food intake, body mass, social experiences, competing nutrient stealers, such as alcohol etc.
However, the information is useful and may add to the existing recommendations concerning folic acid in the overall support of mother and child.
As low folate status has been implicated in depression, high folate intake, in the form of supplements, during pregnancy might offer protection against depression during pregnancy and postpartum.
We examined the association between change in self-reported depressive symptoms (Edinburgh Postnatal Depression Scale) at different time points during and following pregnancy and self-reported folic acid supplementation during pregnancy in a prospective cohort of 6809 pregnant women. We also tested whether there was a main effect of methylenetetrahydrofolate reductase (MTHFR) C677T genotype (which influences folate metabolism and intracellular levels of folate metabolites and homocysteine) on change in depression scores, and carried out our analysis of folic acid supplementation and depression stratifying by genotype.
We found no strong evidence that folic acid supplementation reduced the risk of depression during pregnancy and up to 8 months after pregnancy. However, we did find evidence to suggest that folic acid supplements during pregnancy protected against depression 21 months postpartum, and that this effect was more pronounced in those with the MTHFR C677T TT genotype (change in depression score from 8 months to 21 months postpartum among TT individuals was 0.66 (95% CI=0.31-1.01) among those not taking supplements, compared with -1.02 (95% CI=-2.22-0.18) among those taking supplements at 18 weeks pregnancy, P(difference)=0.01).
Low folate is unlikely to be an important risk factor for depression during pregnancy and for postpartum depression, but may be a risk factor for depression outside of pregnancy, especially among women with the MTHFR C677T TT genotype.
 Lewis SJ, Araya R, Leary S, Smith GD, Ness A. Folic acid supplementation during pregnancy may protect against depression 21 months after pregnancy, an effect modified by MTHFR C677T genotype. Eur J Clin Nutr. 2011 Jul 20. doi: 10.1038/ejcn.2011.136 View Abstract