Postpartum depressive symptoms: the B-vitamin link.

Objective This study examined longitudinal relationships between maternal red-cell folate status and dietary intakes of vitamins B(6), B(12) and folate before and during pregnancy and subsequent postpartum depressive symptoms.Study design and setting Within a cohort study of women aged 20-34 years (the Southampton Women's Survey) dietary data were obtained before pregnancy and at 11 and 34 weeks' gestation. Red-cell folate was measured before pregnancy and at 11 weeks' gestation. We derived relative risks of postpartum depressive symptoms using an Edinburgh Postnatal Depression Scale (EPDS) score of ≥ 13 administered from 6 months to 1 year postpartum.Results No significant differences were found between those with postpartum depressive symptoms (n = 905) and those without (n = 1951) in relation to red-cell folate concentration or dietary intake of folate, vitamin B(12) and vitamin B(6), before or during pregnancy. A prior history of mental illness (relative risk (RR) 1.83; 95% confidence interval (CI) 1.53-2.19) was associated with postpartum depressive symptoms, and women who breastfed until 6 months were less likely to experience postpartum depressive symptoms (RR 0.68; 95% CI 0.55-0.84).Conclusion This study suggests that folate status and dietary folate, B(6) and B(12) intakes before and during pregnancy are not associated with postpartum depressive symptoms. A history of mental illness, however, was a strong risk factor.