Perinatal depression: prevalence, risks, and the nutrition link--a review of the literature.

The purpose of this review is to examine the role of nutrition in perinatal depression. Perinatal (maternal) depression refers to major and minor episodes during pregnancy (termed antenatal) and/or within the first 12 months after delivery (termed postpartum or postnatal). Prevalence of antenatal depression can be as high as 20%, while approximately 12% to 16% of women experience postpartum depression. These are probably conservative estimates, as cases of maternal depression are underreported or underdiagnosed. Risk factors for depression include genetic predisposition and environmental factors, as well as a number of social, psychological, and biological factors. One biological factor given increasing consideration is inadequate nutrition. Credible links between nutrient deficiency and mood have been reported for folate, vitamin B-12, calcium, iron, selenium, zinc, and n-3 fatty acids. For maternal depression, the nutrient that has received the most attention from nutrition researchers has been the n-3 essential fatty acids. Numerous studies, such as randomized controlled trials, cohort studies, and ecological studies, have found a positive association between low n-3 levels and a higher incidence of maternal depression. In addition, nutrient inadequacies in pregnant women who consume a typical western diet might be much more common than researchers and clinicians realize. A number of studies have reported inadequate intakes of n-3, folate, B vitamins, iron, and calcium in pregnant women. Depletion of nutrient reserves throughout pregnancy can increase a woman's risk for maternal depression.