Omega-3 deficiency associated with perinatal depression: case control study.

Women are depleted of omega-3 polyunsaturated fatty acids (n-3 PUFAs) during the perinatal period due to fetal diversion. An association has been shown between lowered n-3 PUFAs and depression in general. We therefore hypothesise that women with lower n-3 PUFA levels are at greater risk of depression during pregnancy. Sixteen depressed and 22 non-depressed women were recruited during the third trimester and fasting bloods were taken for plasma fatty acid analysis. High docosahexaenoic acid (DHA), high total n-3 and a low n-6:n-3 ratio were associated with significantly lower odds of depression. After adjustment for parity, age and education level, those with high DHA still had significantly lower odds of being depressed. Those with high total n-3 and a low n-6:n-3 ratio were also at significantly reduced risk of depression, although the magnitude of the difference was reduced. Study results quantified women with lower omega-3 PUFA levels as being six times more likely to be depressed antenatally, compared to women who had higher omega-3 PUFA levels. The prophylactic benefits of supplementation either prenatally or during pregnancy require close study to assess whether omega-3 PUFAs play a role in the prevention of perinatal depression.