Is essential fatty acid status in late pregnancy predictive of post-natal depression?

We tested the hypothesis that abnormal levels of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) during late pregnancy are associated with antenatal and post-natal depression.

We interviewed a sample of more than 900 women in late pregnancy. We assessed whether they met criteria for depression on a standardized measure of post-natal depression [the Edinburgh Post-natal Depression Scale (EPDS)] and met DSM-IV criteria for major depression and/or were in receipt of antidepressant medication. Blood was collected at that time to generate data on nine PUFA variables. Sample members were re-interviewed post-natally to determine depressive experience in the 3 months following the birth of their baby.

Univariate associations were demonstrated between pre-natal depression categorized using DSM criteria and measures of blood fatty acids including total omega-3, the ratio of omega-6 to omega-3, docosahexaenoic acid (DHA) omega-3 and DHA plus eicosapentaenoic acid (EPA) omega-3. Such associations were not found post-natally, but different associations were quantified between EPDS-diagnosed depression and total omega-6, total omega-3 and EPA omega-3. In multivariate analyses, slight associations were maintained between EPDS and lower omega-3, lower EPA and higher omega-6 when neuroticism, stress during pregnancy, a lifetime episode of depression and older age were included in the analysis.

Findings in such a large sample indicate that PUFA status in late pregnancy is only slightly linked with the risk of post-natal depression when depression was quantified by the EPDS. There were no associations between post-natal depression diagnosed by DSM criteria and any fatty acid variables.