Polyunsaturated fatty acids and inflammatory markers in major depressive episodes during pregnancy

Prenatal depression (PND) is a common psychiatric disorder in pregnant women and leads to psychosocial dysfunction, high suicidal rate, and adverse childcare. Patients with PND have omega-3 polyunsaturated fatty acid (omega-3 or n-3 PUFAs) deficits, which might link to chronic low-grade inflammatory process and the pathophysiological mechanisms of depression. In this case-control study, we examined the levels of PUFAs and inflammatory cytokines in PND.

Blood samples were obtained and analyzed from 16 healthy controls and 17 depressed cases (PND group) diagnosed with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Independent sample t-test and correlation analysis were performed with Statistical Package for the Social Sciences (SPSS) logistics correlation analysis.

PND group had significantly lower levels of total n-3 (p=0.026), docosahexaenoic acid (DHA) (p=0.020) and eicosapentaenoic (EPA) (p=0.019) but a higher omega-6 (n-6)/n-3 PUFAs ratio (p=0.007) and tumor necrosis factor alpha (TNF-α) (p=0.016) level. Moreover, the duration of current PND episodes were also significantly correlated with DHA, EPA, n-3 PUFAs, n-6/n-3 ratio and TNF-α. In terms of PUFAs and cytokine levels, only DHA was inversely correlated with TNF-α.

PND is significantly associated with lower DHA, EPA, and total n-3 PUFAs levels and an increased n-6/n-3 PUFAs ratio, while the duration of PND is associated with lower levels of n-3 PUFAs, including DHA and EPA. The correlation of PUFAs levels with depression and TNF-α level grant further investigation into the inflammatory process underlying PND, mediated by PUFAs.