The biological underpinnings of perinatal depressive symptoms: A multisystems approach

Background: Well-established evidence exists of an association between depressive symptoms and alterations in<br> the stress and inflammatory response systems; however, the picture is far less coherent during the perinatal<br> period. This study combines the assessment of multiple stress and inflammatory biomarkers in late pregnancy<br> and after delivery in order to investigate cross-sectional and prospective associations with perinatal depressive<br> symptoms.<br> Methods: One-hundred-ten healthy women were assessed in late pregnancy (mean gestational age=34.76;<br> SD=1.12) and 89 were re-evaluated after delivery (mean hours after delivery=52.36; SD=19.70) for depressive<br> and anxiety symptoms through the Edinburgh Postnatal Depression Scale and the State-Trait Anxiety Inventory.<br> Serum Interleukin-6 (IL-6), C-Reactive Protein (CRP) and diurnal salivary cortisol levels were measured on both<br> occasions, while diurnal salivary alpha amylase (sAA) levels were assessed in late pregnancy.<br> Results: Using Hierarchical Linear Models, higher depressive symptoms were found to be associated with higher<br> IL-6 levels, lower morning cortisol levels and a flatter cortisol diurnal slope during pregnancy, while adjusting<br> for potential confounders. No significant associations were found after delivery or with change in biomarker<br> levels from pre- to post-partum. Furthermore, preliminary evidence of a positive association between inflammation<br> and stress markers in women with higher antenatal depressive symptoms was found.<br> Limitations: The sample was relatively small and highly selected, thus limiting generalizability of the findings.<br> Conclusions: Results emphasize the need for an integrated multi-systems approach to the understanding of the<br> biological underpinnings of perinatal depression and suggest that the stress-immune interactions represent a promising avenue for future endeavor