The biological underpinnings of perinatal depressive symptoms: A multisystems approach

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