Maternal Anxiety and Depression From Pregnancy to Postpartum: Associations With Infants' Cortical Functional Connectivity at 1 Month

ABSTRACT

Maternal anxiety and depression have been associated with alterations in functional connectivity (FC) in infancy, a period in which rapid brain development and functional network organization have been linked to longer term socioemotional outcomes. Investigating maternal anxiety and depression within the same sample is important, given that they frequently co‐occur and may show distinct associations with infant brain development. A longitudinal approach is key to understanding whether and how changes in maternal mental health across the perinatal period relate to infant brain development. We examined associations of subclinical prenatal and postnatal maternal depression and anxiety, measured via questionnaires at 32 weeks of gestation and 1 month postpartum, with infants' FC at 1 month of age. Task‐free FC data were collected during natural sleep using High‐Density Diffuse Optical Tomography (HD‐DOT) in the home. No associations were observed between maternal anxiety symptoms and FC, and neither postnatal depression nor anxiety alone predicted infant FC. Lower maternal prenatal depression scores were associated with stronger FC in the infants' frontal network ( n  = 39). In contrast, greater increases in maternal depressive symptoms from the prenatal to postnatal periods were linked to increased frontal FC, particularly when mothers had higher prenatal depression levels ( n  = 28). Most symptom changes were small in magnitude and did not cross clinical thresholds, suggesting largely subclinical and transient mood shifts. We speculate that while early prenatal exposure may signal vulnerability in specific neural circuits, the subsequent increase in symptoms could trigger compensatory or accelerated development in the same networks. Replication with larger, more diverse, samples and longitudinal research is needed to determine whether these subtle early fluctuations in maternal symptoms are associated with longer‐term trajectories of infant brain development beyond the perinatal window.