Neural reactivity to infant faces and trait mindfulness as prospective predictors of postpartum depressive symptoms

Postpartum depression (PPD) impacts the health of both mothers and their offspring, underscoring the importance of early identification of risk factors for PPD. While both low-trait mindfulness and blunted neural processing to emotional stimuli (indexed by the late positive potential; LPP) have been separately associated with depression, previous work has highlighted an inverse relationship between trait mindfulness and neural emotional processing. Thus, it remains unclear how facets of trait mindfulness and neural emotional processing interact as risk factors for PPD. During the second trimester, pregnant women (n = 117) completed the Five Facet Mindfulness Questionnaire, the Inventory of Depression and Anxiety Symptoms (IDAS), and an infant face matching task while continuous electroencephalography was recorded. At 9 weeks postpartum, participants' PPD symptoms were reassessed with the IDAS. A series of hierarchical linear regression models revealed that acting with awareness, a trait mindfulness facet, and LPP to happy infant faces interacted to predict PPD symptoms (β = .217, p = .014, 95% CI [.045, .390]) after adjusting for depression levels in mid-pregnancy, such that low acting with awareness was associated with greater PPD symptoms when LPP to happy infant faces was 1 standard deviation below (β = -.548, SE = .150 , p < .001) and at the mean (β = -.309, SE = .106, p = .004). Findings suggest that an enhanced LPP to positively valenced stimuli may be protective against postpartum depression for those with low-trait mindfulness.