Biological Sensitivity to the Effects of Maternal Postpartum Depressive Symptoms on Children's Behavior Problems.

Resting respiratory sinus arrhythmia (RSA) may confer infant susceptibility to the postpartum environment. Among infants with higher RSA, there may be a positive relation between depressive symptoms across the first 6 months postpartum (PPD) and later behavior problems, and toddlers' dysregulation during mother-child interactions may partially explain the effects. Among a sample of low-income Mexican-American families, infant RSA (N = 322; 46% male) was assessed at 6 weeks of age; mothers (Mage  = 27.8, SD = 6.5) reported PPD symptoms every 3 weeks from 6 to 24 weeks and infant behavior problems at 36 months. Dysregulation was observed at 24 months. PPD was positively associated with behavior problems only among infants with lower RSA; however, this relation was not mediated by dysregulation.