Postnatal trajectories of maternal depressive symptoms: Postpartum antecedents and differences in toddler adjustment

Infants are uniquely vulnerable to maternal depression's noxious effects, but few longitudinal studies have tried to identify discrete postnatal trajectories of maternal depressive symptoms (MDS) beginning in infancy. This study extends evidence of heterogeneous change in postnatal MDS by examining their cross-contextual antecedents in infancy and their consequences for children's early behavior problems and language skills in late toddlerhood. A community sample of mother-child dyads (N = 235, 72% Caucasian) was assessed when children were 7, 15, and 33 months old. Mothers reported their socioeconomic status (SES), social support, marital relationship quality, family dysfunction, parenting stress, and infants' functional regulatory problems at 7 months postpartum, and children's internalizing and externalizing symptoms at 33 months. Children completed a receptive vocabulary assessment at 33 months in the lab. Latent class growth analysis identified three postnatal MDS trajectory classes that fit the data best: low-decreasing, moderate, and increasing. Psychosocial measures at seven months postpartum primarily predicted membership to these postnatal trajectory classes, which subsequently differed in children's internalizing, externalizing, and receptive vocabulary in late toddlerhood, controlling for family SES and functional regulatory problems in infancy. We discuss salient antecedents and consequences of postnatal depression for mothers and their offspring.