Association between maternal postnatal depressive symptoms and infants' communication skills: A longitudinal study

Postnatal depression (PND) is associated with adverse effects on a broad range of child outcomes, including language problems. The current study aimed to investigate if the time of exposure to maternal PND symptoms measured with the Edinburgh Postnatal Depression Scale (EPDS) at 6 weeks, 4 months and 6 months postpartum were related to the infants' communication skills measured with the Ages and Stages Questionnaires (ASQ) at 12 and 24 months. Secondly, to study to what extent the number of exposures to high level of PND symptoms (i.e., EPDS score≥10) might be associated with level of communication skills later (at 12 and 24 months), and last, to determine to what extent maternal PND symptoms at 6 weeks were related to changes in the developmental course of communication skills from 4 to 24 months. 1555 children and their mothers participate in the study. Regression analyses indicated that PND at 4 months were associated with lower levels of communicative skills at 12 (coefficient -0.37, 95% CI -0.63 to -0.12, p=0.004) and 24 months (coefficient -0.34, CI -0.56 to -0.13, p=0.002). Infants of mothers with an EPDS sum score≥10 obtained at a minimum of two time points, had significantly worse communicative skills at 12 months than infants of mothers with no indication of PND (difference -6.12, CI -11.14 to -1.09, p=0.017). No such significant relations were found at 24 months. However, linear mixed effects analysis showed that mothers' depressive symptoms at 6 weeks were not significantly related to changes in infant communication scores from age 4 to 24 months. These findings suggest that symptoms of maternal PND symptoms should be taken into account for communication development in infancy.