Background: Postpartum depression (PPD) is known to have important negative effects on mother, infant and mother-child relationship.
Methods: We present a case-control study of 35 mothers and their 18-month-old infants. These mothers suffered from postpartum depressive symptoms (PDS) when the infants were three months old, as rated with the Edinburgh Postnatal Depression Scale (EPDS, Cox 1987). A control group of 35 mothers without postpartum depressive symptoms (NPDS) with their 18-month-old infants was also evaluated. The infants were assessed using the Infant Behavior Record of the Bayley Scales of Infant Development, the Strange Situation and an object concept task.
Results: 15 months later, the PDS mothers were less affectionate and more anxious than the NPDS mothers. The PDS dyads demonstrated less verbal interaction and less playing interaction. 18-month-old infants of PDS mothers performed less well on object concept tasks, and were more often insecurely attached to their mothers. Only some results were linked to the mothers' depressive state (D-mothers) diagnosed at 18 months (e. g. responsiveness to persons).
Conclusions: The important negative effects observed at 18 months on mother and infant of maternal PDS at 3 months confirm the need for early identification and therapeutic or preventive interventions.