Differences in interactional behaviour in postpartum depression with and without pre-existing mental disorder

Mothers with postpartum depression (PPD) show impaired affects and behaviour patterns in the mother-child interaction, which affects an infant's emotional and cognitive development and the maternal course of disease. However, impairment of the mother-child relationship does not occur in every case of PPD.

The aim of this exploratory-descriptive video-based study was to investigate the possible associations between mother-child interactions and aspects of maternal biography and clinical history, with a focus on pre-existing mental disorder.

Sixty-two mother-child dyads (31 mothers with PPD and pre-existing mental disorders and 31 mothers with PPD but no further mental disorder) hospitalized at the mother and baby unit (MBU) of the LWL-Hospital Herten were included in this study. The Marcé Clinical Checklist and the "Mannheimer Beurteilungsskala zur Erfassung der Mutter-Kind-Interaktion im Säuglingsalter" (MBS-MKI-S) were used to explore sociodemographic and clinical parameters, and video-based interaction behaviour was examined.

Mother-infant interaction behaviour showed a significant group difference on the MBS-MKI-S-Vm subscale (variability in maternal behaviour) before psychiatric treatment (exact Mann-Whitney U test: U = 555, p = 0.023), with higher scores in mothers with a pre-existing mental disorder. Furthermore, significant differences were shown on the MBS-MKI-S-RSm (maternal reactivity/sensitivity) (U = 259, p = 0.019) and MBS-MKI-S-Rc (child's reactivity) subscales at discharge (U = 251, p = 0.021). Among mothers with a pre-existing diagnosis, the MBS-MKI-S-Tm (maternal tenderness) and MBS-MKI-S-Rc (child's reactivity) subscales were significantly correlated after treatment.

Mothers with PPD and a pre-existing mental disorder displayed significantly more behavioural variability than mothers with only PPD. Maternal behaviour seems to influence the child's responsive behaviour; thus, mothers and their children can benefit from inpatient treatment at an MBU. Further investigations with larger samples should be conducted.