Efficacy of parent-infant psychotherapy with mothers with postpartum mental disorder: results from a randomized controlled trial

Postpartum maternal mental health problems affect the development of mother-child interaction and of children’s attachment security. Focus-based brief parent-infant psychotherapy (PIP-f) was developed to support parents ‘mentalize’ their child’s affective states and promote a healthy parent-child relationship and child development. Efficacy of PIP-f was evaluated against care-as-usual (CAU) in a randomized controlled trial within the SKKIPPI project. N = 120 mothers diagnosed with an ICD-10 psychopathological disorder and their infants under one year were randomly assigned to PIP-f (n = 57) or CAU (n = 63). Primary outcome was maternal sensitivity in mother-child interaction after 6 weeks of intervention. Secondary outcomes include maternal and child psychopathological symptoms, child development, parenting stress, emotional availability, parental reflective functioning and child attachment after 6 weeks and 12 months. PIP-f was not superior to CAU in maternal sensitivity (b = 0.129, 95%CI [-0.161, 0.418], p = 0.378) at post-intervention, nor in maternal symptoms (b =-0.702, [-2.603, 1.198], p = 0.463) or child symptoms of regulatory disorder (b = 1.079, [-2.344, 4.502], p = 0.531). Attachment security assessed at 12 months did not differ between intervention groups (OR = 2.0, [0.64, 6.33], p = 0.226). Moderator analyses suggest that emotional availability and parental reflective functioning improve up to 12 months for more severe cases. Differences between PIP-f and CAU were smaller than expected, but PIP-f seemed to reduce symptoms of mental health problems. Some evidence exists that mothers with higher symptom burden benefit from PIP-f. High dropout rates and initially high emotional availability prevent generalizability. Trial registration: The trial was registered in the German Register for Clinical Studies (DRKS00016353) on January 16, 2019.