A successful parent–child interaction is essential for the adequate social, emotional, and cognitive development of an infant. Psychiatric disorders in the postpartum period can lead to disturbance of this interaction. An increased risk of reduced parent–child bonding and a changed mother–infant interaction was shown in postpartum depression. Early and comprehensive multimodal therapy of psychiatric symptoms in the mother, interaction-focussed therapy approaches, and involvement of the family and social network are essential in this context. The included case report is intended to illustrate the complexity and specific challenges in the treatment of mothers with psychiatric disorders.