Children’s optimal social-emotional functioning is crucial for their adaptive behavior in different situations. Studies show that mother–infant interaction as well as maternal psychological distress pre- and postnatally associate with children’s negative emotional reactivity and with their social-emotional problems and competencies. Little is known about how these factors are associated with the aforementioned child outcomes when assessed simultaneously. We also lack knowledge about the possible moderating role of mother–infant interaction on the associations between maternal psychological distress and children’s negative emotional reactivity and social-emotional development.

The aim of this thesis was to investigate if 1) different types or timing of maternal pre- and postnatal psychological distress associate with different EA dimensions at 8 months of child’s age, 2) mother–infant interaction at 8 months associates with children’s negative emotional reactivity at 12, 24 and 30 months, and 3) mother– infant interaction at 8 months associates with children’s social-emotional problems and social-emotional competencies at 24 and 48 months. In addition, the aim was to study the possible moderating effects of mother–infant interaction on the associations between maternal psychological distress and children’s negative emotional reactivity and social-emotional development.

We found that maternal pre- and postnatal psychological distress was associated with mother–infant interaction. Furthermore, mother–infant interaction was associated with children’s negative emotional reactivity at 24 months and socialemotional problems and social-emotional competencies at 24 months. Finally, maternal postnatal, but not prenatal, psychological distress was associated with children’s negative emotional reactivity and social-emotional development.

Interventions to reduce problems in mother-infant interaction and maternal psychological distress are needed.