Drug-dependency during pregnancy affects the mother’s welfare and the child’s socioemotional development Marjo Flykt Ritva Belt Raija-Leena Punamäki Kuva 1 / 2 Background A sample of 51 pregnant drug-dependent mothers in outpatient interventions, and 50 controls were followed from pregnancy to school age. The aim was to examine the short- and long-term effects of maternal drug addiction on maternal and child wellbeing and child development. Methods This study analysed maternal mental health by questionnaires, video-assessed mother-infant interaction by the emotional availability method, and the children’s cognitive and socioemotional development by mother-reported questionnaires and psychological tests during the first year and at school age. Results Drug-dependent mothers showed more depression and anxiety than controls in early motherhood, and more severe substance use and mental health problems when the children were at school age. They had more interaction problems with the child at both times. At one year there were no group differences in child development, yet at school age the drug-exposed children had more attention and mental health problems. Conclusions Early interventions increased maternal emotional availability, and the development of the drug-exposed children proceeded well during the first year. Yet, the accumulation of multiple adversities formed a risk for school age development. Long-term follow-up and support targeting parenting and child development would thus be crucial.