First 1,000 days: enough for mothers but not for children? Long-term outcomes of an early intervention on maternal depressed mood and child cognitive development: follow-up of a randomised controlled trial

Background Child cognitive development is often compromised in contexts of poverty and adversity, and these deficits tend to endure and affect the child across the life course. In the conditions of poverty and violence that characterise many low- and middle-income countries (LMIC), the capacity of parents to provide the kind of care that promotes good child development may be severely compromised, especially where caregivers suffer from depression. One avenue of early intervention focuses on the quality of the early mother-infant relationship. The aim of this study was to examine the long-term impact of an early intervention to improve the mother-infant relationship quality on child cognitive outcomes at 13 years of age. We also estimated the current costs to replicate the intervention. Method We re-recruited 333 children from an early childhood maternal-infant attachment intervention, 'Thula Sana', when the children were 13 years old, to assess whether there were impacts of the intervention on child cognitive outcomes, and maternal mood. We used the Kaufman Assessment Battery to assess the child cognitive development and the Patient Health Questionnaire (PHQ-9) and the Self-Reporting Questionnaire (SRQ-20) to assess maternal mental health. Results Effect estimates indicated a pattern of null findings for the impact of the intervention on child cognitive development. However, the intervention had an effect on caregiver psychological distress (PHQ-9, ES = -0.17 [CI: -1.95, 0.05] and SRQ-20, ES = -0.30 [CI: -2.41, -0.19]), but not anxiety. The annual cost per mother-child pair to replicate the Thula Sana intervention in 2019 was estimated at ZAR13,365 ($780). Conclusion In a socio-economically deprived peri-urban settlement in South Africa, a home visiting intervention, delivered by community workers to mothers in pregnancy and the first six postpartum months, had no overall effect on child cognitive development at 13 years of age. However, those caregivers who were part of the original intervention showed lasting improvements in depressed mood. Despite the fact that there was no intervention effect on long-term child outcomes, the improvements in maternal mood are important.