Background Long-standing theory suggests that quality of the mother's (or primary caregiver's) interaction with a child is a key determinant of the child's subsequent resilience or vulnerability and has implications for health in adulthood. However, there is a dearth of longitudinal data with both objective assessments of nurturing behaviour during infancy and sustained follow-up ascertaining the quality of adult functioning.

Methods We used data from the Providence, Rhode Island birth cohort of the National Collaborative Perinatal Project (mean age 34 at follow-up, final N=482) to conduct a prospective study of the association between objectively measured affective quality of the mother–infant interaction and adult mental health. Infant–mother interaction quality was rated by an observer when infants were 8 months old, and adult emotional functioning was assessed from the Symptom Checklist-90, capturing both specific and general types of distress.

Results High levels of maternal affection at 8 months were associated with significantly lower levels of distress in adult offspring (1/2 standard deviation; b=−4.76, se=1.7, p<0.01). The strongest association was with the anxiety subscale. Mother's affection did not seem to be on the pathway between lower parental SES and offspring distress.

Conclusion These findings suggest that early nurturing and warmth have long-lasting positive effects on mental health well into adulthood.