Disturbances in early parenting of depressed mothers and cortisol secretion in offspring: a preliminary study.

BACKGROUND Disturbances in cortisol secretion are associated with risk for psychiatric disorder, including depression. Animal research indicates that early care experiences influence hypothalamic-pituitary-adrenal (HPA) axis functioning in offspring. Similar effects are suggested in human development, but evidence of longitudinal associations between observed early parenting and offspring cortisol secretion is extremely limited. We studied associations between parenting disturbances occurring in the context of maternal postnatal depression (PND), and elevations in morning cortisol secretion in the adolescent offspring of PND mothers. METHODS We observed maternal parenting behaviour on four occasions through the first year and at five-year follow-up in postnatally depressed (n=29) and well (n=20) mothers. Observations were coded for maternal sensitivity and withdrawn behaviour. Basal offspring salivary cortisol secretion was measured at 13-years, using collections over 10-days. RESULTS Postnatal, but not five-year, maternal withdrawal predicted elevated mean and maximum morning cortisol secretion in 13-year-old offspring. There were no significant associations between maternal sensitivity and offspring cortisol secretion. LIMITATIONS The sample size was relatively small, and effects tended to be reduced to trend level when covariates were considered. The correlational nature of the study (albeit longitudinal) limits conclusions regarding causality. CONCLUSIONS Individual differences in early maternal parenting behaviour may influence offspring cortisol secretion, and thereby risk for depression. Parenting interventions that facilitate active maternal engagement with the infant may be indicated for high-risk populations.