Experimental Support for a Family Systems Approach to Child Development: Multiple Mediators of Intervention Effects across the Transition to Parenthood.

The analysis of mediational pathways in intervention trials represents the strongest method available for establishing causal links between developmental factors and child outcomes. This paper assesses mediation of the effects of Family Foundations on toddler emotional and behavioral adjustment through parent-related factors (parental stress, parental depression, coparenting negativity, parenting negativity). Data come from the second trial of Family Foundations, a universal preventive program delivered at the transition to parenthood. Mediating mechanisms were assessed at 10 months postpartum (posttest); and child outcomes were measured at two years post-birth. Results indicated that putative mediators did not significantly mediate outcomes when considered one at a time; but the set of mediators collectively mediated child outcomes. Implications for assessing mediation in future trials are discussed.