Importance: Parenting interventions have been found to normalize cortisol regulation among high-risk children early in development; it is important to investigate the sustainability of these effects and their mechanisms, given the maladaptive outcomes associated with cortisol dysregulation.
Objective: To determine whether the Attachment and Biobehavioral Catch-up (ABC) intervention, implemented in infancy, predicts cortisol regulation in middle childhood via changes in early parental sensitivity.
Design: Double blind randomized clinical trial design; started January 2006, the follow-up for this project concluded March 2016.
Setting: Parents of children under age 2 referred from child protective services agencies in a large, mid-Atlantic city.
Participants: 103 parent-child dyads (45.6% female children) with histories of child protective services involvement, randomly assigned to receive ABC (n = 45) or a control intervention (n = 58); in infancy, the children's ages ranged from 1.60 to 25.30 months (M = 9.87 months); at the middle childhood follow-up, they ranged from 8.0 to 11.0 years old (M = 8.52 years).
Interventions: Both conditions included 10-week, in-home, manualized interventions. The experimental condition, ABC, has 3 primary targets for parents: increasing nurturance to child distress, increasing following the child's lead, and decreasing frightening behavior. The control intervention, Developmental Education for Families (DEF), is an adaptation of a program focused on enhancing cognitive and language development.
Main outcomes and measures: Parental sensitivity was coded from a semi-structured interaction task between the parent and child in early childhood. Middle childhood diurnal cortisol slopes were modeled by collecting salivary cortisol samples from children at wake-up and bedtime over the course of 3 consecutive days.
Results: ABC participation in infancy was associated with increased parental sensitivity post-intervention, β = 0.28, p = .004, and this increased sensitivity predicted steeper decline across the day in children's cortisol concentration in middle childhood, β = -.53, p = .002. The indirect effect of ABC on cortisol regulation via sensitivity was significant, β = -0.15, p = .038.
Conclusions and relevance: ABC has an indirect effect on middle childhood diurnal cortisol regulation via parental sensitivity; future research should seek to determine how this enhanced neurobiological regulation relates to children's behavioral, socioemotional, and psychological outcomes.
Trial registration: clinicaltrials.gov Identifier: NCT02093052.
Keywords: Cortisol; Early adversity; Intervention; Parental sensitivity.
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