Abstract
Our overarching goal is to use new quantitative methods of capturing dynamic family interactions in early
childhood to identify key mechanisms underlying genetic and family intervention effects on substance use and
dependence (SUD) and mental health problems across adolescence. Results will demonstrate the value of
observational data analyzed with modern statistical approaches and inform the specification and refinement of
more potent and effective family-based interventions. Our approach builds on findings from large sample
genome wide association studies to inform formation of polygenic scores that represent genetic risk for SUD
and differential susceptibility to both risky and promotive family relationship dynamics. Developmental theory
on gene-environment interplay has highlighted the need to move away from focusing only on simple main
effect models, thus, we examine genetic association in the context of dynamic social interactions and random
assignment to a family-based intervention. Although SUD is heritable, it develops and progresses within
problematic family interactions and relationships. Family interventions are central to evidence-based
approaches to preventing and treating SUD, and direct observation of family interactions is the most rigorous
way of measuring family interactions. To date, the methodology and analysis of family interactions relevant to
intervening on youth SUD relies on broad aggregate scores. The most commonly used aggregate scores that
define the family interaction may simply miss pathogenic dynamics. With the advancement of statistical
analyses, there is unprecedented potential for accelerating observational family research over the coming
decade. The proposed study involves secondary analysis of existing videotaped observations of
racially/ethnically diverse children and families from the Early Steps Multisite Trial, applying dynamic structural
equation modeling and multivariate multilevel survival analysis to understand the effects of polygenic risk and
family intervention on downstream adolescent SUD and mental health problems. Early Step (N=731) is a
randomized trial with long-term follow-up (ages 2-19) of the effects of the family-centered intervention, Family
Check-Up, on reducing problem behaviors and SUD. The extensive data include videotaped observations of
children and parents across multiple contexts at ages 2, 3, 4, and 5. In addition, children were genotyped using
the contemporary Affymetrix Biobank Array. Such data provide a rare and unique opportunity to utilize new
statistical methods to understand early habitual family dynamics on SUD and mental health problems in
adolescence. These dynamic mechanisms provide key intervention targets for enhancing intervention
effectiveness and efficiency and lead to enhancing potency of family-based interventions.
