Genetic Moderation of Intervention Efficacy: Dopaminergic Genes, The Incredible Years, and Externalizing Behavior in Children

Abstract

This study investigated whether children scoring higher on a polygenic plasticity index based on five dopaminergic genes (DRD4, DRD2, DAT1, MAOA, and COMT) benefited the most from the Incredible Years (IY) parent program. Data were used from a randomized controlled trial including 341 Dutch families with 4- to 8-year-old children (55.7% boys) showing moderate to high levels of problem behavior. IY proved to be most effective in decreasing parent-reported (but not observed) externalizing behavior in boys (but not girls) carrying more rather than fewer dopaminergic plasticity alleles; this Gene × Intervention effect was most pronounced in the case of boys whose parents' manifested the most positive change in parenting in response to the intervention. These results proved robust across a variety of sampling specifications (e.g., intention to treat, ethnicity).

A biopsychosocial approach to processes and pathways in the development of overweight and obesity in childhood: Insights from developmental theory and research

“…Differential susceptibility to environmental influences has been prominent in research and theory in developmental science . This means that developmental outcomes arise from parenting in relation to individual differences in the propensity or vulnerability for poor outcomes such as adjustment difficulties: If children with a higher biological or genetic vulnerability experience a harsh or negative psychosocial parenting environment, adjustment difficulties are more likely . In recognition of the central of role of biologically based individual susceptibility, genetic, biological, and/or temperament indicators are routinely included in longitudinal child development research that includes psychosocial influences …”

“…In developmental science, research on behavioral genetics is extensive through twin studies, adoption studies, molecular genetics, and increasingly genome-wide association studies. 99,[102][103][104][105][106] Genetic contributions have been widely recognized and examined in relation to many areas of development, including adjustment problems such as conduct disorders, antisocial behavior, and externalizing behaviour. 50,95,104,107 Scholarship on children's eating and weight has also examined genetic contributions.…”

“…99,[227][228][229] This means that developmental outcomes arise from parenting in relation to individual differences in the propensity or vulnerability for poor outcomes such as adjustment difficulties: If children with a higher biological or genetic vulnerability experience a harsh or negative psychosocial parenting environment, adjustment difficulties are more likely. 103,229 In recognition of the central of role of biologically based individual susceptibility, genetic, biological, and/or temperament indicators are routinely included in longitudinal child development research that includes psychosocial influences. 50,107,146,[230][231][232][233][234] As outlined in the section on genetic influences, Wardle 11,116,117 proposed a role for behavioral susceptibility to OW/OB that is often expressed in terms of a genetic predisposition.…”

Current and Future Perspectives on Children’s Genetic- and Endophenotype-Based Differential Susceptibility to Parenting

“…In response, several recent studies have used cumulative polygenetic indices (e.g., Belsky and Beaver 2011;Chhangur et al 2017) or examined specific haplotypes (e.g., Li et al 2016). A polygenetic index integrates contributions of separate multiple common genetic variants, typically of small magnitude, predicting a specified outcome.…”

“…One way to overcome this is to (over)sample families that by default display behavior that is considered a "for worse" condition. If families, for example, adopt harsh parenting techniques, especially in the light of stressful tasks, then the unmanipulated control condition can function as a "for worse" condition, eliminating the need to experimentally evoke this condition (Chhangur and Weeland et al 2017). Even though it needs to be considered that intervention effects for at-risk or clinical family settings may merely produce a "less aversive" rather than a "for better" optimally functioning parenting environment, this design represents a good option to circumvent ethical issues associated with inducing negative parenting.…”