Rabia R. Chhangur

ORCHIDS: an Observational Randomized Controlled Trial on Childhood Differential Susceptibility

BackgroundA central tenet in developmental psychopathology is that childhood rearing experiences have a major impact on children’s development. Recently, candidate genes have been identified that may cause children to be differentially susceptible to these experiences (i.e., susceptibility genes). However, our understanding of the differential impact of parenting is limited at best. Specifically, more experimental research is needed. The ORCHIDS study will investigate gene-(gene-)environment interactions to obtain more insight into a) moderating effects of polymorphisms on the link between parenting and child behavior, and b) behavioral mechanisms that underlie these gene-(gene-)environment interactions in an experimental design.Methods/DesignThe ORCHIDS study is a randomized controlled trial, in which the environment will be manipulated with an intervention (i.e., Incredible Years parent training). In a screening, families with children aged 4–8 who show mild to (sub)clinical behavior problems will be targeted through community records via two Dutch regional healthcare organizations. Assessments in both the intervention and control condition will be conducted at baseline (i.e., pretest), after 6 months (i.e., posttest), and after 10 months (i.e., follow-up).DiscussionThis study protocol describes the design of a randomized controlled trial that investigates gene-(gene-)environment interactions in the development of child behavior. Two hypotheses will be tested. First, we expect that children in the intervention condition who carry one or more susceptibility genes will show significantly lower levels of problem behavior and higher levels of prosocial behavior after their parent(s) received the Incredible Years training, compared to children without these genes, or children in the control group. Second, we expect that children carrying one or more susceptibility genes will show a heightened sensitivity to changes in parenting behaviors, and will manifest higher emotional synchronization in dyadic interchanges with their parents. This may lead to either more prosocial behavior or antisocial behavior depending on their parents’ behavior.Trial registrationDutch Trial Register (NTR3594)

Commentary Research on gene–environment interdependence: Honing the tools and examining the angles

The insightful overview by Sir Michael Rutter (this issue) on gene–environment interdependence comes about 10 years after the breakthrough Science publications on gene–environment interactions (G×E) involving the MAOA and 5-HTT genes by Caspi et al. (2002, 2003). Since then, a field of research has burgeoned that has produced replications as well as intriguing new evidence of gene–environment interdependence. At the same time, however, the field has witnessed a growing scepticism about the relevance of studying gene–environment interactions and has seen replication failures (see Duncan & Keller, 2011; Risch et al., 2009). Against this backdrop, we comment and elaborate on several of the key issues raised by Rutter, and suggest some directions for future research on G×E. Specifically, we discuss (1) replication issues; (2) the crucial role of experiments in understanding gene–environment interdependence; (3) current unknowns with regard to differential susceptibility; and (4) clinical and practical implications of G×E research.

Corrigendum to “Intervention Effectiveness of The Incredible Years: New Insights Into Sociodemographic and Intervention-Based Moderators” [Behavior Therapy 48 (2017) 1–18]

The authors regret that the effect sizes in the original manuscript are incorrect. The correct effect sizes, which are on average larger than reported in the original manuscript, are attached to this corrigendum (see corrected Table 4). The corrected effect sizes do not change the interpretation of our results in terms of the effectiveness of The Incredible Years program or the magnitude of the effects (i.e., whether they are small, medium or large). The authors would like to apologise for any inconvenience caused.