Findings from the Gprosper Project

Studies incorporating molecular genetic data are becoming more frequent in psychosocial science, including prevention/intervention research. As part of a poster forum, we first describe the PROSPER project – a substance use prevention/intervention that includes twenty-eight middle schools in Iowa and Pennsylvania that were randomized into 14 control and 14 intervention communities –  and its genetic extension gPROSPER. We then present three sets of findings from gPROSPER based on a subset of data on adolescents and their families who also provided DNA (N = 594). 

First we report on alcohol use among 9^th grade adolescents. Prior research has shown a consistent link between maternal involvement (MI) and lower adolescent alcohol use. However, the way in which MI, as well as intervention experiences, influence adolescent alcohol use may be conditioned by genetics. Results indicate MI was linked to lower alcohol use only for adolescents who carry a DRD4 7-repeat allele, and only if they were in the intervention condition. analysis of 5-HTTLPR short versus long genotype showed the intervention was effective at reducing risk for higher alcohol consumption due to low MI, but only for adolescents with the short allele.

The second set of findings focuses on developmental change in adolescent aggression. Research indicates that parental hostility (PH) is a potent predictor of aggression, although few studies of PH have examined temporal change in aggression. We leveraged gPROSPER’s longitudinal data to examine developmental change in adolescent aggression and the coactive influence of maternal hostility, intervention status, and DRD4 genotype.  Results showed the intervention reduced the influence of maternal hostility on the development of aggressive behavior problems, and this effect was most pronounced among adolescents with a 7-repeat allele.

Finally, we examined the influence of the intervention on high school cigarette smoking in conjunction with the single-nucleotide polymorphism (SNP) rs16969968. As a part of the well-studied CHRNA5/A3/B4 gene cluster, this SNP has repeatedly been implicated in smoking risk. Regression models confirmed our hypotheses that (1) the ‘A’ allele of rs16969968 is associated with smoking during high school and (2) the intervention reduced this genetic risk association.

The common theme of these studies, and the potential benefit of such research to prevention science, is a focus on individual differences in for whom interventions work better or less so. These inquiries can shed light on additional approaches to intervention that can increase the number affected by an intervention.