Gabriel L. Schlomer

The conditioning of intervention effects on early adolescent alcohol use by maternal involvement and dopamine receptor D4 (DRD4) and serotonin transporter linked polymorphic region (5-HTTLPR) genetic variants.

Data drawn from the in-home subsample of the PROSPER intervention dissemination trial were used to investigate the moderation of intervention effects on underage alcohol use by maternal involvement and candidate genes. The primary gene examined was dopamine receptor D4 (DRD4). Variation in this gene and maternal involvement were hypothesized to moderate the influence of intervention status on alcohol use. The PROSPER data used were drawn from 28 communities randomly assigned to intervention or comparison conditions. Participating youth were assessed in five in-home interviews from sixth to ninth grades. A main effect of sixth-grade pretest maternal involvement on ninth-grade alcohol use was found. Neither intervention status nor DRD4 variation was unconditionally linked to ninth-grade drinking. However, moderation analyses revealed a significant three-way interaction among DRD4 status, maternal involvement, and intervention condition. Follow-up analyses revealed that prevention reduced drinking risk, but only for youth with at least one DRD4 seven-repeat allele who reported average or greater pretest levels of maternal involvement. To determine if this conditional pattern was limited to the DRD4 gene, we repeated analyses using the serotonin transporter linked polymorphic region site near the serotonin transporter gene. The results for this supplemental analysis revealed a significant three-way interaction similar but not identical to that found for DRD4.

PROSPER Intervention Effects on Adolescents’ Alcohol Misuse Vary by GABRA2 Genotype and Age

Preventive intervention effects on adolescent alcohol misuse may differ based on genotypes in gene-by-intervention (G x I) interactions, and these G x I interactions may vary as a function of age. The current study uses a novel statistical method, time-varying effect modeling (TVEM), to test an age-varying interaction between a single nucleotide polymorphism in the GABRA2 gene (rs279845) and a preventive intervention in predicting alcohol misuse in a longitudinal study of adolescents (ages 11–20). The preventive intervention was PROSPER, a community-based system for delivery of family and school programs selected from a menu of evidence-based interventions. TVEM results revealed a significant age-varying GABRA2 x intervention interaction from ages 12 to 18, with the peak effect size seen around age 13 (IRR = 0.50). The intervention significantly reduced alcohol misuse for adolescents with the GABRA2 TT genotype from ages 12.5 to 17 but did not reduce alcohol use for adolescents with the GABRA2 A allele at any age. Differences in intervention effects by GABRA2 genotype were most pronounced from ages 13 to 16—a period when drinking is associated with increased risk for alcohol use disorder. Our findings provide additional evidence that intervention effects on adolescent alcohol misuse may differ by genotype, and provide novel evidence that the interaction between GABRA2 and intervention effects on alcohol use may vary with age. Implications for interventions targeting adolescent alcohol misuse are discussed.

Impact of Fathers on Parental Monitoring of Daughters and Their Affiliation with Sexually Promiscuous Peers: A Genetically and Environmentally Controlled Sibling Study.

Girls who receive higher quality fathering engage in less risky sexual behavior (RSB) than their peers. Previous research identifies higher levels of parental monitoring/knowledge and reduced affiliation with deviant peers as potential mediators of this observed fathering effect. Although paternal investment theory posits a causal effect of fathers on daughters’ RSB, and on the intervening processes that mediate this effect, these relations could arise from genetic or environmental confounds. To address this limitation, we employed the genetically- and environmentally controlled differential sibling-exposure design (N = 101 sister pairs; ages 18–36), which retrospectively examines the effects of differential sibling exposure to family disruption/father absence and quality of fathering. Consistent with a causal explanation, differences between older and younger sisters in the effects of fathering quality on parental monitoring and peer RSB were greatest in biologically disrupted families when there was a large age gap between the sisters (thus maximizing differential exposure to fathers), with greater exposure within families to higher quality fathering increasing parental monitoring and reducing affiliation with sexually promiscuous peers. No such differences were found between older and younger sisters in families with little or no differential exposure to fathers (e.g., biologically intact families) or in response to differences in mothering quality. Taken together, these findings suggest that higher quality fathering may decrease daughters’ engagement in RSB by increasing the amount of parental monitoring that they receive and decreasing their affiliation with peers who promote RSB.

Secure Infant-Mother Attachment Buffers the Effect of Early-Life Stress on Age of Menarche

Prior research indicates that being reared in stressful environments is associated with earlier onset of menarche in girls. In this research, we examined (a) whether these effects are driven by exposure to certain dimensions of stress (harshness or unpredictability) during the first 5 years of life and (b) whether the negative effects of stress on the timing of menarche are buffered by secure infant-mother attachment. Results revealed that (a) exposure to greater harshness (but not unpredictability) during the first 5 years of life predicted earlier menarche and (b) secure infant-mother attachment buffered girls from this effect of harsh environments. By connecting attachment research to its evolutionary foundations, these results illuminate how environmental stressors and relationships early in life jointly affect pubertal timing.

An Adolescent Substance Prevention Model Blocks the Effect of CHRNA5 Genotype on Smoking During High School

INTRODUCTION Prevention intervention programs reduce substance use, including smoking, but not all individuals respond. We tested whether response to a substance use prevention/intervention program varies based upon a set of five markers (rs16969968, rs1948, rs578776, rs588765, and rs684513) within the cluster of nicotinic acetylcholine receptor subunit genes (CHRNA5/A3/B4). METHODS Participants (N = 424) were randomly assigned to either control condition, or a family-based intervention in grade 6 and a school-based drug preventive intervention in grade 7. Smoking in the past month was assessed in grades 9-12 using a four-point scale (0 = never smoked, 1 = smoked but not in last month, 2 = one or a few times, 3 = about once a week or more). RESULTS There was a main effect of both the intervention (b = -0.24, P < .05) and genotype at rs16969968 (b = 0.14, P < .05) on high school smoking. Using dummy coding to allow for nonlinear effects, individuals with the A/A genotype smoked more often than those with G/G (b = 0.33, P < .05). A genotype × intervention effect was found with reduced smoking among those with A/A and G/A genotypes to levels similar to those with the G/G genotype (G/G vs. A/A: b = -0.67, P < .05; A/G vs. A/A: b = -0.61, P < .05; G/G vs. A/G ns). Results were nonsignificant for the other four markers. CONCLUSIONS Preventive interventions can reduce the genetic risk for smoking from rs16969968.

Transactions Between Substance Use Intervention, the Oxytocin Receptor ( OXTR ) Gene, and Peer Substance Use Predicting Youth Alcohol Use

This study investigated the oxytocin receptor (OXTR) gene’s moderation of associations between exposure to a substance misuse intervention, average peer substance use, and adolescents’ own alcohol use during the 9th-grade. OXTR genetic risk was measured using five single nucleotide polymorphisms (SNPs), and peer substance use was based on youths’ nominated closest friends’ own reports of alcohol, cigarette, and marijuana use, based on data from the PROSPER project. Regression models revealed several findings. First, low OXTR risk was linked to affiliating with friends who reported less substance use in the intervention condition but not the control condition. Second, affiliating with high substance-using friends predicted youth alcohol risk regardless of OXTR risk or intervention condition. Third, although high OXTR risk youth in the intervention condition who associated with low substance-using friends reported somewhat higher alcohol use than comparable youth in the control group, the absolute level of alcohol use among these youth was still among the lowest in the sample.

Deployment and family functioning: A literature review of US operations in Afghanistan and Iraq

The conflicts in Afghanistan and Iraq have led to historically high rates of military deployment for the United States. The increased deployment tempo of the current conflicts necessitates a closer look at the literature on the impact of deployment on families specific to Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). In this article, we review the qualitative and quantitative literature on the impact of OEF and OIF deployment on families. The review included 38 articles organized into four major areas: (1) Family Changes and Transitions, (2) Child Maltreatment, (3) Spouse Stress and Mental Health, and (4) Marital Relationship Quality. Results of this review are discussed in terms of the need for additional research on individual differences between families and greater emphasis on how deployment impacts the well-being of spouses. We conclude with a discussion of limitations.

The Implications of Genetics for Prevention and Intervention Programming

With recent advances in high-throughput technology, genetic and other biological data have been increasingly incorporated in social science research, including prevention/intervention studies. Understanding the role genetics play in complex behaviors commonly evaluated in prevention/intervention research may have important implications for designing prevention programing, determining who receives certain prevention programs, and understanding individual differences in programming effectiveness (see Jaffee & Price, 2007; Moffitt, Caspi, & Rutter, 2006). This special issue, Incorporating Genetics in Prevention Science: Considering Methodology and Implications, seeks to advance work in this area by presenting empirical research and methodological reviews that examine the role genetics has in behavioral research. This special issue highlights the strengths, challenges, and methodological approaches that can be used to incorporate genetic and other biological data (e.g., epigenetic markers) into prevention science. The papers in this special issue cover several overarching themes that have emerged as critical for adequately incorporating genetics into prevention and other behavioral research, including gene-by-intervention (Gxl) studies. The collection of papers reflect examples, suggestions, opportunities, and pitfalls (and how to avoid them) when incorporating genetics or other biological data into prevention research. Below, we highlight some of the themes and strengths of Gxl research as reflected in the set of studies included in this special issue.

Associations between alcohol dehydrogenase genes and alcohol use across early and middle adolescence: Moderation × Preventive intervention

Data from the in-school sample of the PROSPER preventive intervention dissemination trial were used to investigate associations between alcohol dehydrogenase genes and alcohol use across adolescence, and whether substance misuse interventions in the 6th and 7th grades (targeting parenting, family functioning, social norms, youth decision making, and peer group affiliations) modified associations between these genes and adolescent use. Primary analyses were run on a sample of 1,885 individuals and included three steps. First, we estimated unconditional growth curve models with separate slopes for alcohol use from 6th to 9th grade and from 9th to 12th grade, as well as the intercept at Grade 9. Second, we used intervention condition and three alcohol dehydrogenase genes, 1B (ADH1B), 1C (ADH1C), and 4 (ADH4) to predict variance in slopes and intercept. Third, we examined whether genetic influences on model slopes and intercepts were moderated by intervention condition. The results indicated that the increase in alcohol use was greater in early adolescence than in middle adolescence; two of the genes, ADH1B and ADH1C, significantly predicted early adolescent slope and Grade 9 intercept, and associations between ADH1C and both early adolescent slope and intercept were significantly different across control and intervention conditions.

Decomposing environmental unpredictability in forecasting adolescent and young adult development: A two-sample study

To illuminate which features of an unpredictable environment early in life best forecast adolescent and adult functioning, data from two longitudinal studies were examined. After decomposing a composite unpredictability construct found to predict later development, results of both studies revealed that paternal transitions predicted outcomes more consistently and strongly than did residential or occupational changes across the first 5 years of a childs life. These results derive from analyses of the NICHD Study of Early Child Care and Youth Development, which included diverse families from 10 different sites in the United States, and from the Minnesota Longitudinal Study of Risk and Adaptation, whose participants came from one site, were disproportionately economically disadvantaged, and were enrolled 15 years earlier than the NICHD Study sample. The finding that results from both studies are consistent with evolutionary, life history thinking regarding the importance of males in childrens lives makes this general, cross-study replication noteworthy.