Grounding alcohol simulation models in empirical and theoretical alcohol research: a model for a Northern Plains population in the United States.

The growing number of systems science simulation models for alcohol use (AU) are often disconnected from AU models within empirical and theoretical alcohol research. As AU prevention/intervention efforts are typically grounded in alcohol research, this disconnect may reduce policy testing results, impact, and implementation. We developed a simulation model guided by AU research (accounting for the multiple AU stages defined by AU behavior and risk for harm and diverse transitions between stages). Simulated projections were compared to historical data to evaluate model accuracy and potential policy leverage points for prevention and intervention at risky drinking (RD) and alcohol use disorder (AUD) stages. Results indicated prevention provided the greatest RD and AUD reduction; however, focusing exclusively on AUD prevention may not be effective for long-term change, given the continued increase in RD. This study makes a case for the strength and importance of aligning subject-based research with systems science simulation models.

How Funding Policy Maintains Structural Inequity Within Indigenous Community-Based Organizations.

Despite efforts to increase investment in Indigenous health and well-being in the United States, disparities remain. The way in which health-promoting organizations are funded is one key mechanism driving the systemic, long-term health disparities experienced by Indigenous people in the US. Using Indigenous-led community-based organizations (ICBOs) that provide psychosocial care as a case study, we highlight multiple ways in which policies that regulate the external funding that ICBOs depend on must change to promote equity and allow the organizations to flourish and address unmet psychosocial needs for Indigenous community members. We use a system dynamics approach to discuss how "capability traps" arise from a misfit between external funding regulations and organizations' needs for sustainability and effective care provision. We provide suggestions for reforming funding policies that focus on improving ICBO sustainability.

Rates and Correlates of Intimate Partner Abuse Among Indigenous Women Caregivers.

Intimate partner abuse (IPA) is a public health crisis that disproportionately impacts indigenous women. We know little about rates and correlates of IPA victimization (IPAV) and abuse directed at one's partner (ADP) among indigenous women caregivers (people who take care of children). The purpose of the current study was to address this critical gap in the literature. Participants were 44 indigenous women caregivers in the United States in a current relationship who completed a survey. Most women reported IPAV and ADP experiences in the past 6 months, and IPAV and ADP abuse directed at partner were positively associated. Further, IPAV was positively associated with adverse childhood experiences (ACEs), participants' engagement in harsh parenting, and depressive symptoms. IPAV was negatively associated with age, income, indigenous cultural identity, and social support. ADP was positively associated with ACEs, harsh parenting, and depressive symptoms. ADP was negatively associated with age and income. ADP was not associated with indigenous cultural identity and social support. These data suggest the urgency with which efforts are needed to prevent and respond to IPA among indigenous women caregivers, especially those who are younger and of lower income, and that culturally grounded initiatives that seek to build social support may be especially impactful.

Perinatal Outcomes during versus Prior to the COVID-19 Pandemic and the Role of Maternal Depression and Perceived Stress: A Report from the ECHO Program.

OBJECTIVE: We sought to evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on perinatal outcomes while accounting for maternal depression or perceived stress and to describe COVID-specific stressors, including changes in prenatal care, across specific time periods of the pandemic. STUDY DESIGN: Data of dyads from 41 cohorts from the National Institutes of Health Environmental influences on Child Health Outcomes Program (N = 2,983) were used to compare birth outcomes before and during the pandemic (n = 2,355), and a partially overlapping sample (n = 1,490) responded to a COVID-19 questionnaire. Psychosocial stress was defined using prenatal screening for depression and perceived stress. Propensity-score matching and general estimating equations with robust variance estimation were used to estimate the pandemic's effect on birth outcomes. RESULTS: Symptoms of depression and perceived stress during pregnancy were similar prior to and during the pandemic, with nearly 40% of participants reporting mild to severe stress, and 24% reporting mild depression to severe depression. Gestations were shorter during the pandemic (B = - 0.33 weeks, p = 0.025), and depression was significantly associated with shortened gestation (B = - 0.02 weeks, p = 0.015) after adjustment. Birth weights were similar (B = - 28.14 g, p = 0.568), but infants born during the pandemic had slightly larger birth weights for gestational age at delivery than those born before the pandemic (B = 0.15 z-score units, p = 0.041). More women who gave birth early in the pandemic reported being moderately or extremely distressed about changes to their prenatal care and delivery (45%) compared with those who delivered later in the pandemic. A majority (72%) reported somewhat to extremely negative views of the impact of COVID-19 on their life. CONCLUSION: In this national cohort, we detected no effect of COVID-19 on prenatal depression or perceived stress. However, experiencing the COVID-19 pandemic in pregnancy was associated with decreases in gestational age at birth, as well as distress about changes in prenatal care early in the pandemic. KEY POINTS: · COVID-19 was associated with shortened gestations.. · Depression was associated with shortened gestations.. · However, stress during the pandemic remained unchanged.. · Most women reported negative impacts of the pandemic..

Community-based system dynamics modelling of stigmatized public health issues: Increasing diverse representation of individuals with personal experiences.

Utility of community-based system dynamics (CBSD) models on stigmatized public health issues and health disparities depends upon how representative the model is to real-world experience within the community. "Personal experience" participants (PEP), especially from marginalized groups, are essential model contributors, but are often underrepresented in modeling groups due to multiple barriers. This study details a method to increase PEP representation for models on stigmatized issues. We use a case study from a CBSD project on health disparities within the association between alcohol misuse (AM) and intimate partner violence (IPV) for Northern Plains Indigenous women. Short group model building sessions were held at three community organizations providing relevant resources. Each model contributed unique system components, and there were few similarities between models. A consolidated model provided a rich picture of the complex system. Adding brief PEP-based group modeling sessions can enhance PEP representation in model development for stigmatized public health issues.

Effect of individual or comorbid antenatal depression and anxiety on birth outcomes and moderation by maternal traumatic experiences and resilience.

Background: Although antenatal depression and anxiety (e.g., negative antenatal mental health; NAMH) are individually associated with preterm birth (PTB) and infant neurological impairment, few studies account for comorbidity. Understanding how NAMH impacts PTB and infant neurological functioning by either singular (depression or anxiety) or comorbid status, as well as the way in which these effects can be moderated by additional risk or protective factors (traumatic experiences and trait resiliency) can contribute further understanding of NAMH effects on birth outcomes. Methods: The sample included 3042 mother-infant dyads from U.S. and South Africa cohorts of the Safe Passage Study (N = 3042). A four-category NAMH variable was created to categorize depression-only, anxiety-only, comorbid, or no NAMH statuses. Results: There were no NAMH main effects on PTB, however, anxiety-only and comorbid NAMH increased odds of PTB for mothers with higher rates of traumatic life experiences. Anxiety-only and comorbid NAMH were associated with increased odds of newborn neurological impairment, and the effect of comorbid NAMH was stronger for mothers with higher rates of traumatic experiences. Resiliency decreased odds of neurological impairment for mothers who reported depression-only or anxiety-only NAMH. Limitations: Limitations included potential artefacts of two cohorts that differed in rates of almost all variables, a single time point for measuring NAMH, and lack of pregnancy-specific NAMH measures. Conclusions: Especially when compared to mothers with no NAMH, comorbidity or singular-condition NAMH statuses associate with negative birth outcomes in nuanced ways, especially when considering additional contexts that may foster or protect against NAMH.

Equitable Policies Need Equitable Practices: Alcohol- and Substance-Exposed Pregnancy as a Case Study.

There is clear need for more effective public health policies. Coupled with calls for more effective policies, increasing demand to address public health disparities experienced by systemically marginalized and historically oppressed groups emphasizes the long-standing need for policies that improve public health equity. Such need is highlighted when examining public health issues such as alcohol- and substance-exposed pregnancy (ASEP): Current policies are ineffective at reducing ASEP, and marginalized groups experience disproportionately lower benefits and higher negative consequences as a result of such policies. Powerful strategies to develop more effective policies that can account for the complexity of such issues, such as systems science methods (SSMs), are becoming popular. However, current best practices for such methods often do not emphasize the additional efforts that will be required to develop equitable, not just effective policies. Using ASEP as an example of a crucial complex issue requiring new policy, we suggest additional steps to include in SSM projects for developing more effective policies that will also help stakeholders determine high-equity policies to reduce health disparities. These steps include modeling structural differences experienced by marginalized groups via systemic racism and oppression, incorporating existing cultural and community sources of strength and resilience as key areas for policy development, and evaluating the sustainability of policies as a dimension of efficacy. We also discuss using community-based participatory approaches as a framework for all SSM processes to ensure that policy development itself is grounded in equitable shared decision-making for marginalized individuals.

Where there's a will, there's a way? Strategies to reduce or abstain from alcohol use developed by Northern Plains American Indian women participating in a brief, alcohol-exposed pregnancy preconceptual intervention.

BACKGROUND: Alcohol-exposed pregnancy (AEP) is an ongoing concern, especially within low-resource, high-risk areas such as rural American Indian/Alaska Native (AIAN) communities. Brief, preconceptual AEP-reduction interventions are popular in such areas but have a small impact on alcohol use. Developing a strategic alcohol change plan is a key program component; however, there is little research on strategy selection, especially within contexts that positively or negatively impact selection (e.g., cultural strengths, trauma, collective efficacy within AIAN communities). This study qualitatively analyzed strategies chosen to reduce alcohol use by AIAN women participating in a culturally tailored, brief, preconceptual AEP-reduction intervention. METHODS: One hundred-sixty Northern Plains AIAN women who were participating in a brief AEP-reduction program developed a plan to accomplish an alcohol reduction/abstention goal at the first and last program sessions. The plan included choosing 1 or more strategies to (1) achieve the goal, (2) mitigate barriers, and (3) use cultural strengths. Qualitative analysis of the data involved thematic open and structured coding of all 3 strategies separately. We also examined how many different themes (different individual strategies) participants reported for each strategy component. RESULTS: Most participants reported only 1 strategy (theme) for each of the 3 components. Common goal-achieving and barrier-mitigation strategies included positive social supports and avoiding negative or alcohol-involved social environments. Other strategies involved circular logic (e.g., the strategy to reduce drinking was to drink less). Both traditional and western cultural strengths were reported as important resources, although many participants had no cultural resource strategy. CONCLUSION: Programs aimed at reducing AEPs may need to provide participants more support to develop strong strategies to reduce alcohol use when implemented within areas with high levels of trauma and contextual barriers that can impact strategy selection. Such support could include ways to improve health on both interpersonal and community levels.

Punch-Drunk or Drunken Boxing? The Etiology of Alcohol-Related Physical Violence through Adolescence and Young Adulthood.

BACKGROUND: Alcohol-related physical violence (ARPV) can be a causal consequence of alcohol consumption, but only for specific individuals (e.g., those predisposed to violence). Studies have not accounted for the shared etiology explaining comorbidity between alcohol use and violent behavior as a potential third-variable explanation of ARPV. The current study examined genetically-informed associations between ARPV, heavy alcohol use (HAU) and overall physical violence (OPV) in adolescence and young adulthood, by testing two proposed theories of ARPV processes (HAU causes ARPV, causal relationships depend upon OPV) and how overarching shared covariance may account for these associations. METHODS: Using the twin and sibling subsample from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a series of biometric models tested hypotheses individually in adolescence and young adulthood. This included estimating bivariate Cholesky and direction-of-causality models, and trivariate Cholesky, independent pathway, and common pathway models. RESULTS: HAU had a causal effect on ARPV in adolescence and young adulthood. This effect was not moderated by OPV at either developmental stage. A shared etiology or common latent factor did not explain associations between ARPV, OPV, and HAU, even though ARPV strongly covaried independently with HAU and with OPV. Finally, OPV also had a causal effect on ARPV in adolescence, and in young adulthood for adolescent-onset drinkers. CONCLUSIONS: Causal theories of ARPV still hold when accounting for shared genetic and environmental variance. Further research on the exact role of violence (predispositions, environmental contexts) is required, as both phenotypes substantially (and separately) explain influences driving ARPV.Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1887244.

Dynamic change in the association of a cigarettes-per-day polygenic risk score across the numeric range of its corresponding phenotype over adolescence and young adulthood.

The association between cigarettes per day (CPD) and CPD-calibrated polygenic risk scores (CPD-PGS) is positive, however, the shape of the association is unknown. CPD measurement is inconsistent across studies and different measurement can lead to different results. The pattern shape may also patterns may change over time, given differences in genetic influence on smoking. This study examines the dynamic pattern between number of cigarettes smoked and PGS-CPD over adolescence and young adulthood. A time-varying effects model in which CPD was the continuous dynamic variable, was estimated for ever-smokers in a nationally representative study tracking partiicpants over adolescence and young adulthood. Participants were genotyped and a CPD-PGS score was created using results from a large genome-wide study meta-analysis. Results indicated that the association between CPD and CPD-PGS changed over CPD. Low CPD-PGS related to higher odds of not smoking or smoking very low CPD. A flat positive association at 5-12 CPD suggeted a "low risk" group. The association peaked around 20 CPD, indicating that a high-risk score applied best to those smoking approximately 1 pack of cigarettes per day. Age also moderated the effect of CPD-PGS at specific CPD rates, such that CPD-PGS was stronger at later ages and higher CPD. The association between CPD and CPD-PGS should not be assumed to be linear or static over age; there seem to be CPD-PGS thresholds corresponding to significant CPD risk, although the effect of CPD-PGS also varies over age. More care and attention to measurement can improve behavior genetic addiction science.

Stability in effects of different smoking-related polygenic risk scores over age and smoking phenotypes.

PURPOSE: Polygenic risk scores (PRSs) for smoking behavior largely fail to consider the demonstrated developmental change in genetic influence over age and stage of smoking behaviors. Additionally, few studies have examined how stage-specific smoking PRSs (e.g. for initiation vs. smoking heaviness) generalize to other stages of risk. The current study examines the stability of PRS effects over age, and how specifically calibrated PRSs associate with other smoking phenotypes. METHODS: 7228 participants were from the National Longitudinal Study of Adolescent to Adult Health, who had calculated PRSs for two smoking phenotypes, Centers for Disease Control and Prevention (CDC) smoking initiation status, and cigarettes per day (CPD). Four time-varying effects models estimated associations between both PRSs and four smoking phenotypes (CDC status, cigarettes/day on smoking days, any past-30 day smoking, and past-30 day daily smoking) over adolescence and young adulthood. FINDINGS: The time-varying effects models demonstrated that both PRSs significantly associated with all four phenotypes age. PRS effects were similar, in both odds ratios and the overlap of 95 % confidence intervals. There were increases in PRS associations with quantity of smoking over age, and a decrease in PRS effects over age for the CDC smoking status phenotype over early to late adolescence. CONCLUSIONS: Smoking PRSs can be robust predictors of smoking behavior over age. However, the lack of differentiation between specific PRSs and multiple smoking phenotypes, as well as the added contribution of both PRSs to explaining genetic variance, indicates a need to reconceptualize phenotypic measurement used to calibrate smoking PRSs.

Selection and Socialization Influences on Adolescent Alcohol Use: The Individual and Joint Contexts of Neighborhood Disadvantage and Population Density.

Background: Neighborhood disadvantage (ND) and population density (PD) are two community characteristics contextualizing friends' influence on adolescent alcohol use. However, these community characteristics are rarely examined for potential joint contributions, although it is possible that the way friends are selected or influence alcohol use are shaped by both ND and PD. In addition, prior studies examining ND or PD contexts on friend influence rarely discern between socialization and selection. Objectives: The current study examined how selection and socialization influences on adolescent alcohol use are shaped by unique and joint contexts of ND and PD. Methods: Adolescents from Waves I and II of the National Longitudinal Study of Adolescent and Adult Health (Add Health) were included in three models assessing friends' socialization of alcohol us initiation and binge drinking, and selection of drinking friends. ND and PD were tested for mediation and moderation individually and jointly. Results: Results indicated that socialization of drinking initiation was stronger in high ND contexts, and that continued binge drinking was stronger in low ND contexts. PD indirectly influenced socialization of initiation and binge drinking maintenance via a negative association with number of drinking friends. PD and ND jointly influenced the association between initial binge drinking and next-year selection of drinking friends, such that selection was stronger within areas related to lower levels of drinking friends. Conclusions/Importance: Current results indicate that PD and ND shape friends' influence on alcohol use in unique ways. These must be accounted for to better understand bidirectional effects of friend influence.

Potential Causal Influence of Neighborhood Disadvantage on Disordered Gambling: Evidence From a Multilevel Discordant Twin Design.

The quality of the neighborhood in which one lives has been linked to disordered gambling (DG), but whether this reflects a causal relation has not yet been empirically examined. Participants were 3,450 Australian twins who completed assessments of past-year DG and personality and for whom census-derived indicators of disadvantage were used to characterize their neighborhood. Multilevel models were employed to estimate within-twin-pair and betweentwin-pair effects of neighborhood disadvantage on DG, with the within-twin-pair effect representing a potentially causal association and the between-twin-pair effect representing a noncausal association. There was robust evidence for a potentially causal (as well as a non-causal) effect of neighborhood disadvantage on DG (in contrast, parallel analyses of past-year alcohol use disorder failed to find evidence of a potentially causal effect). These results support efforts focused on identifying the active ingredients contributing to the effect of neighborhood disadvantage on DG and developing interventions to limit their impact.

The Importance of Intimate Partner Violence in Within-Relationship and Between-Person Risk for Alcohol-Exposed Pregnancy.

BACKGROUND: Preconceptual prevention programs geared toward reducing alcohol-exposed pregnancy (AEP) typically emphasize behavioral change of alcohol use and birth control exclusively, but rarely consider other important AEP predictors that may affect behavioral change. Intimate partner violence (IPV) substantially relates to AEP and to AEP predictors; however, few studies have tested if IPV is a unique indicator of prospective AEP risk, as both a main effect and a contextual influence on alcohol use or birth control. METHODS: Using Waves II and III of the National Longitudinal Study of Adolescent to Adult Health, multilevel logistic regression models were estimated, in which IPV and birth control (both within-person and between-person) and adolescent alcohol use (between-person only) were examined as unique predictors of AEP compared to both nonpregnancy and non-AEP (nAEP) outcomes over up to 5 sexual relationships. Interactions between within-person and between-person IPV, and birth control or alcohol use were also tested. RESULTS: Within-person and between-person IPV significantly related to higher odds of AEP compared to nonpregnancy and nAEP. Adolescent alcohol use had similarly increased odds for AEP when compared to nonpregnancy or nAEP outcomes. Only between-person birth control use related to higher odds for AEP compared to nonpregnancy and nAEP. Between-person IPV also moderated adolescent alcohol use on odds of AEP, such that infrequent adolescent drinkers had higher odds of AEP compared to nonpregnancy or nAEP if they experienced IPV over their relationships. CONCLUSIONS: IPV is a substantial predictor for AEP as both a direct influence within relationships (within-person) and between individuals (between-person). Intervention and prevention programs focused on reducing AEP may benefit from including IPV-specific curricula.

Neighborhood alcohol outlet density and genetic influences on alcohol use: evidence for gene-environment interaction.

BACKGROUND: Genetic influences on alcohol involvement are likely to vary as a function of the 'alcohol environment,' given that exposure to alcohol is a necessary precondition for genetic risk to be expressed. However, few gene-environment interaction studies of alcohol involvement have focused on characteristics of the community-level alcohol environment. The goal of this study was to examine whether living in a community with more alcohol outlets would facilitate the expression of the genetic propensity to drink in a genetically-informed national survey of United States young adults. METHODS: The participants were 2434 18-26-year-old twin, full-, and half-sibling pairs from Wave III of the National Longitudinal Study of Adolescent to Adult Health. Participants completed in-home interviews in which alcohol use was assessed. Alcohol outlet densities were extracted from state-level liquor license databases aggregated at the census tract level to derive the density of outlets. RESULTS: There was evidence that the estimates of genetic and environmental influences on alcohol use varied as a function of the density of alcohol outlets in the community. For example, the heritability of the frequency of alcohol use for those residing in a neighborhood with ten or more outlets was 74% (95% confidence limits = 55-94%), compared with 16% (95% confidence limits = 0-34%) for those in a neighborhood with zero outlets. This moderating effect of alcohol outlet density was not explained by the state of residence, population density, or neighborhood sociodemographic characteristics. CONCLUSIONS: The results suggest that living in a neighborhood with many alcohol outlets may be especially high-risk for those individuals who are genetically predisposed to frequently drink.

Dynamic Change Between Intimate Partner Violence and Contraceptive Use Over Time in Young Adult Men's and Women's Relationships.

The negative association between intimate partner violence (IPV) and contraceptive use is well established, but much of this research treats the association as static (e.g., similar across all relationships over development or time). Such studies do not account for individual development of sexual and romantic relationship mental, social, and behavioral well-being, which relate to contraceptive use. These studies are also predominantly woman-focused; such work could be complemented by examining men's associations. The current study examined how associations between sexual and physical IPV and consistent condom and birth control (BC) use changed across up to seven sequential relationships in young adulthood over a five-year period within a nationally representative sample. Results indicated that physical IPV-contraception associations were significant only across earliest or latest relationships. Sexual IPV-contraception associations were significant over more relationships but often changed in valence (negative to positive). There were few significant differences in these associations between men and women. Developmental context (e.g., prior relationship/IPV experience) may be important when considering IPV-contraception associations. In addition, although the IPV-contraception association does not appear to be a unique problem for women, research needs to explore how underlying mechanisms explaining this association may be a result of gendered and nongendered contexts.

Developmental Change in Adolescent Delinquency: Modeling Time-Varying Effects of a Preventative Intervention and GABRA2 Halpotype Linked to Alcohol Use.

Better integrating human developmental factors in genomic research is part of a set of next steps for testing gene-by-environment interaction hypotheses. This study adds to this work by extending prior research using time-varying effect modeling (TVEM) to evaluate the longitudinal associations between the PROSPER preventive intervention delivery system, a GABRA2 haplotype linked to alcohol use, and their interaction on adolescent delinquency. Logistic and Poisson analyses on eight waves of data spanning ages 11 to 19 (60% female, 90% Caucasian) showed the intervention reduced delinquency from ages 13 to 16. Moreover, interaction analysis revealed that the effect of the multicomponent intervention was significantly greater for T-allele carriers of the GABRA2 SNP rs279845, but only during the 13 to 16 age period. The results are discussed in terms of adolescent delinquency normativeness, implications for preventive intervention research, and the utility of incorporating development in GxE research.

Neighborhood density of alcohol outlets moderates genetic and environmental influences on alcohol problems.

BACKGROUND AND AIMS: Geographic differences in rates of alcohol use disorder suggest that environmental factors and gene-environment interactions are likely to play an important role in its genesis. We aimed to examine whether living in a community with more alcohol outlets would facilitate the expression of the genetic propensity to develop alcohol problems. DESIGN: Cross-sectional twin/sibling study. SETTING: United States. PARTICIPANTS: The participants were 18-26-year-old twin, full- and half-sibling pairs from Wave III of the National Longitudinal Study of Adolescent to Adult Health. MEASUREMENTS: Participants completed in-home interviews in which past year alcohol problems were assessed. Alcohol outlet densities were extracted from state-level liquor license databases aggregated at the census tract level. FINDINGS: There was evidence that estimates of genetic and environmental influences on alcohol problems varied as a function of the density of alcohol outlets in the community. The heritability of alcohol problems for those residing in a neighborhood with more than 10 on-premises outlets was 78% (95% confidence limits = 52-100%), compared with 11% (95% confidence limits = 0-29%) for those in a neighborhood with no on-premises outlets. This moderating effect of alcohol outlet density was not explained by state of residence, population density or neighborhood socio-demographic characteristics. CONCLUSIONS: Individuals who are genetically predisposed to develop alcohol problems may be especially sensitive to the influence of many alcohol outlets in their community.

Developmental Etiologies of Alcohol Use and Their Relations to Parent and Peer Influences Over Adolescence and Young Adulthood: A Genetically Informed Approach.

BACKGROUND: Distinct changes in alcohol use etiologies occur during adolescence and young adulthood. Additionally, measured environments known to influence alcohol use such as peers and parenting practice can interact or be associated with this genetic influence. However, change in genetic and environmental influences over age, as well as how associations with measured environments change over age, is understudied. METHODS: The National Longitudinal Study of Adolescent Health (Add Health) sibling subsample was used to examine data-driven biometric models of alcohol use over ages 13 to 27. Associations between friends' drinking, parental autonomy granting, and maternal closeness were also examined. RESULTS: The best-fitting model included a 5-factor model consisting of early (ages 13 to 20) and overall (ages 13 to 27) additive genetic and unique environmental factors, as well as 1 overall common environment factor. The overall additive genetic factor and the early unique environment factor explained the preponderance of mean differences in the alcohol use over this portion of the life span. The most important factors explaining variance attributed to alcohol use changed over age. Additionally, friend use had the strongest associations with genetic and environmental factors at all ages, while parenting practices had almost no associations at any age. CONCLUSIONS: These results supplement previous studies indicating changes in genetic and environmental influences in alcohol use over adolescence and adulthood. However, prior research suggesting that constraining exogenous predictors of genetic and environmental factors to have effects of the same magnitude across age overlooks the differential role of factors associated with alcohol use during adolescence. Consonant with previous research, friend use appears to have a more pervasive influence on alcohol use than parental influence during this age. Interventions and prevention programs geared toward reducing alcohol use in younger populations may benefit from focus on peer influence.

Who's Got the Booze? The Role of Access to Alcohol in the Relations Between Social Status and Individual Use.

OBJECTIVE: The findings of previous research that examined relationships between popularity and alcohol use in adolescents have been mixed, and few hypotheses have proposed mechanisms for this relationship. The current study expands on previous literature (a) by examining a possible mechanism that can explain the relation between popularity and alcohol use (home access to alcohol) and (b) by using another sociometric measure ("betweenness"), beyond popularity, that may relate more to home alcohol access. METHOD: Using network-level data from adolescents in 9th-11th grades in eight schools within two in-home waves of the National Longitudinal Study of Adolescent to Adult Health (Add Health), we examined two sociometric measures of social status: popularity (number of schoolmates who nominated participants as a friend) and betweenness (level of ties participants have to multiple social subgroups within a network). RESULTS: Betweenness, but not popularity, related to later alcohol use. Having home access to alcohol positively related to later alcohol use, and having friends with home access to alcohol negatively related to later alcohol use. Alcohol access was also related to later sociometric status. Friends' alcohol access negatively related to later betweenness, and personal alcohol access moderated other pathways predicting betweenness. CONCLUSIONS: Betweenness appears to play a unique role in the association between social status and alcohol use in adolescent social networks. This is potentially tied to specific ways in which adolescents may be able to access alcohol (through home or through friends with access at home). More research is necessary to examine the ways in which multiple sociometric statuses relate to the contexts in which adolescents access and use alcohol.