A Nationally Representative Study of Sexual Orientation and High-Risk Drinking From Adolescence to Young Adulthood

PURPOSE

To determine whether peer drunkenness, parental knowledge about their adolescent's whereabouts and behaviors, and depressive symptoms contribute to sexual orientation disparities in high-risk drinking behaviors; if they do, they would be potential intervention targets.

METHODS

Longitudinal survey data from 2,051 adolescents who participated in the NEXT Generation Health Study were analyzed. Latent growth curve and longitudinal path analyses were used to test for indirect effects linking sexual orientation in 11th grade (3.4% males and 8.4% females were sexual minorities) to past 30-day heavy episodic drinking (HED) over 6 years and past year high-intensity binge drinking at 4 years after high school.

RESULTS

Sexual minority males were not more likely to engage in high-risk drinking than heterosexual males. In contrast, sexual minority females were more likely than heterosexual females to engage in HED when they were in 11th grade (Odds Ratio = 2.83, 95% confidence interval = 1.43, 5.61), in part because of lower parental knowledge. Sexual minority females also had higher depressive symptoms during the transition from adolescence to young adulthood, which in turn was associated with greater risk of high-intensity binge drinking in young adulthood. Peer drunkenness was a strong risk factor for HED and high-intensity binge drinking among both males and females.

DISCUSSION

Sexual minority females reported lower levels of parental knowledge during adolescence and higher levels of depressive symptoms during the transition to young adulthood than heterosexual females. Both factors were associated with high-risk drinking behavior, suggesting developmentally sensitive opportunities to mitigate sexual orientation disparities in high-risk drinking.

Genes, Roommates, and Residence Halls: A Multidimensional Study of the Role of Peer Drinking on College Students' Alcohol Use

BACKGROUND

Peer drinking is one of the most robust predictors of college students' alcohol use and can moderate students' genetic risk for alcohol use. Peer effect research generally suffers from 2 problems: selection into peer groups and relying more on perceptions of peer alcohol use than peers' self-report. The goal of the present study was to overcome those limitations by capitalizing on a genetically informed sample of randomly assigned college roommates to examine multiple dimensions of peer influence and the interplay between peer effects and genetic predisposition on alcohol use, in the form of polygenic scores.

METHODS

We used a subsample (n = 755) of participants from a university-wide, longitudinal study at a large, diverse, urban university. Participants reported their own alcohol use during fall and spring and their perceptions of college peers' alcohol use in spring. We matched individuals into their rooms and residence halls to create a composite score of peer-reported alcohol use for each of those levels. We examined multiple dimensions of peer influence and whether peer influence moderated genetic predisposition to predict college students' alcohol use using multilevel models to account for clustering at the room and residence hall level.

RESULTS

We found that polygenic scores (β = 0.12), perceptions of peer drinking (β = 0.37), and roommates' self-reported drinking (β = 0.10) predicted alcohol use (all ps < 0.001), while average alcohol use across residence hall did not (β = -0.01, p = 0.86). We found no evidence for interactions between peer influence and genome-wide polygenic scores for alcohol use.

CONCLUSIONS

Our findings underscore the importance of genetic predisposition on individual alcohol use and support the potentially causal nature of the association between peer influence and alcohol use.

An ADH1B variant and peer drinking in progression to adolescent drinking milestones: evidence of a gene-by-environment interaction

BACKGROUND

Adolescent drinking is an important public health concern, one that is influenced by both genetic and environmental factors. The functional variant rs1229984 in alcohol dehydrogenase 1B (ADH1B) has been associated at a genome-wide level with alcohol use disorders in diverse adult populations. However, few data are available regarding whether this variant influences early drinking behaviors and whether social context moderates this effect. This study examines the interplay between rs1229984 and peer drinking in the development of adolescent drinking milestones.

METHODS

One thousand five hundred and fifty European and African American individuals who had a full drink of alcohol before age 18 were selected from a longitudinal study of youth as part of the Collaborative Study on the Genetics of Alcoholism (COGA). Cox proportional hazards regression, with G × E product terms in the final models, was used to study 2 primary outcomes during adolescence: age of first intoxication and age of first DSM-5 alcohol use disorder symptom.

RESULTS

The minor A allele of rs1229984 was associated with a protective effect for first intoxication (HR = 0.56, 95% CI 0.41 to 0.76) and first DSM-5 symptom (HR = 0.45, 95% CI 0.26 to 0.77) in the final models. Reporting that most or all best friends drink was associated with a hazardous effect for first intoxication (HR = 1.81, 95% CI 1.62 to 2.01) and first DSM-5 symptom (HR = 2.17, 95% 1.88 to 2.50) in the final models. Furthermore, there was a significant G × E interaction for first intoxication (p = 0.002) and first DSM-5 symptom (p = 0.01). Among individuals reporting none or few best friends drinking, the ADH1B variant had a protective effect for adolescent drinking milestones, but for those reporting most or all best friends drinking, this effect was greatly reduced.

CONCLUSIONS

Our results suggest that the risk factor of best friends drinking attenuates the protective effect of a well-established ADH1B variant for 2 adolescent drinking behaviors. These findings illustrate the interplay between genetic and environmental factors in the development of drinking milestones during adolescence.

Influenced but unaware: social influence on alcohol drinking among social acquaintances

BACKGROUND

Drinking partners may be influenced by each other's alcohol consumption. However, these effects have only been shown in artificially created social pairings and typically among same-sex young adults. Here, we test whether similarly strong influence effects occur among "real" pairs of social acquaintances (friends and partners) and whether people are aware of this influence on their alcohol consumption.

METHODS

Forty-six pairs of social acquaintances aged between 19 and 60 years old participated in a between-subjects experiment, in a semi-naturalistic bar laboratory setting. One member of each pair (the confederate) was randomly selected and asked to consume only alcoholic (alcohol condition) or soft drinks (nonalcohol condition), while the pair completed a game together in a bar setting. The other participant (naïve) was unaware of these drinking instructions. Postconsumption, we measured the extent to which naïve participants believed that their partner had influenced their own drinking behavior.

RESULTS

A large effect of condition on alcohol consumption was observed, χ² (2) = 15.8, p < 0.001, Cramer's V = 0.59, whereby the number of alcoholic drinks selected by naïve participants in the alcohol confederate condition was significantly greater than in the nonalcohol confederate condition. The majority of naïve participants (81%) also tended to be unaware that their partner had influenced their alcohol consumption.

CONCLUSIONS

Social acquaintances are influenced by each other's alcohol consumption and may not be aware of this influence on their behavior.