Introduction: Special issue on genetic research of alcohol use disorder in diverse racial/ethnic populations

This special issue of The American Journal on Addictions is an extension of a workshop held at the Research Society on Alcoholism (2015) highlighting several important issues related to studies of the genetic bases of alcohol use disorder among racially/ethnically diverse populations. While not exhaustive in their coverage, the papers in this special issue focus on three important topics: (1) the importance of considering the social and environmental context in genetic analyses; (2) social and cultural considerations for engaging diverse communities in genetic research; and (3) methodologies related to phenotype development for use with racially/ethnically diverse populations. A brief overview of each paper included in these three sections is presented. The issue concludes with additional considerations for genetic research with racially/ethnically diverse population groups along with a commentary. (Am J Addict 2017;26:422–423

Ethnicity and Gender Comparisons of Health Consequences in Adults with Alcohol Dependence

The moderating effects of ethnicity and gender on factors associated with physical health consequences in adults with alcohol dependence was examined using data from the 2001–2002 U.S. National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Black and White respondents with a lifetime diagnosis of DSM-IV alcohol dependence were selected for the study (n = 3,852). A multiple-group structural equation model tested ethnicity, gender, and intervening variables as predictors of physical health status in alcohol dependent men and women. Study findings offer implications for clinical practice with alcohol dependent individuals by identifying likely target groups and problems for intervention

Development and vulnerability factors in adolescent alcohol use

This article provides an overview of the characteristics of adolescent alcohol use, normative and subgroup variations in drinking behavior, and important factors associated with an increased risk for developing alcohol problems in later adolescence and young adulthood. A parental/family history of alcoholism, temperament traits, conduct problems, cognitive functioning, alcohol expectancies, and peer and other social relations are identified as influencing an adolescent’s susceptibility for initiating a variety of alcohol use behaviors. The Deviance Prone Model, proposed by Sher (1991), is presented as an important tool for testing possible relationships among the various risk factors and their sequencing that leads to early adolescent alcohol and drug initiation and use. It is also possible to extend the model to allow for an examination of the complex interplay of risk factors that leads to the development of alcohol use problems in late adolescence and young adults

Alcohol problems in young adults transitioning from adolescence to adulthood: The association with race and gender

Race and gender may be important considerations for recognizing alcohol related problems in Black and White young adults. This study examined the prevalence and age of onset of individual alcohol problems and alcohol problem severity across race and gender subgroups from a longitudinal study of a community sample of adolescents followed into young adulthood (N = 166; 23–29 yrs. old who were drinkers). All alcohol problems examined first occurred when subjects were in their late teens and early 20s. Drinking in hazardous situations, blackouts, and tolerance were the most common reported alcohol problems. In race and gender comparisons, more males than females experienced alcohol problems. Blacks generally had a later age of onset of alcohol problems. Multivariate regressions showed greater alcohol problem severity in males compared to females, but no significant differences between Blacks and Whites. Education, family environment and earlier alcohol use behaviors and expectancies were reliable predictors of alcohol problem severity in young adulthood. White males were at particular risk for experiencing more severe alcohol problems. Findings may inform the design of more targeted interventions for alcohol problems in different populations

Predictors of subgroups based on maximum drinks per occasion over six years for 833 adolescents and young adults in COGA.

ObjectiveA person's pattern of heavier drinking often changes over time, especially during the early drinking years, and reflects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than cross-sectional evaluations.MethodThe patterns of maximum drinks per occasion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identified latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership.ResultsFour latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 over time; and Class 4 (6%), with a maximum of about 22 drinks across time. The most consistent predictors of higher drinking classes were female sex, a low baseline level of response to alcohol, externalizing characteristics, prior alcohol and tobacco use, and heavier drinking peers.ConclusionsFour trajectory classes were observed and were best predicted by a combination of items that reflected demography, substance use, level of response and externalizing phenotypes, and baseline environment and attitudes

Familial association of abstinent remission from alcohol use disorder in first-degree relatives of alcohol-dependent treatment-seeking probands

Background and Aims Studies that have included family history of alcohol use disorder (AUD) as a predictor of remission from AUD have yielded few significant results. The goals of this study were to estimate the association of persistent AUD, non-abstinent remission and abstinent remission (‘AUD/remission status’) in a proband with AUD/remission status in a relative and to test whether this association differed in related and unrelated proband-relative pairs. Design High-risk family study of alcohol dependence. Probands were recruited from treatment settings and relatives were invited to participate. Baseline assessments occurred between 1991 and 1998 with follow-up between 1996 and 2005. Half of probands were matched with a biological 1st-degree relative with life-time AUD (related group) and half of probands were paired with an unrelated individual with life-time AUD (unrelated group). Setting Brooklyn, New York; Indianapolis, Indiana; Iowa City, Iowa; San Diego, California; Farmington, Connecticut; and St Louis, Missouri, USA. Participants A total of 606 probands (25.7% female, mean age 37.7) with baseline and follow-up data and 606 of their 1st-degree relatives who had life-ime AUDs (45.8% female, mean age 36.2 years). Measurements Persistent AUD, non-abstinent remission and abstinent remission were based on self-report interview data on most recent AUD symptoms and alcohol consumption. Dependent variable was relatives’ AUD/remission status. Independent variable was probands’ AUD/remission status. Findings A total of 34.6% of probands and 20.6% of relatives were abstinent and 11.1% of probands and 22.8% of relatives were in non-abstinent remission. AUD/remission status was correlated significantly in related (r = 0.23, P = 0.0037) but not in unrelated pairs. A significant interaction of probands’ abstinent remission with a variable representing related (versus unrelated, P = 0.003) pairs suggested a familial association for abstinent remission. In related pairs, individuals with an abstinent proband were more likely to be abstinent themselves than were individuals whose proband had persistent AUD [relative risk ratio = 3.27, 95% confidence interval (CI) = 1.56–6.85, P = 0.002]; this association was not significant in unrelated pairs. Conclusions The likelihood of abstinent remission among people with alcohol use disorder appears to be more than three times greater for individuals who are related to an abstinent proband versus those related to a proband with persistent alcohol use disorder

A GABRA2 Polymorphism Improves a Model for Prediction of Drinking Initiation

Background Survival analysis was used to explore the addition of a single nucleotide polymorphism (SNP) and covariates (sex, interview age, and ancestry) on a previously published model's ability to predict onset of drinking. A SNP variant of rs279871, in the chromosome 4 gene encoding gamma-aminobutyric acid receptor (GABRA2), was selected due to its associations with alcoholism in young adults and with behaviors that increased risk for early drinking. Methods A subsample of 674 adolescents (ages 14–17) participating in the Collaborative Study on the Genetics of Alcoholism (COGA) was examined using a previously derived Cox proportional hazards model containing: 1) number of non-drinking related conduct disorder (CD) symptoms, 2) membership in a high-risk alcohol-dependent (AD) family, 3) most best friends drank (MBFD), 4) Achenbach Youth Self Report (YSR) externalizing score, and 5) YSR social problems score. The above covariates along with the SNP variant of GABRA2, rs279871, were added to this model. Five new prototype models were examined. The most parsimonious model was chosen based on likelihood ratio tests and model fit statistics. Results The final model contained four of the five original predictors (YSR social problems score was no longer significant and hence dropped from subsequent models), the three covariates, and a recessive GABRA2 rs279871 TT genotype (two copies of the high-risk allele containing thymine). The model indicated that adolescents with the high-risk TT genotype were more likely to begin drinking than those without this genotype. Conclusions The joint effect of the gene (rs279871 TT genotype) and environment (MBFD) on adolescent alcohol initiation is additive, but not interactive, after controlling for behavior problems (CD and YSR externalizing score). This suggests that the impact of the high-risk TT genotype on the onset of drinking is affected by controlling for peer drinking and does not include genotype-by-environment interactions

Defining alcohol-related phenotypes in humans. The Collaborative Study on the Genetics of Alcoholism.

Alcoholism is a disease that runs in families and results at least in part from genetic risk factors. The Collaborative Study on the Genetics of Alcoholism (COGA) is a Federally funded effort to identify and characterize those genetic factors. The study involves more than 1,000 alcoholic subjects and their families, with researchers conducting comprehensive psychological, physiological, electrophysiological, and genetic analyses of the participants. These analyses have identified several traits, or phenotypes, that appear to be genetically determined, such as the presence of alcohol dependence, the level of response to alcohol, the presence of coexisting depression, or the maximum number of drinks a person consumes per occasion. Genetic analyses have identified regions on several chromosomes that are associated with these phenotypes and need to be studied further