Interest in Genetic Feedback for Alcohol Use Disorder and Related Substance Use and Psychiatric Outcomes among Young Adults

An exponential growing number of individuals are accessing genetic risk information via direct to consumer companies. Alcohol dependence is the third most accessed genetic risk score on a publicly available direct to consumer website. Better understanding of the degree to which individuals are interested in receiving personalized genetic feedback, the factors that relate to interest, and genetic knowledge will be critical to lay the foundation for precision medicine initiatives, especially for substance use and psychiatric outcomes, where less is known. To assess interest in receiving genetic feedback for alcohol use disorder (AUD) and understanding of genetic concepts related to psychiatric conditions, we conducted a survey with participants recruited from a registry that enrolled incoming cohorts of freshmen at an urban public university; 205 participants (76.5% female; 58.9% self-reported as White; Mage = 24.48 years) completed the survey. Results indicated that participants are highly interested in receiving genetic feedback for AUD (79.0%) but there is a lack of understanding of complex genetic concepts in a sizable proportion of the sample (25.4%). Additional research is needed to assess how to address this lack of knowledge before genetic feedback for AUD can be returned in a way that benefits the individual.

A large-scale genome-wide association study meta-analysis of cannabis use disorder

BACKGROUND

Variation in liability to cannabis use disorder has a strong genetic component (estimated twin and family heritability about 50-70%) and is associated with negative outcomes, including increased risk of psychopathology. The aim of the study was to conduct a large genome-wide association study (GWAS) to identify novel genetic variants associated with cannabis use disorder.

METHODS

To conduct this GWAS meta-analysis of cannabis use disorder and identify associations with genetic loci, we used samples from the Psychiatric Genomics Consortium Substance Use Disorders working group, iPSYCH, and deCODE (20 916 case samples, 363 116 control samples in total), contrasting cannabis use disorder cases with controls. To examine the genetic overlap between cannabis use disorder and 22 traits of interest (chosen because of previously published phenotypic correlations [eg, psychiatric disorders] or hypothesised associations [eg, chronotype] with cannabis use disorder), we used linkage disequilibrium score regression to calculate genetic correlations.

FINDINGS

We identified two genome-wide significant loci: a novel chromosome 7 locus (FOXP2, lead single-nucleotide polymorphism [SNP] rs7783012; odds ratio [OR] 1·11, 95% CI 1·07-1·15, p=1·84 × 10-9) and the previously identified chromosome 8 locus (near CHRNA2 and EPHX2, lead SNP rs4732724; OR 0·89, 95% CI 0·86-0·93, p=6·46 × 10-9). Cannabis use disorder and cannabis use were genetically correlated (rg 0·50, p=1·50 × 10-21), but they showed significantly different genetic correlations with 12 of the 22 traits we tested, suggesting at least partially different genetic underpinnings of cannabis use and cannabis use disorder. Cannabis use disorder was positively genetically correlated with other psychopathology, including ADHD, major depression, and schizophrenia.

INTERPRETATION

These findings support the theory that cannabis use disorder has shared genetic liability with other psychopathology, and there is a distinction between genetic liability to cannabis use and cannabis use disorder.

FUNDING

National Institute of Mental Health; National Institute on Alcohol Abuse and Alcoholism; National Institute on Drug Abuse; Center for Genomics and Personalized Medicine and the Centre for Integrative Sequencing; The European Commission, Horizon 2020; National Institute of Child Health and Human Development; Health Research Council of New Zealand; National Institute on Aging; Wellcome Trust Case Control Consortium; UK Research and Innovation Medical Research Council (UKRI MRC); The Brain & Behavior Research Foundation; National Institute on Deafness and Other Communication Disorders; Substance Abuse and Mental Health Services Administration (SAMHSA); National Institute of Biomedical Imaging and Bioengineering; National Health and Medical Research Council (NHMRC) Australia; Tobacco-Related Disease Research Program of the University of California; Families for Borderline Personality Disorder Research (Beth and Rob Elliott) 2018 NARSAD Young Investigator Grant; The National Child Health Research Foundation (Cure Kids); The Canterbury Medical Research Foundation; The New Zealand Lottery Grants Board; The University of Otago; The Carney Centre for Pharmacogenomics; The James Hume Bequest Fund; National Institutes of Health: Genes, Environment and Health Initiative; National Institutes of Health; National Cancer Institute; The William T Grant Foundation; Australian Research Council; The Virginia Tobacco Settlement Foundation; The VISN 1 and VISN 4 Mental Illness Research, Education, and Clinical Centers of the US Department of Veterans Affairs; The 5th Framework Programme (FP-5) GenomEUtwin Project; The Lundbeck Foundation; NIH-funded Shared Instrumentation Grant S10RR025141; Clinical Translational Sciences Award grants; National Institute of Neurological Disorders and Stroke; National Heart, Lung, and Blood Institute; National Institute of General Medical Sciences.

Expanding the genetic architecture of nicotine dependence and its shared genetics with multiple traits

Cigarette smoking is the leading cause of preventable morbidity and mortality. Genetic variation contributes to initiation, regular smoking, nicotine dependence, and cessation. We present a Fagerström Test for Nicotine Dependence (FTND)-based genome-wide association study in 58,000 European or African ancestry smokers. We observe five genome-wide significant loci, including previously unreported loci MAGI2/GNAI1 (rs2714700) and TENM2 (rs1862416), and extend loci reported for other smoking traits to nicotine dependence. Using the heaviness of smoking index from UK Biobank (N = 33,791), rs2714700 is consistently associated; rs1862416 is not associated, likely reflecting nicotine dependence features not captured by the heaviness of smoking index. Both variants influence nearby gene expression (rs2714700/MAGI2-AS3 in hippocampus; rs1862416/TENM2 in lung), and expression of genes spanning nicotine dependence-associated variants is enriched in cerebellum. Nicotine dependence (SNP-based heritability = 8.6%) is genetically correlated with 18 other smoking traits (rg = 0.40-1.09) and co-morbidities. Our results highlight nicotine dependence-specific loci, emphasizing the FTND as a composite phenotype that expands genetic knowledge of smoking.

College students' use of strategies to hide facial flushing: A target for alcohol education

Alcohol-related facial flushing occurs in individuals who are unable to metabolize ethanol effectively and is associated with increased cancer risk. This study describes college students' understanding of the meaning of flushing for how much alcohol a person should drink and their use of over-the-counter medications and other strategies to reduce its visible effects. Participants: The sample includes 335 White and Asian college students who reported facial flushing after an alcoholic drink. Methods: Students completed an online survey in the spring of their junior year. Results: Most students reported that flushing had no special meaning for drinking or that they did not know what it meant. Six percent reported ever using strategies to hide facial flushing; they were mostly Asian, and those using these strategies drank more alcohol. Conclusions: Findings identify a need for targeted alcohol education with Asian college students who drink alcohol despite experiencing the flushing response.

Mechanisms of Alcohol Addiction: Bridging Human and Animal Studies

AIM

The purpose of this brief narrative review is to address the complexities and benefits of extending animal alcohol addiction research to the human domain, emphasizing Allostasis and Incentive Sensitization, two models that inform many pre-clinical and clinical studies.

METHODS

The work reviewed includes a range of approaches, including: a) animal and human studies that target the biology of craving and compulsive consumption; b) human investigations that utilize alcohol self-administration and alcohol challenge paradigms, in some cases across 10 years; c) questionnaires that document changes in the positive and negative reinforcing effects of alcohol with increasing severity of addiction; and d) genomic structural equation modeling based on data from animal and human studies.

RESULTS

Several general themes emerge from specific study findings. First, positive reinforcement is characteristic of early stage addiction and sometimes diminishes with increasing severity, consistent with both Allostasis and Incentive Sensitization. Second, evidence is less consistent for the predominance of negative reinforcement in later stages of addiction, a key tenant of Allostasis. Finally, there are important individual differences in motivation to drink at a given point in time as well as person-specific change patterns across time.

CONCLUSIONS

Key constructs of addiction, like stage and reinforcement, are by necessity operationalized differently in animal and human studies. Similarly, testing the validity of addiction models requires different strategies by the two research domains. Although such differences are challenging, they are not insurmountable, and there is much to be gained in understanding and treating addiction by combining pre-clinical and clinical approaches.

Genetic feedback for psychiatric conditions: Where are we now and where are we going

Genome-wide association studies are rapidly advancing our understanding of the genetic architecture of complex disorders, including many psychiatric conditions such as major depression, schizophrenia, and substance use disorders. One common goal of genome-wide association studies is to use findings for enhanced clinical prediction in the future, which can aid in identifying at-risk individuals to enable more effective prevention screening and treatment strategies. In order to achieve this goal, we first need to gain a better understanding of the issues surrounding the return of complex genetic results. In this article, we summarize the current literature on: (a) genetic literacy in the general population, (b) the public's interest in receiving genetic test results for psychiatric conditions, (c) how individuals react to and interpret their genotypic information for specific psychiatric conditions, and (d) gaps in our knowledge that will be critical to address as we move toward returning genotypic information for psychiatric conditions in both research and clinical settings. By reviewing extant studies, we aim to increase awareness of the potential benefits and consequences of returning genotypic information for psychiatric conditions.

Alcohol-Related, Drug-Related, and Non-Substance-Related Aggression: 3 Facets of a Single Construct or 3 Distinct Constructs?

BACKGROUND

Aggression often occurs alongside alcohol and drug misuse. However, it is not clear whether the latent and manifest relations among alcohol-related, drug-related, and non-substance-related aggression are separate manifestations of a single construct or instead are 3 distinct constructs.

METHODS

To examine these associations, we conducted a preregistered analysis of 13,490 participants in the Collaborative Study on the Genetics of Alcoholism. In a structured interview, participants reported their lifetime perpetration of these 3 aggression phenotypes.

RESULTS

The data were better fit by a model that treated these aggression phenotypes as 3 distinct latent factors, as compared to models in which the items all loaded onto 1 ("general") or 2 ("substance-related" and "non-substance-related") aggression factors. This 3-factor model fit better for men than women. Subsequent exploratory analyses then showed that among these 3 factors, alcohol-related aggression explained the variance of overall aggression better than the other 2 factors.

CONCLUSIONS

Our findings suggest that these 3 forms of aggression are distinct phenotypes (especially among men). Yet, people's alcohol-related aggression can accurately characterize their overall aggressive tendencies across these domains. Future research will benefit from articulating the unique and shared pathways and risk factors underlying each of these facets of aggression.

Associations between ethnic-racial identity and alcohol problems among diverse emerging adults

Excessive alcohol use and problems during college is a major public health concern, and there are health disparities in patterns of drinking and alcohol-related illnesses based on ethnicity and race. Given the prevalence and disparities in excessive alcohol use and problems and associated negative impacts, it is important to examine potential protective factors such as dimensions of ethnic-racial identity (ERI). Thus, the current study examined how multiple dimensions of ERI were associated with alcohol use and alcohol use disorder (AUD) symptoms, and how these relations varied by individuals' ethnic-racial group among 1850 diverse emerging adults (M = 18.46, SD = .38). Findings indicated that there were significant differences by race/ethnicity. ERI affirmation was negatively associated with AUD symptoms for Asian individuals and African American individuals, while ERI exploration was positively associated with AUD symptoms among African American individuals. ERI resolution was negatively associated with alcohol use for Latinx individuals and positively associated with alcohol use for Multiracial individuals. Among White individuals, ERI exploration was negatively associated with alcohol use and ERI affirmation was negatively associated with AUD symptoms. Overall, the current study builds on our understanding of nuanced ways in which ethnic-racial identity impacts alcohol problems among emerging adults and highlights areas for future research.

Trauma-related drinking to cope: A novel approach to the self-medication model

Multiple etiological models have been proposed to explain posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) comorbidity, but the predominant model to date is the "drinking to cope" self-medication model. Despite its popularity, the self-medication model lacks rigorous empirical support related to inconsistencies and methodological limitations, particularly the failure to operationalize drinking to cope with trauma symptoms specifically. The present study sought to measure trauma-related drinking to cope (TRD) in order to provide a more specific test of the self-medication model among a representative sample of 1,896 undergraduates with a history of trauma exposure and alcohol use. Using a model-building approach in Mplus, a correlated multiple mediator model tested the association between PTSD symptoms and alcohol use problems (AUPs) through TRD and more generalized drinking to cope motives (as assessed by the coping subscale of the Drinking Motives Questionnaire; DMQ-Cope) as moderated by sex. Results indicated that, while accounting for the effects of generalized drinking to cope motives, TRD partially mediated the relation between PTSD symptoms and AUPs and that this relationship was stronger for males than for females. With the exception of moderation by sex, results were substantiated using longitudinal data. Findings were consistent with the self-medication model, suggesting that TRD motives may serve as a mechanism through which PTSD symptoms influence AUPs. TRD may serve as a more specific screening tool for AUP risk among individuals endorsing PTSD symptoms compared with the commonly used DMQ-Cope. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A Family-Based Genome Wide Association Study of Externalizing Behaviors

Shared genetic factors contribute to the high degree of comorbidity among externalizing problems (e.g. substance use and antisocial behavior). We leverage this common genetic etiology to identify genetic influences externalizing problems in participants from the Collaborative Study on the Genetics of Alcoholism (European ancestry = 7568; African ancestry = 3274). We performed a family-based genome-wide association study (GWAS) on externalizing scores derived from criterion counts of five DSM disorders (alcohol dependence, alcohol abuse, illicit drug dependence, illicit drug abuse, and either antisocial personality disorder or conduct disorder). We meta analyzed these results with a similar measure of externalizing in an independent sample, Spit for Science (combined sample N = 15,112). We did not discover any robust genome-wide significant signals. Polygenic scores derived from the ancestry-specific GWAS summary statistics predicted externalizing problems in an independent European ancestry sample, but not in those of African ancestry. However, these PRS were no longer significant after adjusting for multiple testing. Larger samples with deep phenotyping are necessary for the discovery of SNPs related to externalizing problems.

Racial discrimination and alcohol problems among African American young adults: Examining the moderating effects of racial socialization by parents and friends

OBJECTIVE

Racial discrimination is a stressor that may put African Americans at risk for alcohol use and related problems. We examined whether experiences of blatant (racist events) and subtle (racial microaggressions) forms of racial discrimination were associated with alcohol consumption and alcohol problems among African American young adults, and whether childhood/adolescence racial socialization by parents and friends moderated these associations.

METHOD

The sample included 383 African American young adults (Mage = 20.65, SD = 2.28; 81% female) who completed an electronic survey in Fall, 2017. Hierarchical linear regression analyses were conducted in Mplus.

RESULTS

Experiences of racist events and racial microaggressions were associated with higher levels of alcohol consumption and more alcohol problems. Racial socialization by friends, but not parents, moderated these associations. Specifically, cultural socialization by friends buffered the effect of racist events on alcohol consumption and alcohol problems, whereas promotion of mistrust by friends exacerbated the effect of racial microaggressions on alcohol problems.

CONCLUSIONS

Both blatant and subtle forms of racial discrimination were associated with higher risk for alcohol use or problems among African American young adults. Racial socialization by friends while growing up may play an important role in alcohol use outcomes during young adulthood. Findings highlight the importance of considering different forms of racial discrimination and emphasize the unique roles of racial socialization across different social contexts (i.e., parent and peers or friends) in relation to psychosocial outcomes among African American individuals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Population Attributable Fraction of Early Age of Onset of Alcohol Use in Alcohol Abuse and Dependence: A 3-Year Follow-Up Study in University Students

BACKGROUND

we aimed to determine the risk factors and associated population attributable fractions (PAFs) for the age of onset of alcohol use and also to identify protective factors.

METHODS

we analyzed follow-up data collected between autumn 2011 and spring 2016 (n = 5170) from the first two cohorts (2011, 2012) of the Spit for ScienceTM project. The dependent variables were alcohol abuse and dependence, and the independent variables were age of drinking onset, residence, ethnicity, religiosity, sexual orientation and work status. We determined the odds ratios (OR) using multilevel logistic regression for repeated measures in SPSSv.20.

RESULTS

the early onset of alcohol use was associated with an increased risk of alcohol abuse and dependence among females (OR = 14.98; OR = 11.83) and males (OR = 7.41; OR = 6.24). The PAFs for the early onset of alcohol use in alcohol abuse and dependence were respectively 80.9% and 71.7% in females and 71.0% and 63.5% in males. Among females, being white (OR = 1.58; OR = 1.51), living off-campus (OR = 1.73; OR = 2.76) and working full-time (OR = 1.69; OR = 1.78) were also risk factors. Strong religious beliefs were found to protect males from alcohol abuse (OR = 0.58), while same-gender sexual orientation increased the risk among females (OR = 2.09).

CONCLUSION

delaying the age of onset by one year would reduce alcohol abuse among young adults.

Characterization of Service Use for Alcohol Problems Across Generations and Sex in Adults With Alcohol Use Disorder

BACKGROUND

There are gaps in the literature on service use (help-seeking and treatment utilization) for alcohol problems among those with alcohol use disorder (AUD). First, policy changes and cultural shifts (e.g., insurance) related to AUD have occurred over the last few decades, making it important to study generational differences. Second, multiple studies have found that females receive fewer services than males, and exploring whether these sex differences persist across generations can inform public health and research endeavors. The current study examined service use for alcohol problems among individuals with AUD. The aims were as follows: (i) to describe service use for alcohol problems; (ii) to assess generational differences (silent [b. 1928 to 1945], boomer [b. 1946 to 1964], generation X [b. 1965 to 1980], millennial [b. 1981 to 1996]) in help-seeking and treatment utilization; and (iii) to examine sex differences across generations.

METHODS

Data were from affected family members of probands who participated in the Collaborative Study on the Genetics of Alcoholism (N = 4,405). First, frequencies for service use variables were calculated across generations. Pearson chi-square and ANOVA were used to test for differences in rates and types of service use across generations, taking familial clustering into account. Next, Cox survival modeling was used to assess associations of generation and sex with time to first help-seeking and first treatment for AUD, and time from first onset of AUD to first help-seeking and first treatment. Interactions between generation and sex were tested within each Cox regression.

RESULTS

Significant hazards were found in all 4 transitions. Overall, younger generations used services earlier than older generations, which translated into higher likelihoods of these behaviors. Regardless of generation, younger females were less likely to use services than males.

CONCLUSIONS

There are generational and sex differences in service use for alcohol problems among individuals with AUD. Policy and clinical implications are discussed.

Sibling comparisons elucidate the associations between educational attainment polygenic scores and alcohol, nicotine and cannabis

BACKGROUND AND AIMS

The associations between low educational attainment and substance use disorders (SUDs) may be related to a common genetic vulnerability. We aimed to elucidate the associations between polygenic scores for educational attainment and clinical criterion counts for three SUDs (alcohol, nicotine and cannabis).

DESIGN

Polygenic association and sibling comparison methods. The latter strengthens inferences in observational research by controlling for confounding factors that differ between families.

SETTING

Six sites in the United States.

PARTICIPANTS

European ancestry participants aged 25 years and older from the Collaborative Study on the Genetics of Alcoholism (COGA). Polygenic association analyses included 5582 (54% female) participants. Sibling comparisons included 3098 (52% female) participants from 1226 sibling groups nested within the overall sample.

MEASUREMENTS

Outcomes included criterion counts for DSM-5 alcohol use disorder (AUDSX), Fagerström nicotine dependence (NDSX) and DSM-5 cannabis use disorder (CUDSX). We derived polygenic scores for educational attainment (EduYears-GPS) using summary statistics from a large (> 1 million) genome-wide association study of educational attainment.

FINDINGS

In polygenic association analyses, higher EduYears-GPS predicted lower AUDSX, NDSX and CUDSX [P < 0.01, effect sizes (R2 ) ranging from 0.30 to 1.84%]. These effects were robust in sibling comparisons, where sibling differences in EduYears-GPS predicted all three SUDs (P < 0.05, R2 0.13-0.20%).

CONCLUSIONS

Individuals who carry more alleles associated with educational attainment tend to meet fewer clinical criteria for alcohol, nicotine and cannabis use disorders, and these effects are robust to rigorous controls for potentially confounding factors that differ between families (e.g. socio-economic status, urban-rural residency and parental education).

The relationship between on-campus service utilization and common mental health concerns in undergraduate college students

Little research exists into the trends associated with on-campus service utilization for mental health concerns of college students. Rates of broad service utilization exist, but no published study has examined the direct relationship between a range of common mental health symptoms and on-campus service utilization. The aims of the present study are to explore (1) which common mental health concerns are associated with specific on-campus service utilization in undergraduate students and (2) whether endorsement of more mental health concerns will predict a higher number of services utilized. Data were utilized from 3,734 undergraduates at a large (more than 20,000 undergraduates), urban university (Mage = 19.94 years, SD = 0.55 years; female = 66%). Four on-campus services (University Counseling Services, University Health Services, The Wellness Resource Center, and Disability Support Services) were regressed onto mental health concerns associated with symptoms of three disorders (anxiety, depression, alcohol use disorder [AUD]) and two mental health risk factors (stressful life events [SLEs], antisocial behaviors [ASBs]). AUD symptoms predicted the most overall and specific service utilization, followed by depression symptoms and SLEs. Anxiety symptoms and ASBs were not significant predictors when combined with other variables. This is the first study to investigate trends specific to on-campus college student service utilization. Findings will be helpful to mental health professionals on similar college campuses by providing insight into programming and outreach initiatives for these or related services. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Psychosocial moderation of polygenic risk for cannabis involvement: the role of trauma exposure and frequency of religious service attendance

Cannabis use and disorders (CUD) are influenced by multiple genetic variants of small effect and by the psychosocial environment. However, this information has not been effectively incorporated into studies of gene-environment interaction (GxE). Polygenic risk scores (PRS) that aggregate the effects of genetic variants can aid in identifying the links between genetic risk and psychosocial factors. Using data from the Pasman et al. GWAS of cannabis use (meta-analysis of data from the International Cannabis Consortium and UK Biobank), we constructed PRS in the Collaborative Study on the Genetics of Alcoholism (COGA) participants of European (N: 7591) and African (N: 3359) ancestry. The primary analyses included only individuals of European ancestry, reflecting the ancestral composition of the discovery GWAS from which the PRS was derived. Secondary analyses included the African ancestry sample. Associations of PRS with cannabis use and DSM-5 CUD symptom count (CUDsx) and interactions with trauma exposure and frequency of religious service attendance were examined. Models were adjusted for sex, birth cohort, genotype array, and ancestry. Robustness models were adjusted for cross-term interactions. Higher PRS were associated with a greater likelihood of cannabis use and with CUDsx among participants of European ancestry (p < 0.05 and p < 0.1 thresholds, respectively). PRS only influenced cannabis use among those exposed to trauma (R2: 0.011 among the trauma exposed vs. R2: 0.002 in unexposed). PRS less consistently influenced cannabis use among those who attend religious services less frequently; PRS × religious service attendance effects were attenuated when cross-term interactions with ancestry and sex were included in the model. Polygenic liability to cannabis use was related to cannabis use and, less robustly, progression to symptoms of CUD. This study provides the first evidence of PRS × trauma for cannabis use and demonstrates that ignoring important aspects of the psychosocial environment may mask genetic influences on polygenic traits.

Association of Polygenic Liability for Alcohol Dependence and EEG Connectivity in Adolescence and Young Adulthood

Differences in the connectivity of large-scale functional brain networks among individuals with alcohol use disorders (AUD), as well as those at risk for AUD, point to dysfunctional neural communication and related cognitive impairments. In this study, we examined how polygenic risk scores (PRS), derived from a recent GWAS of DSM-IV Alcohol Dependence (AD) conducted by the Psychiatric Genomics Consortium, relate to longitudinal measures of interhemispheric and intrahemispheric EEG connectivity (alpha, theta, and beta frequencies) in adolescent and young adult offspring from the Collaborative Study on the Genetics of Alcoholism (COGA) assessed between ages 12 and 31. Our findings indicate that AD PRS (p-threshold < 0.001) was associated with increased fronto-central, tempo-parietal, centro-parietal, and parietal-occipital interhemispheric theta and alpha connectivity in males only from ages 18-31 (beta coefficients ranged from 0.02-0.06, p-values ranged from 10-6-10-12), but not in females. Individuals with higher AD PRS also demonstrated more performance deficits on neuropsychological tasks (Tower of London task, visual span test) as well as increased risk for lifetime DSM-5 alcohol and opioid use disorders. We conclude that measures of neural connectivity, together with neurocognitive performance and substance use behavior, can be used to further understanding of how genetic risk variants from large GWAS of AUD may influence brain function. In addition, these data indicate the importance of examining sex and developmental effects, which otherwise may be masked. Understanding of neural mechanisms linking genetic variants emerging from GWAS to risk for AUD throughout development may help to identify specific points when neurocognitive prevention and intervention efforts may be most effective.

FinnTwin12 Cohort: An Updated Review

This review offers an update on research conducted with FinnTwin12 (FT12), the youngest of the three Finnish Twin Cohorts. FT12 was designed as a two-stage study. In the first stage, we conducted multiwave questionnaire research enrolling all eligible twins born in Finland during 1983-1987 along with their biological parents. In stage 2, we intensively studied a subset of these twins with in-school assessments at age 12 and semistructured poly-diagnostic interviews at age 14. At baseline, parents of intensively studied twins were administered the adult version of the interview. Laboratory studies with repeat interviews, neuropsychological tests, and collection of DNA were made of intensively studied twins during follow-up in early adulthood. The basic aim of the FT12 study design was to obtain information on individual, familial and school/neighborhood risks for substance use/abuse prior to the onset of regular tobacco and alcohol use and then track trajectories of use and abuse and their consequences into adulthood. But the longitudinal assessments were not narrowly limited to this basic aim, and with multiwave, multirater assessments from ages 11 to 12, the study has created a richly informative data set for analyses of gene-environment interactions of both candidate genes and genomewide measures with measured risk-relevant environments. Because 25 years have elapsed since the start of the study, we are planning a fifth-wave follow-up assessment.

Polygenic risk for alcohol misuse is moderated by romantic partnerships

BACKGROUND AND AIMS

Previous twin research suggests relationship status can moderate underlying genetic liability towards alcohol misuse. This paper examined: (1) whether genome-wide polygenic scores (GPS) for alcohol consumption are associated with alcohol misuse; (2) whether these GPS are moderated by romantic relationships (gene-environment interaction; G × E) and (3) whether G × E results are consistent across sex.

DESIGN

Linear mixed-effects models were used to test associations between genome-wide polygenic scores, relationship status and alcohol use/misuse.

SETTING

Finnish twins born between 1983 and 1987 identified through Finland's central population registry.

PARTICIPANTS

An intensively studied subset of Finnish Twin Study (FinnTwin12) during the young adult phase (aged 20-26 years). The analytical sample includes those with complete interview and genetic data (n = 1201).

MEASUREMENTS

Key measurements included involvement in a romantic partnership, drinking frequency, intoxication frequency and DSM-IV alcohol dependence (AD) symptoms. Genome-wide polygenic scores (GPS) were created from available summary statistics from a large genome-wide association study (GWAS) of drinks per week.

RESULTS

GPS predicted drinking frequency [b = 0.109; 95% confidence interval (CI) = 0.050, 0.168], intoxication frequency (b = 0.111; 95% CI = 0.054, 0.168) and AD symptoms (b = 0.123; 95% CI = 0.064, 0.182). Having a romantic relationship negatively influenced the association between GPS and drinking frequency (b = -0.105; 95% CI = -0.211, -0.001), intoxication frequency (b = -0.118; 95% CI = -0.220, -0.016) and AD symptoms (b = -0.119; 95% CI = -0.229, -0.009). There was a three-way interaction between sex, relationship status and GPS for intoxication frequency (b = 0.223; 95% CI = 0.013, 0.433), such that the reduced association between GPS and intoxication frequency for those in a relationship was only apparent in males. We found no evidence of three-way interactions for drinking frequency or AD symptoms.

CONCLUSIONS

Being in a romantic relationship reduced the association between genetic predisposition and drinking, high-risk drinking and alcohol problems. However, for high-risk drinking the protective effect was limited to males, mapping onto earlier findings suggesting that males benefit more from romantic partnerships.

Unpacking Genetic Risk Pathways for College Student Alcohol Consumption: The Mediating Role of Impulsivity

BACKGROUND

The period of college represents a particularly risky developmental stage with regard to alcohol use, as college students engage in more risky drinking behaviors than their noncollege peers, and such problematic alcohol use is associated with far-reaching negative consequences. Existing findings from genome-wide association studies (GWAS) indicate that alcohol consumption has a complex polygenic etiology. Currently, there is a lack of studies examining genetic risk for alcohol consumption using polygenic risk scores (PRS) in college samples. In this study, we examined whether alcohol-specific and risky behavior-related PRS were longitudinally associated with alcohol consumption among college students and whether this effect might be partially mediated by impulsivity domains.

METHODS

The sample included n = 2,385 European ancestry (EA) and n = 1,153 African ancestry (AA) college students assessed over the course of 4 years. To indicate genetic risk, 2 PRS were created based on recent large-scale GWAS: alcohol consumption (Liu et al., 2019) -drinks per week (DPW)-PRS and risky behaviors (Linnér et al., 2019) -RISK-PRS. The main outcome was alcohol consumption, measured across 4 waves of follow-up data. The UPPS-P impulsivity subscales were examined as mediators of the genetic effect on alcohol consumption.

RESULTS

The results from structural equation modeling showed that among EA students, both DPW-PRS and RISK-PRS had significant positive effects on alcohol consumption above and beyond UPPS dimensions and control variables. RISK-PRS explained larger portion of variance in alcohol consumption than DPW-PRS. RISK-PRS showed a significant indirect effect on alcohol consumption through sensation seeking and lack of perseverance; no significant indirect effect of DPW-PRS was found. No significant association of either PRS or alcohol consumption was found for AA participants.

CONCLUSIONS

The current results found that PRS related to more broadly defined risky behaviors predicted alcohol consumption across college years and that this association was partially mediated via dimensions of impulsivity.

Genome-wide association study identifies eight risk loci and implicates metabo-psychiatric origins for anorexia nervosa

Characterized primarily by a low body-mass index, anorexia nervosa is a complex and serious illness1, affecting 0.9-4% of women and 0.3% of men2-4, with twin-based heritability estimates of 50-60%5. Mortality rates are higher than those in other psychiatric disorders6, and outcomes are unacceptably poor7. Here we combine data from the Anorexia Nervosa Genetics Initiative (ANGI)8,9 and the Eating Disorders Working Group of the Psychiatric Genomics Consortium (PGC-ED) and conduct a genome-wide association study of 16,992 cases of anorexia nervosa and 55,525 controls, identifying eight significant loci. The genetic architecture of anorexia nervosa mirrors its clinical presentation, showing significant genetic correlations with psychiatric disorders, physical activity, and metabolic (including glycemic), lipid and anthropometric traits, independent of the effects of common variants associated with body-mass index. These results further encourage a reconceptualization of anorexia nervosa as a metabo-psychiatric disorder. Elucidating the metabolic component is a critical direction for future research, and paying attention to both psychiatric and metabolic components may be key to improving outcomes.