Genes, Environments, and Sex Differences in Alcohol Research

Sex and gender differences in cognitive resilience to aging and Alzheimer's disease

Sex and gender-biological and social constructs-significantly impact the prevalence of protective and risk factors, influencing the burden of Alzheimer's disease (AD; amyloid beta and tau) and other pathologies (e.g., cerebrovascular disease) which ultimately shape cognitive trajectories. Understanding the interplay of these factors is central to understanding resilience and resistance mechanisms explaining maintained cognitive function and reduced pathology accumulation in aging and AD. In this narrative review, the ADDRESS! Special Interest Group (Alzheimer's Association) adopted a multidisciplinary approach to provide the foundations and recommendations for future research into sex- and gender-specific drivers of resilience, including a sex/gender-oriented review of risk factors, genetics, AD and non-AD pathologies, brain structure and function, and animal research. We urge the field to adopt a sex/gender-aware approach to resilience to advance our understanding of the intricate interplay of biological and social determinants and consider sex/gender-specific resilience throughout disease stages. HIGHLIGHTS: Sex differences in resilience to cognitive decline vary by age and cognitive status. Initial evidence supports sex-specific distinctions in brain pathology. Findings suggest sex differences in the impact of pathology on cognition. There is a sex-specific change in resilience in the transition to clinical stages. Gender and sex factors warrant study: modifiable, immune, inflammatory, and vascular.

Characterizing the dimensions of positive emotion functioning in young adult alcohol use and alcohol-related problems

Emotional functioning figures prominently in most contemporary models of alcohol use (Kassel & Veilleux, 2010). These models posit that alcohol use becomes reinforced due to its ability to regulate a person's affect (Sher & Grekin, 2007). A growing body of literature suggests that for youth, positive reinforcement (i.e., using alcohol to enhance positive feelings or to increase their duration) is a leading mechanism facilitating increased use (Emery & Simons 2020; Howard et al., 2015). However, few, if any, studies have examined the unique associations between multiple indicators of positive emotional functioning and alcohol use as well as alcohol-related problems. We aimed to fill this gap by using secondary data from large college student sample (N = 402) to characterize the unique associations between trait indicators of positive emotional functioning (i.e., positive affect, anhedonia, savoring, positive emotion dysregulation) and alcohol use as well as alcohol-related problems. Results indicated trait positive emotion dysregulation (difficulty managing intense positive emotions) was positively related to both alcohol consumption (IRR = 1.03, p =.019) and alcohol-related problems (IRR = 1.03, p =.001). Interestingly, trait savoring (i.e., ability to increase the intensity/duration of positive emotions) was positively related to alcohol consumption (IRR = 1.18, p =.049) and inversely related to problems (IRR = 0.86, p =.019). None of the other positive emotion indicators were significantly associated with either alcohol use or problems.

Individual Trajectories of Depressive Symptoms Within Racially-Ethnically Diverse Youth: Associations with Polygenic Risk for Depression and Substance Use Intent and Perceived Harm

There are distinct individual trajectories of depressive symptoms across adolescence which are most often differentiated into low, moderate/stable, and high/increasing groups. Research has found genetic predisposition for depression associated with trajectories characterized by greater depressive symptoms. However, the majority of this research has been conducted in White youth. Moreover, a separate literature indicates that trajectories with elevated depressive symptoms can result in substance use. It is critical to identify depressive symptom trajectories, genetic predictors, and substance use outcomes in diverse samples in early adolescence to understand distinct processes and convey equitable benefits from research. Using data from the Adolescent Cognitive Brain Development Study (ABCD), we examined parent-reported depressive symptom trajectories within Black/African American (AA, n = 1783), White/European American (EA, n = 6179), and Hispanic/Latinx (LX, n = 2410) youth across four annual assessments in early adolescence (age 9-10 to 12-13). We examined racially/ethnically aligned polygenic scores (Dep-PGS) as predictors of trajectories as well as substance use intent and perceived substance use harm as outcomes at age 12-13. Differential trajectories were found in AA, EA, and LX youth but low and high trajectories were represented within each group. In EA youth, greater Dep-PGS were broadly associated with membership in trajectories with greater depressive symptoms. Genetic effects were not significant in AA and LX youth. In AA youth, membership in the low trajectory was associated with greater substance use intent. In EA youth, membership in trajectories with higher depressive symptoms was associated with greater substance use intent and less perceived harm. There were no associations between trajectories and substance use intent and perceived harm in LX youth. These findings indicate that there are distinct depressive symptom trajectories in AA, EA, and LX youth, accompanied by unique associations with genetic predisposition for depressive symptoms and substance use outcomes.

Alcohol cues increase behavioral economic demand and craving for alcohol in nontreatment-seeking and treatment-seeking heavy drinkers

BACKGROUND

Behavioral economic research has revealed significant increases in alcohol demand following exposure to alcohol-related cues. Prior research has focused exclusively on nontreatment-seeking heavy drinkers, included only male participants, or used heterogeneous methods. The current studies sought to replicate and extend existing findings in treatment-seeking and nontreatment-seeking heavy drinkers while also examining sex effects and moderation by alcohol use disorder (AUD) severity.

METHODS

Study 1 included 117 nontreatment-seeking heavy drinkers (51.5% women; M age 34.69; 56.4% AUD+), and Study 2 included 89 treatment-seeking heavy drinkers with AUD (40.4% women; M age = 41.35). In both studies, alcohol demand was measured using a hypothetical alcohol purchase task (APT), and subjective alcohol craving was measured using visual analog scales. Measures were collected following exposure to neutral (water) cues in a standard room and alcohol cues in a bar lab.

RESULTS

Alcohol demand (intensity, Omax , breakpoint, and elasticity) and craving were significantly increased following alcohol cues compared to neutral cues (ps < 0.005) with effect sizes ranging from small to large (ηp 2  = 0.074-0.480). Participants with AUD (Study 1) or with higher AUD severity (Study 2) reported higher craving and higher demand for most indices (i.e., main effects; ps < 0.032, ηp 2  = 0.043-0.239). A larger alcohol cue increase in Omax was found for AUD+ participants in Study 1 compared to non-AUD participants (p = 0.028, ηp 2  = 0.041) but not for any other indices in Study 1 or Study 2. There were no significant sex effects.

CONCLUSIONS

These findings replicate and extend prior research by offering additional insight into alcohol cue effects on the reinforcing value of alcohol and subjective motivation to drink. The results also suggest that sex and AUD severity do not meaningfully impact cue effects across most indices of demand.

COVID-19 pandemic stressors are associated with reported increases in frequency of drunkenness among individuals with a history of alcohol use disorder

Some sources report increases in alcohol use have been observed since the start of the COVID-19 pandemic, particularly among women. Cross-sectional studies suggest that specific COVID-19-related stressful experiences (e.g., social disconnection) may be driving such increases in the general population. Few studies have explored these topics among individuals with a history of Alcohol Use Disorders (AUD), an especially vulnerable population. Drawing on recent data collected by the Collaborative Study on the Genetics of Alcoholism (COGA; COVID-19 study N = 1651, 62% women, age range: 30-91) in conjunction with AUD history data collected on the sample since 1990, we investigated associations of COVID-19 related stressors and coping activities with changes in drunkenness frequency since the start of the pandemic. Analyses were conducted for those without a history of AUD (N: 645) and three groups of participants with a history of AUD prior to the start of the pandemic: (1) those experiencing AUD symptoms (N: 606), (2) those in remission who were drinking (N: 231), and (3) those in remission who were abstinent (had not consumed alcohol for 5+ years; N: 169). Gender-stratified models were also examined. Exploratory analyses examined the moderating effects of 'problematic alcohol use' polygenic risk scores (PRS) and neural connectivity (i.e., posterior interhemispheric alpha EEG coherence) on associations between COVID-19 stressors and coping activities with changes in the frequency of drunkenness. Increases in drunkenness frequency since the start of the pandemic were higher among those with a lifetime AUD diagnosis experiencing symptoms prior to the start of the pandemic (14% reported increased drunkenness) when compared to those without a history of AUD (5% reported increased drunkenness). Among individuals in remission from AUD prior to the start of the pandemic, rates of increased drunkenness were 10% for those who were drinking pre-pandemic and 4% for those who had previously been abstinent. Across all groups, women reported nominally greater increases in drunkenness frequency when compared with men, although only women experiencing pre-pandemic AUD symptoms reported significantly greater rates of increased drunkenness since the start of the pandemic compared to men in this group (17% of women vs. 5% of men). Among those without a prior history of AUD, associations between COVID-19 risk and protective factors with increases in drunkenness frequency were not observed. Among all groups with a history of AUD (including those with AUD symptoms and those remitted from AUD), perceived stress was associated with increases in drunkenness. Among the remitted-abstinent group, essential worker status was associated with increases in drunkenness. Gender differences in these associations were observed: among women in the remitted-abstinent group, essential worker status, perceived stress, media consumption, and decreased social interactions were associated with increases in drunkenness. Among men in the remitted-drinking group, perceived stress was associated with increases in drunkenness, and increased relationship quality was associated with decreases in drunkenness. Exploratory analyses indicated that associations between family illness or death with increases in drunkenness and increased relationship quality with decreases in drunkenness were more pronounced among the remitted-drinking participants with higher PRS. Associations between family illness or death, media consumption, and economic hardships with increases in drunkenness and healthy coping with decreases in drunkenness were more pronounced among the remitted-abstinent group with lower interhemispheric alpha EEG connectivity. Our results demonstrated that only individuals with pre-pandemic AUD symptoms reported greater increases in drunkenness frequency since the start of the COVID-19 pandemic compared to those without a lifetime history of AUD. This increase was more pronounced among women than men in this group. However, COVID-19-related stressors and coping activities were associated with changes in the frequency of drunkenness among all groups of participants with a prior history of AUD, including those experiencing AUD symptoms, as well as abstinent and non-abstinent participants in remission. Perceived stress, essential worker status, media consumption, social connections (especially for women), and relationship quality (especially for men) are specific areas of focus for designing intervention and prevention strategies aimed at reducing pandemic-related alcohol misuse among this particularly vulnerable group. Interestingly, these associations were not observed for individuals without a prior history of AUD, supporting prior literature that demonstrates that widespread stressors (e.g., pandemics, terrorist attacks) disproportionately impact the mental health and alcohol use of those with a prior history of problems.

Alcohol use polygenic risk score, social support, and alcohol use among European American and African American adults

Alcohol use is influenced by genetic and environmental factors. We examined the interactive effects between genome-wide polygenic risk scores for alcohol use (alc-PRS) and social support in relation to alcohol use among European American (EA) and African American (AA) adults across sex and developmental stages (emerging adulthood, young adulthood, and middle adulthood). Data were drawn from 4,011 EA and 1,274 AA adults from the Collaborative Study on the Genetics of Alcoholism who were between ages 18-65 and had ever used alcohol. Participants completed the Semi-Structured Assessment for the Genetics of Alcoholism and provided saliva or blood samples for genotyping. Results indicated that social support from friends, but not family, moderated the association between alc-PRS and alcohol use among EAs and AAs (only in middle adulthood for AAs); alc-PRS was associated with higher levels of alcohol use when friend support was low, but not when friend support was high. Associations were similar across sex but differed across developmental stages. Findings support the important role of social support from friends in buffering genetic risk for alcohol use among EA and AA adults and highlight the need to consider developmental changes in the role of social support in relation to alcohol use.

Polygenic Effects on Individual Rule Breaking, Peer Rule Breaking, and Alcohol Sips Across Early Adolescence in the ABCD Study

Alcohol use emerges during early adolescence and is strongly associated with individual and peer risky, delinquent, and rule breaking behaviors. Genetic predisposition for risky behavior contributes to individual rule breaking in adolescence and can also evoke peer rule breaking or lead youth to select into delinquent peer groups via gene-environment correlations (rGE), collectively increasing risk for alcohol use. Little research has examined whether genetic predisposition for risky behavior contributes to individual and peer rule breaking behavior in developmental pathways to alcohol use in early adolescence or in large diverse racial/ethnic populations. To address this, polygenic scores for risky behavior were considered predictors of individual rule breaking, peer rule breaking, and alcohol sips using data from the Adolescent Brain Cognitive Development (ABCD) study at age 11-12 and 12-13 in a cross-time cross-lagged model. This was examined separately in European American (EA; n = 5113; 47% female), African American (AA; n = 1159; 50% female), and Hispanic/Latinx (Latinx; n = 1624; 48% female) subgroups accounting for sociodemographic covariates and genetic ancestry principal components. Polygenic scores were positively associated with all constructs in EAs, with individual rule breaking at age 11-12 in AAs and Latinx, and with alcohol sips at age 11-12 in Latinx. Individual and peer rule breaking were associated with one another across time only in the EA subgroup. In all subgroups, peer rule breaking at 12-13 was associated with alcohol sips at 12-13. Results indicate that alcohol sips in early adolescence are associated with individual and peer rule breaking with rGE implicated in EAs.

Effect of very low nicotine content cigarettes on alcohol drinking and smoking among adult smokers who are at-risk alcohol drinkers

Alcohol and tobacco use are interrelated. This study examined response to very low nicotine content (VLNC) and moderate nicotine content (MNC) cigarettes by problematic drinking. We utilized a double-blind, randomized, within-subjects crossover design of VLNC and MNC cigarettes in two groups of adult cigarette smokers: with at-risk drinking (ARD; n = 23) and without ARD (n = 24). Participants smoked only their assigned experimental cigarette in their home environment for 7 days, and completed laboratory visits, including ad libitum smoking of the assigned experimental cigarette, at the beginning and end of each experimental week. Participants smoked their usual cigarettes for 7 days between conditions. Participants provided daily reports of alcohol and cigarette consumption. Current Diagnostic and Statistical Manual of Mental Disorders-5th edition (DSM-5) alcohol use disorder (AUD) was assessed at baseline and the end of each experimental week. Compliance with smoking of experimental cigarettes was good. Adjusting for baseline drinking, there was no significant effect of experimental cigarette or ARD group on drinks per day or alcohol urges. There was no effect of experimental cigarette or ARD group on cigarettes per day, or on any puff topography outcome or postsmoking exhaled carbon monoxide during laboratory smoking. No participant had a change in AUD status or AUD severity. After 7 days of exposure to VLNC cigarettes, adult cigarette smokers with ARD did not show compensatory drinking or compensatory smoking behavior. A future policy change in the United States to reduce nicotine content in cigarettes may not produce unintended compensatory drinking or smoking among this vulnerable and prevalent population of smokers. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Changes over time in endorsement of 11 DSM-IV alcohol use disorder (AUD) criteria in young adults with persistent or recurrent AUD in The Collaborative Study on the Genetics of Alcoholism

BACKGROUND

Endorsement of specific Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) alcohol use disorder (AUD) criteria have been shown to change significantly over time in men in their thirties who have persistent or recurrent AUD. However, few studies have documented whether the endorsement of AUD items changes over time in younger individuals or in women. We evaluated changes in the endorsement of AUD criteria in 377 men and women with persistent or recurrent AUD during their twenties.

METHODS

Information on AUD-item endorsement over time was available for 223 men and 154 women aged 20-25 with persistent or recurrent AUD in at least three interviews in the Collaborative Study on the Genetics of Alcoholism. The statistical significance of endorsement changes over time was evaluated using the related-sample Cochran's Q test for the full sample and for men and women separately. Additional analyses evaluated sex differences in the patterns of change.

RESULTS

In the full sample, the predominant pattern was for a significant increase in the rates of endorsement for six of the seven alcohol dependence criteria but not in the four abuse criteria. A similar pattern was seen within men, but women had significant changes in only three of the seven dependence criteria.

CONCLUSIONS

Endorsement of the seven alcohol dependence criteria among individuals with persistent or recurrent AUD in their twenties generally increased, but few changes were observed in the rates of endorsement of the four abuse criteria. These results are discussed in terms of how they reflect on the nature of AUD and the DSM criteria.

Measures of self-reported identity associated with sex and gender: Relations with collegiate drinking

OBJECTIVE

Quantitative research has typically relied on categorical measures of sex assigned at birth (SAAB) and gender, with heterogeneous findings in terms of their associations with alcohol-related behavior. This investigation examined continuous indices of self-identification as an alternative to categorical operationalizations in alcohol research.

METHOD

Eight hundred ninety-three undergraduate students (74.6% cisgender women, 20.3% cisgender men, 3.9% nonbinary, and 1.2% transgender), recruited from the Midwest and Pacific Northwest of the United States, completed online measures of SAAB (male/female), gender (categorical), continuous indices of identification (femaleness, maleness, and bidirectional), and alcohol consumption (Cahalan Indices; Daily Drinking Questionnaire-Revised; Alcohol Use Disorders Identification Test [AUDIT]).

RESULTS

Novel continuous measures of identification were associated with categorical indices of SAAB and gender as predicted. While none of the self-identification indices (continuous or categorical) predicted current drinking (consumption in the past 30 days), they evidenced relatively consistent, albeit small effects, across quantity-frequency of drinking and AUDIT scores for current drinkers. Higher scores on maleness and bidirectional indices of identification were associated with greater consumption, while greater endorsement of femaleness and being a cisgender woman (vs. a cisgender man) were related to less drinking.

CONCLUSIONS

Continuous self-reported identification items performed well when describing drinking behavior in college students. The inclusion of dimensional scales of identity broadens our ability to capture differing self-conceptualizations in research.

Clinical characteristics indexing genetic differences in schizophrenia: a systematic review

Genome-wide studies are among the best available tools for identifying etiologic processes underlying psychiatric disorders such as schizophrenia. However, it is widely recognized that disorder heterogeneity may limit genetic insights. Identifying phenotypes indexing genetic differences among patients with non-affective psychotic disorder will improve genome-wide studies of these disorders. The present study systematically reviews existing literature to identify phenotypes that index genetic differences among patients with schizophrenia and related disorders. We systematically reviewed family-based studies and genome-wide molecular-genetic studies investigating whether phenotypic variation in patients with non-affective psychotic disorders (according to DSM or equivalent systems) was associated with genome-wide genetic variation (PROSPERO number CRD42019136169). An electronic database search of PubMed, EMBASE, and PsycINFO from inception until 17 May 2019 resulted in 4347 published records. These records included a total of 813 relevant analyses from 264 articles. Two independent raters assessed the quality of all analyses based on methodologic rigor and power. We found moderate to strong evidence for a positive association between genetic/familial risk for non-affective psychosis and four phenotypes: early age of onset, negative/deficit symptoms, chronicity, and functional impairment. Female patients also tended to have more affected relatives. Severity of positive symptoms was not associated with genetic/familial risk for schizophrenia. We suggest that phenotypes with the most evidence for reflecting genetic difference in participating patients should be measured in future large-scale genetic studies of schizophrenia to improve power to discover causal variants and to facilitate discovery of modifying genetic variants.

Association of Alcohol Consumption with Cognition in Older Population: The A4 Study

BACKGROUND

Alcohol use disorders have been categorized as a 'strongly modifiable' risk factor for dementia.

OBJECTIVE

To investigate the cross-sectional association between alcohol consumption and cognition in older adults and if it is different across sexes or depends on amyloid-β (Aβ) accumulation in the brain.

METHODS

Cognitively unimpaired older adults (N = 4387) with objective and subjective cognitive assessments and amyloid positron emission tomography (PET) imaging were classified into four categories based on their average daily alcohol use. Multivariable linear regression was then used to test the main effects and interactions with sex and Aβ levels.

RESULTS

Individuals who reported no alcohol consumption had lower scores on the Preclinical Alzheimer Cognitive Composite (PACC) compared to those consuming one or two drinks/day. In sex-stratified analysis, the association between alcohol consumption and cognition was more prominent in females. Female participants who consumed two drinks/day had better performance on PACC and Cognitive Function Index (CFI) than those who reported no alcohol consumption. In an Aβ-stratified sample, the association between alcohol consumption and cognition was present only in the Aβ- subgroup. The interaction between Aβ status and alcohol consumption on cognition was not significant.

CONCLUSION

Low or moderate consumption of alcohol was associated with better objective cognitive performance and better subjective report of daily functioning in cognitively unimpaired individuals. The association was present only in Aβ- individuals, suggesting that the pathophysiologic mechanism underlying the effect of alcohol on cognition is independent of Aβ pathology. Further investigation is required with larger samples consuming three or more drinks/day.

The role of adolescent social relationships in promoting alcohol resistance: Interrupting the intergenerational transmission of alcohol misuse

Genetic factors contribute to the intergenerational transmission of alcohol misuse, but not all individuals at high genetic risk develop problems. The present study examined adolescent relationships with parents, peers, and romantic partners as predictors of realized resistance, defined as high biological risk for disorder combined with a healthy outcome, to alcohol initiation, heavy episodic drinking, and alcohol use disorder (AUD). Data were from the Collaborative Study on the Genetics of Alcoholism (N = 1,858; 49.9% female; mean age at baseline = 13.91 years). Genetic risk, indexed using family history density and polygenic risk scores for alcohol problems and AUD, was used to define alcohol resistance. Adolescent predictors included parent-child relationship quality, parental monitoring, peer drinking, romantic partner drinking, and social competence. There was little support for the hypothesis that social relationship factors would promote alcohol resistance, with the exception that higher father-child relationship quality was associated with higher resistance to alcohol initiation (β ^ = - 0.19 , 95% CI = -0.35, -0.03). Unexpectedly, social competence was associated with lower resistance to heavy episodic drinking (β ^ = 0.10 , 95% CI = 0.01, 0.20). This pattern of largely null effects underscores how little is known about resistance processes among those at high genetic risk for AUD.

Coping Flexibility and Alcohol-Related Outcomes: Examining Coping Motives as Mediators

Background: Coping has been implicated in the etiology and treatment of problem drinking. Traditional, static measurement of coping styles (e.g., approach, avoidance, social support) may fail to capture how adaptive a given coping style may be. Coping flexibility is an emerging construct, associated with psychological health, and one that may shed light on coping's role in drinking risk. Coping flexibility includes (1) discontinuation of an ineffective coping strategy ("Discontinuation") and (2) production of an alternative strategy ("Implementation"). This study is the first to our knowledge to examine its association to drinking outcomes. Further, because coping deficits are theorized to lead to drinking through coping motives, we also examined mediated pathways from coping flexibility to alcohol outcomes via coping motives. Methods: College students (N = 528) completed an online assessment. Data were analyzed using path analysis. Control variables included sex and coping styles. Results: In path analytic models, Implementation was negatively associated with alcohol use and, indirectly via coping motives, negatively associated with alcohol consequences. The direct effect on alcohol use remained when controlling for coping styles and sex, but the mediational pathway was no longer significant. Conclusions: This study provides some evidence for the protective role of coping flexibility in alcohol use behavior, which may have implications for how best to address coping skills in alcohol interventions. The direct effect of Implementation on drinking suggests that there may be utility in teaching clients a flexible approach to coping in treatment. Replication, particularly with longitudinal designs, is needed.

Genetic liability for substance use associated with medical comorbidities in electronic health records of African- and European-ancestry individuals

Polygenic risk scores (PRS) represent an individual's summed genetic risk for a trait and can serve as biomarkers for disease. Less is known about the utility of PRS as a means to quantify genetic risk for substance use disorders (SUDs) than for many other traits. Nonetheless, the growth of large, electronic health record-based biobanks makes it possible to evaluate the association of SUD PRS with other traits. We calculated PRS for smoking initiation, alcohol use disorder (AUD), and opioid use disorder (OUD) using summary statistics from the Million Veteran Program sample. We then tested the association of each PRS with its primary phenotype in the Penn Medicine BioBank (PMBB) using all available genotyped participants of African or European ancestry (AFR and EUR, respectively) (N = 18,612). Finally, we conducted phenome-wide association analyses (PheWAS) separately by ancestry and sex to test for associations across disease categories. Tobacco use disorder was the most common SUD in the PMBB, followed by AUD and OUD, consistent with the population prevalence of these disorders. All PRS were associated with their primary phenotype in both ancestry groups. PheWAS results yielded cross-trait associations across multiple domains, including psychiatric disorders and medical conditions. SUD PRS were associated with their primary phenotypes; however, they are not yet predictive enough to be useful diagnostically. The cross-trait associations of the SUD PRS are indicative of a broader genetic liability. Future work should extend findings to additional population groups and for other substances of abuse.

Sex bias in alcohol research: A 20-year comparative study

We aimed to assess the sex-inclusive and sex-based analysis bias in alcohol research for the past 20 years. Data were abstracted from 2988 original research articles published from 2000 through 2019 in 51 representative journals across 9 biomedical disciplines. An analysis in 5-year intervals revealed that the percentage of studies using participants of both sexes was significantly higher between 2015 and 2019 than between 2000 and 2014. When stratified, clinical studies showed a higher percentage of both-sex studies compared to basic studies using animals. The reasons for the use of single-sex cohorts mainly included insufficient participant numbers and misconceptions surrounding the hormonal variability of females. Implementation of the NIH SABV policy promoted the ratio of NIH-funded papers with sex-based analyses. In conclusion, sex bias in alcohol-related biomedical studies has improved over the past 20 years, particularly after the implementation of the SABV policy. Although clinical studies increasingly included sex-based analysis, basic studies were biased towards the use of males.

Concurrent validity of the Alcohol Purchase Task for measuring the reinforcing efficacy of alcohol: an updated systematic review and meta-analysis

BACKGROUND AND AIMS

An early meta-analysis testing the concurrent validity of the Alcohol Purchase Task (APT), a measure of alcohol's relative reinforcing value, reported mixed associations, but predated a large number of studies. This systematic review and meta-analysis sought to: (1) estimate the relationships between trait-based alcohol demand indices from the APT and multiple alcohol indicators, (2) test several moderators and (3) analyze small study effects.

METHODS

A meta-analysis of 50 cross-sectional studies in four databases (n = 18 466, females = 43.32%). Sex, year of publication, number of APT prices and index transformations (logarithmic, square root or none) were considered as moderators. Small study effects were examined by using the Begg-Mazumdar, Egger's and Duval & Tweedie's trim-and-fill tests. Alcohol indicators were quantity of alcohol use, number of heavy drinking episodes, alcohol-related problems and hazardous drinking. APT indices were intensity (i.e. consumption at zero cost), elasticity (i.e. sensitivity to increases in costs), O_max (i.e. maximum expenditure), P_max (i.e. price associated to O_max ) and breakpoint (i.e. price at which consumption ceases).

RESULTS

All alcohol demand indices were significantly associated with all alcohol-related outcomes (r = 0.132-0.494), except P_max , which was significantly associated with alcohol-related problems only (r = 0.064)_. The greatest associations were evinced between intensity in relation to alcohol use, hazardous drinking and heavy drinking and between O_max and alcohol use. All the tested moderators emerged as significant moderators. Evidence of small-study effects was limited.

CONCLUSIONS

The Alcohol Purchase Task appears to have concurrent validity in alcohol research. Intensity and O_max are the most relevant indices to account for alcohol involvement.

Shortening time for access to alcohol drives up front-loading behavior, bringing consumption in male rats to the level of females

Background

Incentives to promote drinking (“happy hour”) can encourage faster rates of alcohol consumption, especially in women. Sex differences in drinking dynamics may underlie differential health vulnerabilities relating to alcohol in women versus men. Herein, we used operant procedures to model the happy hour effect and gain insight into the alcohol drinking dynamics of male and female rats.

Methods

Adult male and female Wistar rats underwent operant training to promote voluntary drinking of 10% (w/v) alcohol (8 rats/sex). We tested how drinking patterns changed after manipulating the effort required for alcohol (fixed ratio, FR), as well as the length of time in which rats had access to alcohol (self-administration session length). Rats were tested twice within the 12 h of the dark cycle, first at 2 h (early phase of the dark cycle, “early sessions”) and then again at 10 h into the dark cycle (late phase of the dark cycle, “late sessions”) with an 8-h break between the two sessions in the home cage.

Results

Adult females consumed significantly more alcohol (g/kg) than males in the 30-min sessions with the FR1 schedule of reinforcement when tested late in the dark cycle. Front-loading of alcohol was the primary factor driving higher consumption in females. Changing the schedule of reinforcement from FR1 to FR3 reduced total consumption. Notably, this manipulation had minimal effect on front-loading behavior in females, whereas front-loading behavior was significantly reduced in males when more effort was required to access alcohol. Compressing drinking access to 15 min to model a happy hour drove up front-loading behavior, generating alcohol drinking patterns in males that were similar to patterns in females (faster drinking and higher intake).

Conclusions

This strategy could be useful for exploring sex differences in the neural mechanisms underlying alcohol drinking and related health vulnerabilities. Our findings also highlight the importance of the time of testing for detecting sex differences in drinking behavior.

Voluntary alcohol drinking is higher in adult female rats compared to adult male rats. This sex difference is most pronounced in the later phase of the dark cycle, and when the operant effort is minimal (when 1 lever press gives 1 reward: fixed ratio 1, FR1).

Higher alcohol intake in females is primarily due to “front-loading”, or the rapid consumption of alcohol within the first 5 min of access.

Increasing the effort required to obtain alcohol from FR1 to FR3 dampens front-loading drinking behavior, resulting in similar levels of total intake in males and females.

Compressing the time of access to 15 min drives up front-loading to such a degree that rats end up consuming more alcohol in total than they do in 30-min sessions. In males, this increase in drinking is large enough that it eliminates the sex difference in total alcohol intake.

Enhanced Brief Motivational Intervention for College Student Drinkers With ADHD: Goal-Directed Activation as a Mechanism of Change

College students with attention-deficit/hyperactivity disorder (ADHD) are at risk for alcohol-related problems and disorders relative to their typically developing peers. Despite risk, the optimal therapeutic approach for reducing problem alcohol use in students with ADHD, and mechanisms of change underlying treatment effects in this population, are largely unknown. The current study evaluated putative mechanisms of change in a randomized controlled trial of two harm reduction interventions for college student drinkers with ADHD (N = 113; 49% male): brief motivational intervention plus supportive counseling (BMI + SC) versus brief motivational intervention plus behavioral activation (BMI + BA). Results showed that participants in the BMI + BA condition engaged in more goal-directed activation and less avoidant behavior over the course of treatment compared to those in the BMI + SC condition, in turn predicting reductions in alcohol-related negative consequences. Effects were more robust 1 month following intervention, and diminished by 3 months. Sensitivity analyses revealed a significant indirect effect of treatment condition on alcohol-related negative consequence via reductions in avoidance over treatment. Post hoc moderated mediations showed that BMI + BA engaged target mechanisms more robustly for students with more severe ADHD and depressive symptoms compared to BMI + SC. These findings support the application of BMI + BA intervention, particularly in targeting goal-directed activation and avoidance/rumination in at-risk student drinkers with ADHD.

Self-Rated Aversion to Taste Qualities and the PROP Taster Phenotype Associate with Alcoholic Beverage Intake and Preference

Consumers often identify “taste” as an important factor when selecting alcoholic beverages. Although it is assumed that reduced alcohol consumption in PROP super-tasters is due to a greater dislike of the nominally aversive sensations that they experience more intensely (e.g., bitterness) when compared to PROP non-tasters, this question has not been specifically asked to them. Therefore, we examined consumers’ self-reported aversion towards specific sensory attributes (bitter, hot/burn, dry, sour, sweet, carbonation) for four alcoholic beverage types (white wine, red wine, beer, spirits) using a convenience sample of U.S. wine consumers (n = 925). Participants rated 18 statements describing different combinations of sensory attributes and alcoholic beverages on a 5-point Likert scale (e.g., Beer tastes too bitter for me). Individuals who tended to agree more strongly with the statements (i.e., they were more averse; p(F) < 0.05) tended to (i) consume less of all beverage types, (ii) consume a higher proportion of white wine (p(r) < 0.05), and (iii) were more likely to be female or PROP super-tasters. The results suggest that self-reported aversion to specific sensory attributes is associated with not only lower overall intake of alcoholic beverages, but also a shift in the relative proportions of beverage type consumed; a key finding for studies investigating how taste perception impacts alcohol consumption.

COVID-19 Pandemic on Fire: Evolved Propensities for Nocturnal Activities as a Liability Against Epidemiological Control

Humans have been using fire for hundreds of millennia, creating an ancestral expansion toward the nocturnal niche. The new adaptive challenges faced at night were recurrent enough to amplify existing psychological variation in our species. Night-time is dangerous and mysterious, so it selects for individuals with higher tendencies for paranoia, risk-taking, and sociability (because of security in numbers). During night-time, individuals are generally tired and show decreased self-control and increased impulsive behaviors. The lower visibility during night-time favors the partial concealment of identity and opens more opportunities for disinhibition of self-interested behaviors. Indeed, individuals with an evening-oriented chronotype are more paranoid, risk-taking, extraverted, impulsive, promiscuous, and have higher antisocial personality traits. However, under some circumstances, such as respiratory pandemics, the psychobehavioral traits favored by the nocturnal niche might be counter-productive, increasing contagion rates of a disease that can evade the behavioral immune system because its disease cues are often nonexistent or mild. The eveningness epidemiological liability hypothesis presented here suggests that during the COVID-19 pandemic, the evening-oriented psychobehavioral profile can have collectively harmful consequences: there is a clash of core tendencies between the nocturnal chronotype and the recent viral transmission-mitigating safety guidelines and rules. The pandemic safety protocols disrupt much normal social activity, particularly at night when making new social contacts is desired. The SARS-CoV-2 virus is contagious even in presymptomatic and asymptomatic individuals, which enables it to mostly evade our evolved contagious disease avoidance mechanisms. A growing body of research has indirectly shown that individual traits interfering with social distancing and anti-contagion measures are related to those of the nocturnal chronotype. Indeed, some of the social contexts that have been identified as superspreading events occur at night, such as in restaurants, bars, and nightclubs. Furthermore, nocturnal environmental conditions favor the survival of the SARS-CoV-2 virus much longer than daytime conditions. We compare the eveningness epidemiological liability hypothesis with other factors related to non-compliance with pandemic safety protocols, namely sex, age, and life history. Although there is not yet a direct link between the nocturnal chronotype and non-compliance with pandemic safety protocols, security measures and future empirical research should take this crucial evolutionary mismatch and adaptive metaproblem into account, and focus on how to avoid nocturnal individuals becoming superspreaders, offering secure alternatives for nocturnal social activities.

A Gender Perspective of Addictive Disorders

Purpose of Review

Substance use disorders (SUD) affect differentially women and men. Although the prevalence has been reported higher in men, those women with addictive disorders present a more vulnerable profile and are less likely to enter treatment than men. The aim of this paper is to present an overview of how sex and gender may influence epidemiology, clinical manifestations, social impact, and the neurobiological basis of these differences of women with SUD, based on human research.

Recent Findings

The differences in prevalence rates between genders are getting narrower; also, women tend to increase the amount of consumption more rapidly than men, showing an accelerated onset of the SUD (telescoping effect). In respect to clinical features, the most important differences are related to the risk of experience psychiatric comorbidity, the exposure to intimate partner violence, and the associated high risks in sexual and reproductive health; and those who are mothers and addicted to substances are at risk of losing the custody of children accumulating more adverse life events. Some of these differences can be based on neurobiological differences: pharmacokinetic response to substances, sensitivity to gonadal hormones, differences in neurobiological systems as glutamate, endocannabinoids, and genetic differences.

Summary

Specific research in women who use drugs is very scarce and treatments are not gender-sensitive oriented. For these reasons, it is important to guarantee access to the appropriate treatment of women who use drugs and a need for a gender perspective in the treatment and research of substance use disorders.

Health policy and genetic endowments: Understanding sources of response to Minimum Legal Drinking Age laws

This paper uses policy-induced variation in legal access to alcohol in the United States to explore interactions between genetic predispositions and health behaviors. It is well known that Minimum Legal Drinking Age (MLDA) laws have discrete impacts on binge drinking behaviors, but less is known about heterogeneity of the effects and the characteristics of individuals most and least affected. Using the Add Health data, this paper explores differential policy effects based on polygenic scores (PGS), which are genome-wide summary measures predicting health outcomes. Specifically, we leverage PGS for alcoholism and for a broader set of risk-taking behaviors to explore heterogeneities in response to the policy and consider mechanisms for the responses. Like previous literature using the Add Health and other datasets, we find main effects of MLDA in increasing recent binge drinking episodes by approximately 5 percentage points. We find MLDA effects are concentrated entirely in individuals with high PGS for alcohol use. We are also able to compare these results with measures of parental alcoholism as a global proxy for family history.

Concurrent validity of the alcohol purchase task in relation to alcohol involvement: protocol for a systematic review and meta-analysis

INTRODUCTION

Alcohol demand, as measured by an alcohol purchase task (APT), provides a multidimensional assessment of the relative reinforcing efficacy of alcohol. The objective of this meta-analysis is to critically appraise the existing literature on the concurrent validity of the APT by meta-analysing the cross-sectional relationships between indices of the APT (ie, breakpoint, O_max, P_max, elasticity and intensity) and alcohol-related measures. It also aims to examine methodological procedures used to obtain APT indices and individual variables as potential moderators on the assessed estimations.

METHODS AND ANALYSIS

A comprehensive literature search conducted from inception to April 2020 will be conducted in the PubMed, PsycINFO, Web of Science and Scopus databases. Two authors will independently screen and extract data from articles using a predefined protocol search and extraction forms. Disagreements will be resolved through discussion with two additional reviewers. All results will be tabulated, and a random-effect meta-analysis will be conducted. Participants' sex, number of prices and APT methodological procedures will be examined as potential moderators on the observed effect sizes.

ETHICS AND DISSEMINATION

Results of this meta-analysis will characterise the concurrent validity of the APT in the existing literature. Further, the results are anticipated to provide evidence on which index (or indices) is most robustly associated with alcohol use and severity. Ethics approval was not required for this study and the results will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019137512.

Using the tools of genetic epidemiology to understand sex differences in neuropsychiatric disorders

Many neuropsychiatric disorders exhibit differences in prevalence, age of onset, symptoms or course of illness between males and females. For the most part, the origins of these differences are not well understood. In this article, we provide an overview of sex differences in psychiatric disorders including autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), anxiety, depression, alcohol and substance abuse, schizophrenia, eating disorders and risk of suicide. We discuss both genetic and nongenetic mechanisms that have been hypothesized to underlie these differences, including ascertainment bias, environmental stressors, X‐ or Y‐linked risk loci, and differential liability thresholds in males and females. We then review the use of twin, family and genome‐wide association approaches to study potential genetic mechanisms of sex differences and the extent to which these designs have been employed in studies of psychiatric disorders. We describe the utility of genetic epidemiologic study designs, including classical twin and family studies, large‐scale studies of population registries, derived recurrence risks, and molecular genetic analyses of genome‐wide variation that may enhance our understanding sex differences in neuropsychiatric disorders.

Prospects for finding the mechanisms of sex differences in addiction with human and model organism genetic analysis

Despite substantial evidence for sex differences in addiction epidemiology, addiction-relevant behaviors and associated neurobiological phenomena, the mechanisms and implications of these differences remain unknown. Genetic analysis in model organism is a potentially powerful and effective means of discovering the mechanisms that underlie sex differences in addiction. Human genetic studies are beginning to show precise risk variants that influence the mechanisms of addiction but typically lack sufficient power or neurobiological mechanistic access, particularly for the discovery of the mechanisms that underlie sex differences. Our thesis in this review is that genetic variation in model organisms are a promising approach that can complement these investigations to show the biological mechanisms that underlie sex differences in addiction.

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.

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.

Gender Differences in Harmful Use of Alcohol Among Korean Adults

Objectives

Harmful alcohol consumption is associated with considerable social and economic damage to individuals and society. Because gender and ethnic background influence alcohol intake differently, examining gender specific factors influencing harmful drinking is necessary. This study investigated gender differences in alcohol consumption, harmful drinking, and the associated factors among Korean adults.

Methods

We analyzed the data from the 2012–2015 Korean National Health and Nutrition Examination Survey. Data from survey participants aged 20–64 years (N = 18,581) were included. The Alcohol Use Disorders Identification Test was used for alcohol dependence, and pooled weights were used. Chi-squared tests and multiple logistic regression analyses were conducted.

Results

The prevalence of harmful alcohol use (Alcohol Use Disorders Identification Test score ≥ 16) was 10.7% in the total sample; 18.4% in men and 3.4% in women, which constituted a significant difference. Education, marital status, smoking, perceived stress, and depressive feeling were associated with harmful drinking in both genders. However, household income, occupation, and perceived health status were associated with harmful drinking only in men.

Conclusion

Since there are gender differences in harmful drinking and alcohol dependence, gender tailored prevention and intervention strategies for alcohol dependence are necessary including consideration of smoking, stress, and depressive feeling.

Predictors of Increases in Alcohol Problems and Alcohol Use Disorders in Offspring in the San Diego Prospective Study

BACKGROUND

The 35-year-long San Diego Prospective Study documented 2-fold increases in alcohol problems and alcohol use disorders (AUDs) in young-adult drinking offspring compared to rates in their fathers, the original probands. The current analyses use the same interviews and questionnaires at about the same age in members of the 2 generations to explore multiple potential contributors to the generational differences in adverse alcohol outcomes.

METHODS

Using data from recent offspring interviews, multiple cross-generation differences in characteristics potentially related to alcohol problems were evaluated in 3 steps: first through direct comparisons across probands and offspring at about age 30; second by backward linear regression analyses of predictors of alcohol problems within each generation; and finally third through R-based bootstrapped linear regressions of differences in alcohol problems in randomly matched probands and offspring.

RESULTS

The analyses across the analytical approaches revealed 3 consistent predictors of higher alcohol problems in the second generation. These included the following: (i) a more robust relationship to alcohol problems for offspring with a low level of response to alcohol; (ii) higher offspring values for alcohol expectancies; and (iii) higher offspring impulsivity.

CONCLUSIONS

The availability of data across generations offered a unique perspective for studying characteristics that may have contributed to a general finding in the literature of substantial increases in alcohol problems and AUDs in recent generations. If replicated, these results could suggest approaches to be used by parents, healthcare workers, insurance companies, and industry in their efforts to mitigate the increasing rates of alcohol problems in younger generations.

Performance of the Self-Report of the Effects of Alcohol Questionnaire Across Sexes and Generations

BACKGROUND

Low level of responses (low LRs) to alcohol established using the Self-Report of the Effects of Alcohol (SRE) questionnaire are genetically influenced phenotypes related to heavy drinking and alcohol problems. To date, most studies using SREs focused on scores for the number of drinks needed for effects across the first 5 times of drinking (SRE-5), and few evaluated scores that also included the prior 3 months and heaviest drinking periods (SRE-T). This paper evaluates characteristics of SRE-5 and SRE-T within and across generations.

METHODS

Data were extracted from 407 participants across 2 generations of 107 families in the San Diego Prospective Study (SDPS). Pearson's product-moment correlations for SRE-5 and SRE-T were determined across first-degree relatives both within and across generations and sexes, as well as correlations of each measure to maximum drinking quantities and alcohol problems.

RESULTS

Responding to 4 hypotheses, first the analyses demonstrated significant within-generation positive correlations for both SRE measures across brother-brother and sister-sister pairs as well as cross-generation correlations for fathers and sons, although correlations for mothers and daughters were not robust. Second, both SRE-5 and SRE-T correlated with maximum drinks and alcohol problems for both sexes and both generations. Third, within parental and offspring generations SRE-T correlated more robustly than SRE-5 to maximum drinks and alcohol problems. Fourth, across generations SRE values for sons were more closely related to drinking quantities and problems than for their fathers, but the mother-daughter SRE relationships to adverse alcohol characteristics were not different.

CONCLUSIONS

Both the SRE-5 and SRE-T offered useful information about propensities toward heavier drinking and alcohol problems in SDPS families. Correlations with adverse alcohol outcomes were greater for the more broad-based SRE-T, but both scores appeared to be genetically influenced and continue to operate in a robust manner in both generations of these families.

Sex-Gender Variable: Methodological Recommendations for Increasing Scientific Value of Clinical Studies

There is a clear sex-gender gap in the prevention and occurrence of diseases, and in the outcomes and treatments, which is relevant to women in the majority of cases. Attitudes concerning the enrollment of women in randomized clinical trials have changed over recent years. Despite this change, a gap still exists. This gap is linked to biological factors (sex) and psycho-social, cultural, and environmental factors (gender). These multidimensional, entangled, and interactive factors may influence the pharmacological response. Despite the fact that regulatory authorities recognize the importance of sex and gender, there is a paucity of research focusing on the racial/ethnic, socio-economic, psycho-social, and environmental factors that perpetuate disparities. Research and clinical practice must incorporate all of these factors to arrive at an intersectional and system-scenario perspective. We advocate for scientifically rigorous evaluations of the interplay between sex and gender as key factors in performing clinical trials, which are more adherent to real-life. This review proposes a set of 12 rules to improve clinical research for integrating sex-gender into clinical trials.

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.

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.

Alcohol Use Among Never-Deployed U.S. Army Reserve and National Guard Soldiers: The Effects of Nondeployment Emotions and Sex

BACKGROUND

Limited research shows that mental health problems are prevalent among never-deployed soldiers and many experience negative emotions related to their nondeployment. U.S. Army Reserve/National Guard (USAR/NG) soldiers are also at high risk for alcohol misuse. However, it is not known if nondeployment emotions contribute to an increased risk of alcohol misuse among never-deployed USAR/NG soldiers.

METHODS

Data are from Operation: SAFETY (Soldiers and Families Excelling Through the Years), an ongoing study of USAR/NG soldiers. We used regression models to examine the relations between nondeployment emotions, assessed by the Non-Deployment Emotions (NDE) Questionnaire, and a range of alcohol use outcomes, assessed by the Alcohol Use Disorders Identification Test and standard quantity and frequency questions, among a sample of never-deployed soldiers who were partnered at baseline (N = 174). Final models controlled for years of military service, current number of close military friends in the social network, marital satisfaction, and depression. We also tested for potential differences in these associations by sex.

RESULTS

Nondeployment emotions were associated with frequency of getting drunk (adjusted risk ratio [aRR] = 1.02, 95% CI: 1.01, 1.04; p < 0.05) and typical number of drinks consumed during a drinking episode (aRR = 1.03, 95% CI: 1.01, 1.04; p < 0.01). Nondeployment emotions had a trend-level association with percent of days drinking (adjusted odds ratio = 1.05, 95% CI: 1.00, 1.11; p = 0.055). Nondeployment emotions had a significant interaction with sex (p < 0.05) on the likelihood of alcohol problems, such that only male soldiers experienced a greater likelihood of alcohol problems when they had highly negative nondeployment emotions. There was no relation between nondeployment emotions and alcohol problems among female soldiers.

CONCLUSIONS

Findings demonstrate that greater nondeployment emotions are associated with increased alcohol use among never-deployed USAR/NG soldiers. The NDE Questionnaire may assist in identifying those at highest risk for alcohol problems.

Socioeconomic Status and Adolescent Alcohol Involvement: Evidence for a Gene-Environment Interaction

OBJECTIVE

Adolescence is an optimal developmental stage for examining the interplay of environmental factors and the genetic risk for alcohol involvement. The current study aimed to examine how socioeconomic status might interact with genetic risk for alcohol involvement among adolescents.

METHOD

A total of 839 same-sex adolescent twin pairs (509 monozygotic and 330 dizygotic) from the 1962 National Merit Twin Study completed a questionnaire containing items assessing alcohol involvement. Twins were approximately 17 years old at the time of participation. Parents provided reports of family income and educational attainment. Models were fit examining parental education and family income as moderators of genetic and environmental influences on alcohol use.

RESULTS

There was evidence for moderation of genetic and environmental influences on alcohol involvement by family income. For twins with the lowest levels of family income, genetic and shared environmental influences accounted for 50% and 26% of the variance in alcohol involvement, respectively, compared with 2% and 67% of the variance among those at the highest level of income.

CONCLUSIONS

These findings suggest that etiological influences on alcohol involvement vary as a function of an adolescent's socioeconomic status.

Socioeconomic Status and Adolescent Alcohol Involvement: Evidence for a Gene-Environment Interaction

OBJECTIVE

Adolescence is an optimal developmental stage for examining the interplay of environmental factors and the genetic risk for alcohol involvement. The current study aimed to examine how socioeconomic status might interact with genetic risk for alcohol involvement among adolescents.

METHOD

A total of 839 same-sex adolescent twin pairs (509 monozygotic and 330 dizygotic) from the 1962 National Merit Twin Study completed a questionnaire containing items assessing alcohol involvement. Twins were approximately 17 years old at the time of participation. Parents provided reports of family income and educational attainment. Models were fit examining parental education and family income as moderators of genetic and environmental influences on alcohol use.

RESULTS

There was evidence for moderation of genetic and environmental influences on alcohol involvement by family income. For twins with the lowest levels of family income, genetic and shared environmental influences accounted for 50% and 26% of the variance in alcohol involvement, respectively, compared with 2% and 67% of the variance among those at the highest level of income.

CONCLUSIONS

These findings suggest that etiological influences on alcohol involvement vary as a function of an adolescent's socioeconomic status.

Childhood socioeconomic status and longitudinal patterns of alcohol problems: Variation across etiological pathways in genetic risk

Childhood socioeconomic status (SES) is an important aspect of early life environment associated with later life health/health behaviors, including alcohol misuse. However, alcohol misuse is modestly heritable and involves differing etiological pathways. Externalizing disorders show significant genetic overlap with substance use, suggesting an impulsivity pathway to alcohol misuse. Alcohol misuse also overlaps with internalizing disorders, suggesting alcohol is used to cope. These differing pathways could lead to different patterns over time and/or differential susceptibility to environmental conditions, such as childhood SES. We examine whether: 1) genetic risk for externalizing and internalizing disorders influence trajectories of alcohol problems across adolescence to adulthood, 2) childhood SES alters genetic risk these disorders on trajectories of alcohol problems, and 3) these patterns are consistent across sex. We find modest evidence of gene-environment interaction. Higher childhood SES increases the risk of alcohol problems in late adolescence/early adulthood, while lower childhood SES increases the risk of alcohol problems in later adulthood, but only among males at greater genetic risk of externalizing disorders. Females from lower SES families with higher genetic risk of internalizing or externalizing disorders have greater risk of developing alcohol problems.

Latent trajectories of alcohol use from early adolescence to young adulthood: Interaction effects between 5-HTTLPR and parenting quality and gender differences

Using a large and nationally representative sample, we examined how adolescents’ 5-HTTLPR genotype and perceived parenting quality independently and interactively associated with trajectories of alcohol use from early adolescence to young adulthood and whether/how gender may moderate these associations. The sample for this study included 13,749 adolescents (53.3% female; 56.3% non-Hispanic White, 21.5% Black, 16.0% Hispanic, and 6.1% Asian) followed prospectively from adolescence to young adulthood. Using growth mixture modeling, we identified four distinct trajectories of alcohol use (i.e., persistent heavy alcohol use, developmentally limited alcohol use, late-onset heavy alcohol use, and non/light alcohol use). Results indicated that the short allele of 5-HTTLPR was associated with higher risk of membership in the persistent and the late-onset heavy alcohol use trajectories. Parenting quality was associated with lower likelihoods of following the persistent heavy and the developmentally limited alcohol use trajectories but was not associated with risk of membership for the late-onset heavy drinking trajectory. 5-HTTLPR interacted with parenting quality to predict membership in the persistent heavy alcohol use trajectory for males but not for females. Findings highlighted the importance of considering the heterogeneity in trajectories of alcohol use across development and gender in the study of Gene Environment interactions in alcohol use.

Post-GWAS in Psychiatric Genetics: A Developmental Perspective on the "Other" Next Steps

As psychiatric genetics enters an era where gene identification is finally yielding robust, replicable genetic associations and polygenic risk scores, it is important to consider next steps and delineate how that knowledge will be applied to ultimately ameliorate suffering associated with substance use and psychiatric disorders. Much of the post-genome-wide association study discussion has focused on the potential of genetic information to elucidate the underlying biology and use this information for the development of more effective pharmaceutical treatments. In this review we focus on additional areas of research that should follow gene identification. By taking genetic findings into longitudinal, developmental studies, we can map the pathways by which genetic risk manifests across development, elucidating the early behavioral manifestations of risk, and studying how various environments and interventions moderate that risk across developmental stages. The delineation of risk across development will advance our understanding of mechanism, sex differences and risk and resilience processes in different racial/ethnic groups. Here, we review how the extant twin study literature can be used to guide these efforts. Together, these new lines of research will enable us to develop more informed, tailored prevention and intervention efforts.

Social Relationships Moderate Genetic Influences on Heavy Drinking in Young Adulthood

OBJECTIVE

Social relationships, such as committed partnerships, limit risky behaviors like heavy drinking, in part, because of increased social control. The current analyses examine whether involvement in committed relationships or social support extend beyond a main effect to limit genetic liability in heavy drinking (gene-environment interaction) during young adulthood.

METHOD

Using data from the young adult wave of the Finnish Twin Study, FinnTwin12 (n = 3,269), we tested whether involvement in romantic partnerships or social support moderated genetic influences on heavy drinking using biometric twin modeling for gene-environment interaction.

RESULTS

Involvement in a romantic partnership was associated with a decline in genetic variance in both males and females, although the overall magnitude of genetic influence was greater in males. Sex differences emerged for social support: increased social support was associated with increased genetic influence for females and reduced genetic influence for males.

CONCLUSIONS

These findings demonstrate that social relationships are important moderators of genetic influences on young adult alcohol use. Mechanisms of social control that are important in limiting genetic liability during adolescence extend into young adulthood. In addition, although some relationships limit genetic liability equally, others, such as extensive social networks, may operate differently across sex.