Sex differences in how a low sensitivity to alcohol relates to later heavy drinking

Subjective response to alcohol in young adults with bipolar disorder and recent alcohol use: a within-subject randomized placebo-controlled alcohol administration study

Limited data exists on mechanisms contributing to elevated risk for alcohol use disorder (AUD) in bipolar disorder. Variation in subjective response to alcohol may relate to alcohol use and risk for AUD. This study used a randomized, placebo-controlled, cross-over, within-subjects design to investigate differences in subjective response to alcohol in 50 euthymic young adults (n = 24 with and n = 26 without bipolar disorder type I). Eighty-three percent of participants with bipolar disorder were medicated. Participants completed assessments of clinical history, alcohol expectancies, and recent alcohol use. Participants were dosed to a .08 g% breath alcohol concentration. The placebo condition occurred on a separate counter-balanced day. Subjective response to alcohol was investigated at similar time points during both conditions. Group, condition, and group-by-condition interactions were modeled, with condition and time of subjective response assessment as repeated within-subject variables, and subjective response to alcohol as the dependent variable. Greater stimulating effects and liking of alcohol were reported in people with bipolar disorder (group-by-condition interactions, p < .05) than healthy young adults. While young adults with bipolar disorder reported anticipating feeling less "mellow/relaxed" when drinking (p = .02), during both beverage conditions they reported feeling more "mellow/relaxed" (main effect of group, p = .006). Feeling more "mellow/relaxed" during the alcohol condition related to greater recent alcohol use in bipolar disorder (p = .001). Exploratory analyses suggested anticonvulsants and sedatives/antihistamines may relate to differences in subjective response to alcohol in bipolar disorder. Results suggest young adults with bipolar disorder may differ in alcohol expectancies and experience alcohol intoxication differently-with distinct relations between subjective response to alcohol and alcohol use-compared to healthy young adults.

The Promise of an Evolutionary Perspective of Alcohol Consumption

The urgent need for medical treatments of alcohol use disorders has motivated the search for novel molecular targets of alcohol response. Most studies exploit the strengths of lab animals without considering how these and other species may have adapted to respond to alcohol in an ecological context. Here, we provide an evolutionary perspective on the molecular and genetic underpinnings of alcohol consumption by reviewing evidence that alcohol metabolic enzymes have undergone adaptive evolution at 2 evolutionary junctures: first, to enable alcohol consumption accompanying the advent of a frugivorous diet in a primate ancestor, and second, to decrease the likelihood of excessive alcohol consumption concurrent with the spread of agriculture and fermentation in East Asia. By similarly considering how diverse vertebrate and invertebrate species have undergone natural selection for alcohol responses, novel conserved molecular targets of alcohol are likely be discovered that may represent promising therapeutic targets.

Cross-sectional and prospective associations of drinking characteristics with scores from the Self-Report of the Effects of Alcohol questionnaire and findings from alcohol challenges

BACKGROUND

Data from 2 generations of participants in the San Diego Prospective Study (SDPS) were used to compare cross-sectional and prospective relationships of 5 measures of the low level of response (low LR) to alcohol to 2 key alcohol-related outcomes.

METHODS

The analyses used data from 373 SDPS male probands and 158 male and female offspring of these individuals to evaluate relationships of 5 LR measures to the prior 5-year maximum drinks per occasion and the number of 11 DSM-IV alcohol use disorder (AUD) criteria experienced. Probands' LR measures included responses to alcohol challenges administered 15 years previously, and ratings for both generations included measures of the number of standard drinks during four periods: the first five times of drinking (SRE-5), the prior three drinking months (SRE-3), the period of heaviest drinking (SRE-H), and a total average across all time frames (SRE-T). Analyses included zero-order correlations, correlations using covariates, and hierarchical multiple regression analyses.

RESULTS

All 5 LR measures were correlated with aspects of maximum drinks and the number of AUD criteria, but the most robust results were seen for SRE-3 and maximum drinks. Correlations were less consistent for SRE-5, a measure more closely related to outcomes in the offspring. Hierarchical regression analyses supported most of these conclusions and showed that alcohol challenge-based LRs added significant information regarding maximum drinks even when evaluated with SRE values. The close correlation between SRE-H and SRE-T argues against the need for studies to include both measures. The patterns of results were similar irrespective of whether covariates were included.

CONCLUSIONS

There were significant correlations of maximum drinks and the number of AUD criteria with findings from prior alcohol challenges and all SRE scores. Challenges and SRE reports are related but not identical LR measures. All SRE scores, including SRE-5, offered useful information regarding subsequent drinking behavior.

Adult and adolescent C57BL/6J and DBA/2J mice are differentially susceptible to fear learning deficits after acute ethanol or MK-801 treatment

Ethanol and other drugs of abuse disrupt learning and memory processes, creating problems associated with drug use and addiction. Understanding individual factors that determine susceptibility to drug-induced cognitive deficits, such as genetic background, age, and sex, is important for prevention and treatment. Comparison of adolescent and adult mice of both sexes across inbred mouse strains can reveal age, sex, and genetic contributions to phenotypes. We treated adolescent and adult, male and female, C57BL/6J and DBA/2J inbred mice with ethanol (1 g/kg or 1.5 g/kg) or MK-801 (0.05 mg/kg or 0.1 mg/kg), an NMDA receptor antagonist, prior to fear conditioning training. Contextual and cued fear retention were tested one day and eight or nine days after training. After ethanol exposure, adult C57BL/6J mice experienced greater deficits in contextual learning than adult DBA/2J mice. C57BL/6 J adolescents were less susceptible to ethanol-induced contextual learning disruptions than C57BL/6J adults, and adolescent males of both strains exhibited greater ethanol-induced contextual learning deficits than adolescent females. After MK-801 exposure, adolescent C57BL/6J mice experienced more severe contextual learning deficits than adolescent DBA/2J mice. Both ethanol and MK-801 had greater effects on contextual learning than cued learning. Collectively, we demonstrate that genetic background contributes to contextual and cued learning outcomes after ethanol or MK-801 exposure. Further, we report age-dependent drug sensitivities that are strain-, sex-, and drug-specific, suggesting that age, sex, and genetic background interact to determine contextual and cued learning impairments after ethanol or MK-801 exposure.

Getting to the Heart of Low Sensitivity to Alcohol: Context Moderates Low Cardiovascular Response to Alcohol in Persons With a Family History of Alcohol Use Disorder

Background

Low sensitivity to alcohol in persons with a family history of alcoholism (FH+), compared to those without (FH−), contributes to risk for alcohol use disorder (AUD). However, sensitivity of FH+ cardiovascular response to alcohol is not well understood. This gap is significant because cardiovascular processes contribute to emotional regulation and stress response problems theorized to be central to the development and persistence of AUD. This study compared changes in heart rate (HR) and HR variability (HRV) between FH groups after consuming alcohol and control beverages and examined how these changes were moderated by emotional and alcohol‐related contexts.

Methods

Young adults (N = 165) with FH+ (n = 110) or FH− (n = 55) each completed 2 sessions, separated by 1 week. They received one of 3 different beverages (alcohol, placebo, and told‐no‐alcohol) in each session. Electrocardiogram data were recorded during pre–beverage consumption and post–beverage consumption baselines, and then during 4 picture cue tasks (neutral, positive, negative, and alcohol‐related). Generalized estimating equations were used to examine differences in cardiovascular reactivity (changes in HR and HRV power at ~ 0.1 Hz) across FH groups, beverage conditions, and picture cue tasks.

Results

A significant beverage condition × cue task × FH interaction effect on HRV was observed. The FH+ group, compared to the FH− group, showed (a) significantly less HRV suppression in specific cue contexts following alcohol, (b) a mixed pattern of more and less HRV suppression across cue contexts following placebo, and (c) a similar HRV reactivity pattern in the told‐no‐alcohol condition across cue tasks. For HR, there were no significant effects involving FH.

Conclusions

Diminished cardiovascular sensitivity to oral alcohol in FH+ persons varied within a given drinking episode depending on emotional and alcohol‐related features of the context, suggesting that environmental characteristics play a role in the expression of low sensitivity to alcohol among FH+ individuals.

Alcohol consumption and consequences in adolescents in 68 low and middle-income countries - a multi-country comparison of risks by sex

AIMS

Alcohol use is a leading risk factor for disease burden among youth. This study estimated sex differences in the prevalence of alcohol use and consequences among adolescents living in low and middle-income countries (LMIC).

DESIGN

Multi-staged cross-sectional international standardized self-report questionnaires administered in the classroom.

SETTING

The Global school-based student health survey (GSHS) comprised adolescents from 68 LMIC between 2003-2014.

PARTICIPANTS

271,156 students aged 13-17 years old.

MEASUREMENTS

Alcohol measures included: past month alcohol consumption, history of intoxication and alcohol-related problems. Regions were based on the World Health Organization definitions: Africa, America, Eastern Mediterranean, Europe, South-east Asia, and Western Pacific.

FINDINGS

Overall, males had higher odds of alcohol use (OR = 2.38 [1.91-2.96]), a history of intoxication (OR = 2.64 [2.11-3.31]), and alcohol-related problems (OR = 1.72 [1.41-2.10]) than females. All regions recorded overall greater odds of alcohol use by males versus females; five regions (excluding Europe) recorded greater odds of intoxication in males; and three regions (America, South-east Asia, and Western Pacific) recorded greater odds of alcohol-related problems amongst males. However, there were country-level differences - in some countries, adolescent drinking rates and consequences were comparable by sex. Countries with the highest odds of alcohol use among males compared to females were Indonesia, Myanmar, Cambodia, Tuvalu, Morocco, Senegal, Kiribati, and Thailand.

CONCLUSIONS

Among adolescents living in LMIC, males had on average two-fold higher odds of drinking alcohol and experiencing adverse consequences. Growing affluence and improvements in sex equality in societies may increase the future prevalence of hazardous drinking in females in LMICs.

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 Differences in Photic Entrainment and Sensitivity to Ethanol-Induced Chronodisruption in Adult Mice After Adolescent Intermittent Ethanol Exposure

BACKGROUND

Evidence supports a role for the circadian system in alcohol use disorders, but the impact of adolescent alcohol exposure on circadian timing later in life is unknown. Acute ethanol (EtOH) attenuates circadian photic phase-resetting in adult, but not adolescent, rodents. However, nearly all studies have focused on males and it is unknown whether this adolescent-typical insensitivity to EtOH persists into adulthood after adolescent drinking.

METHODS

Circadian activity was monitored in C57BL/6J mice receiving adolescent intermittent EtOH (AIE) exposure (15% EtOH and water every other day throughout adolescence) or water alone followed by 24 days wherein EtOH was not available (washout). Mice then received a challenge dose of EtOH (1.5 g/kg, intraperitoneal) or saline 15 minutes prior to a 30-minute phase-delaying light pulse and then were released into constant darkness (DD). To control for possible phase-shifting by EtOH challenge alone, a separate group of mice underwent AIE exposure (or water-only) and washout and then received an EtOH or saline injection, but did not receive a light pulse prior to DD.

RESULTS

Striking sex differences in nearly all measures of circadian photic entrainment were observed during adolescence but AIE effects were subtle and few. Only EtOH-naïve adult male mice showed attenuated photic phase-shifts with EtOH challenge, while all other groups showed normal phase-resetting responses to light. AIE-exposed females showed a persistent delay in activity offset.

CONCLUSIONS

Adult male AIE-exposed mice retained adolescent-like insensitivity to EtOH-induced suppression of photic phase-resetting, suggesting AIE-induced "lock-in" of an adolescent behavioral phenotype. Adult AIE-exposed females showed delayed initiation of the rest phase. Our results also indicate that intermittent EtOH drinking has subtle effects on circadian activity in mice during adolescence that differ from previously reported effects on adult males. The observed sex differences in circadian activity, EtOH consumption and preference, and responses to EtOH challenge merit future mechanistic study.

Sex differences in the association of alcohol with cognitive decline and brain pathology in a cohort of octogenarians

RATIONALE

The beneficial effects of moderate alcohol may differ in aging men versus women.

OBJECTIVES

Cognitive and functional decline and neuropathology were investigated in a cohort of aging men and women with diverse alcohol histories.

METHODS

Non-demented (Clinical Dementia Rating (CDR) of ≤ 0.5 and a Mini-Mental State Examination (MMSE) score of > 24), autonomously living participants were tracked in longitudinal aging studies to examine self-report and objective tests of rates of decline in a cohort (n = 486) of octogenarians. Neurofibrillary tangles (NFTs; Braak stage) and neuritic plaques (NPs) were staged at autopsy in a subset of participants (n = 149) using current standard neuropathologic diagnostic criteria.

RESULTS

Moderate drinking men had an attenuated rate of decline compared to rare/never drinkers and women on the MMSE and CDR sum of boxes. In contrast, moderate drinking women had a reduced rate of decline only in the Logical Memory Delayed Recall Test (LMDR) compared to rare/never drinkers and men. Moderate alcohol consumption was associated with a reduction in the incidence of advanced (stages 5-6) Braak NFT stage in men (p < 0.05), with no effect in women.

CONCLUSIONS

In this cohort, men experienced a broader range of beneficial effects associated with alcohol. Alcohol's effects may differ in men and women in important ways that suggest a narrower beneficial window.

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.

Prior binge-drinking history promotes the positive affective valence of methamphetamine in mice

An alcohol use disorder is a major predisposing factor for methamphetamine (MA) abuse. Further, MA-alcohol co-abuse is a risk factor for treatment discontinuation and non-compliance in MA-dependent individuals. No effective treatment exists for MA addiction, let alone treatments directed at those suffering from MA-alcohol addiction co-morbidity. Thus, it is imperative that we develop high-throughput animal models to study the biobehavioral interactions between MA and alcohol of relevance to the etiology and treatment of co-abuse. To this end, we reported that a history of binge alcohol-drinking [5,10, 20 and 40% (v/v); 2 h/day for 10-14 days] reduces MA reinforcement and intake, but it augments MA-preference and intake when drug availability is behaviorally non-contingent. To reconcile this apparent discrepancy in findings, we employed a comparable 2-week binge-drinking paradigm as that employed in our previous studies followed by place-conditioning procedures (4 pairings of 0.25, 0.5, 1, 2 or 4 mg/kg MA, i.p.). This was meant to determine how a prior binge-drinking history impacts the affective valence of MA and sensitivity to MA-induced psychomotor-activation/sensitization. Prior binge-drinking history blunted spontaneous locomotor activity and shifted the MA dose-place-preference function upwards of water drinking controls. The potentiation of MA-conditioned reward by prior binge-drinking history was independent of any alcohol effects upon the locomotor-activating or -sensitizing effects of MA. Based on these results we propose that the reduced MA reinforcement reported previously by our group likely reflects a compensatory response to an increased sensitivity to MA's positive subjective effects rather than increased sensitivity to the drug's psychomotor-activating effects.

Sex as a biological variable: Drug use and abuse

The study of sex as a biological variable is a necessary emphasis across a wide array of endpoints, including basic neuroscience, medicine, mental health, physiology and behavior. The present review summarizes work from clinical and preclinical populations on sex differences in drug use and abuse, ranging from initiation to escalation/dysregulation and from drug cessation/abstinence to relapse. These differences are analyzed in the context of the addiction cycle conceptualization of Koob and his colleagues and address patterns of drug use (binge/intoxication), motivation underlying its use (withdrawal/negative affect) and likelihood and causes of craving and relapse of drug taking (preoccupation/anticipation). Following this overview, an assessment of the basis for the reported sex differences is discussed in the context of the affective (rewarding and aversive) properties of drugs of abuse and how such properties and their balance vary with sex and contribute to drug intake. Finally, the interaction of sex with several experiential (drug history) and subject (age) factors and how these interactions affect reward and aversion are discussed to highlight the importance of understanding such interactions in predicting drug use and abuse. We note that sex as a biological variable remains one of critical evaluation and that such investigations of sex differences in drug use and abuse continue and be expanded to assess all facets of their mediation, including these affective properties, how their balance may be impacted by the multiple conditions under which drugs are taken and how this overall balance affects drug use and addiction vulnerability.

Alcohol-related blackouts across 55 weeks of college: Effects of European-American ethnicity, female sex, and low level of response to alcohol

BACKGROUND

While high blood alcohol concentrations (BACs) are required for alcohol-related blackouts (ARBs), additional characteristics also contribute to the risk, including a person's ethnicity, sex, and phenotypes relating to heavier drinking. Few prospective studies of ARBs have evaluated how these additional characteristics interact.

METHOD

Data regarding 398 European American (EA), Asian and Hispanic students were extracted from a 55-week prospective study of different approaches to decrease heavy drinking among college freshmen. Information on past month ARB frequency was determined at 8 assessments. While controlling for the prior month maximum BAC and active education vs. control group assignment, the patterns and intensities of ARBs over time across ethnic groups were evaluated with ANOVA at each follow-up for the full sample, and then separately by sex and then by low vs. high levels of response to alcohol status (LR). The overall pattern of ARBs over time was evaluated with a 3 ethnic groups by 2 sexes by 2 LR status by 8 time points mixed-design ANOVA.

RESULTS

Higher rates of ARBs over time were associated with EA ethnicity, female sex and a low LR to alcohol, with the ethnic differences in ARBs most robust in females and drinkers with high LRs. Participation in education programs aimed at heavy drinking was associated with decreases in ARBs.

CONCLUSIONS

The data indicate that in addition to BACs achieved, propensities toward ARBs relate to complex interactions between additional risk factors, including ethnicity, sex, and LR status.

Sex differences in substance use disorders: focus on side effects

Although sex differences in several aspects of substance use disorders (SUDs) have been identified, less is known about the importance of possible sex differences in side effects induced by substances of abuse or by medications used to treat SUDs. In the SUD field, the perception of certain subjective effects are actively sought, while all other manifestations might operationally be considered side effects. This article was aimed at reviewing sex differences in side effects induced by alcohol, nicotine, heroin, marijuana and cocaine and by medications approved for alcohol, nicotine and heroin use disorders. A large body of evidence suggests that women are at higher risk of alcohol-induced injury, liver disease, cardiomyopathy, myopathy, brain damages and mortality. The risk of tobacco-induced coronary heart disease, lung disease and health problems is higher for women than for men. Women also experience greater exposure to side effects induced by heroin, marijuana and cocaine. In addition, women appear to be more vulnerable to the side effects induced by medications used to treat SUDs. Patients with SUDs should be advised that the risk of developing health problems may be higher for women than for men after consumption of the same amount of substances of abuse. Doses of medications for SUD women should be adjusted at least according to body weight. The sex differences observed also indicate an urgent need to recruit adequate numbers of female subjects in pre-clinical and clinical studies to improve our knowledge about SUDs in women.

Small Heat Shock Proteins Are Novel Common Determinants of Alcohol and Nicotine Sensitivity in Caenorhabditis elegans

Addiction to drugs is strongly determined by multiple genetic factors. Alcohol and nicotine produce distinct pharmacological effects within the nervous system through discrete molecular targets; yet, data from family and twin analyses support the existence of common genetic factors for addiction in general. The mechanisms underlying addiction, however, are poorly described and common genetic factors for alcohol and nicotine remain unidentified. We investigated the role that the heat shock transcription factor, HSF-1, and its downstream effectors played as common genetic modulators of sensitivity to addictive substances. Using Caenorhabditis elegans, an exemplary model organism with substance dose-dependent responses similar to mammals, we demonstrate that HSF-1 altered sensitivity to both alcohol and nicotine. Using a combination of a targeted RNAi screen of downstream factors and transgenic approaches we identified that these effects were contingent upon the constitutive neuronal expression of HSP-16.48, a small heat shock protein (HSP) homolog of human α-crystallin. Furthermore we demonstrated that the function of HSP-16.48 in drug sensitivity surprisingly was independent of chaperone activity during the heat shock stress response. Instead we identified a distinct domain within the N-terminal region of the HSP-16.48 protein that specified its function in comparison to related small HSPs. Our findings establish and characterize a novel genetic determinant underlying sensitivity to diverse addictive substances.

Astrocyte Dysfunction Induced by Alcohol in Females but Not Males

Chronic alcohol abuse is associated with brain damage in a sex-specific fashion, but the mechanisms involved are poorly described and remain controversial. Previous results have suggested that astrocyte gene expression is influenced by ethanol intoxication and during abstinence in vivo. Here, bioinformatic analysis of astrocyte-enriched ethanol-regulated genes in vivo revealed ubiquitin pathways as an ethanol target, but with sexually dimorphic cytokine signaling and changes associated with brain aging in females and not males. Consistent with this result, astrocyte activation was observed after exposure in female but not male animals, with reduced S100β levels in the anterior cingulate cortex and increased GFAP(+) cells in the hippocampus. In primary culture, the direct effects of chronic ethanol exposure followed by recovery on sex-specific astrocyte function were examined. Male astrocyte responses were consistent with astrocyte deactivation with reduced GFAP expression during ethanol exposure. In contrast, female astrocytes exhibited increased expression of Tnf, reduced expression of the neuroprotective cytokine Tgfb1, disrupted bioenergetics and reduced excitatory amino acid uptake following exposure or recovery. These results indicate widespread astrocyte dysfunction in ethanol-exposed females and suggest a mechanism that may underlie increased vulnerability to ethanol-induced neurotoxicity in females.

The impact of focusing a program to prevent heavier drinking on a pre-existing phenotype, the low level of response to alcohol

BACKGROUND

Heavy drinking is common during transitions from high school to college. Optimal programs for diminishing risks for high alcohol consumption often tailor the approach to the specific needs of students. This study describes the results of an Internet-based prevention protocol that tailors the information to the risk associated with a pre-existing phenotype, the Low level of Response (Low LR) to alcohol.

METHODS

Using stratified random assignment, 454 freshmen with Low and High LR values were assigned to 2 education groups (LR-based where all examples were given the context of the Low LR model of heavy drinking or a State Of The Art (SOTA) Group where the same lessons were taught but without an emphasis on LR) or a no-intervention Control Group. Individuals in the 2 education groups viewed 50-minute online videos once per week for 4 weeks. Changes in drinking patterns were assessed at Baseline, 4 weeks, and 8 weeks using a 2 (LR status) by 3 (education group) by 3 (time points) analysis of variance, with additional tests for ethnicity and sex.

RESULTS

Low LR participants tended to decrease their usual (p < 0.06) and maximum (p < 0.05) drinks per occasion most prominently when assigned to the LR-based protocol, while those with High LRs improved more in the SOTA Group. The most robust differences were seen when controlling for ethnicity. The effect sizes were small to medium.

CONCLUSIONS

These results support the advantages of carrying out prevention via the Internet and in tailoring the approach to a pre-existing phenotype.

Females uniquely vulnerable to alcohol-induced neurotoxicity show altered glucocorticoid signaling

Women are more sensitive to the harmful effects of alcohol (EtOH) abuse than men, yet the underlying mechanisms remain poorly understood. Previous gene expression analysis of the medial prefrontal cortex (mPFC) following a chronic intoxication paradigm using continuous 72 h vapor inhalation found that females, but not males, exhibit an inflammatory response at peak withdrawal that is associated with cell damage. Given that glucocorticoids can function as anti-inflammatories, are known to increase with EtOH exposure, and influence neurotoxicity, we hypothesized that males and females may exhibit an altered corticosterone (CORT) response following chronic intoxication. Analysis of serum CORT levels revealed the expected increase during withdrawal with no difference between males and females, while control males but not females exhibited higher CORT concentrations than naive animals. Glucocorticoid signaling characterized using focused qPCR arrays identified a sexually dimorphic response in the mPFC during withdrawal, particularly among astrocyte-enriched genes. These genes include aquaporin-1 (Aqp1), sphingosine kinase 1 (Sphk1) and connective tissue growth factor (Ctgf); genes associated with inflammatory signaling, and tissue damage and repair. Bioinformatic analysis also revealed activation of inflammatory signaling and cell death pathways in females. Confirmation studies showed that female mice exhibited significant neuronal degeneration within the anterior cingulate cortex (ACC). By contrast, EtOH exposure lead to a significant reduction in cell death in males. Thus, distinct glucocorticoid signaling pathways are associated with sexually dimorphic neurotoxicity, suggesting one mechanism by which EtOH-exposed females are particularly vulnerable to the damaging effects of alcohol in the CNS.

Understanding the addiction cycle: a complex biology with distinct contributions of genotype vs. sex at each stage

Ethanol abuse can lead to addiction, brain damage and premature death. The cycle of alcohol addiction has been described as a composite consisting of three stages: intoxication, withdrawal and craving/abstinence. There is evidence for contributions of both genotype and sex to alcoholism, but an understanding of the biological underpinnings is limited. Utilizing both sexes of genetic animal models with highly divergent alcohol withdrawal severity, Withdrawal Seizure-Resistant (WSR) and Withdrawal Seizure-Prone (WSP) mice, the distinct contributions of genotype/phenotype and of sex during addiction stages on neuroadaptation were characterized. Transcriptional profiling was performed to identify expression changes as a consequence of chronic intoxication in the medial prefrontal cortex. Significant expression differences were identified on a single platform and tracked over a behaviorally relevant time course that covered each stage of alcohol addiction; i.e., after chronic intoxication, during peak withdrawal, and after a defined period of abstinence. Females were more sensitive to ethanol with higher fold expression differences. Bioinformatics showed a strong effect of sex on the data structure of expression profiles during chronic intoxication and at peak withdrawal irrespective of genetic background. However, during abstinence, differences were observed instead between the lines/phenotypes irrespective of sex. Confirmation of identified pathways showed distinct inflammatory signaling following intoxication at peak withdrawal, with a pro-inflammatory phenotype in females but overall suppression of immune signaling in males. Combined, these results suggest that each stage of the addiction cycle is influenced differentially by sex vs. genetic background and support the development of stage- and sex-specific therapies for alcohol withdrawal and the maintenance of sobriety.

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

OBJECTIVE

A person's pattern of heavier drinking often changes over time, especially during the early drinking years, and reflects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than cross-sectional evaluations.

METHOD

The patterns of maximum drinks per occasion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identified latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership.

RESULTS

Four latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 over time; and Class 4 (6%), with a maximum of about 22 drinks across time. The most consistent predictors of higher drinking classes were female sex, a low baseline level of response to alcohol, externalizing characteristics, prior alcohol and tobacco use, and heavier drinking peers.

CONCLUSIONS

Four trajectory classes were observed and were best predicted by a combination of items that reflected demography, substance use, level of response and externalizing phenotypes, and baseline environment and attitudes.

Is alcohol consumption associated with poor academic achievement in university students?

BACKGROUND

We assessed associations between educational achievement and alcohol consumption.

METHODS

We employed five alcohol consumption measures (length of time of and amount consumed during most recent drinking occasion, frequency of alcohol consumption, heavy episodic drinking, problem drinking); and three educational achievement indicators (students' subjective importance of achieving good grades, students' appraisal of their academic performance in comparison with peers, students' actual module mark).

RESULTS

Males were positively associated with all five alcohol consumption measures. Age was negatively associated with three alcohol consumption measures. While students´ importance of good grades was negatively associated with three alcohol consumption measures, academic performance in comparison with peers was negatively associated with heavy episodic drinking. Actual module mark was not associated with any alcohol consumption measure.

CONCLUSIONS

Alcohol consumption showed negative associations with motivation for and subjectively achieved academic performance. University alcohol prevention activities might have positive impact on students' academic success.

A family history of alcoholism relates to alexithymia in substance use disorder patients

OBJECTIVES

Previous research identified alexithymia as a potential risk factor for substance use disorders (SUD). More insight into the relation between alexithymia and SUD is needed in order to treat SUD effectively. Therefore, we investigated whether a familial vulnerability to alcoholism relates to the presence and severity of alexithymia in SUD patients.

METHOD

Hospitalized, abstinent SUD-patients (n=187), were assessed with the Toronto Alexithymia Scale (TAS-20) and Addiction Severity Index (EuropASI). A maternal, paternal, and total continuous measure of the Family History of Alcohol (FHA) was developed. Kruskal-Wallis tests and Spearman correlations were used to relate the composite scores of FHA to alexithymia as a categorical and continuous measure. Multivariate regression models were performed to control for the effects of confounders on the relation between FHA and alexithymia.

RESULTS

Compared to moderate (33%) and low (17%) alexithymic SUD-patients, high alexithymic (50%) patients were more likely to have fathers with alcohol problems (P=0.004). Such a difference was not found for mothers with alcohol problems. The composite FHA-score was significantly associated with alexithymia (Rs=.19, P=0.01). However, only a paternal FHA, independent from disturbed family functioning, related to the degree of alexithymia (β=.13, P=0.06), especially to the Difficulty Identifying Feelings as measured by the TAS-20 (β=.16, P=0.02).

CONCLUSIONS

The relation between a paternal FHA and a higher degree of alexithymia in SUD-patients suggests that alexithymia could mediate the familiality of alcoholism or SUD in the paternal line.

β-Arrestin-2 inhibits preference for alcohol in mice and suppresses Akt signaling in the dorsal striatum

In this study, we investigated the role of β-arrestin-2 in alcohol preference using the two-bottle choice and conditioned place preference procedures in wild-type (WT) and β-arrestin-2 knockout (KO) mice. Locomotion and righting reflex tests were performed to test alcohol sensitivity. The possible molecular signals regulated by β-arrestin-2 were analyzed by Western blot. We found that β-arrestin-2 KO mice showed a marked increase in voluntary alcohol consumption without significant differences in preference for saccharin or aversion to quinine. These animals also exhibited higher conditioned place preference scores for alcohol than WT mice. Meanwhile, KO mice showed reduced sensitivity to alcohol and increased blood alcohol clearance. Furthermore, after the free consumption of alcohol, the activities of protein kinase B and glycogen synthase kinase 3β (GSK3β) increased in the dorsal striatum of WT mice, but not in KO mice, which showed high basal activity of Akt in the dorsal striatum. These results suggest that β-arrestin-2 negatively regulates alcohol preference and reward, likely through regulating the activation of signaling pathways including Akt/GSK3β in the dorsal striatum.