Acute and chronic effects of alcohol on trail making test performance among underage drinkers in a field setting

Examination of college student health behaviors and self-reported executive functions

Objective: Emerging adulthood is characterized by maturation of executive functions (EF) and changes in health behaviors (HB). Interestingly, EF are bi-directionally related to many specific HB; yet how EF performs in relation to overall patterns of HB engagement is unclear. Groupings of HB and the relationship between these HB groupings and EF were examined.

PARTICIPANTS

Full-time college students were recruited from three large Mid- and Southwest universities (N = 1,387).

METHODS

Online self-report questionnaires assessing demographics, HB, and EF were completed.

RESULTS

Latent class analysis of HB revealed three classes: (1) High Substance Use, (2) Moderately Healthy, (3) Healthy. In general, the Healthy class had significantly greater EF compared to no significant differences between the other two classes.

CONCLUSIONS

Collective engagement in HB is associated with EF. Interventions targeting both HB and EF simultaneously may be most efficacious.

Associations between Adolescent Alcohol Use and Neurocognitive Functioning in Young Adulthood

This study examined the associations between excessive alcohol intake during adolescence and neurocognitive functioning in young adulthood and whether these relations varied by sex. Participants were working-class Chilean adolescents (N = 692; Mage 16.0 years; 54.5% female) who provided frequency of past 30-day bingeing and past-year intoxication. Neurocognitive measures were completed in young adulthood (Mage 21.2 years). Illicit substance users were excluded a priori and other substance use was controlled. When males and females were considered simultaneously, no main effects of intoxication or bingeing were found. However, several sex-specific effects emerged for intoxication, such that more frequent intoxication was associated with poorer visual memory, attention, processing speed, response inhibition, and cognitive flexibility in females, while frequent intoxication related to better attention and processing speed in males. In general, effect sizes were small. No relations emerged for verbal memory, working memory, or spatial learning. Possible factors that contribute to divergent sex effects are discussed.

Gender moderates the association between acute alcohol intoxication and facial emotion recognition in a naturalistic field study setting

BACKGROUND

Alcohol intoxication is associated with significant negative social consequences. Social information processing theory provides a framework for understanding how the accurate decoding and interpretation of social cues are critical for effective social responding. Acute intoxication has the potential to disrupt facial emotion recognition. If alcohol impairs the processing and interpretation of emotional cues, then the resultant behavioral responses may be less effective. The current study tested the association between alcohol intoxication and facial emotion recognition in a naturalistic field study of intoxicated participants.

METHODS

114 participants (59.4% men; M_age  = 24.2 years) who had been consuming alcohol were recruited in the downtown area of a mid-size town surrounded by several drinking establishments in the mid-southern United States. Participants were shown images depicting 5 facial displays of emotions (happy, sad, anger, disgust, and no emotion) portrayed by 1 male and 1 female actor per emotion and breath alcohol concentration (BrAC) was measured by the field breathalyzer test (M = 0.078%, SD = 0.052).

RESULTS

BrAC was significantly negatively associated with emotion recognition accuracy when controlling for average alcohol use, B = -.35, t = -2.08, p < 0.05, F(3, 110) = 5.28, p < 0.01, R²  = 0.13. A significant BrAC × gender interaction was revealed, B = -0.39, t = -2.07, p = 0.04, ΔR²  = 0.033, p = 0.04, such that men (but not women) displayed a significant negative association between BrAC and emotion recognition accuracy.

CONCLUSIONS

Acute intoxication was associated with impaired facial emotion recognition, particularly for men, in a field study context. Findings support and extend some previous experimental laboratory-based research and suggest that intoxication can impair the decoding stage of social information processing.

Adolescent intermittent ethanol exposure induces sex-dependent divergent changes in ethanol drinking and motor activity in adulthood in C57BL/6J mice

With alcohol readily accessible to adolescents, its consumption leads to many adverse effects, including impaired learning, attention, and behavior. Adolescents report higher rates of binge drinking compared to adults. They are also more prone to substance use disorder in adulthood due to physiological changes during the adolescent developmental period. We used C57BL/6J male and female mice to investigate the long-lasting impact of binge ethanol exposure during adolescence on voluntary ethanol intake and open field behavior during later adolescence (Experiment 1) and during emerging adulthood (Experiment 2). The present set of experiments were divided into four stages: (1) adolescent intermittent vapor inhalation exposure, (2) abstinence, (3) voluntary ethanol intake, and (4) open field behavioral testing. During adolescence, male and female mice were exposed to air or ethanol using intermittent vapor inhalation from postnatal day (PND) 28-42. Following this, mice underwent short-term abstinence from PND 43-49 (Experiment 1) or protracted abstinence from PND 43-69 (Experiment 2). Beginning on PND 50-76 or PND 70-97, mice were assessed for intermittent voluntary ethanol consumption using a two-bottle choice drinking procedure over 28 days. Male adolescent ethanol-exposed mice showed increased ethanol consumption following short-term abstinence and following protracted abstinence. In contrast, female mice showed no changes in ethanol consumption following short-term abstinence and decreased ethanol consumption following protracted abstinence. There were modest changes in open field behavior following voluntary ethanol consumption in both experiments. These data demonstrate a sexually divergent shift in ethanol consumption following binge ethanol exposure during adolescence and differences in open field behavior. These results highlight sex-dependent vulnerability to developing substance use disorders in adulthood.

Binge Drinking, Alone or With Cannabis, During Adolescence Triggers Different Effects on Immediate Visual Memory in Men and Women

Background: This study examines the interaction between a history of binge drinking (BD), alone or with cannabis consumption, and the effects of acute alcohol exposure on immediate visual memory (IVM) (faces memory task, scenes memory task and IVM-IQ) in adolescents of both sexes. Method: Two hundred and ninety adolescents, grouped into refrainers, binge drinkers and subjects with a history of simultaneous BD/Cannabis co-use, received a risk dose of alcohol or a control drink. Results: Consumption Pattern (refrainers vs. binge drinkers vs. BD/Cannabis consumers) was not significant, while Treatment (acute alcohol vs. control drink) was significant in both sexes. Also, male binge drinkers' performance in the faces memory task was poorer than that of refrainers and BD/Cannabis consumers who consumed the control drink. BD/Cannabis consumers performed this task as capably as refrainers. In women, binge drinkers performed better than refrainers in scene memory and IVM-IQ tests when given alcohol, and binge drinkers performed worse than refrainers after consuming the control drink. Conclusions: Acute alcohol consumption worsens IVM. Cannabis exerts a buffering effect in men. A cognitive tolerance effect is observed in women. Exposure during adolescence to alcohol, alone or with cannabis, can trigger different cognitive effects in men and women that could endure into adulthood.

Alcohol Intoxication Impairs the Bystander Intervention Process in a Hypothetical Sexual Assault: A Field Investigation

OBJECTIVE

High rates of alcohol-related sexual assault among young adults represent a significant public health problem. Bystander intervention programs are a promising strategy to reduce sexual assault incidence. However, little is known about how bystander intoxication may modify bystander intervention effectiveness. We examined the role of bystander intoxication and intoxication levels of the hypothetical victim and perpetrator on outcomes associated with Latané and Darley's (1970) steps of bystander intervention, which include noticing a situation, assessment of risk and need for intervention, taking personal responsibility for intervening, and selecting an intervention.

METHOD

In a field setting, participants were recruited from a downtown area surrounded by several drinking establishments. After providing informed consent, 327 participants (45% women) ages 21 - 29 years listened to one of four sexual assault vignettes (varied by victim and perpetrator intoxication), responded to questionnaires assessing outcomes related to steps of bystander intervention, and completed a field breathalyzer test to measure intoxication level.

RESULTS

We found that increased participant intoxication was related to decreased accuracy of situation recall and assessment of risk and need for intervention, but not ratings of personal responsibility to intervene, chosen intervention strategy, or confidence to intervene.

CONCLUSIONS

Intoxication could influence how a bystander interprets a hypothetical nonconsensual sexual interaction at the level of accurate situation recall and risk assessment. If the early steps of information processing are impaired by intoxication, later steps of intervention enactment may not occur successfully. Bystander intervention programming may consider incorporating training to overcome the impairing effects of intoxication for identifying harmful situations and choosing to intervene.

Immediate-term cognitive impairment following intravenous (IV) chemotherapy: a prospective pre-post design study

BACKGROUND

Cognitive impairment is commonly reported in patients receiving chemotherapy, but the acuity of onset is not known. This study utilized the psychomotor vigilance test (PVT) and trail-making test B (TMT-B) to assess cognitive impairment immediately post-chemotherapy.

METHODS

Patients aged 18-80 years receiving first-line intravenous chemotherapy for any stage of breast or colorectal cancer were eligible. Patient symptoms, peripheral neuropathy and Stanford Sleepiness Scale were assessed. A five-minute PVT and TMT-B were completed on a tablet computer pre-chemotherapy and immediately post-chemotherapy. Using a mixed linear regression model, changes in reciprocal transformed PVT reaction time (mean 1/RT) were assessed. A priori, an increase in median PVT reaction times by > 20 ms (approximating PVT changes with blood alcohol concentrations of 0.04-0.05 g%) was considered clinically relevant.

RESULTS

One hundred forty-two cancer patients (73 breast, 69 colorectal, median age 55.5 years) were tested. Post-chemotherapy, mean 1/RT values were significantly slowed compared to pre-chemotherapy baseline (p = 0.01). This corresponded to a median PVT reaction time slowed by an average of 12.4 ms. Changes in PVT reaction times were not correlated with age, sex, cancer type, treatment setting, or use of supportive medications. Median post-chemotherapy PVT reaction time slowed by an average of 22.5 ms in breast cancer patients and by 1.6 ms in colorectal cancer patients. Post-chemotherapy median PVT times slowed by > 20 ms in 57 patients (40.1%). Exploratory analyses found no statistically significant association between the primary outcome and self-reported anxiety, fatigue or depression. TMT-B completion speed improved significantly post-chemotherapy (p = 0.03), likely due to test-retest phenomenon.

CONCLUSIONS

PVT reaction time slowed significantly immediately post-chemotherapy compared to a pre-chemotherapy baseline, and levels of impairment similar to effects of alcohol consumption in other studies was seen in 40% of patients. Further studies assessing functional impact of cognitive impairment on patients immediately after chemotherapy are warranted.

Effects of adolescent alcohol consumption on the brain and behaviour

Per occasion, alcohol consumption is higher in adolescents than in adults in both humans and laboratory animals, with changes in the adolescent brain probably contributing to this elevated drinking. This Review examines the contributors to and consequences of the use of alcohol in adolescents. Human adolescents with a history of alcohol use differ neurally and cognitively from other adolescents; some of these differences predate the commencement of alcohol consumption and serve as potential risk factors for later alcohol use, whereas others emerge from its use. The consequences of alcohol use in human adolescents include alterations in attention, verbal learning, visuospatial processing and memory, along with altered development of grey and white matter volumes and disrupted white matter integrity. The functional consequences of adolescent alcohol use emerging from studies of rodent models of adolescence include decreased cognitive flexibility, behavioural inefficiencies and elevations in anxiety, disinhibition, impulsivity and risk-taking. Rodent studies have also showed that adolescent alcohol use can impair neurogenesis, induce neuroinflammation and epigenetic alterations, and lead to the persistence of adolescent-like neurobehavioural phenotypes into adulthood. Although only a limited number of studies have examined comparable measures in humans and laboratory animals, the available data provide evidence for notable across-species similarities in the neural consequences of adolescent alcohol exposure, providing support for further translational efforts in this context.

Binge Drinking's Effects on the Developing Brain-Animal Models

Adolescence typically is a time of experimentation, including alcohol use and, particularly, binge drinking. Because the brain is still developing during adolescence, such exposure could have long-lasting effects. Animal models and adolescent intermittent ethanol exposure (AIE) paradigms have been used to help elucidate the consequences of adolescent binge drinking. These studies have identified cognitive deficits, particularly in challenging cognitive tasks, and behavioral alterations such as greater risk preferences, impulsivity, and disinhibition. AIE also is associated with changes in affect when the animals reach adulthood, including increased social anxiety and, sometimes, general anxiety. Animal models have demonstrated that AIE can result in retention of certain alcohol-related adolescent phenotypes (i.e., reduced sensitivity to alcohol's aversive effects and increased sensitivity to alcohol's rewarding effects) into adulthood, which may motivate continued elevated alcohol use. The detrimental effects of adolescent alcohol exposure extend to a diversity of lasting alterations in the brain, including reduced neurogenesis, increased proinflammatory responses, changes in gene expression through epigenetic mechanisms, and alterations in the activities of various neurotransmitter systems. Further exploration of these mechanisms in animal models and humans may lead to improved prevention and intervention efforts.

Cognitive rehabilitation for individuals with opioid use disorder: A randomized controlled trial. Neuropsychol Rehabil 2017;29:1273-1289. [PMID: 29161998 DOI: 10.1080/09602011.2017.1391103]

Aim: To examine the efficacy of cognitive rehabilitation treatment (CRT) for people with opioid use disorder who were recruited into a methadone maintenance treatment (MMT) programme. Method: 120 male subjects were randomly assigned to (1) MMT plus CRT in two months or (2) MMT plus a control intervention. Subjects were assessed at the beginning, mid-point and post-intervention as well as at 1-, 3- and 6-month follow-up time points. Results: Analysis with repeated measure ANOVA showed that the CRT group performed significantly better in tests of learning, switching, processing speed, working memory and memory span. Moreover, the CRT group had significantly lower opiate use over the control group during 3-months follow-up. Analysis including only those with a history of methamphetamine use showed that the CRT group had significantly lower amphetamine use. No group differences were observed for treatment retention. Conclusions: Our findings provide evidence that adding CRT as an adjunct intervention to MMT can improve cognitive performance as well as abstinence from both opiates and stimulants.

Earlier Alcohol Use Onset Predicts Poorer Neuropsychological Functioning in Young Adults

BACKGROUND

Neurodevelopment may be shaped by environmental factors such as alcohol intake. Over 20% of U.S. high school students begin drinking before age 14, and those who initiated drinking before age 14 are 4 times more likely to develop psychosocial, psychiatric, and substance use difficulties than those who began drinking after turning 20. Little is known, however, about how the age of alcohol use onset influences brain development.

METHODS

This study prospectively examined the effects of alcohol use onset age on neurocognitive functioning in healthy adolescent drinkers (N = 215). Youth were administered a neuropsychological battery before substance use initiation (M = 13.6 years, SD = 0.8) and on average 6.8 years later (M = 20.2 years, SD = 1.5). Hierarchical linear regressions examined if earlier ages of onset for first and regular (i.e., weekly) alcohol use adversely influenced neurocognition, above and beyond baseline neurocognition, substance use severity, and familial and social environment factors.

RESULTS

As hypothesized, an earlier age of first drinking onset (AFDO) predicted poorer performance in the domains of psychomotor speed and visual attention (ps<0.05, N = 215) and an earlier age of weekly drinking onset (AWDO) predicted poorer performances on tests of cognitive inhibition and working memory, controlling for baseline neuropsychological performance, drinking duration, and past-year marijuana use (ps<0.05, N = 127). No relationship between AFDO and AWDO was found with verbal learning and memory and visuospatial ability.

CONCLUSIONS

This is the first study to assess the association between age of adolescent drinking onset and neurocognitive performance using a comprehensive test battery. This study suggests that early onset of drinking increases risk for alcohol-related neurocognitive vulnerabilities and that initiation of any or weekly alcohol use at younger ages appears to be a risk factor for poorer subsequent neuropsychological functioning. Findings have important implications for public policies related to the legal drinking age and prevention programming. Further studies are needed to replicate these preliminary findings and better understand mediating processes and moderating conditions.

Blood Alcohol Concentration-Related Lower Performance in Immediate Visual Memory and Working Memory in Adolescent Binge Drinkers

The binge drinking (BD) pattern of alcohol consumption is prevalent during adolescence, a period characterized by critical changes to the structural and functional development of brain areas related with memory and cognition. There is considerable evidence of the cognitive dysfunctions caused by the neurotoxic effects of BD in the not-yet-adult brain. Thus, the aim of the present study was to evaluate the effects of different blood alcohol concentrations (BAC) on memory during late adolescence (18–19 years old) in males and females with a history of BD. The sample consisted of 154 adolescents (67 males and 87 females) that were classified as refrainers if they had never previously drunk alcoholic drinks and as binge drinkers if they had drunk six or more standard drink units in a row for men or five or more for women at a minimum frequency of three occasions in a month, throughout the previous 12 months. After intake of a high acute dose of alcohol by binge drinkers or a control refreshment by refrainers and binge drinkers, subjects were distributed into four groups for each gender according to their BAC: BAC0-R (0 g/L, in refrainers), BAC0-BD (0 g/L, in binge drinkers), BAC1 (0.3 – 0.5 g/L, in binge drinkers) or BAC2 (0.54 – 1.1 g/L, in binge drinkers). The subjects’ immediate visual memory and working memory were then measured according to the Wechsler Memory Scale (WMS-III). The BAC1 group showed lower scores of immediate visual memory but not of working memory, while lower performance in both memories were found in the BAC2 group. Therefore, the brain of binge drinkers with moderate BAC could be employing compensatory mechanisms from additional brain areas to perform a working memory task adequately, but these resources would be undermined when BAC is higher (>0.5 g/L). No gender differences were found in BAC-related lower performance in immediate visual memory and working memory. In conclusion, immediate visual memory is more sensitive than working memory to the neurotoxic effects of alcohol in adolescent binge drinkers of both genders, being a BAC-related lower performance, and without obvious differences between males and females.

A Review of Developmental Considerations in Human Laboratory Alcohol Research

PURPOSE OF REVIEW

Human laboratory studies involving alcohol administration have generated critical knowledge about individual differences in risk for alcohol use disorder (AUD), but have primarily involved adult populations and cross-sectional research designs. Ethical constraints have largely precluded human laboratory alcohol research in adolescence, and prospective studies have been rare. This paper provides an overview of developmental considerations in human laboratory alcohol research, with a focus on studies conducted with youth.

RECENT FINDINGS

Recent human laboratory studies from Europe and Canada have examined aspects of alcohol response during late adolescence, while recent survey studies from the United States have highlighted methods for circumventing alcohol administration in studies of adolescents.

SUMMARY

Across several decades of research, exceedingly few laboratory studies have examined developmental differences in alcohol responses or utilized prospective designs. Efforts to prioritize prospective research would further clarify the role of alcohol sensitivity traits as predictors or markers of AUD onset and progression.

Effects of acute alcohol intoxication on executive functions controlling self-regulated behavior

Alcohol consumption may lead to deficits in the executive functions that govern self-regulation. These deficits could lead to risk-taking behaviors; therefore, it is important to determine the magnitude of these deficits on executive functioning. The purpose of this experiment was to investigate the acute effects of alcohol on three of the executive functions that are hypothesized to affect self-regulation, which are inhibition, set shifting, and working memory, using a mixed-methods study design. The participants were 75 moderate or heavy drinkers between the ages of 21 and 35 who were randomized into one of three beverage conditions (control, placebo, or 0.65-g alcohol dose/kg body weight). Performance on working memory, set shifting, and inhibition were measured pre- and post-beverage consumption. The results showed only a significant interaction in the working memory data, as there was an increase in performance post-beverage relative to pre-beverage for the control participants as compared to the alcohol and placebo participants. It was concluded that the dose of alcohol (BAC = 0.063%) given to moderate to heavy drinkers was not sufficient to cause significant impairment in the executive functions tested. The results were further discussed and methodological concerns were considered, such as the low BAC achieved, practice effects, and insensitivity of tasks.

Sex and Adolescent Ethanol Exposure Influence Pavlovian Conditioned Approach

BACKGROUND

Alcohol use among adolescents is widespread and a growing concern due to long-term behavioral deficits, including altered Pavlovian behavior, that potentially contribute to addiction vulnerability. We tested the hypothesis that adolescent intermittent ethanol (AIE) exposure alters Pavlovian behavior in males and females as measured by a shift from goal-tracking to sign-tracking. Additionally, we investigated GLT-1, an astrocytic glutamate transporter, as a potential contributor to a sign-tracking phenotype.

METHODS

Male and female Sprague-Dawley rats were exposed to AIE (5 g/kg, intragastric) or water intermittently 2 days on and 2 days off from postnatal day (P) 25 to 54. Around P70, animals began 20 daily sessions of Pavlovian conditioned approach (PCA), where they learned that a cue predicted noncontingent reward delivery. Lever pressing indicated interaction with the cue, or sign-tracking, and receptacle entries indicated approach to the reward delivery location, or goal-tracking. To test for effects of AIE on nucleus accumbens (NAcc) excitatory signaling, we isolated membrane subfractions and measured protein levels of the glutamate transporter GLT-1 after animals completed behavior as a measure of glutamate homeostasis.

RESULTS

Females exhibited elevated sign-tracking compared to males with significantly more lever presses, faster latency to first lever press, and greater probability to lever press in a trial. AIE significantly increased lever pressing while blunting goal-tracking, as indicated by fewer cue-evoked receptacle entries, slower latency to receptacle entry, and lower probability to enter the receptacle in a trial. No significant sex-by-exposure interactions were observed in sign- or goal-tracking metrics. Moreover, we found no significant effects of sex or exposure on membrane GLT-1 expression in the NAcc.

CONCLUSIONS

Females exhibited enhanced sign-tracking compared to males, while AIE decreased goal-tracking compared to control exposure. Our findings support the hypothesis that adolescent binge ethanol can shift conditioned behavior from goal- to cue-directed in PCA, especially in females.

Acute alcohol effects on set-shifting and its moderation by baseline individual differences: a latent variable analysis

AIMS

To compare the acute effects of alcohol on set-shifting task performance (relative to sober baseline performance) during ascending and descending limb breath alcohol concentration (BrAC), as well as possible moderation of these effects by baseline individual differences.

DESIGN

Shifting performance was tested during an initial baseline and a subsequent drinking session, during which participants were assigned randomly to one of three beverage conditions (alcohol, placebo or control) and one of two BrAC limb conditions [ascending and descending (A/D) or descending-only (D-only)].

SETTING

A human experimental laboratory on the University of Missouri campus in Columbia, MO, USA.

PARTICIPANTS

A total of 222 moderate-drinking adults (ages 21-30 years) recruited from Columbia, MO and tested between 2010 and 2013.

MEASUREMENTS

The outcome measure was performance on set-shifting tasks under the different beverage and limb conditions. Shifting performance assessed at baseline was a key moderator.

FINDINGS

Although performance improved across sessions, this improvement was reduced in the alcohol compared with no-alcohol groups (post-drink latent mean comparison across groups, all Ps ≤ 0.05), and this effect was more pronounced in individuals with lower pre-drink performance (comparison of pre- to post-drink path coefficients across groups, all Ps ≤ 0.05). In the alcohol group, performance was better on descending compared with ascending limb (P ≤ 0.001), but descending limb performance did not differ across the A/D and D-only groups.

CONCLUSIONS

Practising tasks before drinking moderates the acute effects of alcohol on the ability to switch between tasks. Greater impairment in shifting ability on descending compared with ascending breath alcohol concentration is not related to task practice.

Voluntary Binge Consumption of Ethanol in a Sweetened, Chocolate-Flavored Solution by Male and Female Adolescent Sprague Dawley Rats

BACKGROUND

The still maturing adolescent brain may be particularly vulnerable to lasting consequences of ethanol (EtOH) exposure. Yet, human adolescents are the age group most likely to engage in binge drinking (a pattern of drinking leading to blood EtOH concentrations (BECs) of 80 mg/dl or greater). Most studies to date assessing the long-term effects of adolescent EtOH exposure in outbred rodent populations have either used experimenter-administered EtOH to produce BECs in the binge range or assessed voluntary intake of EtOH at well below binge levels. Beginning with a modified schedule-induced polydipsia (SIP) procedure, this study examined the suitability of several approaches to induce voluntary binge-like consumption during adolescence in an outbred rat strain.

METHODS

Adolescent male and female Sprague Dawley rats were food deprived to 85% projected free-feeding weights beginning on postnatal day (P) 24 and were given 30 minutes of access to 10% EtOH in chocolate Boost^® or Boost^® alone daily from P28 to P41 (followed later by their daily allocation of food). Animals were tested within operant chambers (Exp. 1a, 1b and Exp. 2) or home and novel cages (Exp. 3). Animals received either scheduled delivery of banana pellets to examine SIP (Exp. 1a,b) or massed pellet presentation (Exp. 2 and Exp. 3). Blood samples were collected via the lateral tail vein on P33 and P41.

RESULTS

Intakes produced BECs frequently in the binge range (>80 mg/dl) and modeled binge-like consumption patterns, with high consumption days typically followed by 1 to 2 days of lower consumption; this variability was less evident with Boost^® alone. Consumption was not schedule induced and was generally high across all studies, although consumption in males appeared to be particularly pronounced when animals were tested in the presence of their cage mate.

CONCLUSIONS

Binge-like patterns of EtOH consumption were produced using these procedures in adolescent Sprague Dawley rats of both sexes and may prove to be a useful model for work examining the short- and long-term consequences of high levels of voluntary EtOH intake in adolescence.

Subjective alcohol responses in a cross-sectional, field-based study of adolescents and young adults: Effects of age, drinking level, and dependence/consequences

BACKGROUND

Adolescents are physically, cognitively, socially, and emotionally different than adults in ways that may partially explain why alcohol misuse typically develops during this period. Ample animal-science evidence and nascent ecological evidence points toward developmentally limited differences in sensitivity to alcohol's stimulatory and sedative effects. Field-based research methods were used to test for such age-related differences in a sample of adolescents through young adults. Potential moderating influences of estimated blood alcohol content (eBAC), as well as typical consumption and level of dependence/consequences were explored.

METHODS

Subjective alcohol responses were collected from 1,364 participants, aged 17 to 32 years, recruited outside of venues where drinking takes place in a small metropolitan bar district.

RESULTS

Self-reports of stimulatory response to alcohol were age-related, such that younger participants reported increased subjective stimulation at the time of data collection relative to older participants. Age-related differences in stimulatory responses were more pronounced at lower eBACs and among younger participants who typically drank more heavily. Stimulatory responses generally diminished among older than younger participants, although individuals with greater dependence/consequences consistently reported greater stimulation from drinking. Contrastingly, age, typical consumption, and dependence/consequences were not related to sedation in this sample.

CONCLUSIONS

This research provides cross-sectional evidence to support age-, consumption-, and dependence/consequences-related differences in stimulatory alcohol responses among adolescents and young adults assessed within a bar-area context. While cross-sectional, the results of this field-based study provide support for the theory that addiction liability is developmentally linked and associated, in part, with age-related differences in subjective alcohol responses.

Binge Drinking in Young University Students Is Associated with Alterations in Executive Functions Related to Their Starting Age

Our aim was to evaluate whether or not alcohol consumption in the form of binge drinking is associated with alterations of memory and executive functions in a population of university students. At the same time, we have studied the role of potential modulating factors, such as the APOE genotype or physical exercise.University students enrolled in academic year 2013–2014 at Escuelas Universitarias Gimbernat-Cantabria, affiliated with the University of Cantabria, were invited to participate in the study. We gathered sociodemographic data and details regarding the lifestyle of 206 students (mean age 19.55 ± 2.39; 67.5% women). We evaluated memory and executive functions via a series of validated cognitive tests. Participants were classified as binge drinkers (BD) and non-BD. Using Student's t-distribution we studied the association between cognitive tests and BD patterns. Multivariate analyses were carried out via multiple linear regression. 47.6% of the students were found to be BD. The BD differed significantly from the non-BD in their results in the executive functions test TMT B (43.41 ± 13.30 vs 37.40 ± 9.77; p = 0.0003). Adjusting by age, sex, academic records, age at which they started consuming alcohol, cannabis consumption, level of physical activity and other possible modifying variables, the association was statistically significant (p = 0.009). We noticed a statistically significant inverse correlation (Pearson’s r² = -0.192; p = 0.007) between TMT B and starting age of alcohol consumption. Differences were observed in another executive functions test, TMT A, but only in the group of women (19.73±6.1 BD vs 17.78±5.4 non-BD p = 0.05). In spite of the young age of our participants, BD was associated with a lower performance in the executive functions test (TMT B). These deficits were related to the age at which they started drinking alcohol, suggesting an accumulative effect.

Adolescent Alcohol Exposure Persistently Impacts Adult Neurobiology and Behavior

Adolescence is a developmental period when physical and cognitive abilities are optimized, when social skills are consolidated, and when sexuality, adolescent behaviors, and frontal cortical functions mature to adult levels. Adolescents also have unique responses to alcohol compared with adults, being less sensitive to ethanol sedative-motor responses that most likely contribute to binge drinking and blackouts. Population studies find that an early age of drinking onset correlates with increased lifetime risks for the development of alcohol dependence, violence, and injuries. Brain synapses, myelination, and neural circuits mature in adolescence to adult levels in parallel with increased reflection on the consequence of actions and reduced impulsivity and thrill seeking. Alcohol binge drinking could alter human development, but variations in genetics, peer groups, family structure, early life experiences, and the emergence of psychopathology in humans confound studies. As adolescence is common to mammalian species, preclinical models of binge drinking provide insight into the direct impact of alcohol on adolescent development. This review relates human findings to basic science studies, particularly the preclinical studies of the Neurobiology of Adolescent Drinking in Adulthood (NADIA) Consortium. These studies focus on persistent adult changes in neurobiology and behavior following adolescent intermittent ethanol (AIE), a model of underage drinking. NADIA studies and others find that AIE results in the following: increases in adult alcohol drinking, disinhibition, and social anxiety; altered adult synapses, cognition, and sleep; reduced adult neurogenesis, cholinergic, and serotonergic neurons; and increased neuroimmune gene expression and epigenetic modifiers of gene expression. Many of these effects are specific to adolescents and not found in parallel adult studies. AIE can cause a persistence of adolescent-like synaptic physiology, behavior, and sensitivity to alcohol into adulthood. Together, these findings support the hypothesis that adolescent binge drinking leads to long-lasting changes in the adult brain that increase risks of adult psychopathology, particularly for alcohol dependence.

Social Ecological Determinants of Substance Use Treatment Entry Among Serious Juvenile Offenders From Adolescence Through Emerging Adulthood

PURPOSE

To examine the social-ecological determinants of substance use treatment entry among serious juvenile offenders over a 7 year period. Using the social-ecological framework, relevant predictors of substance use from the literature were used to assess risk (and protective) factors at the individual, parental, peer and neighborhood level.

METHOD

Serious juvenile offenders (N=1354, M_{age baseline}=16.0 years, SD=1.14) were prospectively followed over 7 years (M_{age Conclusion}=23.0 years, SD=1.15). Cox regression with time invariant and time varying predictors was used to predict time to first substance use treatment entry.

RESULTS

Results for each dimension, separately, varied slightly from the full model. In the full model peer delinquency, peer arrests, post-traumatic stress disorder (PTSD), impulse control, temperament, and emotional regulation remained salient risk (and protective) factors for treatment entry.

CONCLUSION

Associating with more deviant peers and having more of your peers arrested over the 7 year study period was associated with substantial increase in time to treatment entry. Furthermore, one of the strongest risk factors for treatment entry was a PTSD diagnosis. Treatment implications are discussed regarding peer affiliation and PTSD symptomology as well as potential neurological and biological contributors to increased risk for treatment entry.

Consequences of adolescent use of alcohol and other drugs: Studies using rodent models

Studies using animal models of adolescent exposure to alcohol, nicotine, cannabinoids, and the stimulants cocaine, 3,4-methylenedioxymethampethamine and methamphetamine have revealed a variety of persisting neural and behavioral consequences. Affected brain regions often include mesolimbic and prefrontal regions undergoing notable ontogenetic change during adolescence, although it is unclear whether this represents areas of specific vulnerability or particular scrutiny to date. Persisting alterations in forebrain systems critical for modulating reward, socioemotional processing and cognition have emerged, including apparent induction of a hyper-dopaminergic state with some drugs and/or attenuations in neurons expressing cholinergic markers. Disruptions in cognitive functions such as working memory, alterations in affect including increases in social anxiety, and mixed evidence for increases in later drug self-administration has also been reported. When consequences of adolescent and adult exposure were compared, adolescents were generally found to be more vulnerable to alcohol, nicotine, and cannabinoids, but generally not to stimulants. More work is needed to determine how adolescent drug exposure influences sculpting of the adolescent brain, and provide approaches to prevent/reverse these effects.

Effects of Emerging Alcohol and Marijuana Use Behaviors on Adolescents' Neuropsychological Functioning Over Four Years

OBJECTIVE

Adolescence is a period of neuromaturation concomitant with increased substance involvement. Most substance use studies of adolescents have focused on categorical classifications (e.g., dependent vs. nondependent), but little is known about the influence of specific substance use behaviors on cognitive functioning in youth.

METHOD

This study prospectively evaluated the quantitative effects of different substance use behaviors on neuropsychological functioning. A cognitive test battery was administered at baseline (ages 12-14 years), before substance use initiation, and at follow-up (M = 4.0 years, SD = 2.0) to evaluate changes in verbal memory, visuospatial ability, psychomotor speed, processing speed, and working memory. Robust regressions examined substance use behaviors as predictors of neuropsychological functioning (N = 234).

RESULTS

Several substance use behaviors predicted follow-up neuropsychological functioning above and beyond effects of baseline performance on the same measure (ps < .05). Specifically, more alcohol use days predicted worse verbal memory (β = -.15) and visuospatial ability (β = -.19). More postdrinking effects (β = -.15) and greater drug use (β = -.11) predicted worse psychomotor speed. Processing speed was not predicted by substance involvement (ps > .05). Unexpectedly, more alcohol use predicted better working memory performance (β = .12).

CONCLUSIONS

The frequency and intensity of adolescent alcohol use may be more intricately linked to neuropsychological outcomes than previously considered. The low prevalence of substance use disorder in the sample suggests that subdiagnostic users may still experience adverse effects to verbal memory, visuospatial functioning, and psychomotor speed after initiating intense or frequent alcohol use.

Which matters most? Demographic, neuropsychological, personality, and situational factors in long-term marijuana and alcohol trajectories for justice-involved male youth

Justice-involved youth have high rates of alcohol and marijuana use. However, little is known about what may drive these rates over time. Using a large-scale (N = 1,056; 41.4% African American, 33.5% Hispanic) longitudinal study with strong retention (M retention = 90% over Years 1-7), we utilized random-effects regression to determine the comparative contribution of four sets of factors in justice-involved males' patterns of marijuana and heavy alcohol use (number of times drunk) over 7 years of follow-up: demographic, personality, situational, and neuropsychological factors. Across both marijuana and heavy alcohol use models, three factors were particularly strong contributors to lower rates of substance use: (a) Hispanic ethnicity, (b) less exposure (street) time, and (c) better impulse control. Similarly, two factors were strong contributors to increased rates of marijuana and heavy alcohol use: (a) delinquent peers and (b) family member arrest. Together, these findings indicate the relative superiority of these independent variables over other categories (i.e., neuropsychological factors) in predicting high-risk youths' long-term (7-year) rates of substance use. These findings also suggest the importance of evaluating the connection of these areas for high-risk, adjudicated youth.

Assembling Interrelations Between Low Socioeconomic Status and Acute Alcohol-Related Harms Among Young Adult Drinkers

It is well established that alcohol-related harm is disproportionately prevalent among low socioeconomic status (SES) drinkers despite their lower consumption of alcohol, but epidemiological investigations have been unable to explain those links causally. I argue that this inability arises from the consumption-as-harm proposition, which proceeds from the assumption that alcohol acts in stable and predictable ways. In this model, “social factors” have been associated with increasing or decreasing harms by modulating consumption, but their other transformations of alcohol effects have not been registered. Stepping away from this model, I deploy the notion of the causal assemblage, which was developed in science and technology studies and has recently been applied in studies of alcohol and other drug (AOD) use. I analyze data from interviews with a convenience sample of low SES young adult drinkers and develop case studies of drinking events. I demonstrate that, in the case studies, alcohol-related harms are co-produced by troubled family and ethnic patterns of relations to alcohol and associated memories, enforcement of gender norms in public spaces, and a lack of access to private drinking settings. These insights are significant because they make visible the social forces co-producing alcohol-related harms and demonstrate the limitations of a model of causality commonly deployed in AOD studies.

A field investigation of the effects of drinking consequences on young adults' readiness to change

In the research on readiness to change (RTC) one's drinking, there has been little assessment of the influence of positive drinking consequences or other potential moderating variables. To address these limitations, we examined how young adults' RTC their alcohol consumption shortly following a drinking episode was associated with self-reported drinking consequences, as well as any potential moderating effects of gender and Breath Alcohol Concentration (BrAC). In street interviews outside bars, 238 young adults were administered questionnaires about their drinking, including a measure examining participants' current readiness to reduce their alcohol consumption. Within 72h of their drinking episode, 67 participants (36 males; entire sample Mage=20.90years, Range=18-26years) completed an online survey, once again measuring RTC as well as positive and negative drinking consequences. Consistent with our hypothesis, positive drinking consequences were negatively associated with participants' changes in RTC. Additionally, a three-way interaction of gender×BrAC×positive drinking consequences on RTC showed that females with low BrACs reported higher RTC scores when they had endorsed fewer positive drinking consequences. Interestingly, negative drinking consequences alone did not impact individuals' RTC. Because positive drinking consequences were a significantly better predictor of RTC than were negative drinking consequences, researchers are advised to examine both types of consequences in future studies. Finally, effective alcohol education programs for those who have never consumed alcohol as well as social drinkers should include consideration of the experience of positive outcomes.

Effects of ethanol exposure during adolescence or in adulthood on Pavlovian conditioned approach in Sprague-Dawley rats

Human studies have shown that adolescents who repeatedly use alcohol are more likely to be dependent on alcohol and are more likely to suffer from psychological problems later in life. There has been limited research examining how ethanol exposure in adolescence might contribute to later abuse or addiction in adulthood. The present experiment examined effects of intermittent ethanol exposure during adolescence on sign-tracking behavior in adulthood, indexed by a Pavlovian conditioned approach (PCA) task wherein an 8s lever presentation served as a cue predicting subsequent delivery of a flavored food pellet. Although no response was required for food delivery, after multiple pairings, 1 of 2 different responses often emerged during the lever presentation: goal tracking (head entries into the food trough) or sign tracking (engagement with the lever when presented). Sign tracking is thought to reflect the attribution of incentive salience to reward-paired cues and has been previously correlated with addiction-like behaviors. Following the last PCA session, blood samples were collected for analysis of post-session corticosterone levels. Sixty-two rats (n = 10-12/group) were pseudo-randomly assigned to 1 of 2 intragastric (i.g.) exposure groups (water or 4 g/kg ethanol) or a non-manipulated (NM) control group. Animals were intubated with ethanol or water every other session from postnatal session (PND) 28-48 or PND 70-90. Rats were then tested in adulthood (PND 71-79 or PND 113-122) on the PCA task. Animals exposed chronically to ethanol during adolescence exhibited significantly higher levels of sign-tracking behavior in adulthood than NM and water-treated animals, and showed higher corticosterone than NM control animals. These effects were not seen after comparable ethanol exposure in adulthood. These results suggest that adolescent alcohol exposure has long-term consequences on the expression of potential addiction-relevant behaviors in adulthood.

Adolescent alcohol exposure and persistence of adolescent-typical phenotypes into adulthood: a mini-review

Alcohol use is typically initiated during adolescence, which, along with young adulthood, is a vulnerable period for the onset of high-risk drinking and alcohol abuse. Given across-species commonalities in certain fundamental neurobehavioral characteristics of adolescence, studies in laboratory animals such as the rat have proved useful to assess persisting consequences of repeated alcohol exposure. Despite limited research to date, reports of long-lasting effects of adolescent ethanol exposure are emerging, along with certain common themes. One repeated finding is that adolescent exposure to ethanol sometimes results in the persistence of adolescent-typical phenotypes into adulthood. Instances of adolescent-like persistence have been seen in terms of baseline behavioral, cognitive, electrophysiological and neuroanatomical characteristics, along with the retention of adolescent-typical sensitivities to acute ethanol challenge. These effects are generally not observed after comparable ethanol exposure in adulthood. Persistence of adolescent-typical phenotypes is not always evident, and may be related to regionally specific ethanol influences on the interplay between CNS excitation and inhibition critical for the timing of neuroplasticity.

Gender, history of alcohol use and number of drinks consumed predict craving among drinkers in a field setting

To the extent that craving serves to compel excessive drinking, it would be important to predict the intensity of an individual's craving over the course of a drinking episode. Previous research indicates that regular alcohol use (measured by the AUDIT) and the number of drinks individuals have already consumed that evening independently predict craving to drink (Schoenmakers & Wiers, 2010). The current study aims to replicate those findings by testing whether these same variables predict craving to drink in a sample of 1320 bar patrons in a naturalistic setting. In addition, we extend those findings by testing whether regular alcohol use and self-reported number of drinks consumed interact to predict craving, and whether gender independently predicts craving or interacts with other variables to predict craving. Results indicate that for men, AUDIT score alone predicted craving, whereas for women, AUDIT score and number of drinks consumed interacted to predict craving, with craving highest among women with either high AUDIT scores or relatively high consumption levels. Our findings have implications for targeted intervention and prevention efforts, as women who have a history of harmful alcohol use and consume several drinks in an evening might be at the greatest risk for continued alcohol consumption.