Working memory and alcohol use in at-risk adolescents: a 2-year follow-up

Neurocognitive predictors of addiction-related outcomes: A systematic review of longitudinal studies

It is well-established that addiction is typically associated with a distinct pattern of neurocognitive functioning with a consensus that it is typified by impaired top-down executive control and aberrant risk-reward processing. Despite a consensus that neurocognition plays an important role in characterizing and maintaining addictive disorders, there is a lack of systematic, bottom-up synthesis of quantitative evidence showing that neurocognition predicts addictive behaviors, and which neurocognitive constructs have the best predictive validity. This systematic review aimed to assess whether cognitive control and risk-reward processes as defined by the Research Domain Criteria (RDoC) predict the development and maintenance of addictive behaviors specifically, consumption, severity, and relapse. The findings from this review expose the substantial lack of evidence for neurocognition predicting addiction outcomes. However, there is evidence that suggests reward-related neurocognitive processes may be important for the detection of early risk for addiction, as well as a potentially viable target for designing novel, more effective interventions.

Applying Monte Carlo Simulations to a Small Data Analysis of a Case of Economic Growth in COVID-19 Times

Studies on the going-on COVID-19 pandemic face small sample issues. In this context, Bayesian estimation is considered a viable alternative to frequentist estimation. Demonstrating the Bayesian approach's advantage in dealing with this problem, our research conducted a case study concerning ASEAN economic growth during the COVID-19 pandemic. By using Monte Carlo standard errors and interval hypothesis testing to check parameter bias within a Bayesian MCMC simulation study, the author obtained significant conclusions as follows: first, in insufficient sample sizes, in contrast to frequentist estimation, the Bayesian framework can offer meaningful results, that is, expansionary monetary and contractionary fiscal policies are positively associated with economic growth; second, in the face of a small sample, by incorporating more information into prior distributions for the model parameters, Bayesian Monte Carlo simulations perform so far better than naïve Bayesian and frequentist estimation; third, in case of a correctly specified prior, the inferences are robust to different prior specifications. The author strongly recommends applying specific informative priors to Bayesian analyses, particularly in small sample investigations.

Reaction Time and Visual Memory in Connection to Alcohol Use in Persons with Bipolar Disorder

The purpose of this study was to explore the association of cognition with hazardous drinking and alcohol-related disorder in persons with bipolar disorder (BD). The study population included 1268 persons from Finland with bipolar disorder. Alcohol use was assessed through hazardous drinking and alcohol-related disorder including alcohol use disorder (AUD). Hazardous drinking was screened with the Alcohol Use Disorders Identification Test for Consumption (AUDIT-C) screening tool. Alcohol-related disorder diagnoses were obtained from the national registrar data. Participants performed two computerized tasks from the Cambridge Automated Neuropsychological Test Battery (CANTAB) on A tablet computer: the 5-choice serial reaction time task, or reaction time (RT) test and the Paired Associative Learning (PAL) test. Depressive symptoms were assessed with the Mental Health Inventory with five items (MHI-5). However, no assessment of current manic symptoms was available. Association between RT-test and alcohol use was analyzed with log-linear regression, and eβ with 95% confidence intervals (CI) are reported. PAL first trial memory score was analyzed with linear regression, and β with 95% CI are reported. PAL total errors adjusted was analyzed with logistic regression and odds ratios (OR) with 95% CI are reported. After adjustment of age, education, housing status and depression, hazardous drinking was associated with lower median and less variable RT in females while AUD was associated with a poorer PAL test performance in terms of the total errors adjusted scores in females. Our findings of positive associations between alcohol use and cognition in persons with bipolar disorder are difficult to explain because of the methodological flaw of not being able to separately assess only participants in euthymic phase.

Linking RDoC and HiTOP: A new interface for advancing psychiatric nosology and neuroscience

The Research Domain Criteria (RDoC) and the Hierarchical Taxonomy of Psychopathology (HiTOP) represent major dimensional frameworks proposing two alternative approaches to accelerate progress in the way psychopathology is studied, classified, and treated. RDoC is a research framework rooted in neuroscience aiming to further the understanding of transdiagnostic biobehavioral systems underlying psychopathology and ultimately inform future classifications. HiTOP is a dimensional classification system, derived from the observed covariation among symptoms of psychopathology and maladaptive traits, which seeks to provide more informative research and treatment targets (i.e., dimensional constructs and clinical assessments) than traditional diagnostic categories. This article argues that the complementary strengths of RDoC and HiTOP can be leveraged in order to achieve their respective goals. RDoC's biobehavioral framework may help elucidate the underpinnings of the clinical dimensions included in HiTOP, whereas HiTOP may provide psychometrically robust clinical targets for RDoC-informed research. We present a comprehensive mapping between dimensions included in RDoC (constructs and subconstructs) and HiTOP (spectra and subfactors) based on narrative review of the empirical literature. The resulting RDoC-HiTOP interface sheds light on the biobehavioral correlates of clinical dimensions and provides a broad set of dimensional clinical targets for etiological and neuroscientific research. We conclude with future directions and practical recommendations for using this interface to advance clinical neuroscience and psychiatric nosology. Ultimately, we envision that this RDoC-HiTOP interface has the potential to inform the development of a unified, dimensional, and biobehaviorally-grounded psychiatric nosology.

Alcohol use and cognitive functioning in young adults: improving causal inference

BACKGROUND AND AIMS

There have been few longitudinal studies of association between alcohol use and cognitive functioning in young people. We aimed to examine whether alcohol use is a causal risk factor for deficient cognitive functioning in young adults.

DESIGN

Linear regression was used to examine the relationship between longitudinal latent class patterns of binge drinking and subsequent cognitive functioning. Two-sample Mendelian randomization (MR) tested evidence for the causal relationship between alcohol use and cognitive functioning.

SETTING

South West England.

PARTICIPANTS

The observational study included 3155 adolescents and their parents (fully adjusted models) from the Avon Longitudinal Study of Parents and Children (ALSPAC). Genetic instruments for alcohol use were based on almost 1 000 000 individuals from the genome-wide association studies (GWAS) and Sequencing Consortium of Alcohol and Nicotine use (GSCAN). Genome-wide association studies for cognitive outcomes were based on 2500 individuals from ALSPAC.

MEASUREMENTS

Binge drinking was assessed at approximately 16, 17, 18, 21 and 23 years. Cognitive functioning comprised working memory, response inhibition and emotion recognition assessed at 24 years of age. Ninety-nine independent genome-wide significant single nucleotide polymorphisms (SNPs) associated with 'number of drinks per week' were used as the genetic instrument for alcohol consumption. Potential confounders were included in the observational analyses.

FINDINGS

Four binge drinking classes were identified: 'low-risk' (41.3%), 'early-onset monthly' (19.1%), 'adult frequent' (22.5%) and 'early-onset frequent' (17.0%). The association between early-onset frequent binge drinking and cognitive functioning: working memory (b = -0.42, 95% confidence interval (CI) = -1.24 to 0.41), response inhibition (b = 31.9, 95% CI = -25.3 to 89.2), and emotion recognition (b = 0.02, 95% CI = -0.07 to 0.10) in comparison to low-risk drinkers were inconclusive as to whether a difference was present. Two-sample MR analyses similarly provided little evidence that alcohol use is associated with deficits in working memory using the inverse variance weight (b = 0.29, 95% CI = -0.42 to 0.99), response inhibition (b = -0.32, 95% CI = -1.04 to 0.39) and emotion recognition (b = 0.03, 95% CI = -0.55 to 0.61).

CONCLUSIONS

Binge drinking in adolescence and early adulthood may not be causally related to deficiencies in working memory, response inhibition or emotion recognition in youths.

Adiposity, Inflammation, and Working Memory: Evidence for a Vicious Cycle

Overweight and obesity constitute the fifth leading cause of preventable deaths worldwide. One pathway through which excess weight contributes to poor health outcomes is via inflammatory activity and changes in cognitive processes. Prior theory has proposed a vicious cycle whereby obesity potentiates inflammatory activity, which alters cognitive processes such as working memory, which in turn leads to a reduced ability to self-regulate and therefore manage weight. However, to date no longitudinal studies have examined this potential dynamic. In the current study, we addressed this gap by assessing the relations among fat mass, C-reactive protein (CRP), and working memory across time in a large sample of 8536 children followed through adolescence in the Avon Longitudinal Study of Parents and Children in the United Kingdom. Adiposity was quantified via dual emission x-ray absorptiometry (DEXA) at ages 9 and 15.5 years old, and inflammatory activity was indexed via circulating serum C-reactive protein (CRP) levels assessed with a high-sensitivity assay at those same ages. Working memory was assessed between these two time points, at age 10, permitting examination of the temporal relations between working memory, adiposity, and inflammatory activity. As hypothesized, we found that fat mass predicted later poor working memory, and this association was statistically mediated by CRP. Further, we found that poor working memory predicted greater subsequent fat mass and CRP, and the link between working memory and subsequent CRP was partially mediated by fat mass. These results thus could be taken to suggest the existence of a vicious cycle of mutually amplifying adiposity, inflammatory activity, and poor working memory over time.

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Adiposity and inflammatory activity (CRP) was measured at ages 9 and 15.5 ​yrs.

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Working memory was assessed at age 10 ​yrs.

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Adiposity predicted working memory, and this association was mediated by CRP.

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Working memory predicted later adiposity and CRP, this was mediated by adiposity.

The effect of alcohol use on neuroimaging correlates of cognitive and emotional processing in human adolescence

OBJECTIVE

This article provides an overview of the scientific literature pertaining to the effects of alcohol on neural correlates of cognitive and emotional functioning, including reward processing and cue-reactivity, in adolescence and young adulthood.

METHOD

Peer-reviewed, original research articles that included a neuroimaging assessment of alcohol effects on subsequent cognitive or emotional processing in adolescent or young adult samples were searched (through November 2018) and summarized in the review.

RESULTS

Cross-sectional studies provided early evidence of alcohol-related differences in neural processing across a number of cognitive domains. Longitudinal studies have identified neural abnormalities that predate drinking within most domains of cognitive functioning, while a few neural alterations have been observed within the domains of visual working memory, inhibitory control, reward processing, and cue-reactivity that appear to be related to the neurotoxic effect of alcohol use during adolescence. In contrast, neural correlates of emotion functioning appear to be relatively stable to the effects of alcohol.

CONCLUSIONS

Larger prospective studies are greatly needed to disentangle premorbid factors from neural consequences associated with drinking, and to detect subsets of youth who may be particularly vulnerable to alcohol's effects on cognitive and emotional functioning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Pushing the Limits

Abstract. Longitudinal developmental research is often focused on patterns of change or growth across different (sub)groups of individuals. Particular to some research contexts, developmental inquiries may involve one or more (sub)groups that are small in nature and therefore difficult to properly capture through statistical analysis. The current study explores the lower-bound limits of subsample sizes in a multiple group latent growth modeling by means of a simulation study. We particularly focus on how the maximum likelihood (ML) and Bayesian estimation approaches differ when (sub)sample sizes are small. The results show that Bayesian estimation resolves computational issues that occur with ML estimation and that the addition of prior information can be the key to detect a difference between groups when sample and effect sizes are expected to be limited. The acquisition of prior information with respect to the smaller group is especially influential in this context.

Alcohol Use in Adolescence and Later Working Memory: Findings From a Large Population-Based Birth Cohort

Aims

The study aimed to examine the association between adolescent alcohol use and working memory (WM) using a large population sample.

Methods

Data from the Avon Longitudinal Study of Parents and Children were used to investigate the association between alcohol use at age 15 years and WM 3 years later, assessed using the N-back task (N ~ 3300). A three-category ordinal variable captured mutually exclusive alcohol groupings ranging in order of severity (i.e. low alcohol users, frequent drinkers and frequent/binge drinkers). Differential dropout was accounted for using multiple imputation and inverse probability weighting. Adjustment was made for potential confounders.

Results

There was evidence of an association between frequent/binge drinking (compared to the low alcohol group) and poorer performance on the 3-back task after adjusting for sociodemographic confounding variables, WM at age 11 years, and experience of a head injury/unconsciousness before age 11 years (β = −0.23, 95% CI = −0.37 to −0.09, P = 0.001). However, this association was attenuated (β = −0.12, 95% CI = −0.27 to 0.03, P = 0.11) when further adjusted for baseline measures of weekly cigarette tobacco and cannabis use. Weaker associations were found for the less demanding 2-back task. We found no evidence to suggest frequent drinking was associated with performance on either task.

Conclusions

We found weak evidence of an association between sustained heavy alcohol use in mid-adolescence and impaired WM 3 years later. Although we cannot fully rule out the possibility of reverse causation, several potential confounding variables were included to address the directionality of the relationship between WM and alcohol use problems.

Earlier alcohol use onset prospectively predicts changes in functional connectivity

BACKGROUND

Half of all new alcohol initiates are between 12 and 17 years old. This is a period of intense neurodevelopment, including changes in functional connectivity patterns among higher-order function areas. It is crucial to understand how alcohol-related neurotoxicity may be influenced by drinking onset age.

DESIGN

This study prospectively examined the effects of age of first drink on frontoparietal context-dependent functional connectivity (cdFC) during a visual working memory task. Youth 13.5 years of age (SD = 1.2) underwent a neuropsychological and neuroimaging session before drinking initiation and at follow-up 6 years later. Hierarchical linear regressions examined if youth with earlier ages of onset for first and weekly alcohol use showed higher follow-up cdFC between the dorsolateral prefrontal cortex and posterior parietal cortex regions of interest and whole-brain exploratory regions, controlling for pre-drinking cdFC. Higher follow-up cdFC was hypothesized to be correlated with poorer performances in neuropsychological performance.

RESULTS

Exploratory whole-brain analyses showed that, as hypothesized, earlier ages of weekly drinking onset were associated with higher cdFC between the bilateral posterior cingulate and cortical and subcortical areas implicated in attentional processes, which was in turn associated with poorer performance on neuropsychological tasks of attention, ps < .05. No relationship between age of onset and cdFC between the two ROIs were found.

CONCLUSION

Earlier ages of weekly alcohol use initiation may adversely affect neurodevelopment by reducing developmentally appropriate integration of attentional circuits during a cognitive challenge. Delaying the onset of weekly alcohol use patterns well after early adolescence may reduce the risk for harm of alcohol use on the brain.

The structure of psychopathology in adolescence and its common personality and cognitive correlates

The traditional view that mental disorders are distinct, categorical disorders has been challenged by evidence that disorders are highly comorbid and exist on a continuum (e.g., Caspi et al., 2014; Tackett et al., 2013). The first objective of this study was to use structural equation modeling to model the structure of psychopathology in an adolescent community-based sample (N = 2,144) including conduct disorder, attention-deficit/hyperactivity disorder (ADHD), oppositional-defiant disorder (ODD), obsessive–compulsive disorder, eating disorders, substance use, anxiety, depression, phobias, and other emotional symptoms, assessed at 16 years. The second objective was to identify common personality and cognitive correlates of psychopathology, assessed at 14 years. Results showed that psychopathology at 16 years fit 2 bifactor models equally well: (a) a bifactor model, reflecting a general psychopathology factor, as well as specific externalizing (representing mainly substance misuse and low ADHD) and internalizing factors; and (b) a bifactor model with a general psychopathology factor and 3 specific externalizing (representing mainly ADHD and ODD), substance use and internalizing factors. The general psychopathology factor was related to high disinhibition/impulsivity, low agreeableness, high neuroticism and hopelessness, high delay-discounting, poor response inhibition and low performance IQ. Substance use was specifically related to high novelty-seeking, sensation-seeking, extraversion, high verbal IQ, and risk-taking. Internalizing psychopathology was specifically related to high neuroticism, hopelessness and anxiety-sensitivity, low novelty-seeking and extraversion, and an attentional bias toward negatively valenced verbal stimuli. Findings reveal several nonspecific or transdiagnostic personality and cognitive factors that may be targeted in new interventions to potentially prevent the development of multiple psychopathologies.

This study provides support for a spectrum and common liability model of psychopathology, with findings showing that in a community sample of European adolescents: a) internalizing and externalizing psychopathology share substantial variance that can be modeled as a general psychopathology factor; and (b) that the common variance across psychopathologies is associated with personality traits related to high disinhibition/impulsivity, low agreeableness, high neuroticism and hopelessness, as well as different aspect of cognitive function, namely high delay-discounting, poor response inhibition and low performance IQ.

The efficacy of a working memory training in substance use patients: A randomized double-blind placebo-controlled clinical trial

INTRODUCTION

Substance use disorder patients show impairments in working memory (WM) functioning. Previous findings indicate that a WM training results in improvements of working memory capacity (WMC) and in decreased clinical symptoms in a range of mental disorders, including alcohol use disorder.

METHOD

The aim of the current study is to investigate the efficacy of a 24-session WM training in addition to treatment as usual on craving, WMC, substance use, impulsivity, attention bias, and psychopathology using a randomized double-blind placebo-controlled trial. Inpatients (n = 180) diagnosed with an alcohol, cocaine, or cannabis use disorder were included.

RESULTS

Although the WM training resulted in better scores on the trained tasks in both groups, the placebo training resulted in a better or equal WMC compared to the experimental training, as measured with two nontrained transfer tasks. The WM training had no effect on craving, substance use, impulsivity, attention bias, and psychopathology.

CONCLUSION

Overall, we did not find evidence for the efficacy of WM training on WMC or clinical symptoms as compared to a placebo training in a population of substance use disorder patients. Future research needs to investigate further whether WMC is an important factor that is associated with substance-abuse-related behavior, and whether working memory training could be useful in substance use disorders.

Training Behavioral Control in Adolescents Using a Serious Game

OBJECTIVE

Risk taking, such as heavy alcohol use, is commonplace among adolescents. Nevertheless, prolonged alcohol use at this age can lead to severe health problems. The goal of this study was to develop and evaluate a serious game training ("The Fling"), aimed at increasing behavioral control in adolescents and thereby helping them to improve control over their alcohol use. The game training was compared to a game placebo and a nongame training version in a randomized controlled trial.

MATERIALS AND METHODS

A sample of 185 adolescents (mean age 14.9 years) in secondary education participated in the study. They performed four sessions of training, as well as a set of questionnaires and cognitive assessment tasks before and after the training. The basis for the training was the stop-signal paradigm, aimed at increasing behavioral control.

RESULTS

The game variants were shown to motivate adolescents beyond the level of the nongame version. Behavioral control improved significantly over time, but this effect was also present in the game placebo, suggesting that the game activities alone may have had a beneficial effect on our measures of behavioral control. As baseline drinking levels were low, no significant training effects on drinking behavior were found.

CONCLUSIONS

Although the current results are not yet conclusive as to whether "The Fling" is effective as a cognitive training, they do warrant further research in this direction. This study also shows that serious games may be uniquely suitable to bridge the gap between an evidence-based training paradigm and an attractive, motivating training environment.

Working memory over a six-year period in young binge drinkers

Adolescence and early adulthood are periods of particular vulnerability to the neurotoxic effects of alcohol. Young people with alcohol-use disorders display deficits in working memory (WM). This function is supported by the prefrontal cortex, a late-maturing brain region. However, little is known about the progression of cognitive dysfunctions associated with a binge-drinking (BD) pattern of alcohol consumption among non-clinical adolescents. The objective of this study was to analyze the relationship between BD trajectory and WM in university students. An initial sample of 155 male and female first-year university students was followed prospectively over 6 years. The participants were classified as stable non-BDs, stable BDs, and ex-BDs, according to the third item of the Alcohol Use Disorders Identification Test (AUDIT). WM was assessed using the Self-Ordered Pointing Task. Generalized linear mixed models were applied. The results showed that stable BDs committed more total perseverative errors and showed a lower WM span in the difficult blocks than stable non-BDs. Difficulties in WM span showed some improvement, whereas perseveration errors remained constant throughout the follow-ups in the stable BDs. There were no significant differences between ex-BDs and non-BDs. In conclusion, stable BD is associated with WM deficits, particularly perseverations and low WM span in demanding trials, when compensatory mechanisms may no longer be successful. The partial improvement in WM span may support the notion of a neuromaturational delay, whereas the temporal stability of perseveration deficits may reflect either neurotoxic effects of alcohol or premorbid characteristics. Abandoning the BD pattern of alcohol consumption may lead to partial recovery.

Executive functioning and substance use in adolescence: Neurobiological and behavioral perspectives

The current review is guided by the theoretical perspective that emphasizes the regulating role of executive functioning (Carver et al., 2009) and presents studies that elucidate the ways that executive functioning (inhibition and working memory) explain individual differences in adolescent substance use independently or by regulating the reactive system (reward and punishment sensitivity). Behavioral studies indicate that main effects of executive functioning on adolescent substance use are often nonsignificant or weak in effect sizes. In contrast, emerging evidence suggests consistent and stronger regulating effects of executive functioning over reward and punishment sensitivity. Functional neuroimaging studies reveal significant associations between executive functioning task-related hemodynamic responses and substance use with strong effect sizes. There is also direct evidence from studies testing statistical interactions of the regulating effects of EF-related brain activation, and indirect evidence in studies examining functional connectivity, temporal discounting, and reinforced control. We note key future directions and ways to address limitations in existing work.

Psychometric properties of the German version of the CRAFFT

INTRODUCTION

The CRAFFT questionnaire is a widely utilized measure of problematic alcohol and drug use. The brief screening instrument has been translated into multiple languages, and some studies regarding its psychometric properties have been published. However, investigations on the factorial validity of the CRAFFT in a clinical sample are not available yet and empirical findings on the psychometric properties of the German version of the CRAFFT are very limited.

METHODS

Data were collected in a German sample of 316 adolescent patients treated in emergency departments following alcohol intoxication. Problematic alcohol use was assessed using the German version of the CRAFFT. Data concerning frequency and quantity of alcohol consumption were collected. A confirmatory factor analysis using the 6 items of the CRAFFT modelled as categorical indicators of a single latent factor using a robust weighted least squares estimator was conducted. We also calculated a reliability coefficient and correlations between the CRAFFT and external criteria of alcohol use.

RESULTS

The unidimensional model showed excellent global goodness-of-fit (χ(2)=9.76, df=8, χ(2)/df=1.22, RMSEA=0.027, CFI=0.983, TLI=0.976) and satisfying local parameters (standardized factor loadings between 0.37 and 0.69). We observed a poor reliability coefficient of 0.525. A positive association with alcohol use indicated construct validity of the German CRAFFT.

DISCUSSION

Concerning its factorial and construct validity the German version of the CRAFFT is a promising instrument for measuring problematic alcohol use in clinical adolescent populations, but the reliability has definitely to be investigated again in further studies.

Anxiety sensitivity and working memory capacity: Risk factors and targets for health behavior promotion

Understanding the nature and influence of specific risk profiles is increasingly important for health behavior promotion. The purpose of this article is to document the value of two factors-anxiety sensitivity (AS) and working memory capacity (WMC)-for enhancing risk for the initiation and/or maintenance of a range of negative health behaviors. AS is a distress-related risk factor that potentiates avoidance/coping motivations for negative health behaviors. Stress provides the conditions for negative somatic and affective states, and AS amplifies the aversiveness of these experiences and correspondingly hinders adaptive functioning. In contrast, low WMC is hypothesized to exert its effect by decreasing the capacity to filter out current temptations, attenuating a focus on longer-term goals and impairing the application of relevant coping skills at times of stress. In this review, we provide conceptual models for the separate roles of high AS and low WMC in negative health behaviors, review the influence of these factors on specific health behavior exemplars (eating behaviors/obesity, physical activity, smoking, alcohol use, and sleep promotion), provide preliminary evidence for their value as independent treatment targets for health-behavior promotion, and encourage specific research directions in relation to these variables.

Emotional working memory training as an online intervention for adolescent anxiety and depression: A randomised controlled trial

Objective

Anxiety and depression are highly prevalent disorders in adolescence. They are associated with deficits in working memory (WM), which also appears to increase rumination, worry, and negative mood. WM training, especially in an emotional context, might help in reducing or preventing these disorders. The current study investigated the direct effects of online emotional WM training on WM capacity, and short‐ and long‐term effects on symptoms of anxiety and depression, and secondary measures of emotional functioning.

Methods

Unselected adolescents (n = 168, aged 11–18) were randomised over an active or placebo emotional WM training. WM was assessed before and after 4 weeks of bi‐weekly training. Emotional functioning was assessed pre‐ and post‐training and at 3, 6, and 12 months follow‐up.

Results

Improvements in WM capacity and both short‐ and long‐term emotional functioning were found in both training groups, with the only group difference being a trend for a larger increase in self‐esteem in the active group compared to the placebo group.

Conclusions

The general improvements irrespective of training condition suggest non‐specific training or time effects, or some shared active ingredient in both conditions. Future research is necessary to detect potentially effective components of (emotional) WM training and to increase adolescent engagement with online training.

Effects of alcohol-induced working memory decline on alcohol consumption and adverse consequences of use

RATIONALE

Alcohol use appears to decrease executive function acutely in a dose-dependent manner, and lower baseline executive function appears to contribute to problematic alcohol use. However, no studies, to our knowledge, have examined the relationship between individual differences in working memory (a subcomponent of executive function) after alcohol consumption and drinking behaviors and consequences.

OBJECTIVES

The current study assessed the relationship between drinking behavior, alcohol-related consequences, and alcohol-induced changes in working memory (as assessed by Trail Making Test-B).

METHOD

Participants recruited from the community (n = 41), 57.3 % male, mean age 39.2, took part in a three-session, within-subjects, repeated-measures design. Participants were administered a placebo, 0.4 g/kg, or 0.8 g/kg dose of alcohol. Working memory, past 30-day alcohol consumption, and consequences of alcohol use were measured at baseline; working memory was measured again after each beverage administration.

RESULTS

Poorer working memory after alcohol administration (controlling for baseline working memory) was significantly associated with a greater number of drinks consumed per drinking day. Additionally, we observed a significant indirect relationship between the degree of alcohol-induced working memory decline and adverse consequences of alcohol use, which was mediated through greater average drinks per drinking day.

CONCLUSIONS

It is possible that greater individual susceptibility to alcohol-induced working memory decline may limit one's ability to moderate alcohol consumption as evidenced by greater drinks per drinking day and that this results in more adverse consequences of alcohol use.

Ethanol dose-dependently elicits opposing regulatory effects on hippocampal AMPA receptor GluA2 subunits through a zeta inhibitory peptide-sensitive kinase in adolescent and adult Sprague-Dawley rats

AMPA receptor GluA2 subunits are strongly implicated in cognition, and prior work suggests that these subunits may be regulated by atypical protein kinase C (aPKC) isoforms. The present study assessed whether hippocampal and cortical AMPA receptor GluA2 subunit regulation may be an underlying factor in known age-related differences to cognitive-impairing doses of ethanol, and if aPKC isoforms modulate such responses. Hippocampal AMPA receptor GluA2 subunit, protein kinase Mζ (PKMζ), and PKCι/λ expression were elevated during adolescence compared to adults. 1 h following a low-dose (1.0-g/kg) ethanol exposure, hippocampal AMPA receptor GluA2 subunit serine 880 phosphorylation was decreased in adolescents, but was increased in adults. Age-dependent changes in GluA2 subunit phosphorylation were paralleled by alterations in aPKC isoforms, and zeta inhibitory peptide (ZIP) administration prevented ethanol-induced increases in both in adults. Ethanol-induced changes in GluA2 subunit phosphorylation were associated with delayed regulation in synaptosomal GluA2 subunit expression 24 h later. A higher ethanol dose (3.5-g/kg) failed to elicit changes in most measures in the hippocampus at either age. Similar to the hippocampus, analysis of cerebral cortical tissue also revealed age-related declines. However, no demonstrable effects were found following a low-dose ethanol exposure at either age. High-dose ethanol exposure reduced adolescent GluA2 subunit phosphorylation and aPKC isoform expression that were again accompanied by delayed reductions in synaptosomal GluA2 subunit expression. Together, these results suggest that GluA2-containing AMPA receptor modulation by aPKC isoforms is age-, region- and dose-dependently regulated, and may potentially be involved in developmentally regulated ethanol-induced cognitive impairment and other ethanol behaviors.