A longitudinal examination of adolescent response inhibition: neural differences before and after the initiation of heavy drinking

Prospective Associations between BOLD Markers of Response Inhibition and the Transition to Frequent Binge Drinking

BACKGROUND

Altered brain activation during response inhibition has been linked to a greater risk for alcohol and other substance use behaviors in late adolescence. However, the ability of neural markers of response inhibition, acquired during adolescence, to temporally predict the transition from less frequent and lower quantity alcohol use to high-risk, frequent (≥ weekly) binge drinking behavior remains unclear.

METHODS

Adolescents (N = 29; 9 females) were selected from a larger ongoing longitudinal study to include those who transitioned to at least weekly binge drinking (≥5/4 alcoholic drinks for males/females per occasion) over a 15-year follow-up period. Prior to the onset of weekly binge drinking (mean age = 18.0), participants underwent a functional MRI including a go/no-go task. Whole-brain activation from the no-go correct rejection versus no-go false alarm contrast was used to predict time to transition to frequent binge drinking.

RESULTS

Less no-go correct rejection versus no-go false alarm activation in a cluster including the precentral gyri, insula, and inferior frontal gyri predicted a more rapid transition into frequent binge drinking (voxel-wise alpha < 0.001, cluster-wise alpha < 0.05, cluster threshold ≥ 18 voxels).

CONCLUSIONS

Results from this study are supported by literature suggesting that frontoinsular involvement is important for successful inhibition and cognitive control. Altered brain activation during response inhibition may thus represent neural antecedents of impulse regulation difficulties related to alcohol consumption. The magnitude of this activation provides temporal information that may be used to inform and optimize timing of interventions aimed at preventing the escalation and transition to problematic drinking for youth who have already begun to engage in drinking behaviors.

The Role of Impulsivity Facets on the Incidence and Development of Alcohol Use Disorders

Alcohol Use Disorder (AUD) is a chronic relapsing disorder defined according to the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5; American Psychiatric Association 2013), "by a cluster of behavioural and physical symptoms, which can include, withdrawal, tolerance and craving". Social, emotional, behavioural and cognitive factors are important contributors to AUD. Impulsivity, a multifaceted behavioural concept, defined as a predisposition for rapid and unplanned actions, without considering potential negative consequences of these actions, represents an important such factor. In this chapter, research on the role of distinct impulsivity dimensions in different severity stages of alcohol use is presented.Increased self-reported (trait) impulsivity and an inability to wait, as well as difficulty to adjust behaviour appropriately following a failure to withhold a response are observed across the spectrum of alcohol-use severities. Research on temporal impulsivity (inability to delay gratification) consistently shows deficits in more severe alcohol users. Data on temporal impulsivity in early stages of alcohol use are less consistent, with some studies showing no differences between high and moderate drinkers, while others indicating increased impulsivity in high alcohol users. Data on reflexion impulsivity are currently limited to draw conclusions. Recent research is also presented suggesting the importance of perception and interpretation of physiological and emotional signals on alcohol use behaviour highlighting the necessity of comprehensive integration of the field of the study of emotion and interoception with impulsivity research.

Modeling the Comorbidity of Cannabis Abuse and Conduct Disorder/Conduct Problems from a Cognitive Neuroscience Perspective

Objective: A cognitive neuroscience perspective seeks to understand behavior, in this case the comorbidity of cannabis abuse and conduct disorder/conduct problems, in terms of dysfunction in cognitive processes underpinned by neural processes. The goal of this review is to articulate a cognitive neuroscience account of this comorbidity. Methods: Literature on the following issues will be reviewed: (i) the longitudinal relationship between cannabis abuse and conduct disorder/conduct problems (CD/CP); (ii) the extent to which there are genetic and environmental (specifically maltreatment) factors that underpin this relationship; (iii) forms of neurocognitive function that are reported dysfunctional in CD/CP and also, when dysfunctional, appear to be risk factors for future cannabis abuse; and (iv) the extent to which cannabis abuse may further compromise these systems leading to increased future abuse and greater conduct problems. Results: CD/CP typically predate cannabis abuse. There appear to be shared genetic factors that contribute to the relationship between CD/CP and cannabis abuse. Moreover, trauma exposure increases risk for both cannabis abuse and CP/CD. One form of neurocognitive dysfunction, response disinhibition, that likely exacerbates the symptomatology of many individuals with CD also appears to increase the risk for cannabis abuse. The literature with respect to other forms of neurocognitive dysfunction remains inconclusive. Conclusions: Based on the literature, a causal model of the comorbidity of cannabis abuse and CD/CP is developed.

Response Inhibition and Binge Drinking During Transition to University: An fMRI Study

BACKGROUND

Binge Drinking (BD), a highly prevalent drinking pattern among youth, has been linked with anomalies in inhibitory control. However, it is still not well characterized whether the neural mechanisms involved in this process are compromised in binge drinkers (BDs). Furthermore, recent findings suggest that exerting inhibitory control to alcohol-related stimuli requires an increased effort in BDs, relative to controls, but the brain regions subserving these effects have also been scarcely investigated. Here we explored the impact of BD on the pattern of neural activity mediating response inhibition and its modulation by the motivational salience of stimuli (alcohol-related content).

METHODS

Sixty-seven (36 females) first-year university students, classified as BDs (n = 32) or controls (n = 35), underwent fMRI as they performed an alcohol-cued Go/NoGo task in which pictures of alcoholic or non-alcoholic beverages were presented as Go or NoGo stimuli.

RESULTS

During successful inhibition trials, BDs relative to controls showed greater activity in the bilateral inferior frontal gyrus (IFG), extending to the anterior insula, a brain region usually involved in response inhibition tasks, despite the lack of behavioral differences between groups. Moreover, BDs displayed increased activity in this region restricted to the right hemisphere when inhibiting a prepotent response to alcohol-related stimuli.

CONCLUSIONS

The increased neural activity in the IFG/insula during response inhibition in BDs, in the absence of behavioral impairments, could reflect a compensatory mechanism. The findings suggest that response inhibition-related activity in the right IFG/insula is modulated by the motivational salience of stimuli and highlight the role of this brain region in suppressing responses to substance-associated cues.

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).

Functional and structural connectivity of the executive control network in college binge drinkers

Binge Drinking (BD) is a pattern of excessive alcohol consumption highly prevalent among college students, and has been associated with structural and functional alterations of brain networks. Recent advances in the resting-state connectivity analysis have boosted the research of the network-level connectivity disturbances associated with many psychiatric and neurological disorders, including addiction. Accordingly, atypical functional connectivity patterns in resting-state networks such as the Executive Control Network (ECN) have been found in substance users and alcohol-dependent individuals. In this study, we assessed for the first time the ECN functional and structural connectivity in a group of 34 college students, 20 (10 women) binge drinkers (BDs) in comparison with a group of 14 (8 women) alcohol abstinent controls (AACs). Overall, our findings documented increased resting-state functional connectivity (rsFC) in the BDs left middle frontal cortex of the left ECN in comparison to the AACs, while no structural connectivity differences were observed between groups. Pearson correlations revealed a positive association between the left middle frontal gyrus rsFC and the frequency of BD episodes per month, in the BD group. These findings suggest that maintaining a pattern of acute and intermittent alcohol consumption during important stages of brain development, as the transition from adolescence to adulthood, is associated with impaired ECN rsFC despite no group differences being yet noticed in the ECN structural connectivity.

Poverty and Puberty: A Neurocognitive Study of Inhibitory Control in the Transition to Adolescence

Pubertal development during early adolescence is modestly associated with individual differences in slowly developing inhibitory control of impulses-an aspect of self-regulation associated with reward-seeking behaviors such as the onset and frequency of sexual activity. However, this effect may be much stronger in resource-poor environments. On the basis of life-history and r/K-selection theories, we tested the hypothesis that early pubertal timing would be more strongly associated with less mature neurocognitive inhibitory control in lower-income environments. In an economically diverse Appalachian sample (N = 157; 138 with complete neuroimaging data) of 14-year-olds (52% male), inhibitory control was measured using the multisource-interference task during functional MRI. Results showed that among poor youths only, more advanced puberty for one's age was linked with lower inhibitory control for the neural but not the behavioral measure. This finding has implications regarding poverty, neurocognitive development, and health-risk behaviors in adolescence.

Brief, computerized inhibitory control training to leverage adolescent neural plasticity: A pilot effectiveness trial

Adolescence is a time of heightened neural plasticity. Many brain networks show protracted development through this period, such as those underlying inhibitory control (IC), a neurocognitive skill implicated in risk-taking and therefore relevant to public health. Although IC appears to be trainable in adults and young children, whether and how IC may be malleable during adolescence is not fully understood. In this pilot RCT, we tested the effects of a school-based IC training paradigm (versus active control) on IC performance and neural function in adolescents (N = 19) aged 15 to 17 recruited from a low-income school district. We also examined the extent to which training effects transferred to a nontrained IC task and real-world risk behavior, as well as potential moderation effects by early adversity exposure. Training altered brain function related to attention during IC preparation and implementation, though it did not alter IC performance in the training group compared to the control group. There was limited evidence of training transfer. Results have implications for translational neuroscience research in adolescents.

Neurobiological and Cognitive Profile of Young Binge Drinkers: a Systematic Review and Meta-Analysis

This review provides the first systematic and quantitative synthesis of the literature examining the relationship between binge drinking, cognition, brain structure and function in youth aged 10 to 24 years. PubMed, EMBASE, Medline, PsychINFO and ProQuest were searched for neuroimaging, neurophysiological, and neuropsychological studies. A total of 58 studies (21 neuroimaging, 16 neurophysiological, 21 neuropsychological) met the eligibility criteria and were included in the review. Overall, abnormal or delayed development of key frontal executive-control regions may predispose youth to binge drink. These abnormalities appear to be further exacerbated by the uptake of binge drinking, in addition to alcohol-related neural aberrations in reward-seeking and incentive salience regions, indexed by cognitive deficits and maladaptive alcohol associations. A meta-analysis of neuropsychological correlates identified that binge drinking in youth was associated with a small overall neurocognitive deficit (g = -0.26) and specific deficits in decision-making (g = -1.70), and inhibition (g = -0.39). Using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) Evidence Profile, the certainty in outcomes ranged from very low to low. Future prospective longitudinal studies should address concomitant factors, exposure thresholds, and age-related vulnerabilities of binge drinking, as well as the degree of recovery following discontinuation of use.

Meta-analysis of aberrant post-error slowing in substance use disorder: implications for behavioral adaptation and self-control

Individual with substance use disorders have well-recognized impairments in cognitive control, including in behavioral adaptation after mistakes. One way in which this impairment manifests is via diminished post-error slowing, the increase in reaction time following a task-related error that is posited to reflect cautionary or corrective behavior. Yet, in the substance use disorder literature, findings with regard to post-error slowing have been inconsistent, and thus could benefit from quantitative integration. Here, we conducted a meta-analysis of case-control studies examining post-error slowing in addiction. Twelve studies with 15 unique comparisons were identified, comprising 567 substance users and 384 healthy controls across three broad types of inhibitory control paradigms (go-no/go, conflict resolution, and stop signal tasks, respectively). Results of the random-effects meta-analysis revealed a moderate group difference across all studies (Cohen's d = 0.31), such that the individuals with substance use disorder had diminished post-error slowing compared with controls. Despite this omnibus effect, there was also large variability in the magnitude of the effects, explained in part by differences between studies in task complexity. These findings suggest that post-error slowing may serve as a promising and easy-to-implement measure of cognitive control impairment in substance use disorder, with potential links to aberrant brain function in cognitive control areas such as the anterior cingulate cortex.

Neural correlates of inhibition and reward are negatively associated

Individuals with impulsive and addictive disorders, including drug addiction, binge eating/obesity, and problem gambling, exhibit both impaired control over behavior and heightened sensitivity to reward. However, it is not known whether such deviation in inhibitory and reward circuitry among clinical populations is a cause or consequence of the disorders. Recent evidence suggests that these constructs may be related at the neural level, and together, increase risk for engaging in maladaptive behaviors. The current study examined the degree to which brain function during inhibition relates to brain function during receipt of reward in healthy young adults who have not yet developed problem behaviors. Participants completed the stop signal task to assess inhibitory control and the doors task to assess reactivity to monetary reward (win vs loss) during functional magnetic resonance imaging (fMRI). Brain activation during response inhibition was negatively correlated with brain activation during reward. Specifically, less brain activation in right prefrontal regions during inhibition, including the right inferior frontal gyrus, middle frontal gyrus, and supplementary motor area, was associated with greater brain activation in left ventral striatum during receipt of monetary reward. Moreover, these associations were stronger in binge drinkers compared to non-binge drinkers. These findings suggest that the systems are related even before the onset of impulsive or addictive disorders. As such, it is possible that the association between inhibitory and reward circuitry may be a prospective marker of risk.

Behavioral and Cerebral Impairments Associated with Binge Drinking in Youth: A Critical Review

Binge drinking is a widespread alcohol consumption pattern in youth that is linked to important behavioral and cerebral impairments, in both the short and the long term. From a critical review of the current literature on this topic, we conclude that binge drinkers display executive impairments, cerebral modifications, and problems with emotion-related processes. Five key empirical and theoretical topics are discussed to pave the way for future research in the field: (1) the specificity of the brain modifications observed in binge drinkers that may index a compensatory mechanism or result from multiple withdrawals; (2) the nature of the relationship between binge drinking and impairments, suggesting reciprocal influences between excessive alcohol consumption and executive deficits; (3) the possible recovery of brain and cognitive functioning after the cessation of binge drinking; (4) the validity of the continuum hypothesis, suggesting links between binge drinking and severe alcohol use disorders; and (5) the existing strategies to reduce binge drinking habits or rehabilitate the associated cognitive deficits. Future perspectives are described in relation to the questions raised to identify the crucial variables to be addressed in research and clinical practice.

Neural mechanisms of risky decision making in adolescents reporting frequent alcohol and/or marijuana use

Because adolescence is a period of heightened exploration of new behaviors, there is a natural increase in risk taking including initial use of alcohol and marijuana. In order to better understand potential differences in neurocognitive functioning among adolescents who use drugs, the current study aimed to identify the neural substrates of risky decision making that differ among adolescents who are primary users of alcohol or marijuana, primary users of both alcohol and marijuana, and controls who report primary use of neither drug. Participants completed the Balloon Analogue Risk Task (BART) while undergoing functional magnetic resonance imaging. Comparison of brain activation during risky decisions versus non-risky decisions across all subjects revealed greater response to risky decisions in dorsal anterior cinguate cortex (dACC), anterior insula, ventral striatum, and lateral prefrontal cortex. Group comparisons across non-using controls, primary marijuana, primary alcohol, and alcohol and marijuana users revealed several notable differences in the recruitment of brain regions. Adolescents who use both alcohol and marijauna show decreased response during risky decision making compared to controls in insula, striatum, and thalamus, and reduced differentiation of increasing risk in dACC, insula, striatum, and superior parietal lobe compared to controls. These results provide evidence of differential engagement of risky decision making circuits among adolescents with varying levels of alcohol and marijuana use, and may provide useful targets for longitudinal studies that explicitly address causality of these differences.

Accelerated alcohol use across adolescence predicts early adult symptoms of alcohol use disorder via reward-related neural function

BACKGROUND

Alcohol use is commonly initiated during adolescence, with earlier onset known to increase the risk for alcohol use disorder (AUD). Altered function in neural reward circuitry is thought to increase the risk for AUD. To test the hypothesis that adolescent alcohol misuse primes the brain for alcohol-related psychopathology in early adulthood, we examined whether adolescent alcohol consumption rates predicted reward responsivity in the ventral striatum (VS), and in turn, AUD symptoms in adulthood.

METHODS

A total of 139 low income, racially diverse urban males reported on their alcohol use at ages 11, 12, 15, and 17; completed self-reports of personality, psychiatric interviews, and a functional magnetic resonance imaging (fMRI) scan at age 20; and completed a psychiatric interview at age 22. We measured adolescent alcohol use trajectories using latent growth curve modeling and measured neural responses to monetary reward using a VS region of interest. We tested indirect effects of adolescent alcohol use on AUD symptoms at age 22 via VS reward-related reactivity at age 20.

RESULTS

Greater acceleration in adolescent alcohol use predicted increased VS response during reward anticipation at age 20. VS reactivity to reward anticipation at age 20 predicted AUD symptoms at age 22, over and above concurrent symptoms. Accelerated adolescent alcohol use predicted AUD symptoms in early adulthood via greater VS reactivity to reward anticipation.

CONCLUSIONS

Prospective findings support a pathway through which adolescent alcohol use increases the risk for AUD in early adulthood by impacting reward-related neural functioning. These results highlight increased VS reward-related reactivity as a biomarker for AUD vulnerability.

P3 Component as a Potential Endophenotype for Control Inhibition in Offspring of Alcoholics

Aims

To assess inhibitory processes and the ongoing event-related potential (ERP) activity of offspring of alcoholics (OA) during a Go/No-Go task, with the purpose of characterizing possible psychophysiological endophenotypes for alcohol-dependent vulnerability.

Short summary

EEG recordings and ERP measurements of young adults with positive and negative family history of alcoholism where obtained while they performed a Go/No-Go task to assess inhibitory processes. Offspring of alcoholics showed a different ERP pattern compared to the control group and exerted greater effort than the control group.

Methods

ERP measurements were obtained by electroencephalogram (EEG) recordings of 65 participants divided into two groups: one group of 30 subjects with positive family history of alcoholism and a control group of 35 subjects with negative family history of alcoholism. They performed a Go/No-Go task, where each individual was required to classify visual stimuli by colour (Go) and inhibit their response to a No-Go signal.

Results

OA have higher P3 amplitudes during the Go condition in all of the regions analysed and higher No-Go P3 amplitudes than control subjects in the frontal region. Unlike controls, OA have no differences between the P3 amplitudes across conditions.

Conclusions

The absence of differences between the P3 Go and No-Go observed in the OA group can be interpreted as a possible alteration related with inhibition, in a way that they may need to recruit similar resources for inhibitory and classificational processes for both conditions. Therefore, the P3 component may be considered as a useful endophenotype and a vulnerability marker to develop addictive behaviour.

Review of Neurobiological Influences on Externalizing and Internalizing Pathways to Alcohol Use Disorder

Purpose of review

Two developmental courses through which alcohol use disorder (AUD) may emerge include externalizing and internalizing pathways. We review recent neuroimaging studies of potential neural risk factors for AUD and link findings to potential behavioral risk factors for AUD.

Recent findings

There is evidence that early-emerging weakness in prefrontal functioning and later-emerging differences in reward-system functioning contribute to an externalizing risk pathway. Stress may be an important contributor in the internalizing pathway through a blunting of reward-related activation, which may act alone or in combination with heightened emotion-related reactivity.

Summary

This review highlights areas for future work, including investigation of the relative balance between prefrontal and subcortical circuitry, attention to stages of AUD, and consideration of environmental factors such as stress and sleep. Particularly important is longitudinal work to understand the temporal ordering of associations among brain maturation, behavioral risk, and alcohol use.

Prenatal and concurrent cocaine, alcohol, marijuana, and tobacco effects on adolescent cognition and attention

BACKGROUND

Prenatal cocaine/polydrug exposure (PCE) may increase vulnerability to substance use disorders due to associated cognitive deficits. We examined whether neurocognitive deficits in executive functions and attention observed in PCE children persisted to adolescence when compared to non-cocaine/polydrug (NCE) children, and whether adolescent substance use (tobacco, alcohol, marijuana) was also associated with neurocognitive deficits.

METHODS

354 (180 PCE, 174 NCE) adolescents in a longitudinal study from birth were administered the Wechsler Intelligence Scales for Children - IV (WISC-IV), and the Integrated Visual and Auditory Continuous Performance Test (IVA/CPT) at age 15.5. Assessments of prenatal exposure to cocaine, alcohol, marijuana, and tobacco and measures of use at age 15.5 were taken. Confounding factors measured included lead, the caregiving environment, and violence exposure. Relationships between drug use and prenatal exposures on outcomes were assessed through multiple regression.

RESULTS

Adolescents with PCE had deficits in Perceptual Reasoning IQ and visual attention. Prenatal alcohol exposure predicted verbal and working memory IQ and visual and auditory attention deficits. Adolescent tobacco, alcohol, and marijuana use predicted attention in addition to PCE, lead and the caregiving environment.

CONCLUSION

Prenatal cocaine and alcohol exposure and adolescent use of substances are associated with neurocognitive deficits known to increase vulnerability to SUDs.

Neurobiology of substance use in adolescents and potential therapeutic effects of exercise for prevention and treatment of substance use disorders

Substance use (e.g., alcohol, marijuana, opioids, cocaine., etc,) use often initiates during adolescence, a critical period of physiological and social development marked by an increase in risk-taking due, in part, to heightened motivation to obtain arousal from rewards. Substance use during adolescence has been associated with a greater risk of substance use disorders (SUD) in adulthood. Although use rates for most substances have remained relatively stable, the frequency of marijuana use and the perception that regular marijuana use is not harmful has increased in adolescents. Furthermore, the nonmedical use of opioids has increased, particularly in the South, Midwest, and rural low-income communities. Substance use in adolescence has been associated with adverse structural and functional brain changes and, may exacerbate the natural "imbalance" between frontal/regulatory and cortical-subcortical circuits, leading to further heightened impulsive and reward-driven behaviors. Exercise increases growth and brain-derived neurotrophic factors that stimulate endogenous dopaminergic systems that, in turn, enhance general plasticity, learning, and memory. Exercise may help to reinforce the "naïve" or underdeveloped connections between neurological reward and regulatory processes in adolescence from the "bottom up" and "offset" reward seeking from substances, while concomitantly improving cardiovascular health, as well as academic and social achievement. In this review, we provide an overview of the current state of substance use in adolescents and rationale for the utilization of exercise, particularly "assisted" exercise, which we have shown increases neural activity in cortical-subcortical regions and may modulate brain dopamine levels during adolescence, a unique window of heightened reward sensitivity and neural plasticity, for the prevention and adjunctive treatment of SUD.

Adolescent neurocognitive development and impacts of substance use: Overview of the adolescent brain cognitive development (ABCD) baseline neurocognition battery

Adolescence is characterized by numerous social, hormonal and physical changes, as well as a marked increase in risk-taking behaviors. Dual systems models attribute adolescent risk-taking to tensions between developing capacities for cognitive control and motivational strivings, which may peak at this time. A comprehensive understanding of neurocognitive development during the adolescent period is necessary to permit the distinction between premorbid vulnerabilities and consequences of behaviors such as substance use. Thus, the prospective assessment of cognitive development is fundamental to the aims of the newly launched Adolescent Brain and Cognitive Development (ABCD) Consortium. This paper details the rationale for ABC'lected measures of neurocognition, presents preliminary descriptive data on an initial sample of 2299 participants, and provides a context for how this large-scale project can inform our understanding of adolescent neurodevelopment.

Neural correlates of correct and failed response inhibition in heavy versus light social drinkers: an fMRI study during a go/no-go task by healthy participants

The ability to suppress responses that are inappropriate, as well as the mechanisms monitoring the accuracy of actions in order to compensate for errors, is central to human behavior. Neural alterations that prevent stopping an inaccurate response, combined with a decreased ability of error monitoring, are considered to be prominent features of alcohol abuse. Moreover, (i) alterations of these processes have been reported in heavy social drinkers (i.e. young healthy individuals who do not yet exhibit a state of alcohol dependence); and (ii) through longitudinal studies, these alterations have been shown to underlie subsequent disinhibition that may lead to future alcohol use disorders. In the present functional magnetic resonance imaging study, using a contextual Go/No-Go task, we investigated whether different neural networks subtended correct inhibitions and monitoring mechanisms of failed inhibitory trials in light versus heavy social drinkers. We show that, although successful inhibition did not lead to significant changes, neural networks involved in error monitoring are different in light versus heavy drinkers. Thus, while light drinkers exhibited activations in their right inferior frontal, right middle cingulate and left superior temporal areas; heavy drinkers exhibited activations in their right cerebellum, left caudate nucleus, left superior occipital region, and left amygdala. These data are functionally interpreted as reflecting a "visually-driven emotional strategy" vs. an "executive-based" neural response to errors in heavy and light drinkers, respectively. Such a difference is interpreted as a key-factor that may subtend the transition from a controlled social heavy consumption to a state of clinical alcohol dependence.

Adolescents show differential dysfunctions related to Alcohol and Cannabis Use Disorder severity in emotion and executive attention neuro-circuitries

Alcohol and cannabis are two substances that are commonly abused by adolescents in the United States and which, when abused, are associated with negative medical and psychiatric outcomes across the lifespan. These negative psychiatric outcomes may reflect the detrimental impact of substance abuse on neural systems mediating emotion processing and executive attention. However, work indicative of this has mostly been conducted either in animal models or adults with Alcohol and/or Cannabis Use Disorder (AUD/CUD). Little work has been conducted in adolescent patients. In this study, we used the Affective Stroop task to examine the relationship in 82 adolescents between AUD and/or CUD symptom severity and the functional integrity of neural systems mediating emotional processing and executive attention. We found that AUD symptom severity was positively related to amygdala responsiveness to emotional stimuli and negatively related to responsiveness within regions implicated in executive attention and response control (i.e., dorsolateral prefrontal cortex, anterior cingulate cortex, precuneus) as a function of task performance. In contrast, CUD symptom severity was unrelated to amygdala responsiveness but positively related to responsiveness within regions including precuneus, posterior cingulate cortex, and inferior parietal lobule as a function of task performance. These data suggest differential impacts of alcohol and cannabis abuse on the adolescent brain.

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Alcohol and cannabis are the most widely abused substances by adolescents.

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AUDIT scores are related to amygdala hyperactivity to emotional stimuli.

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AUDIT scores are related to hypoactivity in executive attention neuro-circuitry.

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CUDIT scores are related to hyperactivity in executive attention neuro-circuitry.

Research Review: What have we learned about adolescent substance use?

BACKGROUND

Adolescence is a critical biological, psychological, and social developmental stage involving heightened risk for substance use and associated adverse consequences. This review, synthesizing emerging findings on this complex topic, is intended to inform research and clinical care focused on adolescents.

METHODS

Literature searches were conducted using PubMed, yielding a cross-section of observational and interventional studies focused on adolescent substance use. Findings were organized and categorized to cover key areas of epidemiology, neurobiology, prevention, and treatment.

FINDINGS

Adolescent substance-related attitudes and use patterns have evolved over time, informed by adult and peer behaviors, public policy, media messaging, substance availability, and other variables. A number of risk and resiliency factors contribute to individual differences in substance use and related consequences. Advances in observational techniques have provided enhanced understanding of adolescent brain development and its implications for substance use. Prevention efforts have yielded mixed results, and while a number of adolescent-targeted evidence-based treatments for substance use disorders have been developed, effect sizes are generally modest, indicating the need for further research to enhance prevention and treatment outcomes.

CONCLUSIONS

Substance use in adolescence is heterogeneous, ranging from normative to pathological, and can lead to significant acute and long-term morbidity and mortality. Understanding risk and resiliency factors, underlying neurobiology, and optimal developmentally sensitive interventions is critical in addressing substance-associated problems in adolescence.

Neural correlates of enhanced executive functions: is less more?

Musical training has been associated with superior performance in various executive function tasks. To date, only a few neuroimaging studies have investigated the neural substrates of the supposed "musician advantage" in executive functions, precluding definite conclusions about its neural basis. Here, we provide a selective review of neuroimaging studies on plasticity and typical maturation of executive functions, with the aim of investigating how proficient performance in executive function tasks is reflected in brain activity. Specifically, we examine the evidence for the hypothesis that enhanced or mature executive functions are manifested as efficient use of neural systems supporting those functions. We also present preliminary results from a functional magnetic resonance imaging study suggesting-in line with this hypothesis-that musically trained adolescents recruit frontoparietal regions less strongly during executive functions tasks than untrained peers.

Positive and Negative Affect and Adolescent Adjustment: Moderation Effects of Prefrontal Functioning

We examined whether cognitive control moderates the effects of emotion on adolescent internalizing and externalizing symptomatology in a longitudinal study of 138 adolescents. Self-reported positive affect (PA) and negative affect and behavioral and neural indicators of cognitive control, indexed by performance and prefrontal hemodynamic response during a cognitive interference task, were collected at Time 1. Self-reported internalizing and externalizing symptomatology were collected at Time 1 and Time 2 (1 year later). Results indicated that higher PA predicted decreases in externalizing symptomatology, but only for adolescents with poor neural cognitive control. No moderation effects were found for behavioral cognitive control. Findings imply the beneficial effects of PA on the development of externalizing problems among adolescents with poor prefrontal functioning.

The intersection between response inhibition and substance use among adolescents

Problems related to the capacity to successfully engage response inhibition are considered a risk factor for the development of substance use disorders (SUDs), but the evidence has been predominantly cross-sectional. In this commentary, we argue that recent longitudinal studies with multi-modal measures of response inhibition can improve understanding of how response inhibition may intersect with substance use among adolescents. Most Stop-Signal studies suggest that slower response inhibition predicts substance use progressions, with one multi-site study showing greater fronto-parietal activity indicative of risk. Most Go-NoGo studies suggest that blunted activation of prefrontal cortical areas during response inhibition predicts substance use progressions, while commission errors are less effective in identifying adolescents at risk. Studies differ in subject populations, outcome measures, statistical methods, and BOLD response contrasts, which challenge the capacity to compare and generalize findings. We encourage research teams throughout the globe to undertake multi-modal, longitudinal studies to assess brain functioning with large sample sizes, and when possible, before significant substance use potentially obscures interpretation of findings. Systematic review and meta-analysis of this growing literature are also important goals for future research.

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.

Altered cortical thickness and attentional deficits in adolescent girls and women with bulimia nervosa

BACKGROUND

Frontostriatal and frontoparietal abnormalities likely contribute to deficits in control and attentional processes in individuals with bulimia nervosa and to the persistence of dysregulated eating across development. This study assessed these processes and cortical thickness in a large sample of adolescent girls and women with bulimia nervosa compared with healthy controls.

METHODS

We collected anatomical MRI data from adolescent girls and women (ages 12-38 yr) with full or subthreshold bulimia nervosa and age-matched healthy controls who also completed the Conners Continuous Performance Test-II (CPT-II). Groups were compared on task performance and cortical thickness. Mediation analyses explored associations among cortical thickness, CPT-II variables, bulimia nervosa symptoms and age.

RESULTS

We included 60 girls and women with bulimia nervosa and 54 controls in the analyses. Compared with healthy participants, those with bulimia nervosa showed increased impulsivity and inattention on the CPT-II, along with reduced thickness of the right pars triangularis, right superior parietal and left dorsal posterior cingulate cortices. In the bulimia nervosa group, exploratory analyses revealed that binge eating frequency correlated inversely with cortical thickness of frontoparietal and insular regions and that reduced frontoparietal thickness mediated the association between age and increased symptom severity and inattention. Binge eating frequency also mediated the association between age and lower prefrontal cortical thickness.

LIMITATIONS

These findings are applicable to only girls and women with bulimia nervosa, and our cross-sectional design precludes understanding of whether cortical thickness alterations precede or result from bulimia nervosa symptoms.

CONCLUSION

Structural abnormalities in the frontoparietal and posterior cingulate regions comprising circuits that support control and attentional processes should be investigated as potential contributors to the maintenance of bulimia nervosa and useful targets for novel interventions.

Behavioral and Brain Activity Indices of Cognitive Control Deficits in Binge Drinkers

Heavy episodic drinking is prevalent among young adults and is a public issue of increasing importance. Its initiation and maintenance are associated with deficits in the capacity to inhibit automatic processing in favor of non-habitual responses. This study used functional magnetic resonance imaging (fMRI) to examine behavioral and brain activity indices of cognitive control during the Stroop task as a function of binge drinking. Heavy episodic drinkers (HED) reported consuming 5+/6+ drinks in two hours at least five times in the past six months and were compared to light drinkers (LED) who reported two or fewer binge episodes but were matched on demographics, intelligence and family history of alcoholism. Greater conflict-induced activity in the ventrolateral prefrontal cortex (VLPFC) and thalamus was observed in HED participants and it was positively correlated with alcohol intake and alcohol-related harmful consequences. HEDs maintained intact accuracy but at a cost of prolonged reaction times to high-conflict trials and increased ratings of task difficulty. Greater activation of the areas implicated in cognitive control is consistent with compensatory network expansion to meet higher cognitive demands. These results provide further insight into degradation of cognitive control in HEDs which may benefit development of detection and prevention strategies.

Effects of Binge Drinking on the Developing Brain

Binge drinking is a pattern of alcohol drinking that raises a person's blood alcohol concentration to at least .08%, which amounts to consuming five alcoholic drinks for men and four alcoholic drinks for women in about 2 hours. It is the most common form of alcohol misuse in adolescents and young adults. Heavy drinking includes the same criterion as binge drinking, but with higher frequency (i.e., 5 or more days in the past 30 days). Although binge drinking or heavy drinking alone is insufficient to meet the criteria for an alcohol use disorder (AUD) diagnosis, there are neurobiological changes, as well as an increased risk of developing an AUD later in life, associated with this form of alcohol misuse. This review describes the recent neuroimaging findings in binge drinking and heavy-drinking adolescents and young adults, a developmental period during which significant neuromaturation occurs.

Low-level alcohol consumption during adolescence and its impact on cognitive control development

Adolescence is a critical period for maturation of cognitive control and most adolescents start experimenting with alcohol around that time. On the one hand, recent studies indicate that low control abilities predict future problematic alcohol use. On the other hand, binge drinking during young adulthood can (further) impair cognitive control. However, so far no study examined the effects of low-level alcohol use during adolescence. In the present longitudinal fMRI study, we therefore investigated the development of cognitive control in a community-based sample of 92 adolescents at ages 14, 16 and 18. Two different cognitive control functions, i.e. inhibition of pre-potent responses (operationalized by incongruence effects) and switching between different task sets, were measured within one task. Alcohol use in our sample was low (mean: 54 g/week at age 18). The study revealed that neither behavioural nor neural measures of cognitive control function at age 14 predicted alcohol use at age 18 but confirmed established predictors such as gender and personality. As expected, from age 14 to 18, cognitive control abilities were improving (decreased reaction times and/or errors), and activation of cognitive control networks (dorsal anterior cingulate cortex and pre-supplementary motor area) during incongruent trials increased. Unexpectedly, higher alcohol consumption during adolescence was associated with a more pronounced increase in cognitive performance and a smaller increase of neural activation when incongruent trials afforded inhibitory control. We conclude that low-level alcohol use during adolescence does not severely impair ongoing maturation of cognitive control abilities and networks.

Brain circuitry associated with the development of substance use in bipolar disorder and preliminary evidence for sexual dimorphism in adolescents

Substance use disorders and mood disorders are highly comorbid and confer a high risk for adverse outcomes. However, data are limited on the neurodevelopmental basis of this comorbidity. Substance use initiation typically occurs during adolescence, and sex-specific developmental mechanisms are implicated. In this preliminary study, we review the literature and investigate regional gray matter volume (GMV) associated with subsequent substance use problems in adolescents with bipolar disorder (BD) and explore these associations for females and males. Thirty adolescents with DSM-IV-diagnosed BD and minimal alcohol/substance exposure completed baseline structural magnetic resonance imaging scans. At follow-up (on average 6 years post baseline), subjects were administered the CRAFFT interview and categorized into those scoring at high ( ≥ 2: CRAFFT_HIGH ) vs. low ( < 2: CRAFFT_LOW ) risk for alcohol/substance problems. Lower GMV in prefrontal, insular, and temporopolar cortices were observed at baseline among adolescents with BD reporting subsequent alcohol and cannabis use compared to adolescents with BD who did not (P < 0.005, clusters ≥ 20 voxels). Lower dorsolateral prefrontal GMV was associated with future substance use in both females and males. In females, lower orbitofrontal and insula GMV was associated with future substance use, while in males, lower rostral prefrontal GMV was associated with future use. Lower orbitofrontal, insular, and temporopolar GMV was observed in those who transitioned to smoking tobacco. Findings indicate that GMV development is associated with risk for future substance use problems in adolescents with BD, with results implicating GMV development in regions subserving emotional regulation in females and regions subserving executive processes and attention in males. © 2016 Wiley Periodicals, Inc.

College Binge Drinking Associated with Decreased Frontal Activation to Negative Emotional Distractors during Inhibitory Control

The transition to college is associated with an increase in heavy episodic alcohol use, or binge drinking, during a time when the prefrontal cortex and prefrontal-limbic circuitry continue to mature. Traits associated with this immaturity, including impulsivity in emotional contexts, may contribute to risky and heavy episodic alcohol consumption. The current study used blood oxygen level dependent (BOLD) multiband functional magnetic resonance imaging (fMRI) to assess brain activation during a task that required participants to ignore background images with positive, negative, or neutral emotional valence while performing an inhibitory control task (Go-NoGo). Subjects were 23 college freshmen (seven male, 18-20 years) who engaged in a range of drinking behavior (past 3 months' binge episodes range = 0-19, mean = 4.6, total drinks consumed range = 0-104, mean = 32.0). Brain activation on inhibitory trials (NoGo) was contrasted between negative and neutral conditions and between positive and neutral conditions using non-parametric testing (5000 permutations) and cluster-based thresholding (z = 2.3), p ≤ 0.05 corrected. Results showed that a higher recent incidence of binge drinking was significantly associated with decreased activation of dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontal cortex (DMPFC), and anterior cingulate cortex (ACC), brain regions strongly implicated in executive functioning, during negative relative to neutral inhibitory trials. No significant associations between binge drinking and brain activation were observed for positive relative to neutral images. While task performance was not significantly associated with binge drinking in this sample, subjects with heavier recent binge drinking showed decreased recruitment of executive control regions under negative versus neutral distractor conditions. These findings suggest that in young adults with heavier recent binge drinking, processing of negative emotional images interferes more with inhibitory control neurocircuitry than in young adults who do not binge drink often. This pattern of altered frontal lobe activation associated with binge drinking may serve as an early marker of risk for future self-regulation deficits that could lead to problematic alcohol use. These findings underscore the importance of understanding the impact of emotion on cognitive control and associated brain functioning in binge drinking behaviors among young adults.

Neural predictors of alcohol use and psychopathology symptoms in adolescents

Adolescence is a period marked by increases in risk taking, sensation seeking, and emotion dysregulation. Neurobiological models of adolescent development propose that lagging development in brain regions associated with affect and behavior control compared to regions associated with reward and emotion processing may underlie these behavioral manifestations. Cross-sectional studies have identified several functional brain networks that may contribute to risk for substance use and psychopathology in adolescents. Determining brain structure measures that prospectively predict substance use and psychopathology could refine our understanding of the mechanisms that contribute to these problems, and lead to improved prevention efforts. Participants (N = 265) were healthy substance-naïve adolescents (ages 12-14) who underwent magnetic resonance imaging and then were followed annually for up to 13 years. Cortical thickness and surface area measures for three prefrontal regions (dorsolateral prefrontal cortex, inferior frontal gyrus, and orbitofrontal cortex) and three cortical regions from identified functional networks (anterior cingulate cortex, insular cortex, and parietal cortex) were used to predict subsequent binge drinking, externalizing symptoms, and internalizing symptoms. Thinner dorsolateral prefrontal cortex and inferior frontal cortex in early adolescence predicted more binge drinking and externalizing symptoms, respectively, in late adolescence (ps < .05). Having a family history of alcohol use disorder predicted more subsequent binge drinking and externalizing symptoms. Thinner parietal cortex, but not family history, predicted more subsequent internalizing symptoms (p < .05). This study emphasizes the temporal association between maturation of the salience, inhibition, and executive control networks in early adolescence and late adolescent behavior outcomes. Our findings indicate that developmental variations in these brain regions predate behavioral outcomes of substance use and psychopathology, and may therefore serve as prospective biomarkers of vulnerability.

Effects of depression and past-year binge drinking on cognitive control processes during a flanker task in college-aged adults

BACKGROUND

Recent but largely separate literatures have examined neurocognitive alterations related to both depression and binge drinking, suggesting similar patterns of impairments in attention control and decisional processes. However, depression and problematic alcohol use tend to co-occur, and few studies have examined whether cognitive processing effects of depression and binge drinking are independent or interacting.

OBJECTIVE

The current study examined joint effects of depressive symptoms and past-year binge drinking on cognitive processing (measured via EEG assessment).

METHODS

University students aged 18 and over (N = 46; 63.4% female) were recruited based on self-reported depressive symptoms and also provided reports of alcohol use (51% reported significant depression; 46% reported at-least one past-year binge-drinking episode). Participants completed a computerized flanker task, assessing cognitive control processes. Forty-one participants providing useable data were included in analyses.

RESULTS

Past-year binge drinking was associated with slower and more accurate behavioral responding. The interaction of binge-drinking and depressive symptoms was related to the magnitude of early attentional components (N1 and N2), with individuals reporting high depressive symptoms and a history of binge-drinking exhibiting attenuated early attentional engagement (e.g., less negative N1) coupled with enhanced attention control processing (e.g., more negative N2). Depressive symptoms also predicted a lack of discriminated P3 amplitudes on congruent versus incongruent trials.

CONCLUSION

The data suggest that depression and binge drinking in the past-year jointly interact to predict early attentional processing, with the pattern of responding consistent with a compensatory response process. Results highlight the importance of future work on binge-drinking accounting for co-occurring depression.

Working memory capacity and addiction treatment outcomes in adolescents

BACKGROUND

Brief addiction treatments including motivational interviewing (MI) have shown promise with adolescents, but the factors that influence treatment efficacy in this population remain unknown. One candidate is working memory, the ability to hold a fact or thought in mind. This is relevant, as in therapy, a client must maintain and manipulate ideas while working with a clinician. Working memory depends upon brain structures and functions that change markedly during neurodevelopment and that can be negatively impacted by substance use.

OBJECTIVES

In a secondary analysis of data from a clinical trial for adolescent substance use comparing alcohol/marijuana education and MI, we evaluated the relationship between working memory and three-month treatment-outcomes with the hypothesis that the relationship between intervention conditions and outcome would be moderated by working memory.

METHODS

With a diverse sample of adolescents currently using alcohol and/or marijuana (N = 153, 64.7% male, 70.6% Hispanic), we examined the relationship between baseline measures of working memory and alcohol and cannabis-related problem scores measured at the three-month follow-up.

RESULTS

The results showed that lower working memory scores were associated with poorer treatment response only for alcohol use, and only within the education group. No relationship was found between working memory and treatment outcomes in the MI group.

CONCLUSION

The results suggest that issues with working memory capacity may interfere with adolescents' ability to process and implement didactic alcohol and marijuana content in standard education interventions. These results also suggest that MI can be implemented equally effectively across the range of working memory functioning in youth.

The Burden of Binge and Heavy Drinking on the Brain: Effects on Adolescent and Young Adult Neural Structure and Function

Introduction: Adolescence and young adulthood are periods of continued biological and psychosocial maturation. Thus, there may be deleterious effects of consuming large quantities of alcohol on neural development and associated cognition during this time. The purpose of this mini review is to highlight neuroimaging research that has specifically examined the effects of binge and heavy drinking on adolescent and young adult brain structure and function. Methods: We review cross-sectional and longitudinal studies of young binge and heavy drinkers that have examined brain structure (e.g., gray and white matter volume, cortical thickness, white matter microstructure) and investigated brain response using functional magnetic resonance imaging (fMRI). Results: Binge and heavy-drinking adolescents and young adults have systematically thinner and lower volume in prefrontal cortex and cerebellar regions, and attenuated white matter development. They also show elevated brain activity in fronto-parietal regions during working memory, verbal learning, and inhibitory control tasks. In response to alcohol cues, relative to controls or light-drinking individuals, binge and heavy drinkers show increased neural response mainly in mesocorticolimbic regions, including the striatum, anterior cingulate cortex (ACC), hippocampus, and amygdala. Mixed findings are present in risky decision-making tasks, which could be due to large variation in task design and analysis. Conclusions: These findings suggest altered neural structure and activity in binge and heavy-drinking youth may be related to the neurotoxic effects of consuming alcohol in large quantities during a highly plastic neurodevelopmental period, which could result in neural reorganization, and increased risk for developing an alcohol use disorder (AUD).

Connecting brain responsivity and real-world risk taking: Strengths and limitations of current methodological approaches

In line with the goal of limiting health risk behaviors in adolescence, a growing literature investigates whether individual differences in functional brain responses can be related to vulnerability to engage in risky decision-making. We review this body of work, investigate when and in what way findings converge, and provide best practice recommendations. We identified 23 studies that examined individual differences in brain responsivity and adolescent risk taking. Findings varied widely in terms of the neural regions identified as relating to risky behavior. This heterogeneity is likely due to the abundance of approaches used to assess risk taking, and to the disparity of fMRI tasks. Indeed, brain-behavior correlations were typically found in regions showing a main effect of task. However, results from a test of publication bias suggested that region of interest approaches lacked evidential value. The findings suggest that neural factors differentiating riskier teens are not localized to a single region. Therefore, approaches that utilize data from the entire brain, particularly in predictive analyses, may yield more reliable and applicable results. We discuss several decision points that researchers should consider when designing a study, and emphasize the importance of precise research questions that move beyond a general desire to address adolescent risk taking.

Overlapping Neural Endophenotypes in Addiction and Obesity

Impulsivity refers to a tendency to act rapidly without full consideration of consequences. The trait is thought to result from the interaction between high arousal responses to potential rewards and poor self-control. Studies have suggested that impulsivity confers vulnerability to both addiction and obesity. However, results in this area are unclear, perhaps due to the high phenotypic complexity of addictions and obesity. Focusing on impulsivity, the aim of this review is to tackle the putative overlaps between addiction and obesity in four domains: (1) personality research, (2) neurocognitive tasks, (3) brain imaging, and (4) clinical evidence. We suggest that three impulsivity-related domains are particularly relevant for our understanding of similarities between addiction and obesity: lower self-control (high Disinhibition/low Conscientiousness), reward sensitivity (high Extraversion/Positive Emotionality), and negative affect (high Neuroticism/Negative Emotionality). Neurocognitive studies have shown that obesity and addiction are both associated with increased impulsive decision-making and attention bias in response to drug or food cues, respectively. Mirroring this, obesity and different forms of addiction seem to exhibit similar alterations in functional MRI brain activity in response to reward processing and during self-control tasks. Overall, our review provides an integrative approach to understand those facets of obesity that present similarities to addictive behaviors. In addition, we suggest that therapeutic interventions targeting inhibitory control may represent a promising approach for the prevention and/or treatment of obesity.

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.

Inhibitory control and response monitoring are not systematically related to weekly alcohol consumption in the general population

BACKGROUND

In alcohol use disorder, deficits in cognitive control (i.e., inhibition and response monitoring) might underlie the loss of self-control and, thereby, failure to adjust alcohol consumption in response to associated negative consequences. According to the continuum hypothesis, the magnitude of these deficits should be related in a stair-case manner, with the greatest deficits among its heaviest consumers. The current study aims at investigating this association in the general population.

METHODS

This is a cross-sectional study of 397 participants aged 18-64 years, who self-reported their mean weekly alcohol consumption and were assessed with the stop-signal task, estimating inhibitory efficiency (stop-signal reaction time; SSRT) and response monitoring (post-error slowing; PES). Set-shifting ability was investigated by the intra-extra dimensional (IED) set-shifting task. Three ANCOVAs were performed with SSRT, PES, and IED as the dependent variables (DV), respectively, and alcohol consumption levels as the independent variable. Covariates were included when they were significantly associated with the DV.

RESULTS

Compared to the teetotalers, all levels of alcohol consumption were significantly associated to lower SSRT, which implies more efficient inhibitory control; however, there was no significant difference in SSRT between other consumption levels. The two highest consumption groups had significantly shorter PES when compared to teetotalers and/or the lowest consumption group, implying less behavioral adjustment after failures. IED was not significantly related to the alcohol consumption levels.

CONCLUSIONS

There was no stair-case relation between weekly consumption levels and cognitive control functions within this general population, which might be due to the limited consumption range investigated.

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.

Effects of early life stress and adolescent ethanol exposure on adult cognitive performance in the 5-choice serial reaction time task in Wistar male rats

RATIONALE

Early life stress combined with heavy adolescent alcohol use predicts impaired neuropsychological functioning in adulthood. We investigated whether adolescent intermittent ethanol (AIE) exposure combined with neonatal maternal separation in rats altered attentional processes and impulsivity in adulthood.

METHODS

Male Wistar rat pups were exposed to maternal separation (postnatal days (PNDs) 1-14) and moderate AIE exposure (PNDs 28-57). Adult rats were tested in the five-choice serial reaction time task, which provides separate measures of attention, motor impulsivity, and compulsivity. Rats were tested under baseline conditions and in response to task manipulations that increased attentional load and impulsive behaviors, and after acute ethanol administration.

RESULTS

Short stimulus and short intertrial interval (ITI) durations disrupted attention while long ITI durations impaired impulsivity in all rats. Moderate- and high-dose ethanol challenges impaired attention in all rats. Rats exposed to maternal separation and/or AIE exposure had significantly decreased omissions than non-handled water-exposed rats at baseline and tended to retain this effect in response to task challenges (i.e., the shorter stimulus and ITI durations, longer test session) and ethanol challenges, indicating moderate improvement of attentional performance. Maternal separation significantly increased perseverative responses at baseline and in response to decreased stimulus duration challenge, suggesting increased compulsivity.

CONCLUSIONS

Separate or combined exposure to early life stress and AIE exposure moderately disrupts some aspects of adult executive control functions (e.g., increased compulsivity) but improves others (e.g., increased attention). The relative intensity of either manipulation during neonatal and adolescent periods may influence the direction in which cognitive behaviors are affected in adulthood.

The potential of neuroimaging for identifying predictors of adolescent alcohol use initiation and misuse

BACKGROUND AND AIMS

Dysfunction in brain regions underlying impulse control, reward processing and executive function have been associated previously with adolescent alcohol misuse. However, identifying pre-existing neurobiological risk factors, as distinct from changes arising from early alcohol-use, is difficult. Here, we outline how neuroimaging data can identify the neural predictors of adolescent alcohol-use initiation and misuse by using prospective longitudinal studies to follow initially alcohol-naive individuals over time and by neuroimaging adolescents with inherited risk factors for alcohol misuse.

METHOD

A comprehensive narrative of the literature regarding neuroimaging studies published between 2010 and 2016 focusing on predictors of adolescent alcohol use initiation and misuse.

FINDINGS

Prospective, longitudinal neuroimaging studies have identified pre-existing differences between adolescents who remained alcohol-naive and those who transitioned subsequently to alcohol use. Both functional and structural grey matter differences were observed in temporal and frontal regions, including reduced brain activity in the superior frontal gyrus and temporal lobe, and thinner temporal cortices of future alcohol users. Interactions between brain function and genetic predispositions have been identified, including significant association found between the Ras protein-specific guanine nucleotide releasing factor 2 (RASGRF2) gene and reward-related striatal functioning.

CONCLUSIONS

Neuroimaging predictors of alcohol use have shown modest utility to date. Future research should use out-of-sample performance as a quantitative measure of a predictor's utility. Neuroimaging data should be combined across multiple modalities, including structural information such as volumetrics and cortical thickness, in conjunction with white-matter tractography. A number of relevant neurocognitive systems should be assayed; particularly, inhibitory control, reward processing and executive functioning. Combining a rich magnetic resonance imaging data set could permit the generation of neuroimaging risk scores, which could potentially yield targeted interventions.

Do Executive Functions Predict Binge-Drinking Patterns? Evidence from a Longitudinal Study in Young Adulthood

Background: Impairments in executive functions (EFs) are related to binge drinking in young adulthood, but research on how EFs influence future binge drinking is lacking. The aim of the current report is therefore to investigate the association between various EFs and later severity of, and change in, binge drinking over a prolonged period during young adulthood.

Methods: At baseline, 121 students reported on their alcohol habits (Alcohol use disorder identification test; Alcohol use questionnaire). Concurrently, EFs [working memory, reversal, set-shifting, response inhibition, response monitoring and decision-making (with ambiguity and implicit risk)] were assessed. Eighteen months later, information on alcohol habits for 103 of the participants were gathered. Data were analyzed by means of multilevel regression modeling.

Results: Future severity of binge drinking was uniquely predicted by performance on the Information sampling task, assessing risky decision-making (β = -1.86, 95% CI: -3.69, -0.04). None of the study variables predicted severity or change in binge drinking.

Conclusion: Future severity of binge drinking was associated with making risky decisions in the prospect for gain, suggesting reward hypersensitivity. Future studies should aim at clarifying whether there is a causal association between decision-making style and binge drinking. Performance on all executive tasks was unrelated to change in binge drinking patterns; however, the finding was limited by overall small changes, and needs to be confirmed with longer follow-up periods.

Behavioral Control and Reward Sensitivity in Adolescents' Risk Taking Behavior: A Longitudinal TRAILS Study

Neurodevelopmental theories of risk behavior hypothesize that low behavioral control in combination with high reward sensitivity explains adolescents’ risk behavior. However, empirical studies examining this hypothesis while including actual risk taking behavior in adolescence are lacking. In this study we tested whether the imbalance between behavioral control and reward sensitivity underlies risk taking behavior in adolescence, using a nationally representative longitudinal sample of 715 adolescents, of which 66% revealed an increased risk for mental health problems. To assess behavioral control at age 11 we used both self-report (effortful control) as well as behavioral measures of cognitive control (i.e., working memory and response inhibition). Reward sensitivity was assessed with the Bangor Gambling Task. The main finding of this study was that effortful control at age 11 was the best predictor of risk taking behavior (alcohol and cannabis use) at age 16, particularly among adolescents who were more reward sensitive. Risk taking behavior in adolescents might be explained by relatively weak behavioral control functioning combined with high sensitivity for reward.

Adolescence and Drug Use Vulnerability: Findings from Neuroimaging

Adolescence is a period of vulnerability for developing substance use disorder. Recent neuropsychological and neuroimaging studies have elucidated underlying neural vulnerabilities that contribute to initiation of substance use during adolescence. Findings suggest poorer performance on tasks of inhibition and working memory, smaller brain volumes in reward and cognitive control regions, less brain activation during executive functioning tasks, and heightened reward responsivity are predictive of youth initiating substance use during adolescence. In youth who are family history positive (FHP) for substance use disorder, poorer executive functioning, smaller volume of limbic brain regions (e.g., amygdala), sex-specific patterns of hippocampal volume, and a positive association between nucleus accumbens volume and family history density have been reported. Further, reduced white matter integrity, altered brain response during inhibitory control, including both greater and less frontal lobe response, blunted emotional processing, and weaker neural connectivity have also been found in FHP youth. Thus, there is significant overlap among the neural precursors shown to be predictive of alcohol and substance use initiation during adolescence and those that distinguish FHP from youth without a family history of substance use disorder, suggesting common targets for prevention and intervention. Understanding these predictive factors helps identify at-risk youth for prevention efforts, as well as create interventions targeting cognitive weaknesses or brain regions involved in substance use initiation.

Neural Predictors of Initiating Alcohol Use During Adolescence

OBJECTIVE

Underage drinking is widely recognized as a leading public health and social problem for adolescents in the United States. Being able to identify at-risk adolescents before they initiate heavy alcohol use could have important clinical and public health implications; however, few investigations have explored individual-level precursors of adolescent substance use. This prospective investigation used machine learning with demographic, neurocognitive, and neuroimaging data in substance-naive adolescents to identify predictors of alcohol use initiation by age 18.

METHOD

Participants (N=137) were healthy substance-naive adolescents (ages 12-14) who underwent neuropsychological testing and structural and functional magnetic resonance imaging (sMRI and fMRI), and then were followed annually. By age 18, 70 youths (51%) initiated moderate to heavy alcohol use, and 67 remained nonusers. Random forest classification models identified the most important predictors of alcohol use from a large set of demographic, neuropsychological, sMRI, and fMRI variables.

RESULTS

Random forest models identified 34 predictors contributing to alcohol use by age 18, including several demographic and behavioral factors (being male, higher socioeconomic status, early dating, more externalizing behaviors, positive alcohol expectancies), worse executive functioning, and thinner cortices and less brain activation in diffusely distributed regions of the brain.

CONCLUSIONS

Incorporating a mix of demographic, behavioral, neuropsychological, and neuroimaging data may be the best strategy for identifying youths at risk for initiating alcohol use during adolescence. The identified risk factors will be useful for alcohol prevention efforts and in research to address brain mechanisms that may contribute to early drinking.