Functional magnetic resonance imaging (fMRI) response to alcohol pictures predicts subsequent transition to heavy drinking in college students

Drawbacks to Strengthening Neural Salience Encoding: A Link Between Cortisol and Risky Drinking

Emotionally salient experiences are encoded and remembered more strongly, an effect that can be amplified by hormones like cortisol. Such memories can in turn profoundly influence later behavior. However, little is known about the link between amplified salience encoding and subsequent behavior. This pathway may be particularly important for risky alcohol drinking, which has been linked to sensitized salience responses, memory, and cortisol. To test this possibility, we integrated pharmacology using a double-blind cross-over design with fMRI, cognitive, and motivation assays across a range of healthy male and female social drinkers. As anticipated, cortisol enhanced memory for salient alcohol-related events; critically, this bias was in turn associated with later alcohol motivation. Increased alcohol motivation was particularly pronounced in more susceptible risky drinkers, for whom cortisol enhanced brain salience responses to alcohol. These sensitized salience responses predicted both memory biases and alcohol motivation. Together, these findings reveal maladaptive consequences of enhanced salience encoding.

Joyful growth vs. compulsive hedonism: A meta-analysis of brain activation on romantic love and addictive disorders

Due to the similarities in behavioral characteristics between romantic love and addictive disorders, the concept of being "addicted to someone" transcends mere literary metaphor, expanding perspectives on the study of romantic love and inspiring interventions for addiction. However, there has been a lack of studies systematically exploring the similarities and differences between romantic love and addiction at the neural level. In this study, we conducted an extensive literature search, incorporating 21 studies on romantic love and 28 on addictive disorders, focusing on fMRI research utilizing the cue reactivity paradigm. Using Activation Likelihood Estimation, we examined the similarities and differences in the neural mechanisms underlying love and addiction. The results showed that the anterior cingulate cortex (ACC) exhibited both shared and distinct activation clusters between romantic love and addictive disorders. Furthermore, ventromedial prefrontal cortex (VMPFC) was more frequently activated in romantic love than in addictive disorders, while greater activation within the posterior cingulate cortex (PCC) was found in addictive disorder compared with romantic love. We discussed that the activation of ACC and VMPFC may symbolize self-expansion, a process that characterizes the development of romantic love, contributing to a more enriched self. Our study suggests that while romantic love and addictive disorders share a common neural foundation, the discernible differences in their neural representations distinguish them as joyful growth versus compulsive hedonism.

Neuroimaging Biomarkers in Addiction

As a neurobiological process, addiction involves pathological patterns of engagement with substances and a range of behaviors with a chronic and relapsing course. Neuroimaging technologies assess brain activity, structure, physiology, and metabolism at scales ranging from neurotransmitter receptors to large-scale brain networks, providing unique windows into the core neural processes implicated in substance use disorders. Identified aberrations in the neural substrates of reward and salience processing, response inhibition, interoception, and executive functions with neuroimaging can inform the development of pharmacological, neuromodulatory, and psychotherapeutic interventions to modulate the disordered neurobiology. Based on our systematic search, 409 protocols registered on ClinicalTrials.gov include the use of one or more neuroimaging paradigms as an outcome measure in addiction, with the majority (N=268) employing functional magnetic resonance imaging (fMRI), followed by positron emission tomography (PET) (N=71), electroencephalography (EEG) (N=50), structural magnetic resonance imaging (MRI) (N=35) and magnetic resonance spectroscopy (MRS) (N=35). Furthermore, in a PubMed systematic review, we identified 61 meta-analyses including 30 fMRI, 22 structural MRI, 8 EEG, 7 PET, and 3 MRS meta-analyses suggesting potential biomarkers in addictions. These studies can facilitate the development of a range of biomarkers that may prove useful in the arsenal of addiction treatments in the coming years. There is evidence that these markers of large-scale brain structure and activity may indicate vulnerability or separate disease subtypes, predict response to treatment, or provide objective measures of treatment response or recovery. Neuroimaging biomarkers can also suggest novel targets for interventions. Closed or open loop interventions can integrate these biomarkers with neuromodulation in real-time or offline to personalize stimulation parameters and deliver the precise intervention. This review provides an overview of neuroimaging modalities in addiction, potential neuroimaging biomarkers, and their physiologic and clinical relevance. Future directions and challenges in bringing these putative biomarkers from the bench to the bedside are also discussed.

Multi-modal neuroimaging reveals differences in alcohol-cue reactivity but not neurometabolite concentrations in adolescents who drink alcohol

BACKGROUND

The objective of this multi-modal neuroimaging study was to identify neuroscience-informed treatment targets for adolescent alcohol use disorder (AUD) by examining potential neural alterations associated with adolescent alcohol use.

METHODS

Adolescents (ages 17-19) who heavily used (n=49) or did not use alcohol (n=22) were recruited for a multi-modal neuroimaging protocol, including proton magnetic resonance spectroscopy within the dorsal anterior cingulate cortex (dACC) and an fMRI alcohol cue-reactivity task. The alcohol cue-reactivity task was analyzed across 11 a priori regions-of-interest (ROI), including the dACC, and in an exploratory whole-brain approach. Correlations were run between neurometabolite levels and alcohol cue-reactivity in the dACC.

RESULTS

There were no significant group differences in absolute neurometabolite concentrations. Compared to the control group, the alcohol-using group exhibited heightened alcohol cue reactivity in the left amygdala ROI (p=0.04). The whole-brain approach identified higher alcohol cue reactivity in the alcohol-using group compared to controls in the amygdala and occipital regions, and lower reactivity in the parietal lobe. Whole-brain sex effects were noted, with females displaying higher reactivity regardless of group. No significant correlations were found between neurometabolite levels and alcohol cue-reactivity in the dACC.

CONCLUSIONS

The null neurometabolic findings may be due to age, relatively low severity of alcohol use, and non-treatment-seeking status of the participants. Females showed overall higher reactivity to alcohol cues, indicating a sex effect regardless of alcohol use history. Higher amygdala reactivity in alcohol-using adolescents suggests that emotional processing related to alcohol cues may be a useful target for future adolescent AUD interventions.

Predictive utility of the P3 event-related potential (ERP) response to alcohol cues for ecologically assessed alcohol craving and use

Neural measures of alcohol cue incentive salience have been associated with retrospective reports of riskier alcohol use behaviour and subjective response profiles. This study tested whether the P3 event-related potential (ERP) elicited by alcohol-related cues (ACR-P3) can forecast alcohol use and craving during real-world drinking episodes. Participants (N = 262; Mage  = 19.53; 56% female) completed a laboratory task in which they viewed images of everyday objects (Neutral), non-alcohol drinks (NonAlc) and alcohol beverages (Alc) while EEG was recorded and then completed a 21-day ecological momentary assessment (EMA) protocol in which they recorded alcohol craving and consumption. Anthropometrics were used to derive estimated blood alcohol concentration (eBAC) throughout drinking episodes. Multilevel modelling indicated positive associations between P3 amplitudes elicited by all stimuli and within-episode alcohol use measures (e.g., eBAC, cumulative drinks). Focal follow-up analyses indicated a positive association between AlcP3 amplitude and eBAC within episodes: Larger AlcP3 was associated with a steeper rise in eBAC. This association was robust to controlling for the association between NonAlcP3 and eBAC. AlcP3 also was positively associated with episode-level measures (e.g., max drinks, max eBAC). There were no associations between any P3 variables and EMA-based craving measures. Thus, individual differences in neural measures of alcohol cue incentive salience appear to predict the speed and intensity of alcohol consumption but not reports of craving during real-world alcohol use episodes.

Functional Domains of Substance Use and their Implications to Trauma: A Systematic Review of Neuroimaging Studies

Substance use disorder (SUD) is a significant health problem, and trauma exposure is a known risk factor for the escalation of substance use. However, the shared neural mechanisms through which trauma is associated with substance use are still unknown. Therefore, we systematically review neuroimaging studies focusing on three domains that may contribute to the overlapping mechanisms of SUD and trauma-reward salience, negative emotionality, and inhibition. Using PRISMA guidelines, we identified 45 studies utilizing tasks measuring these domains in alcohol, tobacco, and cannabis use groups. Greater reward, lesser regulation of inhibitory processes, and mixed findings of negative emotionality processes in individuals who use substances versus controls were found. Specifically, greater orbitofrontal cortex, ventral tegmental area, striatum, amygdala, and hippocampal activation was found in response to reward-related tasks, and reduced activation was found in the inferior frontal gyrus and hippocampus in response to inhibition-related tasks. Importantly, no studies in trauma-exposed individuals met our review criteria. Future studies examining the role of trauma-related factors are needed, and more studies should explore inhibition- and negative-emotionality domains in individuals who use substances to uncover clinically significant alterations in these domains that place an individual at greater risk for developing a SUD.

People who binge drink show neuroendocrine tolerance to alcohol cues that is associated with immediate and future drinking- results from a randomized clinical experiment

Neuroendocrine tolerance to alcohol, i.e., a blunted cortisol response to alcohol, has been linked to Ventromedial Prefrontal Cortex (VmPFC) alcohol cue reactivity and relapse risk in severe Alcohol Use Disorders (AUDs), but its role in the development of AUDs is not clear. Recent work suggests that blunted cortisol responses to alcohol cues in individuals who engage in binge drinking (BD) may play a role in motivation to consume larger amounts of alcohol, but the link between this dysregulated endocrine response and BD's neural responses to alcohol cues remains unclear. To examine this, two groups of participants were recruited based on their recent drinking history. Thirty-three BD and 31 non-binging, social drinkers (SD) were exposed to alcohol cues and water cues in two separate 7 T functional magnetic resonance imaging (fMRI) scans. Each scan was followed by the Alcohol Taste Test (ATT) of implicit motivation for alcohol and a post-experiment, one-month prospective measurement of their "real world" drinking behavior. During each scan session, blood plasma was collected repeatedly to examine the separate effects of alcohol cues and alcohol consumption on cortisol levels. Relative to water cues and SD, BD demonstrated blunted cortisol cue reactivity that was negatively associated with VmPFC cue reactivity. In BD, both blunted cortisol and greater VmPFC cue reactivity were related to immediate and future alcohol consumption in the month following the scans. Thus, neuroendocrine tolerance in BD may be associated with increased incentive salience of cues and contribute mechanistically to increased alcohol consumption seen in the development of AUDs.

Hippocampal Mechanisms Support Cortisol-Induced Memory Enhancements

Stress can powerfully influence episodic memory, often enhancing memory encoding for emotionally salient information. These stress-induced memory enhancements stand at odds with demonstrations that stress and the stress-related hormone cortisol can negatively affect the hippocampus, a brain region important for episodic memory encoding. To resolve this apparent conflict and determine whether and how the hippocampus supports memory encoding under cortisol, we combined behavioral assays of associative memory, high-resolution fMRI, and pharmacological manipulation of cortisol in a within-participant, double-blinded procedure (in both sexes). Behaviorally, hydrocortisone promoted the encoding of subjectively arousing, positive associative memories. Neurally, hydrocortisone led to enhanced functional connectivity between hippocampal subregions, which predicted subsequent memory enhancements for emotional associations. Cortisol also modified the relationship between hippocampal representations and associative memory: whereas hippocampal signatures of distinctiveness predicted memory under placebo, relative integration predicted memory under cortisol. Together, these data provide novel evidence that the human hippocampus contains the necessary machinery to support emotional associative memory enhancements under cortisol.SIGNIFICANCE STATEMENT Our daily lives are filled with stressful events, which powerfully shape the way we form episodic memories. For example, stress and stress-related hormones can enhance our memory for emotional events. However, the mechanisms underlying these memory benefits are unclear. In the current study, we combined functional neuroimaging, behavioral tests of memory, and double-blind, placebo-controlled hydrocortisone administration to uncover the effects of the stress-related hormone cortisol on the function of the human hippocampus, a brain region important for episodic memory. We identified novel ways in which cortisol can enhance hippocampal function to promote emotional memories, highlighting the adaptive role of cortisol in shaping memory formation.

Using lickometry to infer differential contributions of salience network regions during compulsion-like alcohol drinking

Alcohol use disorder extracts substantial personal, social and clinical costs, and continued intake despite negative consequences (compulsion-like consumption) can contribute strongly. Here we discuss lickometry, a simple method where lick times are determined across a session, while analysis across many aspects of licking can offer important insights into underlying psychological and action strategies, including their brain mechanisms. We first describe studies implicating anterior insula (AIC) and dorsal medial prefrontal cortex (dMPF) in compulsion-like responding for alcohol, then review work suggesting that AIC/ventral frontal cortex versus dMPF regulate different aspects of behavior (oral control and overall response strategy, versus moment-to-moment action organization). We then detail our lickometer work comparing alcohol-only drinking (AOD) and compulsion-like drinking under moderate- or higher-challenge (ModChD or HiChD, using quinine-alcohol). Many studies have suggested utilization of one of two main strategies, with higher motivation indicated by more bouts, and greater palatability suggested by longer, faster bouts. Instead, ModChD shows decreased variability in many lick measures, which is unexpected but consistent with the suggested importance of automaticity for addiction. Also surprising is that HiChD retains several behavior changes seen with ModChD, reduced tongue variability and earlier bout start, even though intake is otherwise disrupted. Since AIC-related measures are retained under both moderate- and higher-challenge, we propose a novel hypothesis that AIC sustains overall commitment regardless of challenge level, while disordered licking during HiChD mirrors the effects of dMPF inhibition. Thus, while AIC provides overall drive despite challenge, the ability to act is ultimately determined within the dMPF.

The impact of age on olfactory alcohol cue-reactivity: A functional magnetic resonance imaging study in adolescent and adult male drinkers

BACKGROUND

Adolescence is marked not only by rapid surges in the prevalence of alcohol use disorders (AUDs) but also by remarkable recovery rates, as most adolescent-onset AUDs naturally resolve over time. Little is known about the differential vulnerability of adolescents and adults. Therefore, this study aimed to unravel the moderating role of age by comparing neural alcohol cue-reactivity, an important AUD biomarker, between low-to-high beer-drinking adolescent (n = 50, 16 to 18 years), and adult (n = 51, 30 to 35 years) males matched on drinking severity.

METHODS

Associations between beer odor-induced brain activity and AUD diagnosis, severity of alcohol use-related problems, recent alcohol use, binge-drinking frequency, and task-induced craving were investigated across and between age groups in regions of interest thought to be central in alcohol cue-reactivity: the medial prefrontal cortex, anterior cingulate cortex, and striatal subregions (nucleus accumbens and caudate putamen). These analyses were complemented by exploratory whole-brain analyses.

RESULTS

Pre-task beer craving increased pre-to-post task in adolescents only. Individual differences in alcohol use, binge drinking, and craving did not relate to beer odor-induced activity. Although region-of-interest analyses did not reach significance, whole-brain analyses showed that adolescents with AUD, compared with adolescents without AUD and adults with AUD, had higher beer odor-induced activity in a large mesocorticolimbic cluster encompassing the right caudate, nucleus accumbens, orbitofrontal cortex, and the olfactory sulcus. Activity in the right caudate and putamen was positively associated with the severity of alcohol use-related problems in adolescents but negatively associated in adults.

CONCLUSION

These findings suggest a differential role of alcohol cue-reactivity in adolescents compared with adults with AUD and highlight the need for further studies investigating the role of age in the fundamental processes underlying the development of and recovery from of AUD.

Hippocampal mechanisms support cortisol-induced memory enhancements

Stress can powerfully influence episodic memory, often enhancing memory encoding for emotionally salient information. These stress-induced memory enhancements stand at odds with demonstrations that stress and the stress-related hormone cortisol can negatively affect the hippocampus, a brain region important for episodic memory encoding. To resolve this apparent conflict and determine whether and how the hippocampus supports memory encoding under cortisol, we combined behavioral assays of associative memory, high-resolution functional magnetic resonance imaging (fMRI), and pharmacological manipulation of cortisol in a within-participant, double-blinded procedure. Hydrocortisone led to enhanced functional connectivity between hippocampal subregions, which predicted subsequent memory enhancements for emotional information. Cortisol also modified the relationship between hippocampal representations and memory: whereas hippocampal signatures of distinctiveness predicted memory under placebo, relative integration predicted memory under cortisol. Together, these data provide novel evidence that the human hippocampus contains the necessary machinery to support emotional memory enhancements under stress.

The Dopamine System in Mediating Alcohol Effects in Humans

Brain-imaging studies show that the development and maintenance of alcohol use disorder (AUD) is determined by a complex interaction of different neurotransmitter systems and multiple psychological factors. In this context, the dopaminergic reinforcement system appears to be of fundamental importance. We focus on the excitatory and depressant effects of acute versus chronic alcohol intake and its impact on dopaminergic neurotransmission. Furthermore, we describe alterations in dopaminergic neurotransmission as associated with symptoms of alcohol dependence. We specifically focus on neuroadaptations to chronic alcohol consumption and their effect on central processing of alcohol-associated and reward-related stimuli. Altered reward processing, complex conditioning processes, impaired reinforcement learning, and increased salience attribution to alcohol-associated stimuli enable alcohol cues to drive alcohol seeking and consumption. Finally, we will discuss how the neurobiological and neurochemical mechanisms of alcohol-associated alterations in reward processing and learning can interact with stress, cognition, and emotion processing.

Modeling Aversion Resistant Alcohol Intake in Indiana Alcohol-Preferring (P) Rats

With the substantial social and medical burden of addiction, there is considerable interest in understanding risk factors that increase the development of addiction. A key feature of alcohol use disorder (AUD) is compulsive alcohol (EtOH) drinking, where EtOH drinking becomes “inflexible” after chronic intake, and animals, such as humans with AUD, continue drinking despite aversive consequences. Further, since there is a heritable component to AUD risk, some work has focused on genetically-selected, EtOH-preferring rodents, which could help uncover critical mechanisms driving pathological intake. In this regard, aversion-resistant drinking (ARD) takes >1 month to develop in outbred Wistar rats (and perhaps Sardinian-P EtOH-preferring rats). However, ARD has received limited study in Indiana P-rats, which were selected for high EtOH preference and exhibit factors that could parallel human AUD (including front-loading and impulsivity). Here, we show that P-rats rapidly developed compulsion-like responses for EtOH; 0.4 g/L quinine in EtOH significantly reduced female and male intake on the first day of exposure but had no effect after one week of EtOH drinking (15% EtOH, 24 h free-choice paradigm). Further, after 4−5 weeks of EtOH drinking, males but not females showed resistance to even higher quinine (0.5 g/L). Thus, P-rats rapidly developed ARD for EtOH, but only males developed even stronger ARD with further intake. Finally, rats strongly reduced intake of quinine-adulterated water after 1 or 5 weeks of EtOH drinking, suggesting no changes in basic quinine sensitivity. Thus, modeling ARD in P-rats may provide insight into mechanisms underlying genetic predispositions for compulsive drinking and lead to new treatments for AUDs.

The prediction of resilience to alcohol consumption in youths: insular and subcallosal cingulate myeloarchitecture

BACKGROUND

The prediction of alcohol consumption in youths and particularly biomarkers of resilience, is critical for early intervention to reduce the risk of subsequent harmful alcohol use.

METHODS

At baseline, the longitudinal relaxation rate (R1), indexing grey matter myelination (i.e. myeloarchitecture), was assessed in 86 adolescents/young adults (mean age = 21.76, range: 15.75-26.67 years). The Alcohol Use Disorder Identification Test (AUDIT) was assessed at baseline, 1- and 2-year follow-ups (12- and 24-months post-baseline). We used a whole brain data-driven approach controlled for age, gender, impulsivity and other substance and behavioural addiction measures, such as problematic cannabis use, drug use-related problems, internet gaming, pornography use, binge eating, and levels of externalization, to predict the change in AUDIT scores from R1.

RESULTS

Greater baseline bilateral anterior insular and subcallosal cingulate R1 (cluster-corrected family-wise error p < 0.05) predict a lower risk for harmful alcohol use (measured as a reduction in AUDIT scores) at 2-year follow-up. Control analyses show that other grey matter measures (local volume or fractional anisotropy) did not reveal such an association. An atlas-based machine learning approach further confirms the findings.

CONCLUSIONS

The insula is critically involved in predictive coding of autonomic function relevant to subjective alcohol cue/craving states and risky decision-making processes. The subcallosal cingulate is an essential node underlying emotion regulation and involved in negative emotionality addiction theories. Our findings highlight insular and cingulate myeloarchitecture as a potential protective biomarker that predicts resilience to alcohol misuse in youths, providing novel identifiers for early intervention.

Effects of binge drinking during adolescence and emerging adulthood on the brain: A systematic review of neuroimaging studies

Binge drinking (BD) is a common pattern of alcohol consumption which is generating great concern because of its deleterious consequences. We selected 33 neuroimaging studies of healthy young binge drinkers (BDs) by following PRISMA guidelines. This review provides a comprehensive overview of the relationship between BD and neurocognitive anomalies reported across magnetic resonance studies. Moreover, this work is the first in which results of relatively new imaging techniques, such as resting-state functional connectivity (RS-FC) and neurite orientation dispersion and density imaging (NODDI), have been reviewed using a systematic procedure. We established strict inclusion criteria in order to isolate the various potential effects of BD on the adolescent brain. Two authors independently evaluated the methodological quality, assessing different aspects related to sample size, and statistical correction methods, which are of particular importance in neuroimaging studies. BD is associated with structural and functional anomalies in several cortical and subcortical brain regions intimately involved in the control and regulation of impulsive or risky behaviours, as well as in the processing of reinforcing stimuli.

Mindfulness-Based Interventions for the Treatment of Aberrant Interoceptive Processing in Substance Use Disorders

Altered interoception, or the processing of bodily signals, has been argued to play a role in the development and maintenance of substance use disorders (SUD). Therefore, interoceptive interventions focusing on bodily awareness, such as mindfulness meditation, may improve treatment outcomes for individuals with SUD. Here we review: (1) subjective, behavioral and brain evidence for altered interoceptive processing in SUD, focusing on insular and anterior cingulate cortices (INS, ACC), key regions for interoceptive processing; (2) research highlighting links between mindfulness and brain function; and (3) extant brain research investigating mindfulness-based interventions in SUD. SUD tend to be characterized by heightened INS and ACC responses to drug cues but blunted interoceptive awareness and attenuated INS and ACC responses during tasks involving bodily attention and/or perturbations. In contrast, mindfulness interventions in healthy individuals are linked to enhanced INS and ACC responses and heightened interoceptive awareness. It is crucial for future research to identify: (1) whether mindfulness-based treatments are efficacious across substance classes; (2) what particular approaches and dosages show the largest effect sizes in enhancing INS and ACC function to non-drug stimuli and reducing responsivity to substance cues, thereby improving SUD treatment outcomes (reducing drug craving and relapse).

Alcohol use and interoception - A narrative review

Interoception, defined as the ability to perceive and interpret body signals, may play an important role in alcohol use disorder (AUD). Earlier studies suggested an association between interoception impairment and known risk factors for AUD (e.g., alexithymia, emotion dysregulation, impulsivity, pain). Neurobiological studies show that the neurotoxicity of alcohol affects various elements of the interoceptive system (especially the insula) at structural and functional levels, with differential short/long term impacts. Conversely, primary interoceptive impairments may promote alcohol consumption and foster the evolution towards addiction. Despite convincing evidence demonstrating that interoception impairment may be an important contributor to the development and course of AUD, only a few studies directly evaluated interoceptive abilities in AUD. The research shows that interoceptive accuracy, the objective component of interoception, is lower in AUD individuals, and is correlated with craving and emotion dysregulation. Interoceptive sensibility is in turn higher in AUD individuals compared to healthy controls. Moreover, there is evidence that therapy focused on improving the ability to sense signals from the body in addiction treatment is effective. However, important methodological limitations in interoceptive measures persist, and it is therefore necessary to further investigate the associations between interoception and AUD.

Alcohol and the Brain

Alcohol works on the brain to produce its desired effects, e.g., sociability and intoxication, and hence the brain is an important organ for exploring subsequent harms. These come in many different forms such as the consequences of damage during intoxication, e.g., from falls and fights, damage from withdrawal, damage from the toxicity of alcohol and its metabolites and altered brain structure and function with implications for behavioral processes such as craving and addiction. On top of that are peripheral factors that compound brain damage such as poor diet, vitamin deficiencies leading to Wernicke-Korsakoff syndrome. Prenatal alcohol exposure can also have a profound impact on brain development and lead to irremediable changes of fetal alcohol syndrome. This chapter briefly reviews aspects of these with a particular focus on recent brain imaging results. Cardiovascular effects of alcohol that lead to brain pathology are not covered as they are dealt with elsewhere in the volume.

Trajectories of brain development reveal times of risk and factors promoting resilience to alcohol use during adolescence

Alcohol use disorder (AUD) is recognized as harmful for the developing brain. Numerous studies have sought environmental and genetic risk factors that predict the development of AUD, but recently identified resilience factors have emerged as protective. This chapter reviews normal processes of brain development in adolescence and emerging adulthood, delineates disturbed growth neurotrajectories related to heavy drinking, and identifies potential endogenous, experiential, and time-linked brain markers of resilience. For example, concurrent high dorsolateral prefrontal activation serving inhibitory control and low nucleus accumbens activation serving reward functions engender positive adaptation and low alcohol use. Also discussed is the role that moderating factors have in promoting risk for or resilience to AUD. Longitudinal research on the effects of all levels of alcohol drinking on the developing brain remains crucial and should be pursued in the context of resilience, which is a promising direction for identifying protective biomarkers against developing AUDs.

Neurobiological correlates of cue-reactivity in alcohol-use disorders: A voxel-wise meta-analysis of fMRI studies

Altered brain responses to alcohol-associated stimuli are a neural hallmark of alcohol-use disorder (AUD) and a promising target for pharmacotherapy. However, findings in cue-reactivity based functional MRI (fMRI) studies are inconclusive. To investigate the neural substrates of cue-reactivity and their relevance to treatment outcomes, alcohol craving and relapse in AUD patients, we performed five meta-analyses using signed differential mapping software. Our meta-analysis revealed that alcohol cues evoke greater cue-reactivity than neutral cues in the mesocorticolimbic circuit and lower reactivity in the parietal and temporal regions in AUD patients. Compared to controls, AUD individuals displayed hyperactivations in the medial prefrontal cortex and anterior/middle part of the cingulate cortex. After receiving AUD treatment, AUD patients exhibited greater activations in the precentral gyrus but reduced activations in the bilateral caudate nucleus, insula, right DLPFC, and left superior frontal gyrus. No significant results were found in cue-reactivity correlates of alcohol craving and relapse. Our results implicate cue-induced abnormalities in corticostriatal-limbic circuits may underline the pathophysiology of AUD, and have translational value for treatment development.

The role of the orbitofrontal cortex and the nucleus accumbens for craving in alcohol use disorder

This study aimed to investigate structural and functional alterations of the reward system and the neurobiology of craving in alcohol use disorder (AUD). We hypothesized reduced volume of the nucleus accumbens (NAcc), reduced structural connectivity of the segment of the supero-lateral medial forebrain bundle connecting the orbitofrontal cortex (OFC) with the NAcc (OFC-NAcc), and reduced resting-state OFC-NAcc functional connectivity (FC). Furthermore, we hypothesized that craving is related to an increase of OFC-NAcc FC. Thirty-nine recently abstinent patients with AUD and 18 healthy controls (HC) underwent structural (T1w-MP2RAGE, diffusion-weighted imaging (DWI)) and functional (resting-state fMRI) MRI-scans. Gray matter volume of the NAcc, white matter microstructure (fractional anisotropy (FA)) and macrostructure (tract length) of the OFC-NAcc connection and OFC-NAcc FC were compared between AUD and HC using a mixed model MANCOVA controlling for age and gender. Craving was assessed using the thoughts subscale of the obsessive-compulsive drinking scale (OCDS) scale and was correlated with OFC-NAcc FC. There was a significant main effect of group. Results were driven by a volume reduction of bilateral NAcc, reduced FA in the left hemisphere, and reduced tract length of bilateral OFC-NAcc connections in AUD patients. OFC-NAcc FC did not differ between groups. Craving was associated with increased bilateral OFC-NAcc FC. In conclusion, reduced volume of the NAcc and reduced FA and tract length of the OFC-NAcc network suggest structural alterations of the reward network in AUD. Increased OFC-NAcc FC is associated with craving in AUD, and may contribute to situational alcohol-seeking behavior in AUD.

Unraveling the role of cigarette use in neural cannabis cue reactivity in heavy cannabis users

Cue reactivity is an important biomarker of cannabis use disorder (CUD). Despite high rates of cigarette and cannabis co‐use, its role in cannabis cue reactivity remains unclear. Using a visual functional magnetic resonance imaging cue reactivity paradigm, we investigated interactive effects of cannabis and cigarette use on cannabis cue relative to cigarette and neutral cue reactivity in a priori regions of interest—the amygdala, striatum, anterior cingulate cortex (ACC), ventral tegmental area (VTA), and orbitofrontal cortex—and a whole‐brain analysis. In our sample of cannabis users and controls closely matched on cigarette use, significant interactions between cannabis and cigarette use status emerged in the amygdala, striatum, ACC, frontal pole, and inferior frontal gyrus. Cannabis‐only users showed heightened cue reactivity in the amygdala compared with nonusing controls. Co‐users did not show heightened cue reactivity compared with cigarette smoking controls, although cue‐induced VTA activity was positively correlated with grams per week of cannabis. Cigarette smoking controls showed unexpectedly heightened cue reactivity compared to co‐users and nonsmoking controls. These findings and the high prevalence of cannabis and cigarette co‐use underscore the importance of considering cigarette smoking status when investigating the role of cue reactivity in heavy cannabis use.

A Systematic Review of the Balloon Analogue Risk Task (BART) in Alcohol Research

Risk-taking propensity has been crucial to the investigation of alcohol use and consequences. One measure, the balloon analogue risk task (BART), has been used consistently over the past two decades. However, it is unclear how this measure is related to alcohol outcomes. This paper systematically reviews the literature on the BART and alcohol outcomes. First, direct associations between the BART and alcohol use are reviewed including correlations, group comparisons, the BART's prediction of alcohol outcomes and BART performance after consuming alcohol. Then, potential moderators that explain when and for whom the BART is related to alcohol outcomes are reviewed. Finally, potential mechanisms that explain how the BART and alcohol outcomes are related are reviewed. This review reveals patterns in the BART suggesting risk-taking propensity may be related to changes in alcohol use over time; however, there is little evidence to suggest BART scores increase after consuming alcohol. Yet, additional research suggests adjusted average pump scores may be too simplistic for the amount of information the BART captures and understanding individual's patterns of responses on the BART is important for investigating its relation to alcohol outcomes. Finally, this review opens up several future directions for research to understand how risk-taking propensity is related to alcohol outcomes.

It's more than just interoception: The insular cortex involvement in alcohol use disorder

Understanding brain structures and circuits impacted by alcohol use disorder is critical for improving our future prevention techniques and treatment options. A brain region that has recently gained traction for its involvement in substance use disorder is the insular cortex. This brain region is multi-functional and spatially complex, resulting in a relative lack of understanding of the involvement of the insular cortex in alcohol use disorder. Here we discuss the role of the insular cortex in alcohol use disorder, particularly during periods of abstinence and in response to alcohol and alcohol-related cues and contexts. We also discuss a broader role of the insular in alcohol-associated risky decision making and impulse control. Finally, we canvas potential challenges associated with targeting the insular cortex to treat individuals with alcohol use disorder.

Behavioral and brain signatures of substance use vulnerability in childhood

The prevalence of risky behavior such as substance use increases during adolescence; however, the neurobiological precursors to adolescent substance use remain unclear. Predictive modeling may complement previous work observing associations with known risk factors or substance use outcomes by developing generalizable models that predict early susceptibility. The aims of the current study were to identify and characterize behavioral and brain models of vulnerability to future substance use. Principal components analysis (PCA) of behavioral risk factors were used together with connectome-based predictive modeling (CPM) during rest and task-based functional imaging to generate predictive models in a large cohort of nine- and ten-year-olds enrolled in the Adolescent Brain & Cognitive Development (ABCD) study (NDA release 2.0.1). Dimensionality reduction (n = 9,437) of behavioral measures associated with substance use identified two latent dimensions that explained the largest amount of variance: risk-seeking (PC1; e.g., curiosity to try substances) and familial factors (PC2; e.g., family history of substance use disorder). Using cross-validated regularized regression in a subset of data (Year 1 Fast Track data; n>1,500), functional connectivity during rest and task conditions (resting-state; monetary incentive delay task; stop signal task; emotional n-back task) significantly predicted individual differences in risk-seeking (PC1) in held-out participants (partial correlations between predicted and observed scores controlling for motion and number of frames [r_p]: 0.07-0.21). By contrast, functional connectivity was a weak predictor of familial risk factors associated with substance use (PC2) (r_p: 0.03-0.06). These results demonstrate a novel approach to understanding substance use vulnerability, which—together with mechanistic perspectives—may inform strategies aimed at early identification of risk for addiction.

Review of Orbitofrontal Cortex in Alcohol Dependence: A Disrupted Cognitive Map?

Alcoholism is a persistent worldwide problem associated with long-lasting impairments to decision making processes. Some aspects of dysfunction are thought to reflect alcohol-induced changes to relevant brain areas such as the orbitofrontal cortex (OFC). In this review, we will examine how chronic alcohol exposure alters OFC function to potentially contribute to maladaptive decision making, and explore experimental behavioral approaches that may be better suited to test whether alcohol dependence disrupts OFC's function. We argue that although past works suggest impairments in aspects of OFC function, more information may be gained by specifically targeting tasks to the broader function of OFC as put forth by the recent hypothesis of OFC as a "cognitive map" of task space. Overall, we suggest that such a focus could provide a better understanding of how OFC function changes in alcohol dependence, and could inform better assessment tools and treatment options for clinicians working with this population.

Adolescent Substance Use and the Brain: Behavioral, Cognitive and Neuroimaging Correlates

Adolescence is an important ontogenetic period that is characterized by behaviors such as enhanced novelty-seeking, impulsivity, and reward preference, which can give rise to an increased risk for substance use. While substance use rates in adolescence are generally on a decline, the current rates combined with emerging trends, such as increases in e-cigarette use, remain a significant public health concern. In this review, we focus on the neurobiological divergences associated with adolescent substance use, derived from a cross-sectional, retrospective, and longitudinal studies, and highlight how the use of these substances during adolescence may relate to behavioral and neuroimaging-based outcomes. Identifying and understanding the associations between adolescent substance use and changes in cognition, mental health, and future substance use risk may assist our understanding of the consequences of drug exposure during this critical window.

Alcohol Cue-Induced Ventral Striatum Activity Predicts Subsequent Alcohol Self-Administration

BACKGROUND

Human laboratory paradigms are a pillar in medication development for alcohol use disorders (AUD). Neuroimaging paradigms, in which individuals are exposed to cues that elicit neural correlates of alcohol craving (e.g., mesocorticolimbic activation), are increasingly utilized to test the effects of AUD medications. Elucidation of the translational effects of these neuroimaging paradigms on human laboratory paradigms, such as self-administration, is warranted. The current study is a secondary analysis examining whether alcohol cue-induced activation in the ventral striatum is predictive of subsequent alcohol self-administration in the laboratory.

METHODS

Non-treatment-seeking heavy drinkers of East Asian descent (n = 41) completed a randomized, placebo-controlled, double-blind, crossover experiment on the effects of naltrexone on neuroimaging and human laboratory paradigms. Participants completed 5 days of study medication (or placebo); on day 4, they completed a neuroimaging alcohol taste cue-reactivity task. On the following day (day 5), participants completed a 60-minute alcohol self-administration paradigm.

RESULTS

Multilevel Cox regressions indicated a significant effect of taste cue-elicited ventral striatum activation on latency to first drink, Wald χ2  = 2.88, p = 0.05, such that those with higher ventral striatum activation exhibited shorter latencies to consume their first drink. Similarly, ventral striatum activation was positively associated with total number of drinks consumed, F(1, 38) = 5.90, p = 0.02. These effects were significant after controlling for alcohol use severity, OPRM1 genotype, and medication. Other potential regions of interest (anterior cingulate, thalamus) were not predictive of self-administration outcomes.

CONCLUSIONS

Neuroimaging alcohol taste cue paradigms may be predictive of laboratory paradigms such as self-administration. Elucidation of the relationships among different paradigms will inform how these paradigms may be used synergistically in experimental medicine and medication development.

Do Adolescents Use Substances to Relieve Uncomfortable Sensations? A Preliminary Examination of Negative Reinforcement among Adolescent Cannabis and Alcohol Users

Alcohol and cannabis use are highly prevalent among adolescents and associated with negative consequences. Understanding motivations behind substance use in youth is important for informing prevention and intervention efforts. The present study aims to examine negative reinforcement principles of substance use among adolescent cannabis and alcohol users by pairing a cue reactivity paradigm with an aversive interoceptive stimulus. Adolescents (ages 15–17), classified as controls (CTL; n = 18), cannabis and/or alcohol experimenters (CAN+ALC-EXP; n = 16), or individuals meeting clinical criteria for cannabis and/or alcohol use disorder (CAN+ALC-SUD; n = 13) underwent functional magnetic resonance imaging during which they experienced an aversive interoceptive probe delivered via breathing load while simultaneously performing a cue reactivity paradigm. Participants also provided self-report ratings of how their substance use is positively or negatively reinforced. While experiencing the breathing load, CAN+ALC-SUD exhibited greater (p < 0.05) deactivation in the right amygdala, the left inferior frontal gyrus, and the left parahippocampal gyrus than CAN+ALC-EXP and CTL, who did not differ. Across all substance users, activation during the breathing load within the left parahippocampal gyrus negatively correlated with cannabis and alcohol lifetime use episodes and the left inferior frontal gyrus activity negatively correlated with lifetime alcohol use episodes. CAN+ALC-SUD reported experiencing more positive and negative reinforcement of using their substance of choice than CAN+ALC-EXP; both user groups reported higher levels of positive than negative reinforcement. Adolescents with a cannabis/alcohol use disorder demonstrate an altered response to interoceptive perturbations. However, adolescent cannabis/alcohol use does not appear to be driven by negative reinforcement, as viewing substance images did not dampen this response. Based on self-report data, the experience of positive reinforcement may be stronger for adolescents. Future studies should examine whether positive reinforcement contributes to adolescent substance use.

Meta-analysis and review of functional neuroimaging differences underlying adolescent vulnerability to substance use

Adolescence is increasingly viewed as a sensitive period in the development of substance use disorders (SUDs). Neurodevelopmental 'dual-risk' theories suggest adolescent vulnerability to problematic substance use is driven by an overactive reward drive mediated by the striatum, and poor cognitive control mediated by the prefrontal cortex. To this end, there has been a growing number of neuroimaging studies examining cognitive and affective neural systems during adolescence for markers of vulnerability to problematic substance use. Here, we perform a coordinate-based meta-analysis on this emerging literature. Twenty-two task-based voxelwise fMRI studies with activation differences associated with substance use vulnerability, representative of approximately 1092 subjects, were identified through a systematic literature search (PubMed, Scopus) and coordinates of activation differences (N ​= ​190) were extracted. Adolescents were defined as 'at-risk' for problematic substance use based on a family history of SUD or through prospective prediction of substance use initiation or escalation. Multilevel kernel density analysis was used to identify the most consistent brain regions associated with adolescent substance use vulnerability. Across the included studies, substance use vulnerability was most reliably associated with activation differences in the striatum, where at-risk adolescents had hyper-activation in the dorsal subdivision (putamen). Follow-up analyses suggested striatal differences were driven by tasks sharing a motivational and/or reward component (e.g., monetary incentive) and common across subgroups of substance use risk (family history and prospective prediction studies). Analyses examining the role of psychiatric comorbidity revealed striatal activation differences were significantly more common in samples whose definition of substance use risk included cooccurring externalizing psychopathology. Furthermore, substance use risk meta-analytic results were no longer significant when excluding these studies, although this may reflect limitations in statistical power. No significant activation differences were observed in prefrontal cortex in any analysis. These results suggest striatal dysfunction, rather than prefrontal, may be a more primary neural feature of adolescent vulnerability to problematic substance use, possibly through a dimension of individual variability shared with externalizing psychopathology. However, our systematic literature search confirms this is still an emerging field. More studies, increased data sharing, and further quantitative integration are necessary for a comprehensive understanding of the neuroimaging markers of adolescent substance use risk.

A dual-process exploration of binge drinking: Evidence through behavioral and electrophysiological findings

The dual-process model, describing addictive disorders as resulting from an imbalance between increased automatic approach behaviors towards the substance and reduced abilities to control these behaviors, constitutes a sound theoretical framework to understand alcohol-use disorders. The present study aimed at exploring this imbalance at behavioral and cerebral levels in binge drinking, a pattern of excessive alcohol consumption frequently observed in youth, by assessing both reflective control abilities and automatic processing of alcohol-related stimuli. For this purpose, 25 binge drinkers and 25 comparison participants performed a Go/No-Go task during electrophysiological recording. Inhibition abilities were investigated during explicit (ie, distinguishing alcoholic versus nonalcoholic drinks) and implicit (ie, distinguishing sparkling versus nonsparkling drinks, independently of their alcohol content) processing of beverage cues. Binge drinkers presented poorer inhibition for the explicit processing of beverage cues, as well as reduced N200 amplitude for the specific processing of alcohol-related stimuli. As a whole, these findings indicated inhibition impairments in binge drinkers, particularly for alcohol cues processing and at the attentional stage of the cognitive stream. In line with the dual-process model, these results support that binge drinking is already characterized by an underactivation of the reflective system combined with an overactivation of the automatic system. Results also underlined the influence of explicit processing compared with implicit ones. At the clinical level, our findings reinforce the need to develop intervention methods focusing on the inhibition of approach behaviors towards alcohol-related stimuli.

Alcohol Use Disorder Interventions Targeting Brain Sites for Both Conditioned Reward and Delayed Gratification

Alcohol use disorder is a destructive compulsion characterized by chronic relapse and poor recovery outcomes. Heightened reactivity to alcohol-associated stimuli and compromised executive function are hallmarks of alcohol use disorder. Interventions targeting these two interacting domains are thought to ameliorate these altered states, but the mutual brain sites of action are yet unknown. Although interventions on alcohol cue reactivity affect reward area responses, how treatments alter brain responses when subjects exert executive effort to delay gratification is not as well-characterized. Focusing on interventions that could be developed into effective clinical treatments, we review and identify brain sites of action for these two categories of potential therapies. Using activation likelihood estimation (ALE) meta-analysis, we find that interventions on alcohol cue reactivity localize to ventral prefrontal cortex, dorsal anterior cingulate, and temporal, striatal, and thalamic regions. Interventions for increasing delayed reward preference elicit changes mostly in midline default mode network regions, including posterior cingulate, precuneus, and ventromedial prefrontal cortex-in addition to temporal and parietal regions. Anatomical co-localization of effects appears in the ventromedial prefrontal cortex, whereas effects specific to delay-of-gratification appear in the posterior cingulate and precuneus. Thus, the current available literature suggests that interventions in the domains of cue reactivity and delay discounting alter brain activity along midline default mode regions, specifically in the ventromedial prefrontal cortex for both domains, and the posterior cingulate/precuneus for delay-of-gratification. We believe that these findings could facilitate targeting and development of new interventions, and ultimately treatments of this challenging disorder.

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.

Brain activation to cannabis- and alcohol-related words in alcohol use disorder

Cannabis abuse commonly co-occurs with alcohol use disorder (AUD). With increased acceptance and accessibility to cannabis in the US, it is imperative to understand the psychological and neural mechanisms of concurrent alcohol and cannabis use. We hypothesized that neural alcohol-cue conditioning may extent to other drug-related stimuli, such as cannabis, and underwrite the loss of control over reward-driven behavior. Task-activated fMRI examined the neural correlates of alcohol- and cannabis-related word cues in 21 abstinent AUD and 18 control subjects. Relative to controls, AUD showed behavioral attentional biases and frontal hypoactivation to both alcohol- and cannabis-related words. This cue-elicited prefrontal hypoactivation was related to higher lifetime alcohol consumption (pcorrected < 0.02) and modulated by past cannabis use histories (p ≦ 0.001). In particular, frontal hypoactivation to both alcohol and cannabis cues was pronounced in AUD without prior cannabis exposure. Overall, frontal control mechanisms in abstinent AUD were not sufficiently engaged to override automatic alcohol and cannabis-related intrusions, enhancing the risk for relapse and potentially for alcohol and cannabis co-use with the increased social acceptance and accessibility in the US.

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).

Electrophysiological Correlates of an Alcohol-Cued Go/NoGo Task: A Dual-Process Approach to Binge Drinking in University Students

Binge drinking is a common pattern of alcohol consumption in adolescence and youth. Neurocognitive dual-process models attribute substance use disorders and risk behaviours during adolescence to an imbalance between an overactivated affective-automatic system (involved in motivational and affective processing) and a reflective system (involved in cognitive inhibitory control). The aim of the present study was to investigate at the electrophysiological level the degree to which the motivational value of alcohol-related stimuli modulates the inhibition of a prepotent response in binge drinkers. First-year university students (n = 151, 54 % females) classified as binge drinkers (n = 71, ≥6 binge drinking episodes, defined as 5/7 standard drinks per occasion in the last 180 days) and controls (n = 80, <6 binge drinking episodes in the last 180 days) performed a beverage Go/NoGo task (pictures of alcoholic and nonalcoholic drinks were presented according to the condition as Go or NoGo stimuli; Go probability = 0.75) during event-related potential recording. In binge drinkers but not controls, the amplitude of the anterior N2-NoGo was larger in response to nonalcohol than in response to alcohol pictures. No behavioural difference in task performance was observed. In terms of dual-process models, binge drinkers may require increased activation to monitor conflict in order to compensate for overactivation of the affective-automatic system caused by alcohol-related bias.

Predicting development of adolescent drinking behaviour from whole brain structure at 14 years of age

Adolescence is a common time for initiation of alcohol use and development of alcohol use disorders. The present study investigates neuroanatomical predictors for trajectories of future alcohol use based on a novel voxel-wise whole-brain structural equation modeling framework. In 1814 healthy adolescents of the IMAGEN sample, the Alcohol Use Disorder Identification Test (AUDIT) was acquired at three measurement occasions across five years. Based on a two-part latent growth curve model, we conducted whole-brain analyses on structural MRI data at age 14, predicting change in alcohol use score over time. Higher grey-matter volumes in the caudate nucleus and the left cerebellum at age 14 years were predictive of stronger increase in alcohol use score over 5 years. The study is the first to demonstrate the feasibility of running separate voxel-wise structural equation models thereby opening new avenues for data analysis in brain imaging.

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.

Prospective changes in neural alcohol cue reactivity in at-risk adolescents

Adolescence represents an ideal time for elucidating the etiology of cue reactivity profiles. This study examined the influence of three risk factors consistently associated with heavy adolescent drinking on alcohol cue reactivity. Youth were first assessed while still naïve to alcohol (12-14 years old) and followed after transitioning into alcohol use (17-21 years old). The effects of family history of substance use disorder, sex, and history of early of dating (i.e., before 14 years of age) on BOLD response contrast to alcohol picture cues were examined in a linear mixed model, controlling for age and alcohol use patterns at follow-up. Activation to alcohol picture cues differed as a function of risk factor and time. At baseline, family history positive youth showed greater activation to alcohol cues than family history negative peers in the right middle occipital and anterior cingulate gyri. Youth with a history of early-dating showed greater activation to alcohol cues, compared to non-early daters, in the left anterior cingulate/white matter region. Girls showed greater activation to alcohol than boys at baseline in left middle frontal gyrus. At follow-up, after drinking started, patterns reversed for each risk factor. These results indicate that even prior to initiating alcohol use, adolescents showed differences in activation to alcohol cues based on their family history, dating history, and sex.

Elucidating the Effect of a Brief Drinking Intervention Using Neuroimaging: A Preliminary Study

BACKGROUND

Brief interventions have empirical support for acutely reducing alcohol use among non-treatment-seeking heavy drinkers. Neuroimaging techniques allow for the examination of the neurobiological effect of behavioral interventions, probing brain systems putatively involved in clinical response to treatment. Few studies have prospectively evaluated whether psychosocial interventions attenuate neural cue reactivity that in turn reduces drinking in the same population. This study aimed to examine the effect of a brief intervention on drinking outcomes, neural alcohol cue reactivity, and the ability of neural alcohol cue reactivity to prospectively predict drinking outcomes.

METHODS

Non-treatment-seeking heavy drinking participants were randomized to receive a brief interview intervention (n = 22) or an attention-matched control (n = 24). Immediately following the intervention or control, participants underwent a functional magnetic resonance imaging scan comprised of the alcohol taste cues paradigm. Four weeks after the intervention (or control), participants completed a follow-up visit to report on their past-month drinking. Baseline and follow-up percent heavy drinking days (PHDD) were calculated for each participant.

RESULTS

There was no significant effect of the brief intervention on PHDD at follow-up or on modulating neural activation to alcohol relative to water taste cues. There was a significant association between neural response to alcohol taste cues and PHDD across groups (Z > 2.3, p < 0.05), such that individuals who had greater neural reactivity to alcohol taste cues in the precuneus and prefrontal cortex (PFC) had fewer PHDD at follow-up.

CONCLUSIONS

This study did not find an effect of the brief intervention on alcohol use in this sample, and the intervention was not associated with differential neural alcohol cue reactivity. Nevertheless, greater activation of the precuneus and PFC during alcohol cue exposure predicted less alcohol use prospectively suggesting that these neural substrates subserve the effects of alcohol cues on drinking behavior.

Perceptions of Alcohol Advertising Vary Based on Psychological Characteristics

BACKGROUND

The alcohol industry recognizes children and pregnant women as population sub-groups vulnerable to the effects of alcohol marketing. Research indicates that heavy alcohol users are also potentially vulnerable to alcohol marketing. The purpose of the current study is to determine if sub-groups defined by psychological characteristics should be classified as potentially vulnerable as well.

METHODS

College students (n = 326) from two northeast schools were recruited to complete a survey containing questions on demographics, alcohol use, and psychological characteristics (alcohol expectancies, alcohol dependence, sensation seeking traits, and past delinquent behaviors). Additionally, after viewing each of five alcohol ads (4 television and 1 magazine), participants answered questions about their perceptions of alcohol consumption, responsible drinking, excessive drinking, and appeal of the ads. Main effects were assessed using hierarchical linear modeling, with adjustment for age, sex, race, ethnicity, and AUDIT score.

RESULTS

Alcohol expectancies (p < .001), particularly the social and physical pleasure and social expressiveness sub-scales, and sensation seeking traits (p = .002) were positively associated with alcohol ad appeal. Alcohol dependence symptoms, specifically impaired control and tolerance, were positively associated with perceptions of responsible drinking (p = .035), even though mean perceived number of drinks consumed met the definition of binge drinking.

CONCLUSIONS

Individuals with positive alcohol expectancies, sensation seeking traits, and alcohol dependence may be vulnerable to alcohol advertising and marketing. Because alcohol advertising often contains content that can serve as a cue or reinforce to drink, specific regulations may be needed to prevent alcohol-related harm from occurring in these sub-populations.

Application of Research Domain Criteria to childhood and adolescent impulsive and addictive disorders: Implications for treatment

The Research Domain Criteria (RDoC) initiative provides a large-scale, dimensional framework for the integration of research findings across traditional diagnoses, with the long-term aim of improving existing psychiatric treatments. A neurodevelopmental perspective is essential to this endeavor. However, few papers synthesizing research findings across childhood and adolescent disorders exist. Here, we discuss how the RDoC framework may be applied to the study of childhood and adolescent impulsive and addictive disorders in order to improve neurodevelopmental understanding and to enhance treatment development. Given the large scope of RDoC, we focus on a single construct highly relevant to addictive and impulsive disorders - initial responsiveness to reward attainment. Findings from genetic, molecular, neuroimaging and other translational research methodologies are highlighted.

Relationship between fMRI response during a nonverbal memory task and marijuana use in college students

Marijuana (MJ) is widely used among college students, with peak use between ages 18-22. Research suggests memory dysfunction in adolescent and young adult MJ users, but the neural correlates are unclear. We examined functional magnetic resonance imaging (fMRI) response during a memory task among college students with varying degrees of MJ involvement. Participants were 64 college students, ages 18-20, who performed a visual encoding and recognition task during fMRI. MJ use was ascertained for 3 months prior to scanning; 27 individuals reported past 3-month MJ use, and 33 individuals did not. fMRI response was modeled during encoding based on whether targets were subsequently recognized (correct encoding), and during recognition based on target identification (hits). fMRI response in left and right inferior frontal gyrus (IFG) and hippocampal regions of interest was examined between MJ users and controls. There were no group differences between MJ users and controls on fMRI response during encoding, although single sample t-tests revealed that MJ users failed to activate the hippocampus. During recognition, MJ users showed less fMRI response than controls in right hippocampus (Cohen's d = 0.55), left hippocampus (Cohen's d = 0.67) and left IFG (Cohen's d = 0.61). Heavier MJ involvement was associated with lower fMRI response in left hippocampus and left IFG. This study provides evidence of MJ-related prefrontal and hippocampal dysfunction during recognition memory in college students. These findings may contribute to our previously identified decrements in academic performance in college MJ users and could have substantial implications for academic and occupational functioning.

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.

Longitudinal Effects of Alcohol Consumption on the Hippocampus and Parahippocampus in College Students

BACKGROUND

The hazardous effects of alcohol consumption on both the hippocampus and memory have been well established. However, the longitudinal effects of ethanol on the developing brain and related consequences on memory are not well explored. Given the above, we investigated the longitudinal effects of college drinking on hippocampal volume in emerging college adults.

METHODS

Data were derived from the longitudinal Brain and Alcohol Research with College Students study. A subset of 146 freshmen (mean age at baseline = 18.5 years) underwent brain magnetic resonance imaging scans at baseline and 24 months later. Four drinking-related measures derived from monthly surveys were reduced to a single alcohol use index using principal component analysis. Gray matter volumetric change (GMV-c) data were derived using a longitudinal pipeline. Voxelwise hippocampal/para-hippocampal GMV-c associations with the drinking index were derived using a multiple regression framework within SPM12. Supplementary associations were assessed between GMV-c and memory scores computed from the California Verbal Learning Test-II (assessed at the end of the study), and between GMV-c and total alcohol-induced memory blackouts.

RESULTS

Larger alcohol use index was associated with an accelerated GMV decline in the hippocampus/para-hippocampus. Also, larger hippocampal volume decline was associated with poorer memory performance and more memory blackouts.

CONCLUSIONS

Our study extends prior cross-sectional literature by showing that a heavier drinking burden while in college is associated with greater hippocampal GMV decline that is in turn associated with poorer memory scores, all of which could ultimately have a significant impact on student success.

The neural correlates of the unified percept of alcohol-related craving: a fMRI and EEG study

Alcohol addiction is accompanied by aberrant neural activity. Previously, task-based fMRI and resting-state EEG studies have revealed that craving, a critical component of addiction, is linked to abnormal activity in cortical regions including the dorsal anterior cingulate cortex (dACC), nucleus accumbens (NAcc), posterior cingulate cortex (PCC) and pregenual anterior cingulate cortex (pgACC), etc. In this study, we combine these two imaging techniques to investigate a group of alcohol-addicted patients and provide convergent evidence for the neural correlates of craving not only in alcohol but substance abuse in general. We observe abnormal BOLD signal levels in the dACC, NAcc, pgACC, PCC, amygdala, and parahippocampus (PHC) in a cue-reactivity fMRI experiment. These findings are consistent with increased beta-band activity in the dACC and pgACC in resting-state EEG. We further observe desynchronization characterized by decreased functional connectivity in cue-based fMRI and hypersynchronization characterized by increased functional connectivity between these regions in the theta frequency band. The results of our study show a consistent pattern of alcohol craving elicited by external cues and internal desires. Given the advantage of superior spatial and temporal resolution, we hypothesize a "central craving network" that integrates the different aspects of alcohol addiction into a unified percept.

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.

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.

Attentional blink to alcohol cues in binge drinkers versus non-binge drinkers

Previous studies have shown alcohol-related attentional biases in social drinkers; however, the temporal dynamics of these biases are not well understood. The current study examined this issue in 94 participants (27 male) categorized as binge drinkers (BD) or non-binge drinkers (NBD). Two versions of an alcohol-related attentional blink (AB) paradigm were used: one with words and one with images. It was predicted that BDs (versus NBDs) would exhibit reduced AB for alcohol cues, which would be enhanced for the pictorial version of the task (versus words). The relationships between AB and alcohol craving, quantity and frequency of alcohol consumption, symptoms of alcohol use disorder, and family history of alcohol use disorder (AUD) were also examined. While an AB was observed for both alcohol and non-alcohol targets in the NBD group, no AB was found for alcohol targets in the BD group. Furthermore, the magnitude of the AB was related to drinking, such that higher self-reported hazardous drinking was associated with smaller ABs to alcohol-related targets. However, AB was not related to craving or family history of AUD. These results suggest that alcohol-related stimuli are processed more efficiently by BDs, especially those with hazardous alcohol consumption patterns. These results may inform treatment and prevention efforts targeting binge drinkers.

Structural deficits in salience network regions are associated with increased impulsivity and compulsivity in alcohol dependence

BACKGROUND

Convergent preclinical and clinical evidence has linked the anterior insula to impulsivity and alcohol-associated compulsivity. The anterior insula is functionally connected to the anterior cingulate cortex, together comprising the major nodes of the salience network, which serves to signal salient events, including negative consequences. Clinical studies have found structural and functional alterations in the anterior insula and anterior cingulate cortices of alcohol dependent individuals. No studies have yet investigated the association between morphometric abnormalities in salience network regions and the phenotype of high levels of impulsivity and compulsivity seen in alcohol dependent individuals.

METHODS

In the current study, we compared self-report impulsivity, decisional impulsivity, self-report compulsivity, and structural neuroimaging measures in a sample of alcohol dependent individuals (n=60) and a comparison group of healthy controls (n=49). From the structural magnetic resonance images, we calculated volume and cortical thickness for 6 regions of interest: left and right anterior insula, posterior insula, and anterior cingulate.

RESULTS

We found that alcohol dependent individuals had smaller anterior insula and anterior cingulate volumes, as well as thinner anterior insula cortices. There were no group differences in posterior insula morphometry. Anterior insula and anterior cingulate structural measures were negatively associated with self-report impulsivity, decisional impulsivity, and compulsivity measures.

CONCLUSIONS

Our results suggest that addiction endophenotypes are associated with salience network morphometry in alcohol addiction. These relationships indicate that salience network hubs represent potential treatment targets for impulse control disorders, including alcohol addiction.