Tackling addictive behaviors through memory suppression: A scoping review and perspective.

Forgetting is often viewed as a human frailty. However, over the years, it has been considered an adaptive process that allows people to avoid retrieval of undesirable memories, preventing them from suffering and discomfort. Evidence shows that the ability to suppress memories is affected by several psychopathological conditions characterized by persistent unwanted thoughts, including anxiety and posttraumatic stress disorders. Nevertheless, memory suppression (MS) mechanisms in addiction-a clinical condition characterized by recurrent drug-related thoughts that contribute to repeated drug use-have received little attention so far. Addiction theories reveal that drugs change behavior by working on memory systems, particularly on declarative memory, which is related to the retrieval and encoding of drug-related memories. In this review, the main behavioral and neurofunctional findings concerning the Think/No-Think task-an adaptation of the classical Go/No-Go tasks typically used to evaluate the suppression of motor response-are presented. We then show how the memory system can be involved in the craving or anticipation/preoccupation stage of the addiction cycle. Subsequently, the study of MS in the context of addictive behaviors is highlighted as a promising approach for gaining knowledge about the mechanisms contributing to the continuation of addiction. Finally, we discuss how interventions aiming to strengthen this ability could impact the anticipation/preoccupation stage by (i) reducing the accessibility of drug-related memories, (ii) decreasing craving and attention toward drug-related stimuli, and (iii) improving overall inhibition abilities. In conclusion, this review aims to illustrate how the study of MS may be a valuable approach to enhance our understanding of substance use disorders by unveiling the underlying cognitive and neural mechanisms involved, which could have important implications for addiction treatment.

Trying to forget alcohol: Brain mechanisms underlying memory suppression in young binge drinkers.

People are able to voluntarily suppress unwanted thoughts or memories, a phenomenon known as suppression-induced forgetting or memory suppression. Despite harmful alcohol use, such as binge drinking, has been linked to impaired inhibitory control (IC) and augmented alcohol-cue reactivity, no study to date has assessed memory inhibition abilities towards alcohol-related cues in binge drinkers (BDs). Thus, the present preregistered study aimed to evaluate the behavioral and neurofunctional mechanisms associated with memory inhibition, specifically those related to the suppression of alcohol-related memories, in young BDs. For this purpose, electroencephalographic activity was recorded in eighty-two college students aged between 18 and 24 years old from the University of Minho (50% females; 40 non/low-drinkers [N/LDS] and 42 BDs) while they performed the Think/No-Think Alcohol task. Brain functional connectivity (FC) was calculated using the phase locking value and, subsequently, a dynamic seed-based analysis was conducted to explore the FC patterns between IC and memory networks. Comparatively to N/LDs, BDs exhibited decreased alpha-band FC between the anterior cingulate cortex and the left fusiform gyrus during attempts to suppress non-alcohol memories, accompanied by unsuccessful forgetting of those memories. Conversely, BDs displayed augmented gamma-band FC between the IC network and memory regions -i.e., hippocampus, parahippocampus and fusiform gyrus- during suppression of alcohol-related memories. Inhibitory abnormalities in BDs may lead to hypoconnectivity between IC and memory networks and deficient suppression of non-alcohol-related memories. However, while suppressing highly salient and reward-predicting stimuli, such as alcohol-related memories, BDs display a hyperconnectivity pattern between IC and memory networks, likely due to their augmented attention towards intrusive alcoholic memories and the attempts to compensate for potential underlying IC deficits. These findings hold important implications for alcohol research and treatment, as they open up new avenues for reducing alcohol use by shifting the focus to empowering suppression/control over alcohol-related memories. CLINICAL TRIAL REGISTRATION: [http://www.ClinicalTrials.gov], identifier [NCT05237414].

Neurocognitive effects of binge drinking on verbal episodic memory. An ERP study in university students.

Background: Verbal memory may be affected by engagement in alcohol binge drinking during youth, according to the findings of neuropsychological studies. However, little is known about the dynamics of the neural activity underlying this cognitive process in young, heavy drinkers. Aims: To investigate brain event-related potentials associated with cued recall from episodic memory in binge drinkers and controls. Methods: Seventy first-year university students were classified as binge drinkers (32: 17 female) or controls (38: 18 female). The participants completed a verbal paired associates learning task during electroencephalogram (EEG) recording. ERPs elicited by old and new word pairs were extracted from the cued-recall phase of the task by using Principal Component Analysis. Subjects also performed a standardized neuropsychological verbal learning test. Results: Two of the three event-related potentials components indicating old/new memory effects provided evidence for anomalies associated with binge drinking. The old/new effects were absent in the binge drinkers in the two subsequent posterior components, identified with the late parietal component and the late posterior negativity The late frontal component revealed similar old/new effects in both groups. Binge drinkers showed similar behavioural performance to controls in the verbal paired associates task, but performed poorly in the more demanding short-term cued-recall trial of a neuropsychological standardized test. Conclusion: Event-related potentials elicited during a verbal cued-recall task revealed differences in brain functioning between young binge drinkers and controls that may underlie emergent deficits in episodic memory linked to alcohol abuse. The brain activity of binge drinkers suggests alterations in the hippocampal - posterior parietal cortex circuitry subserving recognition and recollection of the cue context and generation of the solution, in relation to verbal information shallowly memorised.

Corrigendum: Neurocognitive effects of binge drinking on verbal episodic memory. An ERP study in university students.

[This corrects the article DOI: 10.3389/fphar.2023.1034248.].

Forgetting Alcohol: A Double-Blind, Randomized Controlled Trial Investigating Memory Inhibition Training in Young Binge Drinkers.

Background: Binge Drinking (BD) has been associated with altered inhibitory control and augmented alcohol-cue reactivity. Memory inhibition (MI), the ability to voluntarily suppress unwanted thoughts/memories, may lead to forgetting of memories in several psychiatric conditions. However, despite its potential clinical implications, no study to date has explored the MI abilities in populations with substance misuse, such as binge drinkers (BDs). Method: This study-registered in the NIH Clinical Trials Database (ClinicalTrials.gov identifier: NCT05237414)-aims firstly to examine the behavioral and electroencephalographic (EEG) correlates of MI among college BDs. For this purpose, 45 BDs and 45 age-matched non/low-drinkers (50% female) will be assessed by EEG while performing the Think/No-Think Alcohol task, a paradigm that evaluates alcohol-related MI. Additionally, this work aims to evaluate an alcohol-specific MI intervention protocol using cognitive training (CT) and transcranial direct current stimulation (tDCS) while its effects on behavioral and EEG outcomes are assessed. BDs will be randomly assigned to one MI training group: combined [CT and verum tDCS applied over the right dorsolateral prefrontal cortex (DLPFC)], cognitive (CT and sham tDCS), or control (sham CT and sham tDCS). Training will occur in three consecutive days, in three sessions. MI will be re-assessed in BDs through a post-training EEG assessment. Alcohol use and craving will be measured at the first EEG assessment, and both 10-days and 3-months post-training. In addition, behavioral and EEG data will be collected during the performance of an alcohol cue reactivity (ACR) task, which evaluates attentional bias toward alcoholic stimuli, before, and after the MI training sessions. Discussion: This study protocol will provide the first behavioral and neurofunctional MI assessment in BDs. Along with poor MI abilities, BDs are expected to show alterations in event-related potentials and functional connectivity patterns associated with MI. Results should also demonstrate the effectiveness of the protocol, with BDs exhibiting an improved capacity to suppress alcohol-related memories after both combined and cognitive training, along with a reduction in alcohol use and craving in the short/medium-term. Collectively, these findings might have major implications for the understanding and treatment of alcohol misuse. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT05237414].

On the syllable structure effect in European Portuguese: Evidence from ERPs.

Syllable effects during visual word recognition have been observed for CV but not for CVC syllables, a puzzling effect that is not explained either by the distributional frequencies of CV and CVC syllables, syllable complexity, or syllabic neighbourhood density. Furthermore, in European Portuguese (EP), syllable effects have not been found for pseudowords, suggesting that syllable activation might not precede lexical activation. Here, we combined a colour-congruency lexical decision task with the collection of electroencephalographic (EEG) data to investigate syllable effects in EP for CV and CVC words and pseudowords, with the latter presenting a match (CVCO+P+) or a mismatch (CVCO+P-) between their orthographic (O) and phonological (P) syllable structure to further ascertain the locus (i.e., orthographic and/or phonological) of syllable effects. Results showed syllable congruency effects in the N100, P200, and N400 ERP components for CV and CVC words suggesting the influence of different factors underlying the syllable structure effect.

"It's a beer!": Brain functional hyperconnectivity during processing of alcohol-related images in young binge drinkers.

Alcohol attentional bias has been pointed as a major marker of alcohol misuse. Recent evidence has revealed that brain functional connectivity (FC) may be a valuable index of the brain networks' integrity in young binge drinkers (BDs). However, there is no study to date examining the FC networks linked to the processing of alcohol-related images in this population. The present study aimed to explore the FC signatures underlying alcohol attention bias in young BDs. Thus, electroencephalographic (EEG) activity was recorded in 54 college students (55.5% females; 27 non/low-drinkers and 27 BDs) while performing a visual alcohol cue-reactivity task. We evaluated whole-brain FC profiles during the processing of alcoholic and non-alcoholic cues, as well as their potential relationship with craving and severity of alcohol use. Results showed that, at the behavioural level, BDs rated alcohol-related images as more pleasant/attractive than non/low-drinkers. Furthermore, at the electrophysiological level, BDs exhibited increased beta-band FC-particularly in the fronto-parieto-occipital network-when processing alcoholic cues. Conversely, they displayed reduced theta-band FC relatively to non/low-drinkers for non-alcoholic images. These hyper-/hypo-connectivity patterns were associated with higher alcohol craving levels. Findings are congruent with previous neurofunctional studies reporting an attentional bias towards alcohol-related information in BDs. These results may have important clinical implications as this neural reactivity to alcoholic cues may contribute to the maintenance and/or escalation of the drinking pattern. Finally, the present study constitutes the first evidence showing that FC networks may be a sensitive indicator to alcohol attentional bias in BDs.

Effects of the COVID-19 Mitigation Measures on Alcohol Consumption and Binge Drinking in College Students: A Longitudinal Survey.

To "flatten the curve" of COVID-19 contagion, several countries ordered lockdowns amid the pandemic along with indications on social distancing. These social isolation measures could potentially bring alterations to healthy behavior, including to alcohol consumption. However, there is hardly any scientific evidence of the impact of such measures on alcohol consumption and binge drinking (BD) among young adults, and how they relate to alcohol craving, stress, anxiety, and depression levels. We addressed these questions by conducting a longitudinal study with 146 Portuguese college students-regular binge drinkers (regular BDs), infrequent binge drinkers (infrequent BDs) and non-binge drinkers (non-BDs)-in three moments: before the pandemic (Pre-Lockdown), during lockdown (Lockdown) and 6 months after (Post-Lockdown). Results revealed that regular BDs decreased alcohol use during Lockdown, a change in behavior that was even greater during Post-Lockdown, when regular BDs displayed similar levels of consumption to infrequent/non-BDs. Additionally, alcohol craving and living with friends were predictive of alcohol use during Lockdown, whereas stress, anxiety, and depression symptoms did not contribute to explain changes in drinking behavior. Collectively, the results suggest that BD in young Portuguese college students can be stopped when the contexts in which alcohol intake usually takes place are suppressed, which may have important implications for future prevention and intervention strategies.

Portuguese validation of the Alcohol Craving Questionnaire-Short Form-Revised.

Alcohol craving has been described as a strong subjective desire to drink, being considered highly valuable in the clinical practice, as it is recognized as a strong predictor of alcohol relapse in alcohol-dependent individuals. However, to date, there is not a multifactorial questionnaire available for assessing short-term acute craving experience in Portugal. The aim of the present study was to validate a swift and efficient tool for the assessment of acute alcohol craving in a sample of Portuguese citizens. For that purpose, the Alcohol Craving Questionnaire-Short Form-Revised (ACQ-SF-R) was translated into European Portuguese and administered to a sample of 591 college participants with ages between 18 and 30 years. Results suggested that a three-factor model (i.e., Emotionality, Purposefulness, and Compulsivity) proved to be most suitable for the Portuguese sample. Overall, the ACQ-SF-R exhibited good psychometric properties, having a good internal consistency both for the general craving index (Cronbach's α = 0.85) and each subscale (Cronbach's α = 0.66-0.83), as well as an appropriate convergent validity with the Penn Alcohol Craving Scale (r = 0.65, p<0.001), suggesting a good construct validity. In addition, the ACQ-SF-R also showed a good concurrent validity with the Alcohol Use Disorders Identification Test (r = 0.57, p<0.001), indicating that risky alcohol use patterns are associated with increased craving scores in the ACQ-SF-R. Collectively, these findings suggest that the Portuguese version of the ACQ-SF-R can accurately measure alcohol craving at a multifactorial level, being a valid and reliable tool to use in Portuguese samples in research settings.

Emotional processes in binge drinking: A systematic review and perspective.

Binge drinking is a widespread alcohol consumption pattern commonly engaged by youth. Here, we present the first systematic review of emotional processes in relation to binge drinking. Capitalizing on a theoretical model describing three emotional processing steps (emotional appraisal/identification, emotional response, emotional regulation) and following PRISMA guidelines, we considered all identified human studies exploring emotional abilities among binge drinkers. A literature search was conducted in PubMed, Scopus, and PsychINFO, and a standardized methodological quality assessment was performed for each study. The main findings offered by the 43 studies included are: 1) regarding emotional appraisal/identification, binge drinking is related to heightened negative emotional states, including greater severity of depressive and anxiety symptoms, and have difficulties in recognizing emotional cues expressed by others; 2) regarding emotional response, binge drinkers exhibit diminished emotional response compared with non-binge drinkers; 3) regarding emotional regulation, no experimental data currently support impaired emotion regulation in binge drinking. Variability in the identification and measurement of binge drinking habits across studies limits conclusions. Nevertheless, current findings establish the relevance of emotional processes in binge drinking and set the stage for new research perspectives to identify the nature and extent of emotional impairments in the onset and maintenance of excessive alcohol use.

Electroencephalographic signatures of the binge drinking pattern during adolescence and young adulthood: A PRISMA-driven systematic review.

Research on neurophysiological impairments associated with binge drinking (BD), an excessive but episodic alcohol use pattern, has significantly increased over the last decade. This work is the first to systematically review -following PRISMA guidelines- the empirical evidence regarding the effects of BD on neural activity -assessed by electroencephalography- of adolescents and young adults. A systematic review was conducted in 34 studies (N = 1723). Results indicated that binge drinkers (BDs) showed similar behavioral performance as non/low drinkers. The most solid electrophysiological finding was an augmented P3 amplitude during attention, working memory and inhibition tasks. This increased neural activity suggests the recruitment of additional resources to perform the task at adequate/successful levels, which supports the neurocompensation hypothesis. Similar to alcoholics, BDs also displayed increased reactivity to alcohol-related cues, augmented resting-state electrophysiological signal and reduced activity during error detection -which gives support to the continuum hypothesis. Evidence does not seem to support greater vulnerability to BD in females. Replication and longitudinal studies are required to account for mixed results and to elucidate the extent/direction of the neural impairments associated with BD.

A biological framework for emotional dysregulation in alcohol misuse: from gut to brain.

Alcohol use disorder (AUD) has been associated with impairments in social and emotional cognition that play a crucial role in the development and maintenance of addiction. Repeated alcohol intoxications trigger inflammatory processes and sensitise the immune system. In addition, emerging data point to perturbations in the gut microbiome as a key regulator of the inflammatory cascade in AUD. Inflammation and social cognition are potent modulators of one another. At the same time, accumulating evidence implicates the gut microbiome in shaping emotional and social cognition, suggesting the possibility of a common underlying loop of crucial importance for addiction. Here we propose an integrative microbiome neuro-immuno-affective framework of how emotional dysregulation and alcohol-related microbiome dysbiosis could accelerate the cycle of addiction. We outline the overlapping effects of chronic alcohol use, inflammation and microbiome alterations on the fronto-limbic circuitry as a convergence hub for emotional dysregulation. We discuss the interdependent relationship of social cognition, immunity and the microbiome in relation to alcohol misuse- from binge drinking to addiction. In addition, we emphasise adolescence as a sensitive period for the confluence of alcohol harmful effects and emotional dysregulation in the developing gut-brain axis.

Special Report on the Impact of the COVID-19 Pandemic on Clinical EEG and Research and Consensus Recommendations for the Safe Use of EEG.

INTRODUCTION: The global COVID-19 pandemic has affected the economy, daily life, and mental/physical health. The latter includes the use of electroencephalography (EEG) in clinical practice and research. We report a survey of the impact of COVID-19 on the use of clinical EEG in practice and research in several countries, and the recommendations of an international panel of experts for the safe application of EEG during and after this pandemic. METHODS: Fifteen clinicians from 8 different countries and 25 researchers from 13 different countries reported the impact of COVID-19 on their EEG activities, the procedures implemented in response to the COVID-19 pandemic, and precautions planned or already implemented during the reopening of EEG activities. RESULTS: Of the 15 clinical centers responding, 11 reported a total stoppage of all EEG activities, while 4 reduced the number of tests per day. In research settings, all 25 laboratories reported a complete stoppage of activity, with 7 laboratories reopening to some extent since initial closure. In both settings, recommended precautions for restarting or continuing EEG recording included strict hygienic rules, social distance, and assessment for infection symptoms among staff and patients/participants. CONCLUSIONS: The COVID-19 pandemic interfered with the use of EEG recordings in clinical practice and even more in clinical research. We suggest updated best practices to allow safe EEG recordings in both research and clinical settings. The continued use of EEG is important in those with psychiatric diseases, particularly in times of social alarm such as the COVID-19 pandemic.

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.

Is (poly-) substance use associated with impaired inhibitory control? A mega-analysis controlling for confounders.

Many studies have reported that heavy substance use is associated with impaired response inhibition. Studies typically focused on associations with a single substance, while polysubstance use is common. Further, most studies compared heavy users with light/non-users, though substance use occurs along a continuum. The current mega-analysis accounted for these issues by aggregating individual data from 43 studies (3610 adult participants) that used the Go/No-Go (GNG) or Stop-signal task (SST) to assess inhibition among mostly "recreational" substance users (i.e., the rate of substance use disorders was low). Main and interaction effects of substance use, demographics, and task-characteristics were entered in a linear mixed model. Contrary to many studies and reviews in the field, we found that only lifetime cannabis use was associated with impaired response inhibition in the SST. An interaction effect was also observed: the relationship between tobacco use and response inhibition (in the SST) differed between cannabis users and non-users, with a negative association between tobacco use and inhibition in the cannabis non-users. In addition, participants' age, education level, and some task characteristics influenced inhibition outcomes. Overall, we found limited support for impaired inhibition among substance users when controlling for demographics and task-characteristics.

Increased Nucleus Accumbens Volume in College Binge Drinkers - Preliminary Evidence From Manually Segmented MRI Analysis.

INTRODUCTION: Binge drinking (BD) is characterized by high alcohol intake in a short time followed by periods of withdrawal. This pattern is very common during adolescence and early adulthood, a developmental stage marked by the maturation of the fronto-striatal networks. The basal ganglia, specifically the nucleus accumbens (NAcc) and the caudate nucleus (CN), are part of the fronto-striatal limbic circuit involved in reward processes underlying addictive behaviors. Abnormal NAcc and CN morphometry has been noted in alcoholics and other drug abusers, however the effects of BD on these subcortical regions have been poorly explored. Accordingly, the main goal of the present study was to address potential morphological alterations in the NAcc and CN in a sample of college binge drinkers (BDs). METHOD: Manual segmentation of the NAcc and the CN was performed in Magnetic Resonance Imaging (MRI) of 20 college BDs and 16 age-matched alcohol abstainers (18-23 years-old). RESULTS: A two-way mixed ANOVA revealed no group differences in the volumetry of the CN, whereas increased NAcc volume was observed in the BD group when compared to their abstinent control peers. DISCUSSION: These findings are in line with previous automatically segmented MRI reports highlighting abnormalities in a key region involved in drug rewarding processes in BDs.

The Think/No-Think Alcohol Task: A New Paradigm for Assessing Memory Suppression in Alcohol-Related Contexts.

BACKGROUND: Research with the Think/No-Think (TNT) task has shown that voluntary suppression of an unwanted memory may lead to its later forgetting. To date, however, no study has assessed the memory suppression abilities in alcohol-related contexts despite the potential implications that it might have for alcohol research. With this aim, we developed a new version of the TNT paradigm, the TNT Alcohol (TNTA) task, which consists of 36 neutral pictures paired with 36 alcohol/no-alcohol images that are instructed to be suppressed or recollected. METHODS: Electroencephalographic activity was recorded from 64 electrodes while 20 young healthy females performed the TNTA task. The event-related potentials (ERPs) typically involved in memory suppression/recollection were analyzed, namely the fronto-central N2, the late parietal positivity (LPP), and the frontal slow wave (FSW). RESULTS: Findings revealed reduced recall for previously learned images that were subsequently instructed to be suppressed (No-Think) relative to those instructed to be retrieved (Think) and those not cued to be suppressed or retrieved (Baseline). This reduction seemed to be more prominent for alcohol-related memories. In addition, ERP analysis showed that compared to attempts of recollection, attempts of memory suppression were associated with attenuated LPP amplitude-more pronounced for alcohol-related memories-(indicating reduced conscious recollection for No-Think images) as well as with increased FSW (suggesting strategic control aiming at decrease accessibility of unwanted memories). CONCLUSIONS: These results replicate and extend previously reported behavioral and ERP findings in the TNT paradigm and suggest that the TNTA task may be a useful instrument to measure the ability to suppress alcohol-related memories.

Trends in alcohol use among young people according to the pattern of consumption on starting university: A 9-year follow-up study.

AIM: To identify differences in Risky Consumption (RC) and Binge drinking (BD) trends in students who already followed these patterns of alcohol consumption on starting university and those who did not, and also to try to understand what leads students to engage in these types of behaviour at university. MATERIAL AND METHODS: Cohort study among university students in Spain (n = 1382). BD and RC were measured with the Alcohol Use Disorders Identification Test at ages 18, 20, 22, 24 and 27 years. Multilevel logistic regression for repeated measures was used to calculate the adjusted Odds Ratios (ORs). RESULTS: The prevalence rates of RC and BD were lower throughout the study in students who did not follow these patterns of consumption at age 18. For RC and BD, the differences at age 27 years, expressed as percentage points (pp), were respectively 24 pp and 15 pp in women and 29 pp and 25 pp in men. Early age of onset of alcohol use increased the risk of engaging in RC and BD patterns at university, for men (OR = 2.91 & 2.80) and women (OR = 8.14 & 5.53). The same was observed in students living away from the parental home for BD (OR = 3.43 for men & 1.77 for women). Only women were influenced by having positive expectancies for engaging in RC (OR = 1.82) and BD (OR = 1.96). CONCLUSIONS: The prevalence rates of both RC and BD at age 27 years were much higher among university students who already followed these patterns of consumption at age 18 years, with the differences being proportionally higher among women. Focusing on the age of onset of alcohol consumption and hindering access to alcohol by minors should be priority objectives aimed at preventing students from engaging in these patterns of alcohol consumption at university.