Profiles of impaired, spared, and recovered neuropsychologic processes in alcoholism

Predictive factors of cognitive impairment in alcohol use disorder inpatients

BACKGROUND

Cognitive impairments are common in patients with AUD and worsen the prognosis of addiction management. There are no clear guidelines for screening cognitive impairments in hospitalized patients with AUD.

METHODS

Fifty-seven patients with an AUD history who were admitted to an acute hospital and assessed by the addiction care team were included. Those patients were screened for cognitive impairments using the Montreal Cognitive Assessment (MoCA) test. We collected clinical information regarding addiction history, comorbidities, and current treatments. Chi-square tests, t-tests, and Mann-Whitney tests were performed to determine factors associated with a pathological MoCA score (<26).

RESULTS

A pathological MoCA score was positively associated with spatial-temporal disorientation, difficulty in recalling addiction history, patient underreporting of AUD and a date of last alcohol consumption lower than 11 days ago, and negatively associated with a reason for hospitalization due to alcohol-related health issues. No medication was associated with cognitive impairments.

CONCLUSIONS

Clinical elements from assessment by the addiction care team allow for relevant indication for screening cognitive impairments.

Cognitive Alterations Associated with Remission and Alcohol Dependence Severity in Ethnically Diverse Patients of Siberia

Background

Impaired cognition in individuals with alcohol dependence may be associated with increased relapse risk. It has been recorded in more than half of patients during six months after treatment. In certain ethnic groups, for example, Tuvinians, the indigenous people of Siberia, relapses occur in extremely short periods of one to three months after treatment. An approach currently used to alcohol dependence treatment may be less effective for these patients.

Objective

The study aimed to investigate cognitive sequelae in indigenous Tuvinian patients with alcohol dependence.

Methods

The sample included 166 patients, 74 of indigenous ethnicity (Tuvinians) and 92 non-indigenous white patients. Data on inhibitory control, cognitive flexibility, attention, and working memory were collected from all the patients and processed using cluster analysis. The clustering data were then complemented by indicators of disorder dynamics, impulsivity, and emotion regulation.

Results

The clustering procedure revealed groups with severe cognitive sequelae. More than four-fold attention decrease was found in 43.5% of non-indigenous patients, and more impaired cognitive flexibility was revealed among 60.8% of indigenous patients. Groups with severe cognitive sequelae had higher impulsivity, maladaptive emotion regulation, more hospitalizations, faster disease progression, and shorter remissions. The latter was significantly reduced to 90 days on average in the severe group of indigenous patients versus 135 days of remission in the non-indigenous severe group.

Conclusion

Results obtained may advance tailored intervention in alcohol-dependent patients of the indigenous Tuvinian ethnicity. While little is still known about the alcohol dependence course and consequences in the indigenous Tuvinians of Siberia, this study contributes to the global mental health data on alcohol abuse and dependence in indigenous communities.

Fine-Grained Intoxicated Gait Classification Using a Bilinear CNN

Consuming excessive amounts of alcohol causes impaired mobility and judgment and driving accidents, resulting in more than 800 injuries and fatalities each day. Passive methods to detect intoxicated drivers beyond the safe driving limit can facilitate Just-In-Time alerts and reduce Driving Under the Influence (DUI) incidents. Popularly-owned smartphones are not only equipped with motion sensors (accelerometer and gyroscope) that can be employed for passively collecting gait (walk) data but also have the processing power to run computationally expensive machine learning models. In this paper, we advance the state-of-the-art by proposing a novel method that utilizes a Bi-linear Convolution Neural Network (BiCNN) for analyzing smartphone accelerometer and gyroscope data to determine whether a smartphone user is over the legal driving limit (0.08) from their gait. After segmenting the gait data into steps, we converted the smartphone motion sensor data to a Gramian Angular Field (GAF) image and then leveraged the BiCNN architecture for intoxication classification. Distinguishing GAF-encoded images of the gait of intoxicated vs. sober users is challenging as the differences between the classes (intoxicated vs. sober) are subtle, also known as a fine-grained image classification problem. The BiCNN neural network has previously produced state-of-the-art results on fine-grained image classification of natural images. To the best of our knowledge, our work is the first to innovatively utilize the BiCNN to classify GAF encoded images of smartphone gait data in order to detect intoxication. Prior work had explored using the BiCNN to classify natural images or explored other gait-related tasks but not intoxication Our complete intoxication classification pipeline consists of several important pre-processing steps carefully adapted to the BAC classification task, including step detection and segmentation, data normalization to account for inter-subject variability, data fusion, GAF image generation from time-series data, and a BiCNN classification model. In rigorous evaluation, our BiCNN model achieves an accuracy of 83.5%, outperforming the previous state-of-the-art and demonstrating the feasibility of our approach.

Anterior cingulate metabolite levels, memory, and inhibitory control in abstinent men and women with alcohol use disorder

Alcohol use disorder (AUD) has been shown to have harmful cognitive and physiological effects, including altered brain chemistry. Further, although men and women may differ in vulnerability to the neurobiological effects of AUD, the results of existing studies have been conflicting. We examined brain metabolite levels and cognitive functions in a cross-section of men with AUD (AUDm) and women with AUD (AUDw) to determine the degree of abnormalities after extended periods of abstinence (mean, 6 years) and to evaluate gender differences in neuropsychological and metabolite measures. Participants were 40 abstinent individuals with AUD (22 AUDw, 18 AUDm) and 50 age-equivalent non-AUD comparison participants (26 NCw, 24 NCm). Proton magnetic resonance spectroscopy (MRS) was employed at 3 Tesla to acquire metabolite spectra from the dorsal anterior cingulate cortex (dACC). Brain metabolites N-acetyl aspartate (NAA), choline (Cho), myo-Inositol (mI), and glutamate & glutamine (Glx) were examined relative to measures of memory and inhibitory control. Metabolite levels did not differ significantly between AUD and NC groups. Memory and inhibitory-control impairments were observed in the AUD group. There also were significant group-specific associations between metabolite ratios and measures of inhibitory control. There were no group-by-gender interactions for the four metabolite ratios. These findings demonstrate that brain metabolite levels in men and women with AUD, following long-term abstinence, do not differ from individuals without AUD. The data also provide preliminary evidence of sustained associations between metabolite levels and measures of inhibitory control, a functional domain important for curtailing harmful drinking.

Impaired Executive Functioning Associated with Alcohol-Related Neurocognitive Disorder including Korsakoff's Syndrome

(1) Background: chronic alcohol use is consistently associated with impaired executive functioning, but its profile across the spectrum from mild to major alcohol-related cognitive impairment is, to date, unclear. This study aims to compare executive performances of patients with alcohol-induced neurocognitive disorder, including Korsakoff's syndrome (KS), by using a computerized assessment battery allowing a fine-grained and precise neuropsychological assessment; (2) Methods: performances of 22 patients with alcohol-related cognitive impairment (ARCI) and 20 patients with KS were compared to those of 22 matched non-alcoholic controls. All participants were diagnosed in accordance with DSM-5-TR criteria and were at least six weeks abstinent from alcohol prior to assessment. Executive function was evaluated using four subtests of Cambridge Neuropsychological Test Automated Battery (CANTAB®); (3) Results: significant differences between groups were found on spatial working memory (updating), sustained attention and inhibitory control, set shifting, and planning. Healthy controls performed significantly better than both patient groups (Games-Howell post hoc; p < 0.05), but no differences in performance were found between the ARCI and KS group; (4) Conclusions: ARCI and KS patients showed significant executive impairments, most prominent in updating, set-shifting and general planning abilities. Findings suggest equivalent levels of executive function in ARCI and KS patients. Our results highlight executive function as a significant hallmark of alcohol-induced neurocognitive disorder and stipulate the importance of early assessment and evaluation of skills to guide treatment.

Neurocognitive Recovery in Abstinent Patients with Alcohol Use Disorder: A Scoping Review for Associated Factors

Objective

Studies have reported inconsistent results regarding the extent to which neurocognitive recovery occurs in abstinent patients with alcohol use disorder (AUD). In addition to abstinence, other factors may have influenced this process and contributed to the inconsistencies. This review examines the factors investigated in this regard and describes the possible influence of each factor based on the evidence collected.

Methodology

PubMed was systematically searched for articles published between January 2000 and July 2023. Longitudinal humane studies investigating neurocognitive recovery in abstinent adult AUD patients were included. Studies with a cross-sectional design were excluded, as were studies that did not classify AUD according to the DSM-IV or 5 criteria, only examined binge use, did not report neuropsychological outcomes or duration of abstinence, or where neurological disorders were present.

Results

Sixteen categories of factors were distinguished from 31 full-text articles. Consistent patterns were found, indicating an association between neurocognitive recovery and the "smoking" and 'brain volume" factors. Consistent patterns were also found indicating that there is no relationship with "quantities of alcohol used" and "education level." A similar consistent pattern was also found for "polysubstance use", "gender" and "verbal reading", but the number of studies is considered limited. The association with "age" is studied frequently but with inconsistent findings. The remaining eight factors were regarded as understudied.

Conclusion

The clearest patterns emerging from the evidence are a predominantly negative influence of smoking on neurocognitive recovery, associations between changes in brain area volume and neurocognitive recovery, and no association between neurocognitive recovery and the amount of alcohol consumed, as measured by self-report, nor with educational attainment. Future research on the understudied factors and factors with inconsistent evidence is needed, preferably through longitudinal designs with multiple assessment periods starting after at least two weeks of abstinence.

WOMEN'S USE OF ALCOHOL: NEUROBIOBEHAVIORAL CONCOMITANTS AND CONSEQUENCES

In this narrative review, we draw from historical and contemporary literature to explore the impact of alcohol consumption on brain and behavior among women. We examine three domains: 1) the impact of alcohol use disorder (AUD) on neurobiobehavioral outcomes, 2) its impact on social cognition/emotion processing, and 3) alcohol's acute effects in older women. There is compelling evidence of alcohol-related compromise in neuropsychological function, neural activation, and brain structure. Investigations of social cognition and alcohol effects in older women represent emerging areas of study. Initial analyses suggest that women with AUD show significant deficits in emotion processing, a finding also observed in older women who have consumed a moderate dose of alcohol. Critically, despite the long-recognized need for programmatic interrogation of alcohol's effect in women, studies with sufficient numbers of women for meaningful analysis represent a small proportion of the literature, constraining interpretation and generalization.

Predicting Alcohol-Related Memory Problems in Older Adults: A Machine Learning Study with Multi-Domain Features

Memory problems are common among older adults with a history of alcohol use disorder (AUD). Employing a machine learning framework, the current study investigates the use of multi-domain features to classify individuals with and without alcohol-induced memory problems. A group of 94 individuals (ages 50-81 years) with alcohol-induced memory problems (the memory group) were compared with a matched control group who did not have memory problems. The random forests model identified specific features from each domain that contributed to the classification of the memory group vs. the control group (AUC = 88.29%). Specifically, individuals from the memory group manifested a predominant pattern of hyperconnectivity across the default mode network regions except for some connections involving the anterior cingulate cortex, which were predominantly hypoconnected. Other significant contributing features were: (i) polygenic risk scores for AUD, (ii) alcohol consumption and related health consequences during the past five years, such as health problems, past negative experiences, withdrawal symptoms, and the largest number of drinks in a day during the past twelve months, and (iii) elevated neuroticism and increased harm avoidance, and fewer positive "uplift" life events. At the neural systems level, hyperconnectivity across the default mode network regions, including the connections across the hippocampal hub regions, in individuals with memory problems may indicate dysregulation in neural information processing. Overall, the study outlines the importance of utilizing multidomain features, consisting of resting-state brain connectivity data collected ~18 years ago, together with personality, life experiences, polygenic risk, and alcohol consumption and related consequences, to predict the alcohol-related memory problems that arise in later life.

Age as a potential modulator of alcohol-related deficits

Although their individual significance is well-documented, the interaction effects of age, sex, and alcohol use disorder (AUD) have undergone little systematic investigation. Here, we extend prior work interrogating sex and group (AUD vs. community comparison [CC]) by probing the main and interaction effects of age on emotion processes as well as two conventional neuropsychological tests. Main effects for age and group were anticipated; however, interaction effects comprise our primary focus. While sex differences in AUD prevalence are commonly reported, sex differences within AUD samples are inconsistently found. Therefore, we pose our inquiry regarding sex as exploratory. In this study, 54 CC (n = 30 women) and 55 AUD (n = 14 women) subjects completed a battery that included an emotional face discrimination task, the Trail-Making Test-B (TMT-B), and the Digit Symbol Substitution Test (DSST). The initial/full models included the main and interaction effects of age (as a continuous variable; 25-59 years of age), sex, and group (AUD, CC). In analysis of the emotional face discrimination task, performance on a non-affective face discrimination task was entered as a covariate. Analysis of emotion identification revealed group and age main (p = .02; d = .53 & .003; d = .50, respectively) and interaction effects (p = .05; d = .41). The latter suggested that age and emotion processing performance were positively correlated in the AUD group, but unrelated in the CC group. Notably, neither sex, main, nor interaction effects achieved significance. Using the full model, analysis of the TMT-B and DSST failed to show sex effects or reveal expected performance decrement in the AUD group. To clarify the latter, simple models including only group as well as correlations between age and performance by group for each task were conducted. These analyses demonstrated the expected AUD-related deficits and suggested differential relationships between age and neurocognitive performance as a function of both group and task. Outcomes across tasks emphasize the need to reframe aging effects, particularly in the context of AUD.

Alterations of theta power and synchrony during encoding in young adult binge drinkers: Subsequent memory effects associated with retrieval after 48 h and 6 months

Introduction

Young emerging adults commonly engage in binge drinking which is associated with a range of neurocognitive deficits, including memory impairments. However, evidence on neural oscillations mediating episodic memory in this population is lacking. To address this gap, we recorded theta oscillatory activity in young binge (BDs) and light drinkers (LDs) during memory encoding and analyzed it prospectively as a function of subsequent retrieval. Theta underlies successful encoding of novel items in memory through corticolimbic integration. Subsequent memory effects (SMEs) are reflected in stronger theta activity during encoding of the items that are later remembered compared to those that are later forgotten.

Methods

In the present study, 23 BDs (age: 23.3 ± 3.3) and 24 LDs (age: 23.4 ± 3.3) rated emotionally evocative images with negative, positive, and neutral themes during implicit encoding. They performed a recognition memory task on two follow-up occasions after a short (48 h), and long retention delay (6 months). Electroencephalography (EEG) signal was recorded during the encoding session and analyzed in time-frequency domain with Morlet wavelets in theta band (4-7 Hz). To evaluate SMEs, the event-related theta oscillations acquired during encoding were analyzed based on recognition outcomes after the two retention intervals.

Results

The BD and LD groups did not differ on recognition memory. However, BDs showed attenuated event-related theta power during encoding of images that were successfully retained after 6 months compared to LDs. In addition, theta synchronous activity between frontal and left posterior regions during encoding successfully predicted recognition of the images after both retention delays in LDs but not in BDs. These SMEs on theta power and synchrony correlated negatively with high-intensity drinking in the previous 6 months. No differences between men and women were observed for any analysis.

Discussion

It has been well established that long-range neural synchrony between cortical and limbic nodes underlies successful memory encoding and retention which, in turn, depends on neural excitation/inhibition (E/I) balance. Given that binge drinking is associated with E/I dysregulation, the observed SME deficiencies are consistent with other evidence of neural hyperexcitability in BDs, and may be indicative of increased risk of developing alcohol use disorders.

Meta-analysis of associations between empathy and alcohol use and problems in clinical and non-clinical samples

AIMS

To (1) measure the aggregated effect size of empathy deficits in individuals with alcohol use disorder (AUD) compared with healthy controls, (2) measure the aggregated effect sizes for associations between lower empathy and heavier alcohol consumption and more alcohol problems in non-clinical samples and (3) identify potential moderators on the variability of effect sizes across studies in these meta-analyses.

METHOD

PsycINFO, PubMed and Google Scholar were searched following a pre-registered International Prospective Register of Systematic Reviews (PROSPERO) protocol (CRD42021225392) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. We meta-analyzed (using random-effects models) mean differences in empathy between individuals with AUD compared with healthy controls and associations between empathy and alcohol consumption and alcohol problems in non-clinical samples. A total of 714 participants were included in the meta-analysis on clinical samples; 3955 were included in the meta-analyses on non-clinical samples.

RESULTS

Individuals with AUD reported significantly lower empathy than healthy controls [Hedges' g = -0.53, 95% confidence interval (CI) = -0.91, -0.16, k = 9, P < 0.01, Q = 40.09, I2  = 80.04]. Study quality [Q = 1.88, degrees of freedom (d.f.) = 1, P = 0.17] and gender (β = -0.006, Z = -0.60, P = 0.55) were not moderators. Increases in age corresponded to an increase in effect size (β = 0.095, Z = 3.34, P < 0.001). Individuals with AUD (versus healthy controls) had significantly lower cognitive (Hedges' g = -0.44, CI = -0.79, -0.10, P < 0.05), but not affective empathy (Hedges' g = -0.19, CI = -0.51, 0.14, P = 0.27), and the difference between these was significant (Z = 2.34, k = 6, P < 0.01). In non-clinical samples, individuals with lower (versus higher) empathy reported heavier alcohol consumption (r = -0.12, CI = -0.15, -0.09, k = 11, P < 0.001, Q = 9.68, I2  = 0.00) and more alcohol problems (r = -0.08, CI = -0.14, -0.01, k = 7, P = 0.021, Q = 6.55, I2  = 8.34). There was no significant heterogeneity across studies.

CONCLUSION

Individuals with alcohol use disorder appear to show deficits in empathy compared with healthy controls. Deficits are particularly pronounced for older individuals and for cognitive (versus affective) empathy. In non-clinical samples, lower empathy appears to be associated with heavier alcohol consumption and more alcohol problems.

Exploring Factors Associated With Mobile Phone Behaviors and Attitudes Toward Technology Among Adults With Alcohol Use Disorder and Implications for mHealth Interventions: Exploratory Study

BACKGROUND

Alcohol use disorder (AUD) is associated with severe chronic medical conditions and premature mortality. Expanding the reach or access to effective evidence-based treatments to help persons with AUD is a public health objective. Mobile phone or smartphone technology has the potential to increase the dissemination of clinical and behavioral interventions (mobile health interventions) that increase the initiation and maintenance of sobriety among individuals with AUD. Studies about how this group uses their mobile phone and their attitudes toward technology may have meaningful implications for participant engagement with these interventions.

OBJECTIVE

This exploratory study examined the potential relationships among demographic characteristics (race, gender, age, marital status, and income), substance use characteristics (frequency of alcohol and cannabis use), and clinical variables (anxiety and depression symptoms) with indicators of mobile phone use behaviors and attitudes toward technology.

METHODS

A sample of 71 adults with AUD (mean age 42.9, SD 10.9 years) engaged in an alcohol partial hospitalization program completed 4 subscales from the Media Technology Usage and Attitudes assessment: Smartphone Usage measures various mobile phone behaviors and activities, Positive Attitudes and Negative Attitudes measure attitudes toward technology, and the Technological Anxiety/Dependence measure assesses level of anxiety when individuals are separated from their phone and dependence on this device. Participants also provided demographic information and completed the Epidemiologic Studies Depression Scale (CES-D) and the Generalized Anxiety Disorder (GAD-7) scale. Lastly, participants reported their frequency of alcohol use over the past 3 months using the Drug Use Frequency Scale.

RESULTS

Results for the demographic factors showed a significant main effect for age, Smartphone Usage (P=.003; ηp2=0.14), and Positive Attitudes (P=.01; ηp2=0.07). Marital status (P=.03; ηp2=0.13) and income (P=.03; ηp2=0.14) were associated only with the Technological Anxiety and Dependence subscale. Moreover, a significant trend was found for alcohol use and the Technological Anxiety/Dependence subscale (P=.06; R2=0.02). Lastly, CES-D scores (P=.03; R2=0.08) and GAD symptoms (P=.004; R2=0.13) were significant predictors only of the Technological Anxiety/Dependence subscale.

CONCLUSIONS

Findings indicate differences in mobile phone use patterns and attitudes toward technology across demographic, substance use, and clinical measures among patients with AUD. These results may help inform the development of future mHealth interventions among this population.

Brain oscillatory functioning after long-term alcohol abstinence

The heterogeneity of the population with alcohol use disorder (AUD) sometimes makes the knowledge generated in areas such as neuroscience appear to be contradictory. One aspect that may help elucidate this apparent contradiction is controlling for certain variables that are not usually controlled, such as the abstinence time in people with AUD. This research aims to study the neuroelectrical oscillations in people with AUD with longer and shorter abstinence time in comparison with healthy individuals. We recruited twenty-nine individuals with AUD with abstinence time longer than fifteen days and shorter than six months (STA), twenty-six individuals with AUD with abstinence time longer than six months and shorter than thirteen months (LTA), and sixteen healthy individuals (HC). All participants underwent electroencephalographic recording in resting-state with eyes closed. The oscillatory activity obtained was analyzed to obtain the spectral power and phase synchronization level. Regarding the obtained spectral power results, these revealed that the STA group showed higher theta band power and lower alpha band power than the LTA and HC groups. The obtained results at the phase synchronization level also show two main results. On the one hand, the STA group showed lower alpha band phase synchronization than the LTA and HC groups. On the other hand, the HC group showed higher beta band phase synchronization than the STA and LTA groups. In conclusion, the obtained results reflect that abstinence maintenance for six or more months appears to produce an important oscillatory brain functioning normalization in people with AUD.

Visual abilities in Severe Alcohol Use Disorder: Preserved spatial but impaired temporal resolution

Visuospatial impairments have long been reported in Severe Alcohol Use Disorder but remain poorly understood, notably regarding the involvement of magnocellular (MC) and parvocellular (PC) pathways. This empirical gap hampers the understanding of the implications of these visual changes, especially since the MC and PC pathways are thought to sustain central bottom-up and top-down processes during cognitive processing. They thus influence our ability to efficiently monitor our environment and make the most effective decisions. To overcome this limitation, we measured PC-inferred spatial and MC-inferred temporal resolution in 35 individuals with SAUD and 30 healthy controls. We used Landolt circles displaying small apertures outside the sensitivity range of MC cells or flickering at a temporal frequency exceeding PC sensitivity. We found evidence of preserved PC spatial resolution combined with impaired MC temporal resolution in SAUD. We also measured how spatial and temporal sensitivity is influenced by the prior presentation of fearful faces - as emotional content could favor MC processing over PC one - but found no evidence of emotional modulation in either group. This spatio-temporal dissociation implies that individuals with SAUD may process visual details efficiently but perceive rapidly updating visual information at a slower pace. This deficit has implications for the tracking of rapidly changing stimuli in experimental tasks, but also for the decoding of crucial everyday visual incentives such as faces, whose micro-expressions vary continuously. Future studies should further specify the visual profile of individuals with SAUD to incorporate disparate findings within a theoretically grounded model of vision.

Therapeutic Interventions of Gut-Brain Axis as Novel Strategies for Treatment of Alcohol Use Disorder Associated Cognitive and Mood Dysfunction

Alcohol use disorders (AUD) is characterized by persistent or intermittent alcohol cravings and compulsive drinking. The functional changes in the central nervous system (CNS) after alcohol consumption are alcohol-associated cognitive impairment and mood disorders, which are major health issues reported in AUDs. Studies have shown that transferring the intestinal microbiota from AUDs patients to germ-free animals causes learning and memory dysfunction, depression and anxiety-like behavior, indicating the vital role of intestinal microbiota in development of neuropsychiatric disorders in AUD. Intestinal flora composition of AUD patients are significantly different from normal people, suggesting that intestinal flora imbalance orchestrate the development of neuropsychiatric disorders in AUD. Studies suggests that gut microbiome links bidirectional signaling network of the enteric nervous system (ENS) to central nervous system (CNS), forming gut-microbe-brain axis (brain-gut axis). In this review, we discussed pathogenesis and possible treatment of AUD-induced cognitive deficits, anxiety, and depression disorders. Further, we described the mechanism of intestinal flora imbalance and dysfunction of hippocampus-amygdala-frontal cortex (gut-limbic circuit system dysfunction). Therefore, we postulate therapeutic interventions of gut-brain axis as novel strategies for treatment of AUD-induced neuropsychiatric disorders.

Cognitive training in recently-abstinent individuals with alcohol use disorder improves emotional stroop performance: Evidence from a randomized pilot trial

BACKGROUND

Cognitive training interventions appear capable of improving alcohol-associated neurobehavioral deficits in recently detoxified individuals. However, efficacy remains incompletely characterized in alcohol use disorder (AUD) and available data address only non-affective cognitive outcomes; enhancement of social cognition remains uninvestigated. We utilized a training paradigm in which successfully ignoring emotionally-valent stimuli benefitted task performance. We hypothesized trained individuals would display improvements in an affective inhibitory control task, and that individuals trained with high valence (relative to neutral) stimuli would evince greater improvement.

METHODS

42 recently detoxified inpatients with AUD were assigned to one of three groups (Emotional Training, Neutral Training, or Treatment as Usual [TAU]). Training consisted of two computerized working memory tasks (dual-modality n-back task; attend/ignore task) which included task-irrelevant stimuli (emotional vs. neutral). Post-training performance efficiency (indexing speed-accuracy tradeoffs) in an emotional Stroop task was the outcome of interest.

RESULTS

Significant group by time interactions were detected for emotional Stroop performance, supporting our hypothesis that trained groups would exhibit greater improvement than TAU controls (F[2,39]=8.61, p < .01). Additionally, the emotional training condition appeared to result in greater improvement relative to neutral training (F[1,26]=4.98, p < .01).

CONCLUSION

Results are consistent with current literature suggesting the potential of training to enhance cognitive recovery in early abstinence. Findings inform the development of training protocols, suggesting integration of task-irrelevant distractor stimuli in training may enhance cognitive control outcomes. Further, they expand the relevant domains for application of training approaches, providing novel evidence that among individuals with AUD, training-associated benefits may extend to social cognitive domains.

Intrinsic brain functional connectivity patterns in alcohol use disorder

Alcohol use disorder is associated with damaging effects to the brain. This study aimed to examine differences in static and dynamic intrinsic functional connectivity patterns in individuals with a history of alcohol use disorder in comparison to those with no history of alcohol abuse. A total of 55 participants consisting of 23 patients and 32 control individuals underwent neuropsychological assessments and resting-state functional magnetic resonance imaging on a 3 Tesla MRI scanner. Differences in functional connectivity between the two groups were determined using static and dynamic independent component analysis. Differences in static functional connectivity between the two groups were identified in the default mode network, attention network, frontoparietal network, frontal cortical network and cerebellar network. Furthermore, the analyses revealed specific differences in the dynamic temporal characteristics of functional connectivity between the two groups of participants, in a cluster involving key regions in reward, sensorimotor and frontal cortical functional networks, with some connections correlating with the length of sobriety and some others with the severity of drinking. The findings altogether suggest dysregulation in the intrinsic connectivity of cortico-basal ganglia-thalamo-cortical loops that may reflect persistent alcohol use disorder-related network abnormalities, compensatory recovery-related processes whereby additional neural resources are recruited to achieve normal levels of performance, or a predisposition toward developing alcohol use disorder.

Mental Imagery Skills in Alcohol-Dependent Subjects and Their Associations With Cognitive Performance: An Exploratory Study During Residential Rehabilitation

People in alcohol-detoxification experience deficits in motor and non-motor functions including cognitive performance. Imagery, the cognitive process of generating visual, auditory or kinesthetic experiences in the mind without the presence of external stimuli, has been little studied in Alcohol Use Disorders (AUD). This pilot study aims to observe the cognitive abilities useful for the inspection, maintenance, generation and manipulation of images in these patients during residential rehabilitation and investigate the relationships with their cognitive performance. Thirty-six subjects who completed the 28-day rehabilitation program for alcohol addiction, completed the Mental Imagery Test (MIT) and Neuropsychological Battery (ENB-2). The global score at MIT did not show pathological scores. The 11.1% of AUD patients showed an impaired global score in the cognitive performance and the 5.7% with scoring at limits of norm. Significant correlations were found between Mental Imagery abilities and ENB-2 subscale and stepwise regression analysis showed the close association between the ability of imagery (Mental Imagery Test) and the overall cognitive performance (ENB-2) in alcohol dependent patients and this relationship is stronger than other cognitive tasks.

Memory impairment in alcohol use disorder is associated with regional frontal brain volumes

BACKGROUND

Episodic memory deficits occur in alcohol use disorder (AUD), but their anatomical substrates remain in question. Although persistent memory impairment is classically associated with limbic circuitry disruption, learning and retrieval of new information also relies on frontal systems. Despite AUD vulnerability of frontal lobe integrity, relations between frontal regions and memory processes have been under-appreciated.

METHODS

Participants included 91 AUD (49 with a drug diagnosis history) and 36 controls. Verbal and visual episodic memory scores were age- and education-corrected. Structural magnetic resonance imaging (MRI) data yielded regional frontal lobe (precentral, superior, orbital, middle, inferior, supplemental motor, and medial) and total hippocampal volumes.

RESULTS

AUD were impaired on all memory scores and had smaller precentral frontal and hippocampal volumes than controls. Orbital, superior, and inferior frontal volumes and lifetime alcohol consumption were independent predictors of episodic memory in AUD. Selectivity was established with a double dissociation, where orbital frontal volume predicted verbal but not visual memory, whereas inferior frontal volumes predicted visual but not verbal memory. Further, superior frontal volumes predicted verbal memory in AUD alone, whereas orbital frontal volumes predicted verbal memory in AUD+drug abuse history.

CONCLUSIONS

Selective relations among frontal subregions and episodic memory processes highlight the relevance of extra-limbic regions in mnemonic processes in AUD. Memory deficits resulting from frontal dysfunction, unlike the episodic memory impairment associated with limbic dysfunction, may be more amenable to recovery with cessation or reduction of alcohol misuse and may partially explain the heterogeneity in episodic memory abilities in AUD.

Brain, behavioral, affective, and sex correlates of recovery from alcohol use disorders

BACKGROUND

Recovery from alcohol use disorders (AUDs) consists of salutary changes in behavior and affect. While evidence suggests that recovery-related behavioral changes, such as abstinence, emerge in tandem with both neural and affective changes, the precise relationships among these changes are unknown. To understand these relationships, we examined associations between the duration of abstinence (DOA), affective states, and neuroimaging-based structural measures of the brain reward system (BRS) in AUD men (AUD_M ) and AUD women (AUD_W ).

METHODS

Participants were community respondents from the Boston area comprising right-handed abstinent individuals with AUD (n = 60; 30 men) and controls without AUD (NC; n = 60; 29 men). Multivariate linear regressions compared short-/mid-term abstainers (≤5 years), long-term abstainers (>5 years), and the NC group on measures of BRS volume (3T magnetic resonance imaging scans) and measures of affect (Profile of Mood States [POMS]; Multiple Affect Adjective Check List [MAACL]; Hamilton Rating Scale for Depression [HRSD]). Analyses contrasted sex differences and accounted for age, education, drinking severity, and verbal IQ.

RESULTS

Compared to the NC group, short-/mid-term abstainers exhibited larger posterior insular volume (total (β = 0.019, 95% CI: 0.004, 0.034)), higher negative affect (POMS Mood Disturbance (β = 27.8, 95% CI: 11.56, 44.04), and lower positive affect (POMS Vigor (β = -4.89, 95% CI: -9.06, -0.72)). Compared to the NC group, Long-term abstainers exhibited significantly smaller volumes of aggregate anterior cingulate cortex (β = -0.06, 95% CI: -0.113, -0.008) and higher HRSD scores (β = 1.56, 95% CI: 0.14, 2.98). Relative to AUD_M , AUD_W exhibited significantly larger right anterior insular volumes (β = 0.03, 95% CI: 0.01, 0.06) and significantly greater MAACL Positive Affect scores (β = 7.56, 95% CI: 0.59, 11.55) in association with DOA.

CONCLUSIONS

We found that differences in abstinence from alcohol were correlated with differences in both neural recovery and affective dimensions of recovery from AUDs. The observed sex differences extend evidence of dimorphic effects of AUDs and recovery on brain structure and function. Future longitudinal research will test inferences concerning the directionality of these relationships.

A pilot study assessing the brain gauge as an indicator of cognitive recovery in alcohol dependence

Alcohol dependence (AD) is associated with multiple cognitive deficits, which can affect treatment outcomes. Current measures of tracking brain recovery (e.g., functional magnetic resonance imaging) can be less accessible for practitioners. This study pilots a novel device (the brain gauge; BG) to assess its utility, and track recovery of cognitive function in residential alcohol treatment.

METHODS

A repeated measures design assessed changes in cognitive function during detoxification. Twenty-one participants with AD (16 Male; Mean age 43.85 ± 6.21) completed a battery of alcohol and memory questionnaires and BG tasks at two time-points (∼days 4 and 10) during a single managed detoxification episode.

RESULTS

Repeated measures ANCOVA revealed that some BG metrics significantly improved, with medium to large effect sizes - processing speed, focus, temporal order judgement and overall cortical metric. However, differences in subjective cognitive function were non-significant after controlling for depression and anxiety change scores. Anxiety change emerged as a significant factor in subjective cognitive function.

CONCLUSIONS

We conclude it is possible that the prefrontal cortex (PFC) recovers more slowly compared to other brain areas, and there are compounding effects of improvements in anxiety and depression, and metacognitive deficits on subjective EF assessments. Future research should seek to validate the clinical utility of the BG by comparing against established neuroimaging methods.

Brain responsivity to emotional faces differs in men and women with and without a history of alcohol use disorder

Inclusion of women in research on Alcohol Use Disorder (AUD) has shown that gender differences contribute to unique profiles of cognitive, emotional, and neuropsychological dysfunction. We employed functional magnetic resonance imaging (fMRI) of abstinent individuals with a history of AUD (21 women [AUDw], 21 men [AUDm]) and demographically similar non-AUD control (NC) participants without AUD (21 women [NCw], 21 men [NCm]) to explore how gender and AUD interact to influence brain responses during emotional processing and memory. Participants completed a delayed match-to-sample emotional face memory fMRI task, and brain activation contrasts between a fixation stimulus and pictures of emotional face elicited a similar overall pattern of activation for all four groups. Significant Group by Gender interactions revealed two activation clusters. A cluster in an anterior portion of the middle and superior temporal gyrus, elicited lower activation to the fixation stimulus than to faces for the AUDw as compared to the NCw; that abnormality was more pronounced than the one observed for men. Another cluster in the medial portion of the superior frontal cortex elicited higher activation to the faces by AUDm than NCm, a difference that was more evident than the one observed for women. Together, these findings have added new evidence of AUD-related gender differences in neural responses to facial expressions of emotion.

Decreased information processing speed and decision-making performance in alcohol use disorder: combined neurostructural evidence from VBM and TBSS

Alcohol Use Disorder (AUD) is a chronic relapsing condition characterized by excessive alcohol consumption despite its multifaceted adverse consequences, associated with impaired performance in several cognitive domains including decision-making. While choice deficits represent a core component of addictive behavior, possibly consecutive to brain changes preceding the onset of the addiction cycle, the evidence on grey-matter and white-matter damage underlying abnormal choices in AUD is still limited. To fill this gap, we assessed the neurostructural bases of decision-making performance in 22 early-abstinent alcoholic patients and 18 controls, by coupling the Cambridge Gambling Task (CGT) with quantitative magnetic resonance imaging metrics of grey-matter density and white-matter integrity. Regardless of group, voxel based morphometry highlighted an inverse relationship between deliberation time and grey-matter density, with alcoholics displaying slower choices related to grey-matter atrophy in key nodes of the motor control network. In particular, grey-matter density in the supplementary motor area, reduced in alcoholic patients, explained a significant amount of variability in their increased deliberation time. Tract-based spatial statistics revealed a significant relationship between CGT deliberation time and all white-matter indices, involving the most relevant commissural, projection and associative tracts. The lack of choice impairments other than increased deliberation time highlights reduced processing speed, mediated both by grey-matter and white-matter alterations, as a possible marker of a generalized executive impairment extending to the output stages of decision-making. These results pave the way to further studies aiming to tailor novel rehabilitation strategies and assess their functional outcomes.

Binge drinking is associated with altered resting state functional connectivity of reward-salience and top down control networks

Binge drinking is characterized by bouts of high-intensity alcohol intake and is associated with an array of health-related harms. Even though the transition from occasional impulsive to addictive alcohol use is not well understood, neurobiological models of addiction suggest that repeated cycles of intoxication and withdrawal contribute to the development of addiction in part through dysregulation of neurofunctional networks. Research on the neural sequelae associated with binge drinking is scant but resting state functional connectivity (RSFC) studies of alcohol use disorders (AUD) indicate that the development and maintenance of long-term excessive drinking may be mediated by network-level disruptions. The present study examined RSFC in young adult binge (BD) and light (LD) drinkers with seeds representing the networks subserving reward (the nucleus accumbens and caudate nucleus), salience (anterior cingulate cortex, ACC), and executive control (inferior frontal cortex, IFC). BDs exhibited enhanced connectivity between the striatal reward areas and the orbitofrontal cortex and the ACC, which is consistent with AUD studies and may be indicative of alcohol-motivated appetitive behaviors. Conversely, BDs demonstrated lower connectivity between the IFC and hippocampus which was associated with higher craving. This may indicate impaired ability to suppress unwanted thoughts and a failure to employ memory of the harmful consequences of heavy drinking in prospective plans and intentions. The observed greater connectivity of the reward/salience network and the lower prefrontal-hippocampal connectivity were associated with hazardous drinking levels indicating that dysregulation of neurofunctional networks may underlie binge drinking patterns.

Attenuated cerebral blood flow in frontolimbic and insular cortices in Alcohol Use Disorder: Relation to working memory

Chronic, excessive alcohol consumption is associated with cerebrovascular hypoperfusion, which has the potential to interfere with cognitive processes. Magnetic resonance pulsed continuous arterial spin labeling (PCASL) provides a noninvasive approach for measuring regional cerebral blood flow (CBF) and was used to study 24 men and women with Alcohol Use Disorder (AUD) and 20 age- and sex-matched controls. Two analysis approaches tested group differences: a data-driven, regionally-free method to test for group differences on a voxel-by-voxel basis and a region of interest (ROI) approach, which focused quantification on atlas-determined brain structures. Whole-brain, voxel-wise quantification identified low AUD-related cerebral perfusion in large volumes of medial frontal and cingulate cortices. The ROI analysis also identified lower CBF in the AUD group relative to the control group in medial frontal, anterior/middle cingulate, insular, and hippocampal/amygdala ROIs. Further, years of AUD diagnosis negatively correlated with temporal cortical CBF, and scores on an alcohol withdrawal scale negatively correlated with posterior cingulate and occipital gray matter CBF. Regional volume deficits did not account for AUD CBF deficits. Functional relevance of attenuated regional CBF in the AUD group emerged with positive correlations between episodic working memory test scores and anterior/middle cingulum, insula, and thalamus CBF. The frontolimbic and insular cortical neuroconstellation with dampened perfusion suggests a mechanism of dysfunction associated with these brain regions in AUD.

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.

Meta-analysis of grey matter changes and their behavioral characterization in patients with alcohol use disorder

Alcohol Use Disorder (AUD) is associated with reductions in grey matter (GM) volume which can lead to changes in numerous brain functions. The results of previous studies on altered GM in AUD differ considerably in the regions identified. Three meta-analyses carried out between 2014 and 2017 yielded different results. The present study includes the considerable amount of newer research and delivers a state-of-the art meta-analysis in line with recently published guidelines. Additionally, we behaviorally characterized affected regions using fMRI metadata and identified related brain networks by determining their meta-analytic connectivity patterns. Twenty-seven studies with 1,045 AUD patients and 1,054 healthy controls were included in the analysis and analyzed by means of Anatomical Likelihood Estimation (ALE). GM alterations were identified in eight clusters covering different parts of the cingulate and medial frontal gyri, paracentral lobes, left post- and precentral gyri, left anterior and right posterior insulae and left superior frontal gyrus. The behavioral characterization associated these regions with specific cognitive, emotional, somatosensory and motor functions. Moreover, the clusters represent nodes within behaviorally relevant brain networks. Our results suggest that GM reduction in AUD could disrupt network communication responsible for the neurocognitive impairments associated with high chronic alcohol consumption.

Altered Cerebro-Cerebellar Dynamic Functional Connectivity in Alcohol Use Disorder: a Resting-State fMRI Study

Alcohol use disorder (AUD) is widely associated with cerebellar dysfunction and altered cerebro-cerebellar functional connectivity (FC) that lead to cognitive impairments. Evidence for this association comes from resting-state functional magnetic resonance imaging (rsfMRI) studies that assess time-averaged measures of FC across the duration of a typical scan. This approach, however, precludes the assessment of potentially FC dynamics happening at faster timescales. In this study, using rsfMRI data, we aim at exploring cerebro-cerebellar FC dynamics in AUD patients (N = 18) and age- and sex-matched controls (N = 18). In particular, we quantified group-level differences in the temporal variability of FC between the posterior cerebellum and large-scale cognitive systems, and we investigated the role of the cerebellum in large-scale brain dynamics in terms of the temporal flexibility and integration of its regions. We found that, relative to controls, the AUD group exhibited significantly greater FC variability between the cerebellum and both the frontoparietal executive control (F_1,31 = 7.01, p(FDR) = 0.028) and ventral attention (F_1,31 = 7.35, p(FDR) = 0.028) networks. Moreover, the AUD group exhibited significantly less flexibility (F_1,31 = 8.61, p(FDR) = 0.028) and greater integration (F_1,31 = 9.11, p(FDR) = 0.028) in the cerebellum. Finally, in an exploratory analysis, we found distributed changes in the dynamics of canonical large-scale networks in AUD. Overall, this study brings evidence of AUD-related alterations in dynamic FC within major cerebro-cerebellar networks. This pattern has implications for explaining the development and maintenance of this disorder and improving our understating of the cerebellum's involvement in addiction.

The impact of emotional face stimuli on working memory performance among men and women with alcohol use disorder

BACKGROUND

Individuals with alcohol use disorder (AUD) often display compromise in emotional processing and non-affective neurocognitive functions. However, relatively little empirical work explores their intersection. In this study, we examined working memory performance when attending to and ignoring facial stimuli among adults with and without AUD. We anticipated poorer performance in the AUD group, particularly when task demands involved ignoring facial stimuli. Whether this relationship was moderated by facial emotion or participant sex were explored as empirical questions.

METHODS

Fifty-six controls (30 women) and 56 treatment-seekers with AUD (14 women) completed task conditions in which performance was advantaged by either attending to or ignoring facial stimuli, including happy, neutral, or fearful faces. Group, sex, and their interaction were independent factors in all models. Efficiency (accuracy/response time) was the primary outcome of interest.

RESULTS

An interaction between group and condition (F1,107 = 6.03, p < .02) was detected. Individual comparisons suggested this interaction was driven by AUD-associated performance deficits when ignoring faces, whereas performance was equivalent between groups when faces were attended. Secondary analyses suggested little influence of specific facial emotions on these effects.

CONCLUSIONS

These data provide partial support for initial hypotheses, with the AUD group demonstrating poorer working memory performance conditioned on the inability to ignore irrelevant emotional face stimuli. The absence of group differences when scenes were to be ignored (faces remembered) suggests the AUD-associated inability to ignore irrelevance is influenced by specific stimulus qualities.

Visuoperceptive Impairments in Severe Alcohol Use Disorder: A Critical Review of Behavioral Studies

The present literature review is aimed at offering a comprehensive and critical view of behavioral data collected during the past seventy years concerning visuoperception in severe alcohol use disorders (AUD). To pave the way for a renewal of research and clinical approaches in this very little understood field, this paper (1) provides a critical review of previous behavioral studies exploring visuoperceptive processing in severe AUD, (2) identifies the alcohol-related parameters and demographic factors that influence the deficits, and (3) addresses the limitations of this literature and their implications for current clinical strategies. By doing so, this review highlights the presence of visuoperceptive deficits but also shows how the lack of in-depth studies exploring the visual system in this clinical population results in the current absence of integration of these deficits in the dominant models of vision. Given the predominance of vision in everyday life, we stress the need to better delineate the extent, the specificity, and the actual implications of the deficits for severe AUD.

Neural correlates of visuoperceptive changes in severe alcohol use disorder: A critical review of neuroimaging and electrophysiological findings

Visuoperceptive deficits are frequently reported in severe alcohol use disorder (SAUD) and are considered as pervasive and persistent in time. While this topic of investigation has previously driven researchers' interest, far fewer studies have focused on visuoperception in SAUD since the '90s, leaving open central questions regarding the origin and implications of these deficits. To renew research in the field and provide a solid background to work upon, this paper reviews the neural correlates of visuoperception in SAUD, based on data from neuroimaging and electrophysiological studies. Results reveal structural and functional changes within the visual system but also in the connections between occipital and frontal areas. We highlight the lack of integration of these findings in the dominant models of vision which stress the dynamic nature of the visual system and consider the presence of both bottom-up and top-down cerebral mechanisms. Visuoperceptive changes are also discussed in the framework of long-lasting debates regarding the influence of demographic and alcohol-related factors, together stressing the presence of inter-individual differences. Capitalizing on this review, we provide guidelines to inform future research, and ultimately improve clinical care.

Do Social Cognition Deficits Recover with Abstinence in Alcohol-Dependent Patients?

Background

Despite growing evidence of the presence and clinical relevance of deficits in social cognition in individuals with alcohol use disorder (AUD), less is known about the potential of “natural” recovery with abstinence in this neurocognitive domain. This study investigated the abstinence‐based recovery of neurocognitive social abilities in alcohol‐dependent patients (ADP) using a prospective longitudinal design with follow‐up assessment under controlled conditions of abstinence during alcohol dependence inpatient treatment.

Methods

Seventy‐seven participants (42 ADP and 35 healthy controls [HC]) performed social cognition testing, including facial emotion recognition, perspective taking, and affective responsiveness twice (baseline/T1 and follow‐up/T2) during comparable follow‐up periods. Assessment of social cognition in abstinent ADP was conducted at the beginning (T1; within the first 2 weeks) and at the end (T2; within the last 2 weeks) of long‐term (2 months) abstinence‐oriented alcohol dependence inpatient treatment. Only patients abstinent for >14 days (last heavy drinking day >21 days) at baseline (T1) and who remained abstinent at follow‐up (T2) were included.

Results

ADP, who on average were nearly 2 months abstinent at T1, showed poorer social cognition in all 3 areas (emotion recognition, perspective taking, and affective responsiveness) than HC. There was no difference between groups on the change in performance over time, and group differences (ADP vs. HC) remained significant at T2, indicating persistent social cognition deficits in ADP following controlled abstinence during inpatient treatment.

Conclusions

Our findings indicate no natural recovery of social cognition impairments in ADP during an intermediate to long‐term period of abstinence (2+ months), the usual active treatment phase. Research aimed at developing interventions that focus on the improvement of social cognition deficits (e.g., social cognition training) and determining whether they benefit short‐ and long‐term clinical outcomes in AUD seems warranted.

Neuroimaging and Cognitive Evidence for Combined HIV-Alcohol Effects on the Central Nervous System: A Review

Alcohol use disorder (AUD) among people living with HIV (PLWH) is a significant public health concern. Despite the advent of effective antiretroviral therapy, up to 50% of PLWH still experience worsened neurocognition, which comorbid AUD exacerbates. We report converging lines of neuroimaging and neuropsychological evidence linking comorbid HIV/AUD to dysfunction in brain regions linked to executive function, learning and memory, processing speed, and motor control, and consequently to impairment in daily life. The brain shrinkage, functional network alterations, and brain metabolite disruption seen in individuals with HIV/AUD have been attributed to several interacting pathways: viral proteins and EtOH are directly neurotoxic and exacerbate each other's neurotoxic effects; EtOH reduces antiretroviral adherence and increases viral replication; AUD and HIV both increase gut microbial translocation, promoting systemic inflammation and HIV transport into the brain by immune cells; and HIV may compound alcohol's damaging effects on the liver, further increasing inflammation. We additionally review the neurocognitive effects of aging, Hepatitis C coinfection, obesity, and cardiovascular disease, tobacco use, and nutritional deficiencies, all of which have been shown to compound cognitive changes in HIV, AUD, and in their comorbidity. Finally, we examine emerging questions in HIV/AUD research, including genetic and cognitive protective factors, the role of binge drinking in HIV/AUD-linked cognitive decline, and whether neurocognitive and brain functions normalize after drinking cessation.

Physical activity: A promising adjunctive treatment for severe alcohol use disorder

Substance use disorder develops from complex interactions between socio-environmental and neurobiological factors. A neurocognitive model of addiction, the triadic model, proposes that Alcohol Use Disorder (AUD) is the result of an imbalance between the reflective and the impulsive subcomponents along with a disruption of the regulatory subcomponent. Physical activity is considered as an emerging treatment for severe AUD (sAUD). This short review examines the efficacy and mechanisms of action of physical intervention as an adjunctive treatment in severe AUD (sAUD) within the theoretical framework of the triadic model. Physical activity is a feasible, safe, and less stigmatizing approach than classical treatments. It improves sAUD patients' mental and physical comorbidities. The key finding of this short review is that physical activity could contribute to a rebalancing of the triadic model in sAUD patients by 1) improving neuroplasticity and cognitive functioning, 2) reducing impulsivity and urgency, and improving emotional regulation, and 3) reducing craving. This rebalancing could eventually reduce the risk of relapse. However, due to methodological issues, it remains difficult to observe an effect of physical activity on drinking outcomes. At best, a trend towards a reduction in alcohol consumption was noted. The mechanisms that could explain the benefits of physical activity in sAUD patients involve multiple physiological processes such as dopaminergic or glutamatergic transmission and signaling or neuroplasticity. Future randomized controlled trials should include neuropsychological and impulsivity assessments, in more controlled environments. Physical activity could contribute to a personalization of sAUD treatment using each subcomponent of the triadic model as a therapeutic target. Physical exercise could be an adjunctive treatment for sAUD patients, favoring the benefit of more usual treatments such as cognitive behavioral therapies. It could also be a stand-alone intervention in less severe patients.

Virtual Reality Cognitive Training Among Individuals With Alcohol Use Disorder Undergoing Residential Treatment: Pilot Randomized Controlled Trial

Background

Alcohol use disorder (AUD) has been associated with diverse physical and mental morbidities. Among the main consequences of chronic and excessive alcohol use are cognitive and executive deficits. Some of these deficits may be reversed in specific cognitive and executive domains with behavioral approaches consisting of cognitive training. The advent of computer-based interventions may leverage these improvements, but randomized controlled trials (RCTs) of digital interactive-based interventions are still scarce.

Objective

The aim of this study is to explore whether a cognitive training approach using VR exercises based on activities of daily living is feasible for improving the cognitive function of patients with AUD undergoing residential treatment, as well as to estimate the effect size for this intervention to power future definitive RCTs.

Methods

This study consisted of a two-arm pilot RCT with a sample of 36 individuals recovering from AUD in a therapeutic community; experimental group participants received a therapist-guided, VR-based cognitive training intervention combined with treatment as usual, and control group participants received treatment as usual without cognitive training. A comprehensive neuropsychological battery of tests was used both at pre- and postassessments, including measurement of global cognition, executive functions, attention, visual memory, and cognitive flexibility.

Results

In order to control for potential effects of global cognition and executive functions at baseline, these domains were controlled for in the statistical analysis for each individual outcome. Results indicate intervention effects on attention in two out of five outcomes and on cognitive flexibility in two out of six outcomes, with effect sizes in significant comparisons being larger for attention than for cognitive flexibility. Patient retention in cognitive training was high, in line with previous studies.

Conclusions

Overall, the data suggest that VR-based cognitive training results in specific contributions to improving attention ability and cognitive flexibility of patients recovering from AUD.

Trial Registration

ClinicalTrials.gov NCT04505345; https://clinicaltrials.gov/show/NCT04505345

Magnocellular and Parvocellular Mediated Luminance Contrast Discrimination in Severe Alcohol Use Disorder

BACKGROUND

Severe alcohol use disorder (SAUD) is associated with widespread cognitive impairments, including low-level visual processing deficits that persist after prolonged abstinence. However, the extent and characteristics of these visual deficits remain largely undetermined, impeding the identification of their underlying mechanisms and influence on higher-order processing. In particular, little work has been conducted to assess the integrity of the magnocellular (MC) and parvocellular (PC) visual pathways, namely the 2 main visual streams that convey information from the retina up to striate, extrastriate, and dorsal/ventral cerebral regions.

METHODS

We investigated achromatic luminance contrast processing mediated by inferred MC and PC pathways in 33 patients with SAUD and 32 matched healthy controls using 2 psychophysical pedestal contrast discrimination tasks that promote responses of inferred MC or PC pathways. We relied on a staircase procedure to assess participants' ability to detect small changes in luminance within an array of 4 gray squares that were either continuously presented (steady pedestal, MC-biased) or briefly flashed (pulsed pedestal, PC-biased).

RESULTS

We replicated the expected pattern of MC and PC contrast responses in healthy controls. We found preserved dissociation of MC and PC contrast signatures in SAUD but higher MC-mediated mean contrast discrimination thresholds combined with a steeper PC-mediated contrast discrimination slope compared with healthy controls.

CONCLUSION

These findings indicate altered MC-mediated contrast sensitivity and PC-mediated contrast gain, confirming the presence of early sensory disturbances in individuals with SAUD. Such low-level deficits, while usually overlooked, might influence higher-order abilities (e.g., memory, executive functions) in SAUD by disturbing the "coarse-to-fine" tuning of the visual system, which relies on the distinct functional properties of MC and PC pathways and ensures proper and efficient monitoring of the environment.

Genetically selected alcohol-preferring msP rats to study alcohol use disorder: Anything lost in translation?

For several decades, genetically selected alcohol-preferring rats have been successfully used to mimic and study alcohol use disorders (AUD). These rat lines have been instrumental in advancing our understanding of the neurobiology of alcoholism and enabling pharmacological studies to evaluate drug efficacy on alcohol drinking and relapse. Moreover, the results of these studies have identified genetic variables that are linked to AUD vulnerability. This is an up-to-date review that focuses on genetically selected Marchigian Sardinian alcohol-preferring (msP) rats. To support the translational relevance of the findings that are obtained from msP rats and highlight important similarities to AUD patients, we also discuss the results of recent brain imaging studies. Finally, to demonstrate the importance of studying sex differences in animal models of AUD, we present original data that highlight behavioral differences in the response to alcohol in male and female rats. Female msP rats exhibited higher alcohol consumption compared with males. Furthermore, msP rats of both sexes exhibit higher anxiety- and depressive-like behaviors in the elevated plus maze and forced swim test, respectively, compared with unselected Wistar controls. Notably, voluntary alcohol drinking decreases foot-shock stress and depressive-like behavior in both sexes, whereas anxiety-like behavior in the elevated plus maze is attenuated only in males. These findings suggest that male and female msP rats both drink high amounts of alcohol to self-medicate negative affective symptoms. For females, this behavior may be driven by an attempt to treat stress and depressive-like conditions. For males, generalized anxiety appears to be an important additional factor in the motivation to drink alcohol. This article is part of the special issue on 'Vulnerabilities to Substance Abuse.'

Early Identification of Alcohol Use Disorder Patients at Risk of Developing Korsakoff's Syndrome

BACKGROUND

The aim of the present study was to determine whether the Brief Evaluation of Alcohol-Related Neuropsychological Impairments (BEARNI), a screening tool developed to identify neuropsychological deficits in alcohol use disorder (AUD) patients, can also be used for the early identification of AUD patients at risk of developing Korsakoff's syndrome (KS).

METHODS

Eighteen KS patients, 47 AUD patients and 27 healthy controls underwent BEARNI testing (including 5 subtests targeting episodic memory, working memory, executive function, visuospatial abilities, and ataxia) and a comprehensive neuropsychological examination.

RESULTS

Performance of AUD and KS patients on BEARNI subtests was consistent with the results on the standardized neuropsychological assessment. On BEARNI, ataxia and working memory deficits observed in AUD were as severe as those exhibited by KS patients, whereas for visuospatial abilities, a graded effect of performance was found. In contrast, the subtests involving long-term memory abilities (episodic memory and fluency) were impaired in KS patients only. AUD patients with a score lower than 1.5 points (out of 6) on the episodic memory subtest of BEARNI exhibited the lowest episodic memory performance on the neuropsychological battery and could be considered at risk of developing KS.

CONCLUSIONS

These findings suggest that BEARNI is a useful tool for detecting severe memory impairments, suggesting that it could be used for the early identification of AUD patients at high risk of developing KS.

The contribution of mamillary body damage to Wernicke's encephalopathy and Korsakoff's syndrome

Histopathological alterations of the mamillary bodies are the most conspicuous and the most consistent neuropathological features of several disorders that occur after severe thiamine deficiency, such as Wernicke's encephalopathy and Korsakoff's syndrome. Moreover, they are among the few abnormalities that are visible to the naked eye in these disorders. With a lifetime prevalence of approximately 1.3%, Wernicke's encephalopathy is by far the most frequent cause of damage to the mamillary bodies in humans. Still, there is a persisting uncertainty with regard to the development and the clinical consequences of this damage, because it is virtually impossible to study in isolation. As a rule, it always occurs alongside neuropathology in other subcortical gray matter structures, notably the medial thalamus. Converging evidence from other pathologies and animal experiments is needed to assess the clinical impact of mamillary body damage and to determine which functions can be attributed to these structures in healthy subjects. In this chapter, we describe the history and the current state of knowledge with regard to thiamine deficiency disorders and the contribution of mamillary body damage to their clinical presentations.

Brain Structure and Function in Recovery

Alcohol use disorder (AUD) commonly is associated with compromise in neurobiological and/or neurobehavioral processes. The severity of this compromise varies across individuals and outcomes, as does the degree to which recovery of function is achieved. This narrative review first summarizes neurobehavioral, neurophysiological, structural, and neurochemical aberrations/deficits that are frequently observed in people with AUD after detoxification. Subsequent sections review improvements across these domains during recovery, taking into account modulators of recovery to the extent permitted. Where appropriate, the discussion includes work integrating outcomes across domains, leveraging the strengths of diverse experimental methods. Interventions to ameliorate neurobiological or neurobehavioral deficits do not constitute a primary objective of this review. However, their consideration is a logical inclusion. Therefore, a limited introduction to existing methods is also presented.

Deterioro cognitivo y recuperación espontánea en pacientes con diagnóstico de Consumo Perjudicial o Síndrome de Dependencia Alcohólico

El objetivo de este trabajo era conocer el alcance del deterioro de las funciones cognitivas debido al consumo abusivo de alcohol y su posible recuperación espontánea, así como observar la evolución temporal de esta recuperación, desde el inicio hasta los 24 meses de la abstinencia. Participaron voluntariamente 100 pacientes de ambos sexos, en tratamiento de deshabituación de consumo perjudicial o síndrome de dependencia alcohólico, agrupados en cohortes según tiempo de abstinencia. El grupo control estuvo formado por 20 personas sin antecedentes de alcoholismo, equiparadas con los pacientes en las variables edad, sexo y nivel de estudios. Los datos socio-demográficos y clínicos se recogieron con una anamnesis protocolizada, mientras que para evaluar el deterioro cognitivo se emplearon el Mini-Mental State Examination (MMSE) y el Montreal Cognitive Assessment (MOCA), en sus versiones al español. Para cada participante se obtuvieron 8 variables clínicas y socio-demográficas y 27 variables cognitivas. Se observaron diferencias significativas entre las medidas de las mismas variables cognitivas proporcionadas por ambos instrumentos, siendo más discriminativo el MOCA. Los resultados mostraron que el deterioro y la recuperación espontánea varían para las distintas funciones cognitivas y que los cambios más significativos se dan seis meses después de iniciada la deshabituación y entre los 18 y 24 meses. En base a la evidencia obtenida, atención, memoria y lenguaje se perfilan como las funciones más susceptibles de beneficiarse de un programa de rehabilitación cognitiva, que convendría implementar entre los 6 y 18 meses de abstinencia.

Eye Tracking Studies Exploring Cognitive and Affective Processes among Alcohol Drinkers: a Systematic Review and Perspectives

Acute alcohol intoxication and alcohol use disorders are characterized by a wide range of psychological and cerebral impairments, which have been widely explored using neuropsychological and neuroscientific techniques. Eye tracking has recently emerged as an innovative tool to renew this exploration, as eye movements offer complementary information on the processes underlying perceptive, attentional, memory or executive abilities. Building on this, the present systematic and critical literature review provides a comprehensive overview of eye tracking studies exploring cognitive and affective processes among alcohol drinkers. Using PRISMA guidelines, 36 papers that measured eye movements among alcohol drinkers were extracted from three databases (PsycINFO, PubMed, Scopus). They were assessed for methodological quality using a standardized procedure, and categorized based on the main cognitive function measured, namely perceptive abilities, attentional bias, executive function, emotion and prevention/intervention. Eye tracking indexes showed that alcohol-related disorders are related to: (1) a stable pattern of basic eye movement impairments, particularly during alcohol intoxication; (2) a robust attentional bias, indexed by increased dwell times for alcohol-related stimuli; (3) a reduced inhibitory control on saccadic movements; (4) an increased pupillary reactivity to visual stimuli, regardless of their emotional content; (5) a limited visual attention to prevention messages. Perspectives for future research are proposed, notably encouraging the exploration of eye movements in severe alcohol use disorders and the establishment of methodological gold standards for eye tracking measures in this field.

Stop! - The automatic tendency of action, inhibition and frontal activation in individuals with alcohol-use disorder in abstinence

Studying the functioning of the frontal lobe during the performance of an inhibitory activity according to automatic tendency of action would allow a better understanding of the relationship between the reflexive and impulsive system described in the dual-process models. This study aims to prove which is the inhibitory capacity and the underlying brain activity of people with alcohol-use disorder in abstinence with a greater avoidance tendency compared to those with a higher approach tendency and healthy controls. In order to group participants with AUD, the total approach/avoidance index (TAAI) - obtained from the modified alcohol approach/avoidance task - was used, therefore resulting in three groups: TAAI- (TAAI < Percentile 35: n = 20), TAAI± (TAAI = Percentile 35-65: n = 20) and TAAI+ (TAAI > Percentile 65: n = 20). In addition to this, 15 healthy controls were recruited. They all had an electroencephalographic recording while completing the modified stop-signal task. The results showed that the TAAI+ group had a worse inhibition compared to healthy controls. Moreover, the TAAI+ group showed a hyperactivation of the inferior frontal gyrus, precentral gyrus and orbital gyrus compared to the healthy controls group and the TAAI- group. The results obtained reflect that those people with AUD with a tendency to approach alcohol have a worse inhibitory capacity and a frontal hyperactivation. Moreover, people with AUD with an avoidance tendency to alcohol have also been found to have a similar inhibitory capacity and frontal activation to healthy controls.

Potential association of plasma lysophosphatidic acid (LPA) species with cognitive impairment in abstinent alcohol use disorders outpatients

Lysophosphatidic acid (LPA) species are bioactive lipids participating in neurodevelopmental processes. The aim was to investigate whether the relevant species of LPA were associated with clinical features of alcohol addiction. A total of 55 abstinent alcohol use disorder (AUD) patients were compared with 34 age/sex/body mass index-matched controls. Concentrations of total LPA and 16:0-LPA, 18:0-LPA, 18:1-LPA, 18:2-LPA and 20:4-LPA species were quantified and correlated with neuroplasticity-associated growth factors including brain derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1) and IGF-2, and neurotrophin-3 (NT-3). AUD patients showed dysexecutive syndrome (22.4%) and memory impairment (32.6%). Total LPA, 16:0-LPA, 18:0-LPA and 18:1-LPA concentrations, were decreased in the AUD group compared to control group. Total LPA, 16:0-LPA, 18:2-LPA and 20:4-LPA concentrations were decreased in men compared to women. Frontal lobe functions correlated with plasma LPA species. Alcohol-cognitive impairments could be related with the deregulation of the LPA species, especially in 16:0-LPA, 18:1-LPA and 20:4-LPA. Concentrations of BDNF correlated with total LPA, 18:2-LPA and 20:4-LPA species. The relation between LPA species and BDNF is interesting in plasticity and neurogenesis functions, their involvement in AUD might serve as a biomarker of cognitive impairment.

Alcohol's Unique Effects on Cognition in Women: A 2020 (Re)view to Envision Future Research and Treatment

Alcohol use and misuse is increasing among women. Although the prevalence of drinking remains higher in men than women, the gender gap is narrowing. This narrative review focuses on the cognitive sequelae of alcohol consumption in women. Studies of acute alcohol effects on cognition indicate that women typically perform worse than men on tasks requiring divided attention, memory, and decision-making. Beneficial effects of moderate alcohol consumption on cognition have been reported; however, a number of studies have cautioned that other factors may be driving that association. Although chronic heavy drinking affects working memory, visuospatial abilities, balance, emotional processing, and social cognition in women and men, sex differences mark the severity and specific profile of functional deficits. The accelerated or compressed progression of alcohol-related problems and their consequences observed in women relative to men, referred to as "telescoping," highlights sex differences in the pharmacokinetics, pharmacodynamics, cognitive, and psychological consequences of alcohol. Brain volume deficits affecting multiple systems, including frontolimbic and frontocerebellar networks, contribute to impairment. Taken together, sex-related differences highlight the complexity of this chronic disease in women and underscore the relevance of examining the roles of age, drinking patterns, duration of abstinence, medical history, and psychiatric comorbidities in defining and understanding alcohol-related cognitive impairment.

Hippocampal subfield volumes in abstinent men and women with a history of alcohol use disorder

Alcohol Use Disorder (AUD) has been associated with abnormalities in hippocampal volumes, but these relationships have not been fully explored with respect to sub-regional volumes, nor in association with individual characteristics such as age, gender differences, drinking history, and memory. The present study examined the impact of those variables in relation to hippocampal subfield volumes in abstinent men and women with a history of AUD. Using Magnetic Resonance Imaging at 3 Tesla, we obtained brain images from 67 participants with AUD (31 women) and 64 nonalcoholic control (NC) participants (31 women). The average duration of the most recent period of sobriety for AUD participants was 7.1 years. We used Freesurfer 6.0 to segment the hippocampus into 12 regions. These were imputed into statistical models to examine the relationships of brain volume with AUD group, age, gender, memory, and drinking history. Interactions with gender and age were of particular interest. Compared to the NC group, the AUD group had approximately 5% smaller subiculum, CA1, molecular layer, and hippocampal tail regions. Age was negatively associated with volumes for the AUD group in the subiculum and the hippocampal tail, but no significant interactions with gender were identified. The relationships for delayed and immediate memory with hippocampal tail volume differed for AUD and NC groups: Higher scores on tests of immediate and delayed memory were associated with smaller volumes in the AUD group, but larger volumes in the NC group. Length of sobriety was associated with decreasing CA1 volume in women (0.19% per year) and increasing volume size in men (0.38% per year). The course of abstinence on CA1 volume differed for men and women, and the differential relationships of subfield volumes to age and memory could indicate a distinction in the impact of AUD on functions of the hippocampal tail. These findings confirm and extend evidence that AUD, age, gender, memory, and abstinence differentially impact volumes of component parts of the hippocampus.

Nondisplaceable Binding Is a Potential Confounding Factor in 11C-PBR28 Translocator Protein PET Studies

The PET ligand ¹¹C-PBR28 (N-((2-(methoxy-¹¹C)-phenyl)methyl)-N-(6-phenoxy-3-pyridinyl)acetamide) binds to the 18-kDa translocator protein (TSPO), a biomarker of glia. In clinical studies of TSPO, the ligand total distribution volume, V_T, is frequently the reported outcome measure. Since V_T is the sum of the ligand-specific distribution volume (V_S) and the nondisplaceable-binding distribution volume (V_ND), differences in V_ND across subjects and groups will have an impact on V_T Methods: Here, we used a recently developed method for simultaneous estimation of V_ND (SIME) to disentangle contributions from V_ND and V_S Data from 4 previously published ¹¹C-PBR28 PET studies were included: before and after a lipopolysaccharide challenge (8 subjects), in alcohol use disorder (14 patients, 15 controls), in first-episode psychosis (16 patients, 16 controls), and in Parkinson disease (16 patients, 16 controls). In each dataset, regional V_T estimates were obtained with a standard 2-tissue-compartment model, and brain-wide V_ND was estimated with SIME. V_S was then calculated as V_T - V_ND V_ND and V_S were then compared across groups, within each dataset. Results: A lower V_ND was found for individuals with alcohol-use disorder (34%, P = 0.00084) and Parkinson disease (34%, P = 0.0032) than in their corresponding controls. We found no difference in V_ND between first-episode psychosis patients and their controls, and the administration of lipopolysaccharide did not change V_ND Conclusion: Our findings suggest that in TSPO PET studies, nondisplaceable binding can differ between patient groups and conditions and should therefore be considered.

Selective recall deficits for heterogeneous associations in detoxified individuals with alcohol use disorder

AIM

Alcohol use disorder (AUD) has been associated with recognition memory deficits. However, it remains unclear whether these deficits occur at the general recognition memory level or whether they selectively affect its subcomponents. Evidence suggests that recognition memory deficits may vary according to the heterogeneity of memory stimuli. Our aim was to investigate stimuli pair-dependent recognition memory deficits in AUD, using a cued recall task including homogeneous and heterogeneous stimuli pairs.

METHODS

Twenty-three patients with AUD (days since last alcohol consumption: 11.70 ± 10.20) and 23 healthy controls (HC) underwent a neuropsychological examination tapping attention, verbal fluency, logical, working and long-term memory, and a recognition and recall task involving both homogeneous (tool-tool) and heterogeneous (tool-scene, tool-animal) stimuli pairs. Group (AUD-HC) by condition (tool-tool, tool-scene, tool-animal) ANOVAs were performed on all neuropsychological indices.

RESULTS

In the neuropsychological examination, AUD individuals showed deficits in delayed recall and faster reaction times compared with HC. The administration of the recognition and recall task revealed specific performance decreases in cued recall occurring in the whole sample (AUD + HC) for heterogeneous (tool-scene, tool-animal) pairs compared with homogeneous pairs. Within this pattern, AUD patients showed a lower cued recall rate than HC only for tool-animal pairs.

CONCLUSIONS

Our results support the existence of specific recall/recollection deficits in AUD which occurred for heterogeneous, but not for homogeneous stimuli pairs. This finding calls for further neuroimaging investigations aimed at investigating the neurobiological substrate of (i) different recognition memory subcomponents, and (ii) the processing of stimuli with different degree or type of heterogeneity.