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

Plasma Concentrations of Neurofilament Light Chain Protein and Brain-Derived Neurotrophic Factor as Consistent Biomarkers of Cognitive Impairment in Alcohol Use Disorder

For a long time, Substance Use Disorders (SUDs) were not considered a component in the etiology of dementia. The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders introduced substance-induced neurocognitive disorders, incorporating this notion to clinical practice. However, detection and monitoring of neurodegenerative processes in SUD patients remain a major clinical challenge, especially when early diagnosis is required. In the present study, we aimed to investigate new potential biomarkers of neurodegeneration that could predict cognitive impairment in SUD patients: the circulating concentrations of Neurofilament Light chain protein (NfL) and Brain-Derived Neurotrophic Factor (BDNF). Sixty SUD patients were compared with twenty-seven dementia patients and forty healthy controls. SUD patients were recruited and assessed using the Psychiatric Research Interview for Substance and Mental (PRISM) and a battery of neuropsychological tests, including the Montreal Cognitive Assessment test for evaluation of cognitive impairment. When compared to healthy control subjects, SUD patients showed increases in plasma NfL concentrations and NfL/BDNF ratio, as well as reduced plasma BDNF levels. These changes were remarkable in SUD patients with moderate-severe cognitive impairment, being comparable to those observed in dementia patients. NfL concentrations correlated with executive function and memory cognition in SUD patients. The parameters "age", "NfL/BDNF ratio", "first time alcohol use", "age of onset of alcohol use disorder", and "length of alcohol use disorder diagnosis" were able to stratify our SUD sample into patients with cognitive impairment from those without cognitive dysfunction with great specificity and sensibility. In conclusion, we propose the combined use of NfL and BDNF (NfL/BDNF ratio) to monitor substance-induced neurocognitive disorder.

Vascular Endothelial Growth Factor as a Potential Biomarker of Neuroinflammation and Frontal Cognitive Impairment in Patients with Alcohol Use Disorder

(1) Background: Alcohol Use Disorder (AUD) is associated with functional disruption of several brain structures that may trigger cognitive dysfunction. One of the mechanisms of alcohol-associated cognitive impairment has been proposed to arise from its direct impact on the immune system, which culminates in the release of cytokines and chemokines which can eventually reach the brain. Alcohol can also disrupt the blood–brain barrier, facilitating the penetration of pro-inflammatory molecules throughout vascular endothelial growth factor A (VEGFA). Thus, alcohol-induced alterations in chemokines and VEGFA might contribute to the neuroinflammation and cognitive impairment associated with AUD. (2) Methods: The present cross-sectional study investigates whether patients with AUD (n = 86) present cognitive disability associated to alterations in plasma concentration of SDF-1, fractalkine, eotaxin, MCP-1, MIP-1α and VEGFA when compared to control subjects (n = 51). (3) Results: The analysis indicated that SDF-1 and MCP-1 concentrations were higher in AUD patients than in controls. Concentrations of VEGFA were higher in AUD patients with severe frontal deficits, and the score of frontal lobe functions was negatively correlated with VEGFA and fractalkine. Acute alcohol effects on VEGFA plasma levels in healthy volunteers demonstrated the induction of VEGFA release by heavy alcohol drinking. VEGFA was positively correlated with pro-inflammatory chemokines in AUD patients with frontal cognitive impairment. (4) Conclusions: we propose VEGFA/chemokine monitoring as biomarkers of potential cognitive impairment in AUD patients.

Effects of acute alcohol administration on working memory: a systematic review and meta-analysis

RATIONALE

Alcohol-induced executive function deficits may underlie associations between alcohol, self-regulation, and hazardous behaviors. Studies examining the effects of alcohol administration on working memory, an important executive functioning component, have produced mixed findings. Acute alcohol effects on working memory remain unclear.

OBJECTIVES

We aimed to conduct a systematic review and meta-analysis on the effects of acute alcohol administration on working memory outcomes in studies of healthy adults.

METHODS

We performed a systematic search of PubMed, MEDLINE, and PsycINFO from inception to June 2021. Studies were included if they met criteria, including healthy participants and administration of quantified alcohol doses against comparative controls. Data extracted included primary working memory outcomes, alcohol doses, and study characteristics. Study quality was assessed using an established validity measure. Working memory task type, alcohol dose, control condition type, and sex/gender composition were explored as moderators using mixed-effects models and meta-regressions.

RESULTS

Thirty-two studies (1629 participants) provided sufficient data for 54 comparisons between alcohol and control conditions. Random-effects meta-analysis indicated that alcohol administration produced significant, small- to medium-sized working memory decrements (g [95% CI] =  - 0.300 [- 0.390 to - 0.211], p < 0.001). Moderation analyses suggested that these effects differed as a function of task type, dose, control condition type, and sex/gender composition. The average quality rating across studies was good.

CONCLUSIONS

Alcohol administration significantly impaired working memory performance, particularly when executive-related manipulation processes were involved. Future research is needed to investigate how alcohol-induced working memory impairments relate to compromised self-regulation, hazardous behavior, and negative drinking consequences.

Anti-saccade as a Tool to Evaluate Neurocognitive Impairment in Alcohol Use Disorder

It has been widely shown that chronic alcohol use leads to cognitive dysfunctions, especially inhibitory control. In an extension of the traditional approach, this research field has benefited from the emergence of innovative measures, among which is an anti-saccade, allowing direct and sensitive measure of the eye movements indexing attention bias to alcohol-related cues and the capability of inhibiting the reflexive saccades to the cues. During the past decade, there are numerous reports showing that drinkers make more unwanted reflexive saccades and longer latency in the anti-saccade task. These increased errors are usually explained by the deficits in inhibitory control. It has been demonstrated that inhibitory control on eye movement may be one of the earliest biomarkers of the onset of alcohol-related cognitive impairments. This review summarizes how an anti-saccade task can be used as a tool to investigate and assess the cognitive dysfunctions and the early detection of relapsing risk of alcohol dependence.

Working memory moderates the relation between implicit alcohol associations and heavy episodic drinking in moderate-to-heavy drinking men who have sex with men

INTRODUCTION

Heavy episodic drinking poses a risk for HIV-infection, particularly among men who have sex with men (MSM). Previous research suggests implicit associations may play a role in heavy episodic drinking and that various executive functions (EF) may moderate the relation between implicit associations and heavy episodic drinking. This study investigated the role of two EF - working memory (maintaining and updating information) and response inhibition (inhibiting prepotent responses) - as moderators of the relation between implicit alcohol approach associations and heavy episodic drinking among moderate-to-heavy drinking MSM.

METHODS

Two-hundred and fifty-one participants completed measures of implicit alcohol associations (the implicit alcohol approach association test - IAT), working memory, and response inhibition, as well as a self-report questionnaire assessing heavy episodic drinking. Regression analyses were conducted to examine whether the association between the IAT and heavy episodic drinking was moderated by working memory and response inhibition.

RESULTS

Results showed that working memory moderated the relation between the alcohol IAT and heavy episodic drinking such that IAT alcohol approach scores were positively associated with heavy episodic drinking among those low in working memory but not those high in working memory. Response inhibition did not moderate the association between IAT scores and heavy episodic drinking.

CONCLUSIONS

Results suggest that the relation between implicit alcohol approach associations and heavy episodic drinking is stronger among moderate-to-heavy drinking MSM with lower working memory capacity compared to those with higher working memory capacity, and these individuals may particularly benefit from alcohol intervention approaches that target automatic alcohol responses.

Acute effect of alcohol on working memory updating

AIMS

To examine the acute effects of alcohol on working memory (WM) updating, including potential variation across the ascending limb (AL) and descending limb (DL) of the blood alcohol concentration (BAC) time-course.

DESIGN

A two-session experiment in which participants were randomly assigned to one of three beverage conditions [alcohol (males: 0.80 g/kg; females: 0.72 g/kg), active placebo (0.04 g/kg) or non-alcohol control (tonic)] and one of two BAC limb testing conditions (AL and DL or DL-only) for the second session, yielding a 3 (beverage) × 2 (time-points tested) × 3 (time-point) mixed factorial design with repeated measures on the latter factor. One of the repeated assessments is 'missing by design' in the DL-only condition.

SETTING

A psychology laboratory at the University of Missouri campus in Columbia, MO, USA.

PARTICIPANTS

Two hundred thirty-one community-dwelling young adults (51% female; aged 21-34 years) recruited from Columbia, MO, USA, tested between 2011 and 2013.

MEASUREMENTS

Latent WM updating performance as indexed by shared variance in accuracy on three WM updating tasks (letter memory, keep track, spatial 2-back) at three time-points.

FINDINGS

Multi-group modeling of latent WM updating indicated that performance among participants who consumed placebo or control beverages improved during the second session at time-points corresponding to AL (∆ from baseline in latent mean ± standard error (SE) + 0.5 ± 0.01, P < 0.001) and DL (+ 0.08 ± 0.01, P < 0.001). Alcohol consumption did not impair WM updating (∆ from baseline in latent mean ± SE, at AL: + 0.01 ± 0.01, P = 0.56; at DL: + 0.05 ± 0.01, P < 0.001), but attenuated performance improvements (equality of latent means across beverage groups at AL or DL: Δχ2(1)  ≥ 7.53, P < 0.01).

CONCLUSIONS

Acute alcohol-induced impairment in working memory updating may be limited, but dampening of practice effects by alcohol could interfere with the completion of novel, unpracticed tasks.

Reduced Working Memory is Associated with Heavier Alcohol Consumption History, Role Impairment and Executive Function Difficulties

Both HIV status and heavy alcohol use have been associated with reduced cognitive function, particularly in the domains of working memory and executive function. It is unclear what aspects of working memory and executive function are associated with HIV status and heavy alcohol use and whether performance on these measures are associated with functional impairment. We examined the relationship between HIV, history of heavy alcohol consumption, and HIV/alcohol interaction on speeded tests of frontal inhibitory abilities, a working memory task related to mental manipulation of letters and numbers, cognitive flexibility, and measures of functional impairment. Study participants included 284 individuals (151 HIV +) recruited from two different studies focusing on HIV associated brain dysfunction, one specific to the effects of alcohol, the other specific to the effects of aging. HIV status was not independently associated with working memory and executive function measures. Higher level of alcohol consumption was associated with reduced performance on Letter Number Sequencing. Poorer Letter Number Sequencing performance was associated with role impairment (an inability to do certain kinds of work, housework, or schoolwork) and executive function difficulties. Future studies should examine causal associations and interventions targeting working memory abilities.

Executive functions and emotion regulation in substance use disorder

ABSTRACT Objective The executive functions (EF) and emotion regulation (ER) and their relationship with the substance use disorder (SUD) were analyzed. Methods A cross-sectional design was used. The sample consisted of 130 volunteers divided into three groups: group 01 (n = 60), composed of participants who did not meet the diagnostic criteria for any type of SUD; group 02 (n = 51), with users with alcohol and/or tobacco use disorder; group 03 (n = 19), with users with multiple substance use disorder, including at least one illicit substance. Results Group 02 presented worse performance in EF and ER when compared to group 01, and showed a significant correlation between the working memory and the use of maladaptive ER. Group 03 showed great losses in EF and ER when compared to the other groups. Conclusion This study supports the idea that EF, ER and SUD are related. In addition, it was observed that people with SUD had worse performance in EF and ER when compared to people without SUD, greater damage being observed in people with SUD of polysubstances.

Cannabis use-related working memory deficit mediated by lower left hippocampal volume

The association between cannabis exposure and working memory impairment and its neural substrates remain unclear. In this cross-sectional observational study, we investigated this by examining the relationship between frequency of exposure to cannabis, working memory performance and regional brain volumes and tested whether lower volumes of cortical and subcortical structures mediate the association between cannabis exposure and working memory deficit using the Human Connectome Project data from 234 individuals with self-reported cannabis exposure and 174 individuals unexposed to cannabis. We tested the relationship between self-reported frequency of cannabis exposure and list-sorting working memory task performance (total number of correct responses), between T1 weighted MRI-derived regional grey-matter volumes and working memory task performance as well as between frequency of cannabis exposure and brain volumes after controlling for potential confounders. Finally, mediation analysis was carried out to test whether deficit in working memory performance associated with cannabis use was mediated by its association with lower grey-matter volume. Participants who reported higher frequency of cannabis use tended to have lower number of correct responses in the list-sorting working memory task and lower bilateral hippocampal volumes. Association between severity of cannabis exposure as indexed by frequency of cannabis use and impairment in working memory was mediated by lower left hippocampal volume in cannabis users. We report evidence in support of the left hippocampus volume-mediated working memory impairment associated with recreational cannabis exposure. Future studies employing prospective longitudinal design are necessary to examine the cause-effect relationships of cannabis exposure on working memory and brain volumes.

On the role of (implicit) drinking self-identity in alcohol use and problematic drinking: A comparison of five measures

Objective: Implicit and explicit drinking self-identity appear to be useful in predicting alcohol-related outcomes. However, there are several different implicit and explicit measures which can be used to assess drinking self-identity. Some of these implicit measures can also capture relational information (e.g., I am a drinker, I should be a drinker), which might provide unique advantages. Despite the importance of having good measures of drinking self-identity, to date there has been little direct comparison of these measures. Method: This study (N = 358) systematically compared two commonly used measures of drinking self-identity (one implicit and one explicit: the Implicit Association Test [IAT] and the Alcohol Self-Concept Scale [ASCS]) with three relational measures of implicit self-identity (the autobiographical IAT [aIAT], the Relational Responding Task [RRT], and the Propositional Concealed Information Test [pCIT]) on a range of criteria relevant to experimental and clinical alcohol researchers. Results: Overall, we found mixed performances on the implicit measures. Interestingly, the aIAT, which probed should-based drinking identity, performed better than the standard IAT. However, the explicit measure exhibited superior performance to all other measures across all criteria. Conclusions: Our results suggest that researchers who wish to assess drinking-related self-identity and to predict alcohol-related outcomes cross-sectionally should set their focus primarily on the use (and further development) of the ASCS, rather than any of the implicit measures. Future research focusing on the ASCS should seek to investigate the generalizability of our findings to patient populations, and incorporate relational information within that procedure to further improve upon its already-strong utility. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Effects of working memory training on emotion regulation: Transdiagnostic review

Working memory training is widely used transdiagnostically to improve cognition. However, more recently, studies using working memory training packages have targeted emotion-regulation outcomes to determine whether far transfer effects can be achieved. A narrative review is conducted of studies that have used standardized computerized working memory training packages across healthy volunteers, affect, anxiety, post-traumatic stress disorder (PTSD), and eating disordered populations with emotion-regulation outcomes. Working memory training has been used in children, adolescents, and adults to improve emotion regulation. Many studies have reported gains in mood as well as emotion-regulation strategies following working memory training, regardless of clinical indication and whether near transfer gains were achieved in cognitive domains. Significant emotion-regulation outcomes include: state and trait anxiety, rumination, brooding, positive appraisal, decreasing maladaptive emotion-regulation strategies, and decreasing intrusive thoughts. It is speculated that these far transfer outcomes from working memory training are possible due to the cognitive and neural overlap between cognitive and affective working memory, and emotion regulation. Working memory training could improve cognitive efficiency, which, in turn, increases the availability of cognitive resources during times when emotion regulation is taxed. Future studies need to consider the role of participant expectancy in predicting outcome measure performance, and including subjective and objective outcomes is paramount to study design. Furthermore, sample sizes require additional attention, given that the current review highlights that individual differences in non-clinical and clinical populations influence the outcomes from working memory training. Working memory training offers a possibility for improving emotion regulation transdiagnostically.

History of Alcohol Consumption and HIV Status Related to Functional Connectivity Differences in the Brain During Working Memory Performance

BACKGROUND

Poorer working memory function has previously been associated with alcohol misuse, Human Immunodeficiency Virus (HIV) positive status, and risky behavior. Poorer working memory performance relates to alterations in specific brain networks.

OBJECTIVE

The current study examined if there was a relationship between brain networks involved in working memory and reported level of alcohol consumption during an individual's period of heaviest use. Furthermore, we examined whether HIV status and the interaction between HIV and alcohol consumption was associated with differences in these brain networks.

METHODS

Fifty adults, 26 of whom were HIV positive, engaged in an n-back working memory task (0-back and 2-back trials) administered in a magnetic resonance imaging (MRI) scanner. The Kreek- McHugh-Schluger-Kellogg (KMSK) scale of alcohol consumption was used to characterize an individual's period of heaviest use and correlates well with their risk for alcohol dependence. Connectivity analyses were conducted using data collected during n-back task.

RESULTS

Functional connectivity differences associated with greater alcohol consumption included negative connectivity, primarily from parietal attention networks to frontal networks. Greater alcohol consumption was also associated with positive connectivity from working memory nodes to the precuneus and paracingulate. HIV positive status was associated with more nodes of negative functional connectivity relative to alcohol consumption history alone, particularly in the frontoparietal networks. The HIV positive individuals with heavier drinking history related to negative fronto-parietal connectivity, along with positive connectivity from working memory nodes to mesolimbic regions.

CONCLUSION

Findings allow for a better understanding of brain networks affected by HIV and alcohol and may provide avenues for interventions.

A dual process perspective on advances in cognitive science and alcohol use disorder

There is a tremendous global and national (US) burden associated with alcohol misuse and alcohol use disorder (AUD). Further, of the mental health disorders, AUD has the widest treatment gap. Thus, there is a critical need for improved understanding of the etiology, maintenance, and treatment of AUD. The application of cognitive science to the study of AUD has a longstanding history of attempting to meet this need. In this selective review, we identified and focused on four domains of recent (i.e., in the last decade) applications of cognitive science to the study of AUD: implicit cognitive biases, executive function, behavioral economic approaches to alcohol decision making, and functional connectivity neuroimaging. We highlighted advances within these four domains and considered them in the context of dual process models of addiction, which focus on the contribution and interplay of two complementary neurocognitive systems (impulsive and control systems). Findings across the domains were generally consistent with dual process models. They also suggest the need for further model refinements, including integrating behavioral economic approaches and findings from functional connectivity neuroimaging studies. Research evaluating candidate interventions associated with these domains is emergent but promising, suggesting important directions for future research.

Insomnia moderates the association between alcohol use and consequences among young adult veterans

OBJECTIVE

Symptoms of insomnia and heavy alcohol use tend to co-occur among military and veteran samples. The current study examined insomnia as a moderator of the association between alcohol use and related consequences among young adult veterans in an effort to extend and replicate findings observed in samples of civilian young adults.

METHOD

Young adult veterans (N=622; 83% male; age M=29.0, SD=3.4) reporting alcohol use in the past year completed measures of insomnia severity, alcohol use, and alcohol-related consequences as part of a larger intervention trial. Participants were classified as screening 'positive' (n=383, 62%) or 'negative' (n=239, 38%) for insomnia using the Insomnia Severity Index. Hierarchical regression was used to examine the interaction between drinking quantity and insomnia on alcohol-related consequences. Predictor and outcome variables were measured concurrently.

RESULTS

Both a greater number of drinks per week and a positive insomnia screen were associated with more alcohol-related consequences. Drinks per week and insomnia screen interacted to predict alcohol-related consequences, such that the effect of drinking on alcohol-related consequences was stronger in the context of a positive versus negative insomnia screen.

CONCLUSION

Drinking is associated with more alcohol-related consequences in the presence of clinically significant insomnia symptoms. These findings replicate those documented in civilian young adults and indicate that insomnia may be an appropriate target for alcohol prevention and intervention efforts among young adult veterans.

Optimal control of a social epidemic model with media coverage

A new social epidemic model to depict alcoholism with media coverage is proposed in this paper. Some fundamental properties of the model including existence and positivity as well as boundedness of equilibria are investigated. Stability of all equilibria are studied. The existence of the optimal control pair and mathematical expressions of optimal control are obtained by Pontryagin's maximum principle. Numerical simulations are also performed to illustrate our results. Our results show that media coverage is an effective measure to quit drinking.

Exercise as adjunctive treatment for alcohol use disorder: A randomized controlled trial

Aims

To examine whether physical activity as an adjunct to outpatient alcohol treatment has an effect on alcohol consumption following participation in an exercise intervention of six months’ duration, and at 12 months after treatment initiation.

Methods

The study is a randomized controlled study with three arms: Patients allocated to (A) treatment as usual, (B) treatment as usual and supervised group exercise, (C) treatment as usual and individual physical exercise. The primary outcome measure was excessive drinking six months after treatment start and completion of the intervention. A logistic regression model was used to evaluate the odds of excessive drinking among the three groups, based on intention-to-treat. Changes in level of physical activity in all three groups were tested by using a generalized linear mixed model. A multiple linear model was used to test if there was an association between amount of performed physical activity and alcohol consumption.

Results

A total of 175 patients (68.6% male) participated. Response rates were 77.7% at six months and 57.1% at 12 months follow-up. OR 0.99 [95% CI: 0.46; 2.14], p = 0.976 for excessive drinking in the group exercise condition, and 1.02 [95% CI: 0.47; 2.18], p = 0.968 in the individual exercise condition, which, when compared to the control group as reference, did not differ statistically significantly. Participants with moderate level physical activity had lower odds for excessive drinking OR = 0.12 [0.05; 0.31], p<0.001 than participants with low level physical activity. Amount of alcohol consumption in the intervention groups decreased by 4% [95% CI: 0.03; 6.8], p = 0.015 for each increased exercising day.

Conclusions

No direct effect of physical exercise on drinking outcome was found. Moderate level physical activity was protective against excessive drinking following treatment. A dose-response effect of exercise on drinking outcome supports the need for implementing physically active lifestyles for patients in treatment for alcohol use disorder.

Impulsivity, working memory, and impaired control over alcohol: A latent variable analysis

Impaired control over alcohol is an important risk factor for heavy drinking among young adults and may mediate, in part, the association between personality risk and alcohol problems. Research suggests that trait impulsivity is associated with impaired control over alcohol; however, few studies of this association have included a range of impulsivity facets. The purpose of this study was to examine specific pathways from higher order impulsivity factors to alcohol problems mediated via impaired control over alcohol. We also examined the moderating role of working memory in these associations. Young heavy drinkers (N = 300) completed 2 multidimensional impulsivity measures along with self-report measures of impaired control over alcohol, alcohol use, and alcohol problems. Working memory was assessed using a computerized digit span task. Results showed that the impulsivity facets loaded onto 2 higher order factors that were labeled Response and Reflection Impulsivity. Response impulsivity predicted unique variance in self-reported impaired control and alcohol problems, whereas reflection impulsivity predicted unique variance in heavy drinking frequency only. Further, significant indirect associations were observed from response and reflection impulsivity to alcohol problems mediated via impaired control and heavy drinking frequency, respectively. Working memory and sensation seeking were not uniquely associated with the alcohol variables, and no support was found for the moderating role of working memory. The results help to clarify associations among impulsivity, impaired control, and alcohol problems, suggesting that impaired control may play a specific role in the pathway to alcohol problems from response impulsivity but not from reflection impulsivity. (PsycINFO Database Record