Response shifting and inhibition, but not working memory, are impaired after long-term heavy alcohol consumption

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.

Examination of college student health behaviors and self-reported executive functions

Objective: Emerging adulthood is characterized by maturation of executive functions (EF) and changes in health behaviors (HB). Interestingly, EF are bi-directionally related to many specific HB; yet how EF performs in relation to overall patterns of HB engagement is unclear. Groupings of HB and the relationship between these HB groupings and EF were examined.

PARTICIPANTS

Full-time college students were recruited from three large Mid- and Southwest universities (N = 1,387).

METHODS

Online self-report questionnaires assessing demographics, HB, and EF were completed.

RESULTS

Latent class analysis of HB revealed three classes: (1) High Substance Use, (2) Moderately Healthy, (3) Healthy. In general, the Healthy class had significantly greater EF compared to no significant differences between the other two classes.

CONCLUSIONS

Collective engagement in HB is associated with EF. Interventions targeting both HB and EF simultaneously may be most efficacious.

Risk and resilience for alcohol use disorder revealed in brain functional connectivity

A family history of alcoholism (FH) increases risk for alcohol use disorder (AUD), yet many at-risk individuals never develop alcohol use problems. FH is associated with intermediate levels of risk phenotypes, whereas distinct, compensatory brain changes likely promote resilience. Although several cognitive, behavioral, and personality factors have been associated with AUD, the relative contributions of these processes and their neural underpinnings to risk or resilience processes remains less clear. We examined whole-brain resting-state functional connectivity (FC) and behavioral metrics from 841 young adults from the Human Connectome Project, including healthy controls, individuals with AUD, and their unaffected siblings. First, we identified functional connections in which unaffected siblings were intermediate between controls and AUD, indicating AUD risk, and those in which siblings diverged, indicating resilience. Canonical correlations relating brain risk and resilience FC to behavioral patterns revealed AUD risk and resilience phenotypes. Risk phenotypes primarily implicated frontal-parietal networks corresponding with executive function, impulsivity, externalizing behaviors, and social-emotional intelligence. Conversely, resilience-related phenotypes were underpinned by networks of medial prefrontal, striatal, temporal, brainstem and cerebellar connectivity, which associated with high trait attention and low antisocial behavior. Additionally, we calculated "polyphenotypic" risk and resilience scores, to investigate how the relative load of risk and resilience phenotypes influenced the probability of an AUD diagnosis. Polyphenotypic scores predicted AUD in a dose-dependent manner. Moreover, resilience phenotypes interacted with risk phenotypes, reducing their effects. The hypothesis-generating results revealed interpretable AUD-related phenotypes and offer brain-informed targets for developing more effective interventions.

Heterogeneity of Executive Function Abilities in Recently Detoxified Patients with Alcohol Use Disorder: Evidence from a Cluster Analysis

BACKGROUND

Impairments of executive functions (EF) have been consistently reported in patients with alcohol use disorder (AUD), mostly in studies which were based on comparisons of means between groups. However, given the high heterogeneity in AUD patients, this approach could actually cover a wide range of EF patterns. In the present study, we addressed the paucity of the literature about cognitive heterogeneity in AUD by applying a cluster analytical approach on EF measures.

METHODS

Seventy-eight withdrawn AUD patients and 77 healthy Control participants completed measures targeting a variety of EF components. We then used cluster analysis to identify subgroups of AUD patients. Furthermore, the AUD subgroups were compared to the Control group to establish their specific EF patterns.

RESULTS

Findings showed that AUD patients could be divided into 3 clusters based on their EF performances. A first cluster accounting for half of the AUD sample was characterized by unimpaired EF (Cluster 1). The 2 other clusters displayed major EF deficits but differed regarding the deficient EF component. While Cluster 2 was mainly impaired on measures of rule deduction and mental flexibility, Cluster 3 was mainly characterized by a lower processing speed and impaired inhibition of an ongoing motor response. Differences in EF performances of AUD patients could be related to differences in premorbid cognitive reserve, impulsiveness patterns, and withdrawal complications.

CONCLUSIONS

This study highlights the importance of the cognitive heterogeneity in AUD by showing that AUD patients display substantially different EF patterns. Future studies should try to go beyond mere group comparisons to further deepen our understanding about cognitive differences between AUD patients. In the long run, this could lead to more personalized prevention and treatment programs specifically tailored to the patient's impairments.

Different aspects of impulsivity in chronic alcohol use disorder with and without comorbid problem gambling

BACKGROUND AND AIMS

Alcohol use disorder (AUD) and problem gambling are highly comorbid disorders. This study aims to explore the role of four aspects of impulsivity (trait concept of impulsivity, choice impulsivity, impulsive aggression and response inhibition/decision-making) in long-term chronic AUD patients with and without problem or pathological gambling symptoms.

METHODS

Cognitively intact chronic AUD patients were enrolled with (n = 32) and without (n = 71) problem gambling symptoms in an inpatient clinic for chronic alcohol users. Multiple facets of impulsivity, cognitive ability, psychopathological symptoms, alcohol and gambling severity were measured.

RESULTS

Chronic AUD patients with gambling disorder symptoms showed longer lifetime alcohol consumption, more severe alcohol use and higher psychopathological symptom severity than AUD patients without gambling symptoms. Gambling severity correlated with overall trait impulsivity, but not with choice impulsivity, impulsive aggression or cognitive impulsivity with controlling for lifetime alcohol consumption, lifetime alcohol use and psychopathological symptom severity. High trait impulsivity and non-planning was associated with comorbid gambling symptoms in AUD patients, which was independent of the level of intelligence, age and psychopathological symptoms.

CONCLUSION

Comorbid gambling disorder symptoms in chronic AUD was connected to more severe alcohol-related variables. Higher trait impulsivity was also linked with gambling disorder symptoms in patients with chronic AUD. This accents the need of special focus on comorbid GD symptoms in AUD, since prognosis and treatment for them may vary.

Executive Dysfunction in Patients With Korsakoff's Syndrome: A Theory-Driven Approach

Aims

In addition to amnesia, executive deficits are prominent in Korsakoff's syndrome (KS), yet poorly studied. This study investigates the degree of executive dysfunction in patients with KS for the three main executive subcomponents shifting, updating and inhibition using novel, theory-driven paradigms.

Short summary

Compared to healthy controls, patients with KS show impairments on the executive subcomponents shifting and updating, but not on inhibition.

Methods

Executive functions were measured with six carefully designed tasks in 36 abstinent patients with KS (mean age 62.3; 28% woman) and compared with 30 healthy non-alcoholic controls (mean age 61.8; 40% woman). ANOVAs were conducted to examine group differences and effect sizes were calculated.

Results

Compared to healthy controls, patients with KS were impaired on the executive subcomponents shifting and updating. No statistically significant group difference was found on the factor inhibition.

Conclusions

Executive dysfunction in long-abstinent patients with alcoholic KS shows a profile in which shifting and updating ability are affected most. It also highlights that executive dysfunction is an important feature of KS and requires more attention in scientific and clinical practice, as these deficits may also affect daily functioning.

Changes in Neuropsychological Status during the Initial Phase of Abstinence in Alcohol Use Disorder: Neurocognitive Impairment and Implications for Clinical Care

BACKGROUND

Neuropsychological deficits are common in individuals with alcohol use disorder (AUD) and impact daily functioning and AUD treatment outcomes. Longitudinal studies demonstrate that extended abstinence improves neuropsychological functioning. The effects of short-term abstinence are less clear.

OBJECTIVES

This study examined changes in neuropsychological functioning after acute detoxification over a 10-day period at the beginning of residential AUD treatment. Notably, this study evaluated cognitive functioning according to diagnostic classifications for neurocognitive disorder according to DSM-5.

METHODS

Using a within-subjects design, neuropsychological functioning of participants (N = 28) undergoing a 14-day residential AUD treatment program was assessed at two time points over 10 days (i.e., treatment entry, prior to treatment discharge). Tests of immediate memory, visuospatial abilities, attention, language abilities, delayed memory, and executive functioning were administered.

RESULTS

After completing acute detoxification, almost all participants (93%) were clinically impaired in at least one of the five cognitive domains at residential treatment entry, with one third of the sample impaired on ≥3 domains. Ten days later, 71% remained clinically impaired in at least one of five cognitive domains, with 29% of the sample impaired on ≥3 domains. Significant improvement over the 10-day period was observed for immediate memory, visuospatial abilities, and overall cognitive functioning. Clinical significance of these changes is also reported. Conclusions/Importance: The results from this study help to characterize cognitive functioning in terms of neurocognitive impairment. A brief period of abstinence begins to ameliorate neuropsychological deficits, but many individuals remain cognitively impaired throughout treatment. Implications for treatment are discussed.

Self-reported cognitive scales in a US National Survey: reliability, validity, and preliminary evidence for associations with alcohol and drug use

AIMS

To evaluate relationships between measures of cognitive functioning and alcohol or drug use among adults (≥ 18 years) in the US general population.

DESIGN

Two cognitive scales were created based on dimensionality and reliability of self-reported Executive Function Index items. Relationships between the two scales and validators were evaluated. Associations between the cognitive scales and past-year frequency of alcohol or drug use were estimated with adjusted odds ratios (aOR).

SETTING

United States, using the 2012-13 National Epidemiologic Survey on Alcohol and Related Conditions-III, a nationally representative adult sample selected by multi-stage probability sampling.

PARTICIPANTS

36 085 respondents.

MEASUREMENTS

Past-year substance use outcome variables categorized binge drinking, marijuana, cocaine, opioid, sedative/tranquilizer and stimulant use as frequent (at least weekly to daily), infrequent (any to two to three times/month) or no use, assessed by the Alcohol Use Disorder and Associated Disabilities Interview Schedule-5. Key predictors were the two cognitive scales. Construct validators included education and functional impairment. Covariates included age, gender, income and race/ethnicity.

FINDINGS

Nine cognitive items fitted a two-factor model (comparative fit index = 0.973): attention (five items) and executive functioning (four items). Both scales were associated positively with higher education (Ps < 0.001) and negatively with functional impairment (Ps < 0.001), demonstrating construct validity. Poorer attention was associated with frequent and infrequent binge drinking and use of drugs [aOR range = 1.07 (binge drinking) to 1.72 (stimulants), Ps ≤ 0.01]. Poorer executive functioning was associated with frequent binge drinking and use of drugs [aOR range = 1.22 (binge drinking) to 2.03 (cocaine), Ps < 0.001] and infrequent use of all drugs [aOR range = 1.19 (marijuana) to 1.63 (cocaine), Ps < 0.001].

CONCLUSIONS

Impairments in attention and executive functioning are positively associated with substance use in the US general population.

Autobiographical memory compromise in individuals with alcohol use disorders: Towards implications for psychotherapy research

It has been found that Autobiographical memory (i.e., memory for personal experiences and facts about the self) are not properly maintained in people with alcohol-use disorders (AUD). The present paper offers a comprehensive overview of findings regarding the consequences of AUD on autobiographical memory. More specifically, we offer a theoretical model (the AMAUD Autobiographical Memory and Alcohol Use Disorders model) according to which chronic alcohol consumption compromises emotion regulation as well as executive control, which maintains the construction of autobiographical memory. Compromises in emotional regulation and executive functioning can be linked to a weak aspiration to construct detailed memories (i.e., autobiographical overgenerality), compromises of subjective reliving, anterograde amnesia, negative self-defining memories, and a difficulty to mentally project oneself forward in time to generate complex autobiographical representations and self-images. By gathering cognitive and clinical aspects of autobiographical decline in AUD, this model constitutes a theoretical foundation that may lead to a better understanding of this decline. Different clinical perspectives are proposed for developing personalized autobiographical memory rehabilitation programs for individuals with AUD.

Differential spontaneous recovery across cognitive abilities during detoxification period in alcohol-dependence

OBJECTIVE

There is a lack of consensus regarding the extent to which cognitive dysfunctions may recover upon cessation of alcohol intake by alcohol-dependents (AD), and the divergent findings are most likely due to methodological differences between the various studies. The present study was aimed at conducting a very strict longitudinal study of cognitive recovery in terms of assessment points, the duration of abstinence, control of age and duration of the addiction, and by use of individual analyses in addition to mean group comparisons. Our study further focused on the 2-3 week phase of alcohol detoxification that is already known to positively affect many biological, emotional, motivational, as well as neural variables, followed by longer-term therapies for which good cognitive functioning is needed.

METHODS

41 AD inpatients undergoing a detoxification program, and 41 matched controls, were evaluated twice in terms of five cognitive functions (i.e., short-term memory, working memory, inhibition, cognitive flexibility, and verbal fluency) within a three-week interval [on the first day (T1) and the 18th day (T2) of abstinence for AD patients]. Emotional (positive and negative affectivity and depression) and motivational (craving) variables were also measured at both evaluation times.

RESULTS

Although verbal fluency, short-term memory, and cognitive flexibility did not appear to be affected, the patients exhibited impaired inhibition and working memory at T1. While no recovery of inhibition was found to occur, the average working memory performance of the patients was comparable to that of the controls at T2. Improvements in emotional and motivational dimensions were also observed, although they did not correlate with the ones in working memory. Individual analysis showed that not all participants were impaired or recover the same functions.

CONCLUSIONS

While inhibition deficits appear to persist after 18 days of detoxification, deficits in working memory, which is a central component of cognition, are greatly reduced after alcohol detoxification. Individual differences in the trajectory of recovery do arise however, and it might be worth implementing individual assessments of impaired functions at the end of the detoxification phase in order to maximize the chances of success in longer-term treatments and abstinence.

Self-defining memories in recently detoxified alcohol-dependent patients

Patients with alcohol dependence have been shown to be impaired in recalling specific autobiographical events, yet little is known on how changes in the memory of these events may impact their self-representation. In this study, we examined Self-Defining Memories (SDMs), a specific type of autobiographical memory that plays a key role in the construction of personal identity, in 25 patients with alcohol dependence, abstinent from alcohol from 10 days to 6 months, compared to 28 control subjects. We observed that SDMs in patients were significantly less specific and included more reference to alcohol than those of controls. Patients also reported more SDMs with negative emotional valence and higher emotional intensity. These results suggest that recently abstinent alcohol-dependent patients may be prone to define themselves by negative events referring to alcohol consumption, which may contribute to an unfavorable perception of their self and subsequently of their ability to remain abstinent. These findings should be taken into account to optimize psychological approaches in the treatment of alcohol-dependence.

Binge Drinking in Young University Students Is Associated with Alterations in Executive Functions Related to Their Starting Age

Our aim was to evaluate whether or not alcohol consumption in the form of binge drinking is associated with alterations of memory and executive functions in a population of university students. At the same time, we have studied the role of potential modulating factors, such as the APOE genotype or physical exercise.University students enrolled in academic year 2013–2014 at Escuelas Universitarias Gimbernat-Cantabria, affiliated with the University of Cantabria, were invited to participate in the study. We gathered sociodemographic data and details regarding the lifestyle of 206 students (mean age 19.55 ± 2.39; 67.5% women). We evaluated memory and executive functions via a series of validated cognitive tests. Participants were classified as binge drinkers (BD) and non-BD. Using Student's t-distribution we studied the association between cognitive tests and BD patterns. Multivariate analyses were carried out via multiple linear regression. 47.6% of the students were found to be BD. The BD differed significantly from the non-BD in their results in the executive functions test TMT B (43.41 ± 13.30 vs 37.40 ± 9.77; p = 0.0003). Adjusting by age, sex, academic records, age at which they started consuming alcohol, cannabis consumption, level of physical activity and other possible modifying variables, the association was statistically significant (p = 0.009). We noticed a statistically significant inverse correlation (Pearson’s r² = -0.192; p = 0.007) between TMT B and starting age of alcohol consumption. Differences were observed in another executive functions test, TMT A, but only in the group of women (19.73±6.1 BD vs 17.78±5.4 non-BD p = 0.05). In spite of the young age of our participants, BD was associated with a lower performance in the executive functions test (TMT B). These deficits were related to the age at which they started drinking alcohol, suggesting an accumulative effect.

Do Baseline Executive Functions Mediate Prospective Memory Performance under a Moderate Dose of Alcohol?

Prospective memory (PM) is memory for delayed intentions. While deleterious effects of acute doses of alcohol on PM have been documented previously using between-subjects comparisons, the current study adopted a single blind placebo-controlled within-subjects design to explore whether the extent to which alcohol-related impairments in PM are mediated by executive functions (EFs). To this end, 52 male social drinkers with no history of substance-related treatment were tested using two parallel versions of a clinical measure of PM (the Memory for Intentions Test; Raskin et al., 2010), and a battery of EF measures. Testing took place on two occasions, with the order of administration of the alcohol and placebo conditions being fully counterbalanced. Overall, PM was worse under alcohol and participants showed deficits on five of the six subscales making up the clinical test. Hierarchical multiple regression analyses demonstrated that EFs did not predict PM performance decrements overall but did predict performance when time cues were presented and when verbal responses were required. Phonemic fluency was the strongest of the EF predictors; a greater capacity to gain controlled access to information in long-term memory predicted a smaller difference between placebo- and alcohol-related performance on both the time cue and verbal response scales. PM is crucial to compliance with, and response to, both therapy programs and alcohol harm prevention campaigns. The results indicate that individual differences in cognitive function need to be taken into account when designing such interventions in order to increase their effectiveness.

Disinhibition mediates the relationship between ADHD and problematic alcohol use in college students

OBJECTIVE

High-risk alcohol use among college students has received substantial attention in recent years, and intervention and prevention efforts have increased dramatically. The current study examined ADHD as a risk factor for problematic drinking among college students. Trait disinhibition and difficulty stopping a drinking session were examined as potential mechanisms through which ADHD is associated with alcohol-related problems.

METHOD

Participants included 100 full-time undergraduate students with (n = 48) and without (n = 52) Diagnostic and Statistical Manual of Mental Disorders (4th ed.) ADHD.

RESULTS

Students with ADHD had higher rates of alcohol-related problems and alcohol-use disorders across multiple measures. Both disinhibition and difficulty stopping a drinking session independently mediated the relationship between ADHD and negative consequences of alcohol use.

CONCLUSION

These findings indicate that college students with ADHD are at increased risk for alcohol-related problems. Trait disinhibition and difficulty stopping a drinking session represent mechanisms of high-risk alcohol use among college students with ADHD.

Neural correlates of impulsive aggressive behavior in subjects with a history of alcohol dependence

Alcohol-related aggression is a complex and problematic phenomenon with profound public health consequences. We examined neural correlates potentially moderating the relationship between human aggressive behavior and chronic alcohol use. Thirteen subjects meeting DSM-IV criteria for past alcohol-dependence in remission (AD) and 13 matched healthy controls (CONT) participated in an fMRI study adapted from a laboratory model of human aggressive behavior (Point Subtraction Aggression Paradigm, or PSAP). Blood oxygen level dependent (BOLD) activation was measured during bouts of operationally defined aggressive behavior, during postprovocation periods, and during monetary-reinforced behavior. Whole brain voxelwise random-effects analyses found group differences in brain regions relevant to chronic alcohol use and aggressive behavior (e.g., emotional and behavioral control). Behaviorally, AD subjects responded on both the aggressive response and monetary response options at significantly higher rates than CONT. Whole brain voxelwise random-effects analyses revealed significant group differences in response to provocation (monetary subtractions), with CONT subjects showing greater activation in frontal and prefrontal cortex, thalamus, and hippocampus. Collapsing data across all subjects, regression analyses of postprovocation brain activation on aggressive response rate revealed significant positive regression slopes in precentral gyrus and parietal cortex; and significant negative regression slopes in orbitofrontal cortex, prefrontal cortex, caudate, thalamus, and middle temporal gyrus. In these collapsed analyses, response to provocation and aggressive behavior were associated with activation in brain regions subserving inhibitory and emotional control, sensorimotor integration, and goal directed motor activity.

Is binge drinking in young adults associated with an alcohol-specific impairment of response inhibition?

BACKGROUND/AIMS

Little is known about the association of binge drinking with impulsivity related to trait- or state-like aspects of behavior. The aim of the present study was therefore to investigate whether binge drinkers show an impairment of inhibitory control in comparison to non-binge drinkers when confronted with alcohol-associated or control stimuli, and whether this is reflected in self-reported impulsivity.

METHODS

A go/no-go task with pictures of alcoholic and nonalcoholic beverages as well as control stimuli was administered to binge drinkers and a gender-matched group of non-binge drinkers. All participants also completed the Barratt Impulsiveness Scale (BIS-11).

RESULTS

We found an alcohol-specific impairment of response inhibition for binge drinkers only, while the groups did not differ with regard to overall response inhibition to the experimental stimuli or self-reported impulsiveness (BIS-11). In addition, the number of commission errors in response to alcohol-associated stimuli was the only significant predictor of binge drinking.

CONCLUSION

The findings of the present study suggest that when young adults have established binge drinking as a common drinking pattern, impairment of inhibition in response to alcoholic stimuli is the only significant predictor of binge drinking, but not general impulsive behavior.

Thalamic abnormalities are a cardinal feature of alcohol-related brain dysfunction

Two brain networks are particularly affected by the harmful effect of chronic and excessive alcohol consumption: the circuit of Papez and the frontocerebellar circuit, in both of which the thalamus plays a key role. Shrinkage of the thalamus is more severe in alcoholics with Korsakoff's syndrome (KS) than in those without neurological complication (AL). In accordance with the gradient effect of thalamic abnormalities between AL and KS, the pattern of brain dysfunction in the Papez's circuit results in anterograde amnesia in KS and only mild-to-moderate episodic memory disorders in AL. On the opposite, dysfunction of the frontocerebellar circuit results in a similar pattern of working memory and executive deficits in the AL and KS. Several hypotheses, mutually compatible, can be drawn to explain that the severe thalamic shrinkage observed in KS has different consequences in the neuropsychological profile associated with the two brain networks.

Revisiting the continuum hypothesis: toward an in-depth exploration of executive functions in korsakoff syndrome

Korsakoff syndrome (KS) is a neurological state mostly caused by alcohol-dependence and leading to disproportionate episodic memory deficits. KS patients present more severe anterograde amnesia than Alcohol-Dependent Subjects (ADS), which led to the continuum hypothesis postulating a progressive increase in brain and cognitive damages during the evolution from ADS to KS. This hypothesis has been extensively examined for memory but is still debated for other abilities, notably executive functions (EF). EF have up to now been explored by unspecific tasks in KS, and few studies explored their interactions with memory. Exploring EF in KS by specific tasks based on current EF models could thus renew the exploration of the continuum hypothesis. This paper will propose a research program aiming at: (1) clarifying the extent of executive dysfunctions in KS by tasks focusing on specific EF subcomponents; (2) determining the differential EF deficits in ADS and KS; (3) exploring EF-memory interactions in KS with innovative tasks. At the fundamental level, this exploration will test the continuum hypothesis beyond memory. At the clinical level, it will propose new rehabilitation tools focusing on the EF specifically impaired in KS.

Decreased Verbal Learning but not Recognition Performance in Alcohol-dependent Individuals During Early Abstinence

Objective:Alcoholism ultimately leads to impairment of memory and other cognitive functions. This can interfere with treatment, if cognitively impaired alcohol-dependent individuals have difficulties recalling and implementing skills acquired during therapy. We investigate if alcohol-dependent individuals without clinically apparent withdrawal symptoms may still be impaired in higher-order cognitive functions.

Methods:Thirty-four alcohol-dependent patients and 20 matched healthy controls were tested with the Verbal Learning and Memory Test which includes seven measurement points. The test comprises free recall, free recall after distraction and after 30 minute delay, and a word recognition task. Testing was performed between day seven and day 10 after the beginning of abstinence, when clinical withdrawal symptoms had ceased.

Results:Compared to healthy controls, alcohol-dependent patients performed worse in free recall after delay, but not in word recognition. Healthy controls showed a more linear progression of improvement in verbal memory performance. Overall, alcohol-dependent individuals showed reduced verbal learning efficiency. The extent of impaired recall after distraction was positively associated (one-tailed test) with history of delirium (r=0.34, p=0.04), seizures (r=0.46, p=0.01), and years since diagnosis for alcohol dependency (r=0.39, p=0.01).

Conclusions:Our results provide evidence that unmedicated alcohol-dependent patients without obvious withdrawal symptoms had impaired verbal recall, but normal recognition performance, at seven to 10 days after onset of abstinence. This deficit may deteriorate treatment outcomes due to poorer implementation of skills newly-learned during this time period.

Cognitive control in alcohol use disorder: deficits and clinical relevance

Cognitive control refers to the internal representation, maintenance, and updating of context information in the service of exerting control over thoughts and behavior. Deficits in cognitive control likely contribute to difficulty in maintaining abstinence in individuals with alcohol use disorders (AUD). In this article, we define three cognitive control processes in detail (response inhibition, distractor interference control, and working memory), review the tasks measuring performance in these areas, and summarize the brain networks involved in carrying out these processes. Next, we review evidence of deficits in these processes in AUD, including both metrics of task performance and functional neuroimaging. Finally, we explore the clinical relevance of these deficits by identifying predictors of clinical outcome and markers that appear to change (improve) with treatment. We observe that individuals with AUD experience deficits in some, but not all, metrics of cognitive control. Deficits in cognitive control may predict clinical outcome in AUD, but more work is necessary to replicate findings. It is likely that performance on tasks requiring cognitive control improves with abstinence, and with some psychosocial and medication treatments. Future work should clarify which aspects of cognitive control are most important to target during treatment of AUD.

Working memory training and semantic structuring improves remembering future events, not past events

Objectives. Memory training in combination with practice in semantic structuring and word fluency has been shown to improve memory performance. This study investigated the efficacy of a working memory training combined with exercises in semantic structuring and word fluency and examined whether training effects generalize to other cognitive tasks. Methods. In this double-blind randomized control study, 36 patients with memory impairments following brain damage were allocated to either the experimental or the active control condition, with both groups receiving 9 hours of therapy. The experimental group received a computer-based working memory training and exercises in word fluency and semantic structuring. The control group received the standard memory therapy provided in the rehabilitation center. Patients were tested on a neuropsychological test battery before and after therapy, resulting in composite scores for working memory; immediate, delayed, and prospective memory; word fluency; and attention. Results. The experimental group improved significantly in working memory and word fluency. The training effects also generalized to prospective memory tasks. No specific effect on episodic memory could be demonstrated. Conclusion. Combined treatment of working memory training with exercises in semantic structuring is an effective method for cognitive rehabilitation of organic memory impairment.

Acute and chronic effects of alcohol on trail making test performance among underage drinkers in a field setting

OBJECTIVE

Alcohol's effects on executive functioning are well documented. Research in this area has provided much information on both the acute and chronic effects of alcohol on processes such as working memory and mental flexibility. However, most research on the acute effects of alcohol is conducted with individuals older than 21 years of age. Using field recruitment methods can provide unique empirical data on the acute effects of alcohol on an underage population.

METHOD

The current study examined the independent effects of acute alcohol intoxication (measured by breath alcohol content) and chronic alcohol use (measured by years drinking) on a test of visuomotor performance and mental flexibility (Trail Making Test) among 91 drinkers ages 18-20 years recruited from a field setting.

RESULTS

Results show that breath alcohol predicts performance on Trails B, but not on Trails A, and that years drinking, above and beyond acute intoxication, predicts poorer performance on both Trails A and B.

CONCLUSIONS

These data suggest that, independent of the acute effects of alcohol, chronic alcohol consumption has deleterious effects on executive functioning processes among underage drinkers. Our discussion focuses on the importance of these data in describing the effect of alcohol on adolescents and the potential for engaging in risky behavior while intoxicated.

Component processes of memory in alcoholism: pattern of compromise and neural substrates

Initially, alcohol-related memory deficits were considered only through the prism of Korsakoff's syndrome (KS). It is now clear, however, that chronic alcohol consumption results in memory disorders in alcoholics without ostensible neurologic complications, such as Wernicke's encephalopathy and KS. Most of the principal memory components are affected, including working memory, episodic memory, semantic memory, perceptual memory, and procedural memory. The extent of those cognitive impairments depends on several factors, such as age, gender, nutritional status, and psychiatric comorbidity. While memory disorders, especially episodic memory deficits, are largely definitive in patients with KS, recovery of memory abilities has been described with abstinence in uncomplicated alcoholics. Neuropsychologic impairments, and especially memory disorders, must be evaluated at alcohol treatment entry because they could impede patients from benefiting fully from cognitive and behavioral treatment approaches for alcohol dependence. Screening of memory deficits could also enable clinicians to detect, among alcoholics without ostensible neurologic complications, those at risk of developing permanent and debilitating amnesia that features KS.

Separating intentional inhibition of prepotent responses and resistance to proactive interference in alcohol-dependent individuals

BACKGROUND

Impulsivity is a hallmark of addictive behaviors. Addicts' weakened inhibition of irrelevant prepotent responses is commonly thought to explain this association. However, inhibition is not a unitary mechanism. This study investigated the efficiency of overcoming competition due to irrelevant responses (i.e., inhibition of a prepotent response) and overcoming competition in memory (i.e., resistance to proactive interference) in sober and recently detoxified alcohol-dependent individuals.

METHODS

Three cognitive tasks assessing the inhibition of a prepotent response (Hayling task, anti-saccade task and Stroop task) and two tasks tapping into the capacity to resist proactive interference (cued recall, Brown-Peterson variant) were administered to 30 non-amnesic recently detoxified alcohol-dependent individuals and 30 matched healthy participants without alcohol dependency. In addition, possible confounds such as verbal updating in working memory was assessed.

RESULTS

Alcohol-dependent subjects performed worse than healthy participants on the three cognitive tasks assessing the inhibition of irrelevant prepotent responses but group performance was similar in the tasks assessing overcoming proactive interference in memory, updating of working memory and abstract reasoning.

CONCLUSIONS

These findings suggest that alcohol-dependence is mainly associated with impaired capacity to intentionally suppress irrelevant prepotent response information. Control of proactive interference from memory is preserved. Theoretical and clinical implications are discussed.

Executive functions in adult offspring of alcohol-dependent probands: toward a cognitive endophenotype?

BACKGROUND

Executive function (EF) impairment in alcohol dependence (AD) has been related to the toxic effects of alcohol on frontal lobes. However, this impairment could be partially present before the onset of the disease and might constitute a vulnerability factor. Although a considerable body of research has investigated executive functioning among AD patients, much less attention has been directed toward high-risk individuals. Most studies were carried out among children or adolescents, and very few were conducted in adults. The aim of this study was to examine EF in a group of adult offspring of AD individuals.

METHODS

One hundred and fifty-five nonalcoholic adults with (family history positive [FHP]) or without (family history negative [FHN]) family history of AD were included in the study. All participants were screened for past and current psychiatric diagnoses, and alcohol, tobacco, and other substance use. They were compared on self-rated impulsiveness using the Barratt Impulsiveness Scale-11 (BIS-11) and EF using a neuropsychological test battery.

RESULTS

Group comparison revealed that FHP participants had significantly higher BIS-11 scores than the FHN participants, while neuropsychological examination revealed lower EF scores for FHP participants. Hierarchical regression analysis revealed that the number of AD family members was a predictor of EF results, whereas impulsiveness was not.

CONCLUSIONS

Nonalcoholic adult offspring of AD individuals showed increased impulsiveness and decreased EF, suggesting weakness of 2 distinct neurobehavioral decision systems. Findings support evidence that EF weaknesses may qualify as a suitable endophenotype candidate for AD.

The contribution of executive functions deficits to impaired episodic memory in individuals with alcoholism

Individuals with alcoholism commonly exhibit impaired performance on episodic memory tasks. However, the contribution of their impaired executive functioning to poor episodic memory remains to be clarified. Thirty-six recently detoxified and sober asymptomatic alcoholic men and 36 matched non-alcoholic participants were tested for processing speed, prepotent response inhibition, mental flexibility, coordination of dual-task and a verbal episodic memory task. Compared with non-alcoholic individuals, the alcoholic patients showed impaired executive functions combined with below normal performance on both free and delayed recall. In contrast, processing speed, cued recall and recognition were preserved. Regression analyses revealed that 47% of alcoholics' episodic memory's free recall performance was predicted by mental flexibility and that 49% of their delayed recall performance was predicted by mental flexibility, manipulation of dual-task and prepotent response inhibition. Regarding participants' executive predictors of episodic memory performance, the slopes of β coefficients were significantly different between the two groups, with alcoholics requiring more their executive system than non-alcoholics. Once detoxified, alcoholic patients showed episodic memory deficits mainly characterized by impaired effortful (executive) processes. Compared with controls, patients used effortful learning strategies, which are nonetheless less efficient.

Widespread and sustained cognitive deficits in alcoholism: a meta-analysis

The cognitive repercussions of alcohol dependence are well documented. However, the literature remains somewhat ambiguous with respect to which distinct cognitive functions are more susceptible to impairment in alcoholism and to how duration of abstinence affects cognitive recovery. Some theories claim alcohol negatively affects specific cognitive functions, while others assert that deficits are more diffuse in nature. This is the first meta-analysis to examine cognition in alcohol abuse/dependence and the duration of abstinence necessary to achieve cognitive recovery. A literature search yielded 62 studies that assessed cognitive dysfunction among alcoholics. Effect size estimates were calculated using the Comprehensive Meta-Analysis V2, for the following 12 cognitive domains: intelligence quotient, verbal fluency/language, speed of processing, working memory, attention, problem solving/executive functions, inhibition/impulsivity, verbal learning, verbal memory, visual learning, visual memory and visuospatial abilities. Within these 12 domains, three effect size estimates were calculated based on abstinence duration. The three groups were partitioned into short- (< 1 month), intermediate- (2 to 12 months) and long- (> 1 year) term abstinence. Findings revealed moderate impairment across 11 cognitive domains during short-term abstinence, with moderate impairment across 10 domains during intermediate term abstinence. Small effect size estimates were found for long-term abstinence. These results suggest significant impairment across multiple cognitive functions remains stable during the first year of abstinence from alcohol. Generally, dysfunction abates by 1 year of sobriety. These findings support the diffuse brain hypothesis and suggest that cognitive dysfunction may linger for up to an average of 1 year post-detoxification from alcohol.

The relationships of 'ecstasy' (MDMA) and cannabis use to impaired executive inhibition and access to semantic long-term memory

This study aimed to examine the relationship between the consumption of ecstasy (3,4-methylenedioxymethamphetamine (MDMA)) and cannabis, and performance on the random letter generation task which generates dependent variables drawing upon executive inhibition and access to semantic long-term memory (LTM). The participant group was a between-participant independent variable with users of both ecstasy and cannabis (E/C group, n = 15), users of cannabis but not ecstasy (CA group, n = 13) and controls with no exposure to these drugs (CO group, n = 12). Dependent variables measured violations of randomness: number of repeat sequences, number of alphabetical sequences (both drawing upon inhibition) and redundancy (drawing upon access to semantic LTM). E/C participants showed significantly higher redundancy than CO participants but did not differ from CA participants. There were no significant effects for the other dependent variables. A regression model comprising intelligence measures and estimates of ecstasy and cannabis consumption predicted redundancy scores, but only cannabis consumption contributed significantly to this prediction. Impaired access to semantic LTM may be related to cannabis consumption, although the involvement of ecstasy and other stimulant drugs cannot be excluded here. Executive inhibitory functioning, as measured by the random letter generation task, is unrelated to ecstasy and cannabis consumption.

Distinct effects of protracted withdrawal on affect, craving, selective attention and executive functions among alcohol-dependent patients

AIMS

The present study examined the effects of protracted alcohol withdrawal on affectivity, craving, selective attention and executive functions (EFs) in alcohol-dependent patients.

METHODS

Selective attention (The D2 Cancellation Test), flexibility (Trail Making Test), inhibition (Stroop Task), decision making (Iowa Gambling Task), craving (Obsessive-Compulsive Drinking Scale) and state affectivity (Positive and Negative Affectivity Schedule) were assessed in alcohol-dependent patients (DSM-IV, n = 35) matched to non-alcohol-dependent participants (n = 22) at the onset (T1: day 1 or 2) and at the end (T2: days 14-18) of protracted withdrawal during rehab.

RESULTS

Alcohol-dependent patients' abilities to focus their attention on relevant information, to switch from one pattern to another, to inhibit irrelevant information and to make advantageous choices were lower than those of control participants during both times of a withdrawal cure. No effect of time emerged from analyses for selective attention and EF deficits. Conversely, significant differences between T1 and T2 were observed for craving and affect scores indicating a weakening of alcohol craving and negative affect as well as an improvement of positive affect among patients from onset to the end of cure.

CONCLUSION

Control functions of the Supervisory Attentional System (Norman and Shallice, 1986) were impaired and did not improve during a 3-week withdrawal cure, whereas alcohol craving and negative state affectivity significantly improved in parallel during this period. Implications for understanding the clinical processes of withdrawal are discussed.

Arithmetic difficulties in children with cerebral palsy are related to executive function and working memory

BACKGROUND

Although it is believed that children with cerebral palsy are at high risk for learning difficulties and arithmetic difficulties in particular, few studies have investigated this issue.

METHODS

Arithmetic ability was longitudinally assessed in children with cerebral palsy in special (n = 41) and mainstream education (n = 16) and controls in mainstream education (n = 16). Second grade executive function and working memory scores were used to predict third grade arithmetic accuracy and response time.

RESULTS

Children with cerebral palsy in special education were less accurate and slower than their peers on all arithmetic tests, even after controlling for IQ, whereas children with cerebral palsy in mainstream education performed as well as controls. Although the performance gap became smaller over time, it did not disappear. Children with cerebral palsy in special education showed evidence of executive function and working memory deficits in shifting, updating, visuospatial sketchpad and phonological loop (for digits, not words) whereas children with cerebral palsy in mainstream education only had a deficit in visuospatial sketchpad. Hierarchical regression revealed that, after controlling for intelligence, components of executive function and working memory explained large proportions of unique variance in arithmetic accuracy and response time and these variables were sufficient to explain group differences in simple, but not complex, arithmetic.

CONCLUSIONS

Children with cerebral palsy are at risk for specific executive function and working memory deficits that, when present, increase the risk for arithmetic difficulties in these children.

Recollective experience in alcohol dependence: a laboratory study

AIMS

Alcohol dependence has been linked to dysfunction of fronto-temporo-striatal circuits which mediate memory and executive function. The present study aimed to explore the specificity of recognition memory changes in alcohol dependence.

DESIGN

setting and participants Twenty hospitalized alcohol-dependent detoxified patients and 20 healthy control subjects completed a verbal list discrimination task. Measurements Hits and false alarm rates were analysed. Additionally, both the dual process signal detection model (DPSD) and the process dissociation procedure (PDP) were used to derive estimates of the contribution of recollection and familiarity processes to the recognition memory performance in patients and controls.

FINDINGS

Alcohol-dependent patients showed intact hit rates, but increased false alarm rates and an impaired ability to remember the learning context. Both the DPSD model and PDP estimates yielded significantly reduced recollection estimates in the alcohol-dependent compared to control subjects. Whether or not familiarity was impaired, depended upon the sensitivity of the estimation procedure.

CONCLUSION

Taken together, the result pattern suggests a significant impairment in recollection and mild familiarity changes in recently detoxified, predominantly male, alcohol-dependent subjects.

Cognitive dysfunction associated with elemental mercury ingestion and inhalation: a case study

A 63-year-old man with a history of alcohol dependence ingested elemental mercury as a suicide gesture. Serial abdominal X-rays showed gradual but incomplete clearance of mercury from the colon. Routine chest X-ray showed evidence of punctate radiopaque materials in the lower lobe of the right lung. Blood and urine mercury levels both exceeded thresholds considered to be associated with cognitive dysfunction. Elicited cognitive deficits were most prominent in processing speed, flexibility, and response inhibition. Semantic fluency, visuospatial processing, and recall memory for visual and low-context verbal material were also affected. The deficits may have been attributable primarily to alcohol abuse. Elemental mercury is not readily absorbed from the gastrointestinal tract; however, mercury vapor, which was inhaled inadvertently, readily crosses the blood-brain barrier and is neurotoxic. We argue, therefore, that mercury toxicity is more likely than not to have been a factor contributing to the patient's cognitive dysfunction.

Delay discrimination and reversal eyeblink classical conditioning in abstinent chronic alcoholics

Evidence has shown that alcoholism leads to volume reductions in brain regions critical for associative learning using the eyeblink classical conditioning paradigm (EBCC). Evidence indicates that cerebellar shrinkage causes impairment in simple forms of EBCC, whereas changes in forebrain structures result in impairment in more complex tasks. In this study, the ability of abstinent alcoholics and matched control participants to acquire learned responses during delay discrimination and discrimination reversal was examined and related to severity of drinking history and neuropsychological performance. During discrimination learning, one tone (CS+) predicted the occurrence of an airpuff (unconditioned stimulus), and another tone (CS-) served as a neutral stimulus; then the significance of the tones was reversed. Alcoholics who learned the initial discrimination were impaired in acquiring the new CS+ after the tones reversed; this is a function that has previously been linked to forebrain structures. It is suggested that a factor important to alcoholic addiction may be the presence of alcoholic-related associative responses that interfere with the ability to learn new more adaptive associations.

Impaired stimulus-outcome but preserved stimulus-response shifting in young substance-dependent individuals

Substance dependency has been related to an impairment in executive functions and to a dysfunction of the frontal cortex. In this study we developed two experimental tasks, which are physically identical, to analyze whether substance-dependent individuals are impaired in shifting response patterns (stimulus response links) or preferences (stimulus outcome links). To increase the specificity of the dependent variable, we also used two control tasks to analyze for unspecific performance deficits. We included 35 young subjects with polysubstance abuse (International Classification of Diseases, F19.2 ICD 10 diagnosis, mean age of 22 years, maximum age < 27 years) and 18 normal controls, but for a first step focused on only 22 patients and 15 age-matched controls, because we excluded all patients with an IQ below 100. The results show that the substance-dependent individuals are selectively impaired in shifting object preference (stimulus-outcome links) and not in shifting response patterns. They moreover show a higher general impulsivity as reflected in their faster responses than controls on all tasks except the stimulus-outcome task. In a second step we replicated these results by analyzing the original groups of 35 patients and 18 controls. We argue that substance-dependent subjects show an impairment only on specific executive tasks, and these tasks concern stimulus-outcome link shifting, which has been associated with the functioning of the orbitofrontal cortex, not of the lateral prefrontal cortex.

Rule knowledge aids performance on spatial and object alternation tasks by alcoholic patients with and without Korsakoff's amnesia

Delayed alternation (DA) and object alternation (OA) tasks traditionally have been used to measure defective response inhibition associated with dysfunction of frontal brain systems. However, these tasks are also sensitive to nonfrontal lesions, and cognitive processes such as the induction of rule-learning strategies also are needed in order to perform well on these tasks. Performance on DA and OA tasks was explored in 10 patients with alcohol-induced persisting amnestic disorder (Korsakoff's syndrome), 11 abstinent long-term alcoholics, and 13 healthy non-alcoholic controls under each of two rule provision conditions: Alternation Rule and Correction Rule. Results confirmed that rule knowledge is a crucial cognitive component for solving problems such as DA and OA, and therefore, that errors on these tasks are not due to defective response inhibition alone. Further, rule-induction strategies were helpful to Korsakoff patients, despite their poorer performance on the tasks. These results stress the role of multiple cognitive abilities in successful performance on rule induction tasks. Evidence that these cognitive abilities are served by diffusely distributed neural networks should be considered when interpreting behavioral impairments on these tasks.

Genuine episodic memory deficits and executive dysfunctions in alcoholic subjects early in abstinence

BACKGROUND

Chronic alcoholism is known to impair episodic memory function, but the specific nature of this impairment is still unclear. Moreover, it has never been established whether episodic memory deficit in alcoholism is an intrinsic memory deficit or whether it has an executive origin. Thus, the objectives are to specify which episodic memory processes are impaired early in abstinence from alcohol and to determine whether they should be regarded as genuine memory deficits or rather as the indirect consequences of executive impairments.

METHODS

Forty recently detoxified alcoholic inpatients at alcohol entry treatment and 55 group-matched controls underwent a neuropsychological assessment of episodic memory and executive functions. The episodic memory evaluation consisted of 3 tasks complementing each other designed to measure the different episodic memory components (learning, storage, encoding and retrieval, contextual memory, and autonoetic consciousness) and 5 executive tasks testing capacities of organization, inhibition, flexibility, updating, and integration.

RESULTS

Compared with control subjects, alcoholic patients presented impaired learning abilities, encoding processes, retrieval processes, contextual memory and autonoetic consciousness. However, there was no difference between the 2 groups regarding the storage capacities assessed by the rate of forgetting. Concerning executive functions, alcoholic subjects displayed deficits in each executive task used. Nevertheless, stepwise regression analyses showed that only performances on fluency tasks were significantly predictive of some of the episodic memory disorders (learning abilities for 40%, encoding processes for 20%, temporal memory for 21%, and state of consciousness associated with memories for 26%) in the alcoholic group.

DISCUSSION

At alcohol treatment entry, alcoholic patients present genuine episodic memory deficits that cannot be regarded solely as the consequences of executive dysfunctions. These results are in accordance with neuroimaging findings showing hippocampal atrophy. Moreover, given the involvement of episodic memory and executive functions in alcohol treatment, these data could have clinical implications.

Alcohol cues increase cognitive impulsivity in individuals with alcoholism

BACKGROUND

Individuals with alcoholism are characterized by both attentional bias for alcohol cues and prepotent response inhibition deficit. We tested the hypothesis that alcoholics exhibit greater cognitive disinhibition when the response to be suppressed is associated with alcohol-related information.

METHODS

Forty recently detoxified individuals with alcoholism were compared with 40 healthy non-substance abusers on the "Alcohol-Shifting Task", a variant of the go/no-go paradigm requiring a motor response to targets and no response to distracters. The aim was to test the ability of alcoholics to discriminate between alcohol-related and neutral words. Sometimes, the alcohol-related words were the targets for the "go" response, with neutral words as distracters, sometimes the reverse. Several shifts in target type occurred during the task.

RESULTS

Alcoholics made significantly more commission errors (i.e., press a key when a distracter displayed) and more omission errors (i.e., not press a key when a target displayed) than controls. Moreover, the number of commission errors was greater in alcoholics when alcohol-related stimuli had to be detected.

CONCLUSIONS

These results demonstrate that alcoholics exhibit a basic prepotent response inhibition deficit, which is enhanced when the response to be suppressed is related to alcohol. We discuss clinical and theoretical implications of these findings.

Response inhibition and cognitive flexibility in schizophrenia with and without comorbid substance use disorder

Addiction is a frequent comorbid disorder in schizophrenia related to dopaminergic dysfunction in fronto-subcortical circuits. These brain networks are relevant for both (executive) cognition and the neuropathology of schizophrenia. The aim of the present study was to elucidate whether response inhibition and cognitive flexibility - executive abilities relevant for achieving and maintaining abstinence - are differentially impaired in schizophrenia patients with or without comorbid substance use disorder. Patients suffering from major depression or alcoholism as well as healthy controls served as comparison groups. The ability to inhibit predominant response tendencies during response conflict and to efficiently shift the focus of attention between different task requirements was assessed by verbal and non-verbal cognitive tasks. Contrary to expectation, non-addicted schizophrenia patients showed the most pronounced executive function impairments relative to the control groups, affecting both response suppression and cognitive flexibility. Dual diagnosis patients did not differ significantly from non-addicted schizophrenia patients or from the alcoholic group, but were impaired at cognitive flexibility relative to the depression subgroup and healthy controls. Whether the relative preservation of response inhibition and cognitive flexibility in the dual disorder patients is due to high premorbid functioning, beneficial self-medication effects or compensatory brain activation remains to be elucidated. The relatively intact executive abilities in young, addicted schizophrenia patients might represent a beneficial resource for treatment strategies.