Executive cognitive functioning in alcohol use disorders

Working memory and multi-tasking in paranoid schizophrenia with and without comorbid substance use disorder

AIMS

Addiction is a frequent comorbid disorder in schizophrenia and associated with poor outcome. The present study sought to determine whether addicted and non-addicted schizophrenic patients are impaired differentially on the executive abilities of working memory and multi-tasking which are relevant for maintaining abstinence.

DESIGN

Comparisons of executive performance in clinical and control groups.

SETTING

In-patient setting.

PARTICIPANTS

The cognitive profile of schizophrenic patients with and without comorbid substance abuse disorder was compared with that of patients suffering from major depression or alcoholism and healthy participants.

MEASUREMENTS

A range of cognitive tasks was used to assess: (i) the ability to update continuously context information in working memory and to use it for action selection; and (ii) the capacity to divide attention between different sensory input channels and to coordinate verbal and manual responses.

FINDINGS

Single-diagnosis schizophrenic patients showed pronounced impairments on measures of online maintenance and use of context information. Their ability to coordinate different sensory input channels (divided attention) was also impaired. Addicted schizophrenics showed evidence of impaired sensory input management and of reduced context sensitivity, when age differences were controlled.

CONCLUSIONS

The present study indicates severe working memory and multi-tasking deficits in schizophrenia which are, however, not exacerbated by comorbid addiction.

Brain activation, response inhibition, and increased risk for substance use disorder

BACKGROUND

Youth at high risk for developing substance use disorders (SUDs) often exhibit differences which suggest inhibitory impairments when compared to average risk youth.

METHODS

To examine the underlying neural activity related to these impairments, functional MRI (fMRI) was employed in adolescents during an antisaccade task requiring inhibition of an eye movement response. Each subject's level of neurobehavioral disinhibition (ND) was assessed using a multi-informant, multi-method approach, which has been shown to be highly predictive of SUD onset. The fMRI data was categorized into neural regions of interest according to total frontal, parietal, occipital, and temporal lobe activation.

RESULTS

Results demonstrated that ND score was negatively correlated with total amount of frontal activation, but was not significantly correlated with total activation in any other neural region.

CONCLUSIONS

These results indicate deficits in frontal activation in youth with high amounts of ND, suggesting a possible developmental delay of executive processes in high-risk youth.

Early developmental processes and the continuity of risk for underage drinking and problem drinking

Developmental pathways to underage drinking emerge before the second decade of life. Many scientists, however, as well as the general public, continue to focus on proximal influences surrounding the initiation of drinking in adolescence, such as social, behavioral, and genetic variables related to availability and ease of acquisition of the drug, social reinforcement for its use, and individual differences in drug responses. In the past 20 years, a considerable body of evidence has accumulated on the early (often much earlier than the time of the first drink) predictors and pathways of youthful alcohol use and abuse. These early developmental influences involve numerous risk, vulnerability, promotive, and protective processes. Some of these factors are not related directly to alcohol use, whereas others involve learning and expectancies about later drug use that are shaped by social experience. The salience of these factors (identifiable in early childhood) for understanding the course and development of adult alcohol and other drug use disorders is evident from the large and growing body of findings on their ability to predict adult clinical outcomes. This review summarizes the evidence on early pathways toward and away from underage drinking, with a particular focus on the risk and protective factors and the mediators and moderators of risk for underage drinking that become evident during the preschool and early school years. It is guided by a developmental perspective on the aggregation of risk and protection and examines the contributions of biological, psychological, and social processes within the context of normal development. Implications of this evidence for policy, intervention, and future research are discussed.

The role of self-reported impulsivity and reward sensitivity versus neurocognitive measures of disinhibition and decision-making in the prediction of relapse in pathological gamblers

BACKGROUND

Disinhibition and decision-making skills play an important role in theories on the cause and outcome of addictive behaviors such as substance use disorders and pathological gambling. In recent studies, both disinhibition and disadvantageous decision-making strategies, as measured by neurocognitive tests, have been found to influence the course of substance use disorders. Research on factors affecting relapse in pathological gambling is scarce.

METHOD

This study investigated the effect of both self-reported impulsivity and reward sensitivity, and neurocognitively assessed disinhibition and decision-making under conflicting contingencies, on relapse in a group of 46 pathological gamblers.

RESULTS

Logistic regression analysis indicated that longer duration of the disorder and neurocognitive indicators of disinhibition (Stop Signal Reaction Time) and decision-making (Card Playing Task) were significant predictors of relapse (explaining 53% of the variance in relapse), whereas self-reported impulsivity and reward sensitivity did not significantly predict relapse. Overall classification accuracy was 76%, with a positive classification accuracy of 76% and a negative classification accuracy of 75%.

CONCLUSIONS

Duration of the disorder and neurocognitive measures of disinhibition and decision-making are powerful predictors of relapse in pathological gambling. The results suggest that endophenotypical neurocognitive characteristics are more promising in the prediction of relapse in pathological gambling than phenotypical personality characteristics. Neurocognitive predictors may be useful to guide treatment planning of follow-up contacts and booster sessions.

Social networks and their influence on drinking behaviors: differences related to cognitive impairment in clients receiving alcoholism treatment

OBJECTIVE

Mechanisms of behavioral change that support positive addiction treatment outcomes in individuals with co-occurring alcohol-use disorders and cognitive impairment remain largely unknown. This article combines person- and variable-centered approaches to examine the interrelated influence of cognitive impairment and social support on stability of and changes in drinking behaviors of Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity) outpatients and aftercare clients (N = 1,726) during the first year after their entry into treatment.

METHOD

Latent class analysis identified homogeneous groups of clients based on the nature and extent of social support for abstinence or drinking at treatment entry. Cognitive impairment and drinking outcomes were compared across latent classes, and the interaction between impairment and social support on drinking outcomes was examined using mixture probit regression.

RESULTS

Three independent social support classes (frequent positive, limited positive, and negative) were identified. In the outpatient sample, the frequent positive support class had greater cognitive impairment at treatment entry versus other classes, and extent of impairment significantly predicted improved drinking outcomes in this class. In the aftercare sample, the frequent positive and negative support classes had heightened impairment, yet cognitive impairment significantly predicted relatively poorer drinking outcomes in the negative support class only.

CONCLUSIONS

Cognitive impairment may increase the influence of the social network on the drinking outcomes of persons receiving treatment for alcohol-use disorders, but more research is needed to understand client characteristics that determine whether this influence is more likely to be manifest as increased salience of helping agents or of hindering agents in the social network.

Decision making and binge drinking: a longitudinal study

BACKGROUND

Behavioral decision making, as measured by the Iowa Gambling Task (IGT) is found to be diminished in individuals with substance dependence and other types of disinhibitory psychopathology. However, little is known regarding the relation between heavy alcohol use and decision-making skills in young adults. This study therefore investigated whether binge drinking is related to disadvantageous decision making, as measured by the IGT. We also examined the relation between decision making and impulsivity.

METHODS

Latent class growth analysis was used to classify college students into 4 groups (each group n=50, 50% male), based on their binge drinking trajectories over a 2-year time period (precollege through second year of college). Participants were 200 college students, divided in 4 subgroups: (1) low binge drinkers, (2) stable moderate binge drinkers, (3) increasing binge drinkers, and (4) stable high binge drinkers. A measure of decision making, the IGT, impulsivity questionnaires, and multiple indicators of heavy alcohol use were included.

RESULTS

The stable high binge-drinking group made less advantageous choices on the IGT than the low binge-drinking group. Impulsivity was not related to decision-making performance. Decision-making performance did not differ by gender, but deck preferences and decision time patterns did differ; women preferred low frequency, high amount punishments to a greater extent than men.

CONCLUSIONS

Although disadvantageous decision making is related to binge-drinking patterns in emerging adulthood, this relation is independent of impulsivity. Additionally, the association appears attributable to those who engage in heavy (binge) drinking at an early age, but not to age of onset of drinking in general.

Blunted rostral anterior cingulate response during a simplified decoding task of negative emotional facial expressions in alcoholic patients

BACKGROUND

Alcoholism is characterized by deficits in emotional functioning as well as by deficits in cognitive functioning. However, most brain imaging research on alcoholism has focused on cognition rather than emotion.

METHOD

We used an event-related functional magnetic imaging approach to examine alcoholics' brain blood oxygenation level dependent (BOLD) response to evaluation of emotional stimuli and to compare their response to that of nonalcoholic controls. The task used was a simplified variant of a facial emotion-decoding task in which subjects determined the intensity level of a target emotion displayed as a facial expression. Facial expressions of happy, sad, anger, disgust, and fear were used as stimuli.

RESULTS

Alcoholics and controls did not differ in accurately identifying the intensity level on the simple emotional decoding task but there were significant differences in their BOLD response during evaluation of facial emotion. In general, alcoholics showed less brain activation than nonalcoholic controls. The greatest differences in activation were during decoding of facial expressions of fear and disgust during which alcoholics had significantly less activation than controls in the affective division of the anterior cingulate cortex (ACC). Alcoholics also had significantly less activation than controls in the affective division of the ACC, while viewing sad faces. Only to facial expressions of anger did the alcoholics show significant activation in the affective ACC and in this case, their BOLD response did not significantly differ from that of the controls.

CONCLUSION

Alcoholics show a deficit in the function of the affective division of the ACC during evaluation of negative facial emotions that can serve as cues for flight or avoidance. This deficit may underlie some of the behavioral dysfunction in alcoholism.

Stress-response-dampening effects of alcohol: attention as a mediator and moderator

The present study sought to characterize alcohol's stress-response-dampening (SRD) effects on multiple measures of stress and whether these effects are mediated by reductions in sustained attention and, further, whether baseline levels of sustained attention moderate SRD. One hundred six men consumed either an alcohol (0.70 g/kg) or a placebo beverage prior to learning that they would deliver a self-disclosing speech. Structural equation models controlling for multiple baseline periods indicated that alcohol directly reduced self-reported anxiety and skin conductance levels in response to the stressor. Alcohol's effect on reducing heart rate response, in contrast, was indirect and mediated by effects on prestress baseline. As hypothesized, differences in sustained attention partially mediated the effects of alcohol on skin conductance (but not heart rate or self-reported anxiety) and served as a moderator of alcohol's effects on skin conductance response. Findings are discussed in terms of theoretical links among alcohol consumption, specific cognitive abilities, and stress reactivity.

The underlying role of aggressivity in the relation between executive functioning and alcohol consumption

The research literature on the relation between cognitive functioning and alcohol consumption is inconsistent and difficult to interpret. The purpose of this study was to test a causal model that might help reconcile some of these conflicts. The model specifies that aggressivity is an important intermediary mechanism underlying the relation between executive functioning (EF) and alcohol consumption. Participants were 310 (152 men and 158 women) healthy social drinkers between 21 and 35 years of age tested in a laboratory setting. EF was measured with a battery of neuropsychological tests. Aggressivity and alcohol consumption (as well as cigarette and drug use frequency) were measured with self-report and interview formats. Aggressivity played a mechanistic role in the relation between EF and alcohol/drug use for men but not for women. Women evinced some unexpected positive relations between EF and alcohol use. This study serves as a first step in trying to reconcile previous inconsistent findings regarding the relation between cognitive functioning and alcohol use by demonstrating that a better understanding of this relation involves considering aggressivity as an intermediary variable.

Suppression of early evoked gamma band response in male alcoholics during a visual oddball task

We investigated the early evoked gamma frequency band activity in alcoholics (n=122) and normal controls (n=72) during a visual oddball task. A time-frequency representation method was applied to EEG data in order to obtain phase-locked gamma band activity (29-45 Hz) and was analyzed within a 0-150 ms time window range. Significant reduction of the gamma band response in the frontal region during target stimulus processing was observed in alcoholic compared to control subjects. In contrast, significantly higher gamma band response for the non-target stimulus was observed in alcoholics compared to controls. It is suggested that the reduction in early evoked frontal gamma band response to targets may be associated with frontal lobe dysfunction commonly observed in alcoholics. This perhaps can be characterized by a deficient top-down processing mechanism.

Event-related oscillations in offspring of alcoholics: neurocognitive disinhibition as a risk for alcoholism

BACKGROUND

Event-related oscillations (EROs) are increasingly being used to assess neurocognitive functioning in normal and clinical populations. The current study compares different frequency activities in offspring of alcoholics (OA) and in normal control subjects (NC) to examine whether the OA group exhibits any abnormality in oscillatory activity while performing a Go/NoGo task.

METHODS

The S-transform algorithm was employed to decompose the electroencephalographic (EEG) signals into different time-frequency bands, and the oscillatory responses in the P300 time window (300-700 milliseconds) were statistically analyzed in both groups.

RESULTS

The OA group manifested significantly decreased activity in delta (1-3 Hz), theta (4-7 Hz), and alpha1 (8-9 Hz) bands during the NoGo condition, as well as reduced delta and theta activity during the Go condition. This reduction was more prominent in the NoGo than in the Go condition.

CONCLUSIONS

The decreased response in delta, theta, and alpha1 oscillations, especially during the NoGo condition in high-risk individuals, is perhaps suggestive of cognitive and neural disinhibition and may serve as an endophenotypic marker in the development of alcoholism and/or other disinhibitory disorders.

Neurocognitive skills moderate urban male adolescents' responses to preventive intervention materials

The present experiment was designed to determine whether individual variation in neurobiological mechanisms associated with substance abuse risk moderated effects of a brief preventive intervention on social competency skills. This study was conducted in collaboration with the ongoing preventive intervention study at Johns Hopkins University Prevention Intervention Research Center (JHU PIRC) within the Baltimore City Public Schools. A subsample (N = 120) of male 9th grade students was recruited from the larger JHU study population. Approximately half of the participants had a current or lifetime diagnosis of CD while the other half had no diagnosis of CD or other reported problem behaviors. Measures of executive cognitive function (ECF), emotional perception and intelligence were administered. In a later session, participants were randomly assigned to either an experimental or control group. The experimental group underwent a facilitated session using excerpted materials from a model preventive intervention, Positive Adolescent Choices Training (PACT), and controls received no intervention. Outcomes (i.e., social competency skills) were assessed using virtual reality vignettes involving behavioral choices as well as three social cognition questionnaires. Poor cognitive and emotional performance and a diagnosis of CD predicted less favorable change in social competency skills in response to the prevention curriculum. This study provides evidence for the moderating effects of neurocognitive and emotional regulatory functions on ability of urban male youth to respond to preventive intervention materials.

Recent drinking consequences, motivation to change, and changes in alcohol consumption over a three month period

Little is known about what type of drinking related consequences may enhance motivation to change or may hinder behavior change over time. In order to examine this research question, 120 adult participants abusing alcohol were administered the Drinker Inventory of Consequences-Recent (DrInC-R), the Brief Readiness to Change Questionnaire (BRTC), and the Steady Pattern Chart (SP). Subscale scores from the DrInC-R and the BRTC; and alcohol consumption as assessed by the SP at baseline and three month follow-up were retained for data analyses. Greater intrapersonal DrInC-R consequences scores significantly predicted greater contemplation stage scores (R2=.37, p<.001), and lower precontemplation stage scores (R2=.32, p<.001), and DrInC-R impulse control and interpersonal consequences scores significantly predicted alcohol consumption at three month follow-up after controlling for baseline consumption (R2=.50, p<.001). Increased awareness of intrapersonal drinking related consequences may motivate change, whereas numbers of impulse control and interpersonal consequences may predict changes in drinking behavior over the short-term.

Using Virtual Reality to Study Alcohol Intoxication Effects on the Neural Correlates of Simulated Driving

The use of virtual reality in the form of simulated tasks can provide a realistic environment in which to study complex naturalistic behaviors. Many of the behavioral effects of alcohol intoxication are well known, but there is relatively little imaging evidence examining how alcohol exposure might transiently modulate brain function, especially in the context of task performance. In this review, we provide a brief synopsis of previous work using functional magnetic resonance imaging (fMRI) to study the neural correlates of alcohol intoxication. We describe in detail two studies from our published work, the first involving a visual perception paradigm, and the second involving virtual reality through a naturalistic behavior; simulated driving. Participants received single-blind individualized doses of beverage alcohol designed to produce blood alcohol content (BAC) of 0.04 and 0.08 or placebo. Subjects were fMRI scanned after training to asymptote performance. In both studies we found specific circuits that were differentially modulated by alcohol, we revealed both global and local effects of alcohol, and we examined relationships between behavior, brain function, and alcohol blood levels.

Spatial-anatomical mapping of NoGo-P3 in the offspring of alcoholics: evidence of cognitive and neural disinhibition as a risk for alcoholism

OBJECTIVE

The concept of disinhibition as a behavioral and biological trait has been considered to be involved in the etiology of alcoholism and its co-existing disorders. The magnitude and functional mapping of event-related potential P3(00) components were analyzed, in order to examine the possible response inhibition deficits in the offspring of alcoholics.

METHODS

The P3 components were compared between 50 offspring of alcoholics (OA) and a matched normal control group (NC) using a visual Go/NoGo task. The low-resolution electromagnetic tomography (LORETA) was used to analyze the functional brain mapping between groups.

RESULTS

The results indicated that the OA group manifested decreased P3 amplitude during the NoGo but not the Go condition compared to the NC group. The voxel-by-voxel analysis in LORETA showed group differences at several brain regions including prefrontal areas during the processing of NoGo but not Go signals.

CONCLUSIONS

The decreased NoGo-P3 suggests that cognitive and neural disinhibition in offspring of alcoholics may serve as a neurocognitive index for a phenotypic marker in the development of alcoholism and related disorders.

SIGNIFICANCE

Dysfunctional neural and response inhibition in the offspring of alcoholics perhaps provides an endophenotypic marker of risk for the development of alcoholism and related disorders.

Alcoholism is a disinhibitory disorder: neurophysiological evidence from a Go/No-Go task

Response inhibition is considered a core dimension in alcoholism and its co-existing disorders. The major objective of this study is to compare the magnitude and spatial distribution of ERP components during response activation and inhibition in alcoholics (N = 30) and normal controls (N = 30) using a visual Go/No-Go task. The results indicate that alcoholics manifest a decreased P3(00) amplitude during Go as well as No-Go conditions. The difference between Go and No-Go processing was more evident in controls than in alcoholics. The topography of current source density in alcoholics during the P3 response was found to be very different from that of normals, suggesting that alcoholics perhaps activated inappropriate brain circuitry during cognitive processing. The significantly reduced No-Go P3 along with the relatively less anteriorized CSD topography during No-Go condition suggests poor inhibitory control in alcoholics. It is proposed that the No-Go P3, the electrophysiological signature of response inhibition, can be considered as an endophenotypic marker in alcoholism.

Impulsivity in abstinent alcohol-dependent patients: relation to control subjects and type 1-/type 2-like traits

Extensive literature has linked behavior control problems in childhood to risk for alcoholism, but impulsivity in alcohol-dependent adults has not been well characterized. Using a variety of laboratory measures of impulsivity, we assessed whether detoxified alcohol-dependent patients [(ADP); n = 130] were more impulsive than control subjects [(CS); n = 41]. In comparison with CS, ADP demonstrated (1) increased rates of commission errors, but not omission errors, in a continuous performance test, (2) a more severe devaluation of delayed reward, (3) increased rates of risky responses in a new risk-taking paradigm, and (4) higher psychometric scores of impulsivity and aggression. Across all subjects, aggressiveness correlated significantly with severity of delay discounting. A post hoc analysis of data obtained for male ADP indicated that, in comparison with patients with late onset of problem drinking and no problem-drinking parent, those ADP with earlier age of problem drinking and who reported a problem-drinking father (type 2-like alcohol dependence) demonstrated faster response latencies and more responses to non-target stimuli (commission errors) in the continuous performance test, as well as higher psychometric aggression. In contrast, these subtypes of male ADP did not differ in delay discounting and risk taking. These findings collectively indicate that, in comparison with CS, ADP are more impulsive in several dimensions, with elevated impulsivity in a working memory task as well as aggressivity characteristic of alcohol-dependent men with type 2-like features.

Executive Functioning Early in Abstinence From Alcohol

BACKGROUND

Executive dysfunction is among the cognitive impairments that may persist after abstinence in alcohol-dependent persons. The type(s) and extent of executive dysfunction early in abstinence have not been well characterized, but they may have important implications for the evolution of behavioral treatment strategies.

METHODS

To determine which aspects of executive functioning were impaired in early abstinence, we administered memory and executive function tests to veterans who successively presented for treatment at an outpatient substance abuse clinic. We then compared the neuropsychological performance of these recovering alcoholics (n = 27) with that of age-matched primary care outpatients (n = 18). We also examined group differences in self-evaluation of cognitive decline and evaluated associations between drinking history and cognitive impairment in the index group.

RESULTS

We found that the normal and alcohol-dependent groups differed on abstract reasoning, memory discrimination, and effectiveness on timed tasks. Patients in the alcohol-dependent sample were also more likely to perceive themselves as cognitively impaired. It is interesting to note that the duration of alcohol use did not relate to neuropsychological test performance, but recent quantity consumed and days of sobriety were associated with nonverbal abstract reasoning ability.

CONCLUSIONS

Executive functions are impaired early in abstinence and should, therefore, be taken into account when early behavioral treatments are being developed.

Pathological gambling: a comprehensive review of biobehavioral findings

In this review, findings of biobehavioral research into pathological gambling (PG) are discussed, focusing on neuropsychological, psychophysiological, neuroimaging, neurochemical and genetic studies. Neuropsychological studies indicate deficiencies in certain executive functions. Psychophysiological studies indicate that arousal in PG is of importance when reward is present. Neuroimaging studies point to abnormalities in brain functioning. Recent research into the neurochemistry of PG indicates that abnormalities exist in different neurotransmitter systems. Finally, genetic studies indicate the existence of abnormal dopamine receptor genes in PG. Methodological and theoretical factors that may explain discrepancies between studies include differences in screening and assessment, heterogeneity of gambling problems and different underlying cognitive or motivational mechanisms. Results from the PG studies fit in with recent theoretical models of addiction and PG, which stress the involvement of brain reward pathways, neurotransmitter abnormalities, the frontal cortex and the psychophysiological stress system. A framework for future studies is suggested, indicating the need for studies that integrate knowledge from different research areas, and that employ stricter diagnostic screening methods and inclusion of clinical control groups.

The role of brain oscillations as functional correlates of cognitive systems: a study of frontal inhibitory control in alcoholism

Event-related oscillations play a key role in understanding the brain dynamics and human information processing. In the present study, the Go/No-Go paradigm has been used to examine whether alcoholics have poor inhibitory control as compared to control subjects in terms of different oscillatory brain responses. The matching pursuit algorithm was used to decompose the event-related electroencephalogram into oscillations of different frequencies. It was found that alcoholics (n=58) showed significant reduction in delta (1.0-3.0 Hz) and theta (3.5-7.0 Hz) power during No-Go trials as compared to controls (n=29). This reduction was prominent at the frontal region. The decreased delta and theta power associated with No-Go processing perhaps suggests a deficient inhibitory control and information-processing mechanism. A neuro-cognitive model has been provided to explain the findings. It is suggested that the oscillatory correlates during cognitive processing can be an endophenotypic marker in alcoholism.

Depression and cognitive functioning in alcoholism

AIMS

Studies on cognitive processes in alcoholism have reported changes with respect to executive functions and memory, which have been interpreted within the context of different neuropsychological models. The aims of the present study were to investigate (1) the validity of these models and (2) the influence of depression on cognitive functioning in alcoholism.

DESIGN, SETTING AND PARTICIPANTS

In the present investigation, patients suffering from alcoholism (Alc; n = 30), patients with depression but without alcoholism (Dep; n = 28) and healthy controls (HC; n = 28) were compared on a neuropsychological test battery.

MEASUREMENTS

The test battery included measurements of mood, memory and executive functions. The possible cumulative effect of alcohol and depression was analysed by comparison of depressed alcoholic patients (Dalc) and non-depressed alcoholic patients (NDAlc).

FINDINGS

Group comparisons revealed impairments of alcoholic patients with respect to response inhibition, reasoning and free recall, irrespective of depression. Priming, short-term memory as well as verbal fluency abilities were unaffected. Depressive patients showed verbal fluency as well as free recall deficits. However, there was no difference in performance between depressed and non-depressed alcoholics.

CONCLUSIONS

The specific pattern of neuropsychological deficits of the alcoholic patients supports the frontal lobe hypothesis. The results of the present investigation suggest that these deficits are not generally exacerbated by comorbid depressive symptoms. Further studies, however, are desirable to investigate the relation between executive deficits and depression in alcoholics with evidence of major depression.

Executive functioning, temperament, and drug use involvement in adolescent females with a substance use disorder

BACKGROUND

This study determined whether temperament mediates the relation between executive functioning (EF) and drug use involvement and whether EF and temperament interact to account for unique variance in drug use involvement.

METHOD

Participants were 340, 14-18-year-old, adolescent females with a substance use disorder and controls. EF was measured using a battery of neuropsychological tests, temperament was assessed using the Dimensions of Temperament Survey--Revised, and drug use involvement was measured with the Drug Use Screening Inventory.

RESULTS

Temperament mediated the relation between EF and drug use involvement. Girls with a 'difficult' temperament exhibited significantly greater drug use involvement than girls with a 'good' temperament. Finally, low EF was significantly related to increased drug use involvement for girls with a good temperament, but not for girls with a difficult temperament.

CONCLUSIONS

The results suggest that a difficult temperament is a more important risk factor for drug use than low EF. Given previous studies that have shown significant relations between EF and drug use, further research on this topic is warranted.

Alcohol affects executive cognitive functioning differentially on the ascending versus descending limb of the blood alcohol concentration curve

BACKGROUND

Executive cognitive functioning (ECF), a construct that includes cognitive abilities such as planning, abstract reasoning, and the capacity to govern self-directed behavior, has been recently researched as an antecedent to many forms of psychopathology and has been implicated in alcohol-related aggression. This study was designed to examine whether differential ECF impairments can be noted on the ascending versus the descending limbs of the blood alcohol concentration curve.

METHODS

Forty-one male university students participated in this study. Twenty-one subjects were given 1.32 ml of 95% alcohol per kilogram of body weight, mixed with orange juice, and the remaining 20 were given a placebo. Participants were randomly assigned to either an ascending or descending blood alcohol group and were tested on six tests of ECF on their assigned limb. Subjective mood data were also collected.

RESULTS

Intoxicated participants on both limbs demonstrated ECF impairment; the descending-limb group showed greater impairment than their ascending-limb counterparts. Intoxicated subjects were significantly more anxious at baseline than placebo subjects. The introduction of this covariate nullified any significant differences in subjective mood found on either limb of the blood alcohol concentration curve, but ECF impairments remained robust.

CONCLUSIONS

Our results support the conclusion that alcohol negatively affects cognitive performance and has a differential effect on the descending versus the ascending limb of the blood alcohol concentration curve. The latter finding may have important ramifications relating to the detrimental consequences of alcohol intoxication.

Executive-cognitive functioning in the development of antisocial personality disorder

The present study examined the association of cognitive-executive abilities to two risk factors for alcoholism, i.e., antisocial behaviors and a family history (FH+) of alcohol dependence. A sample of 91 right-handed, non-substance-dependent, young male adults recruited from the community were classified into three groups: (1) a control group of n=32 men with no history of DSM-III-R childhood conduct disorder (CD) or antisocial personality disorder (ASPD); (2) n=25 men who met criteria for a DSM-III-R childhood CD diagnosis, but did not meet diagnostic criteria for ASPD (i.e., CD/ASPD-); and (3) n=34 men who met DSM-III-R criteria for ASPD. They were further divided into those with and without a positive family history of alcoholism. A two-way (Antisocial Profile (3)x Family History of Alcoholism (2)) ANOVA was used to compare several neuropsychological measures of executive-cognitive functioning (ECF) ability. Verbal abstraction ability was found to be significantly lower in ASPD subjects compared with controls and CD-only subjects, inversely related to antisocial behavior severity (as measured by symptom count). CD-only and control subjects' abstraction ability were statistically indistinguishable. FH+ was associated with increased errors in planning performance on the Porteus Maze Test and diminished performance on Luria's simple alternate-tapping motor tasks. The effect was more pronounced when inhibition of prepotent motor planning was required. Results are consistent with previous work examining ECF ability in antisocial samples that find subtle differences in ECF ability compared to controls. The findings suggest that normal versus abnormal behavioral outcome for children with conduct problems may be influenced by cognitive ability profile, perhaps because of varying maturational processes.

Regional cerebral blood flow and neuropsychological functioning in early and late onset alcoholism

The aim of the study was to compare late and early onset alcoholism with regard to regional cerebral blood flow (rCBF) and neuropsychological functioning. Ten late onset and 13 early onset male alcoholics were included in the study, the criterion being the age of onset for alcohol abuse. Six healthy male volunteers were included as a control group. Regional measures of cortical cerebral blood flow were assessed using Tc-99m-HMPAO single photon emission computed tomography (SPECT) after a detoxification period. When compared with the control group, the early onset group showed reduced relative perfusion in the left superior frontal region, while relative perfusion in the late onset group was deficient in both right and left superior frontal regions. Both groups of alcoholic patients also displayed impairment in frontal lobe functions and non-verbal memory. The results of this study indicate that early onset alcoholism is associated with hypoperfusion in the left superior frontal region while the late onset subtype is characterized by uniformly hypoperfused left and right superior frontal regions. Additionally, both groups of alcoholic patients exhibit an almost identical pattern of neuropsychological abnormalities mainly related to frontal lobe functions and non-verbal memory. Collectively these findings support previous evidence suggesting a key role of frontal lobe pathology in understanding the neurobiology of alcoholism.

Chronic alcoholism and the frontal lobe: which executive functions are imparied?

OBJECTIVE

Over the last decade, various hypotheses have been advanced concerning the cognitive functions affected by chronic alcoholism. The aim of this study was to identify the pattern of executive function impairment in chronic alcoholism, shedding light on possible differences between specific functions related to the frontal lobe.

METHODS

Twenty-two male alcoholics and 22 controls, matched for age, educational level and IQ, were enrolled in the study. MMPI and a battery of neuropsychological tests [i.e. digit symbol, trail making test, Stroop test, digit cancellation test, Wisconsin card sorting test (WCST), simple and choice reaction times] for assessing frontal lobe functioning were administered.

RESULTS

The alcoholics were found to be impaired in a wide range of executive domains, with the exception of the Stroop test, which nevertheless showed a trend towards statistically significant differences between patients and controls.

CONCLUSION

With the exception of aggression - our subjects did not have high aggression scale scores - the 'frontal lobe hypothesis', according to which alcoholic patients are impaired on function tests related to the frontal lobe, was therefore confirmed in our sample.