Substance-dependent Individuals Research Articles

Reduced Cognitive Processing of Alcohol Cues in Alcohol-Dependent Patients Seeking Treatment: An ERP Study

Substance-dependent individuals have been shown to display increased P3 amplitudes in response to substance-related stimuli. The P3 component of the event-related potential (ERP) has been associated with ‘motivated attention’ for substance cues. Enhanced processing of substance cues has not been unequivocally demonstrated in alcohol-dependent patients. The main goal of the present study was to further investigate electrophysiological processing of alcohol and non-alcohol (soft drink) cues in alcohol-dependent patients and controls. In addition, it was examined whether groups differed in the processing of positive emotional cues. Results showed that alcohol-dependent patients did not respond with more enlarged P3 amplitudes to alcohol cues than soft drink cues. At fronto-central sites they even showed reduced alcohol cue-elicited P3 amplitudes as compared to controls. These results are in line with results from studies using behavioral measures of cognitive processing and might be explained by the use of avoidance strategies, i.e., patients' effort to remain abstinent or control their alcohol use. There were no differences between groups regarding the processing of positive cues. Interpretations and implications of the findings are discussed.

Sex modulates approach systems and impulsivity in substance dependence

BackgroundPersonality traits such as pathological engagement in approach behaviors, high levels of impulsivity and heightened negative affect are consistently observed in substance dependent individuals (SDI). The clinical course of addiction has been shown to differ between sexes. For example, women increase their rates of consumption of some drugs of abuse more quickly than men. Despite the potential influence of personality and sex on features of addiction, few studies have investigated the interaction of these factors in substance dependence. MethodsFifty-one SDI (26 males, 25 females) and 66 controls (41 males, 25 females) completed the Behavioral Inhibition/Behavioral Activation System (BIS/BAS) Scales, the Barratt Impulsiveness Scale, and the Positive and Negative Affect Schedule (PANAS-X). Data were analyzed with 2×2 ANCOVAs testing for main effects of group, sex and group by sex interactions, adjusting for education level. ResultsSignificant group by sex interactions were observed for BAS scores [F(1,116)=7.03, p<.01] and Barratt Motor Impulsiveness [F(1,116)=6.11, p<.02] with female SDI showing the highest approach tendencies and impulsivity followed by male SDI, male controls, and finally female controls. SDI scored higher on negative affect [F(1,116)=25.23, p<.001] than controls. Behavioral Inhibition System scores were higher in women than men [F(1,116)=14.03, p<.001]. ConclusionHigher BAS and motor impulsivity in SDI women relative to SDI men and control women suggest that personality traits that have been previously associated with drug use may be modulated by sex. These factors may contribute to differences in the disease course observed in male compared to female drug users.

Decision making among HIV+ drug using men who have sex with men: A preliminary report from the Chicago Multicenter AIDS Cohort Study

HIV+ substance-dependent individuals (SDIs) make significantly poorer decisions than HIV– SDIs, but the neurocognitive mechanisms underlying this impairment have not been identified. We administered the Iowa Gambling Task (IGT), a measure of decision making under uncertain risk, and the Cups Task, a measure of decision making under specified risk, to a group of 56 HIV+ and 23 HIV– men who have sex with men (MSMs) with a history of substance dependence enrolled in the Multicenter AIDS Cohort Study. The IGT provides no explicit information regarding the contingencies for each possible choice, and the probability of each outcome remains ambiguous at least for the early trials; in contrast, the Cups Task provides explicit information about the probability of each outcome. The HIV+ group made significantly poorer decisions on the IGT than the HIV– group. Cups Task performance did not differ significantly between HIV– and HIV+ groups. Exploratory analyses of the IGT data suggested that HIV+ subjects tended to perform more poorly during the early learning phase when uncertainty about specific outcomes was greatest. Additionally, performance on the final two trial blocks was significantly correlated with Stroop Interference scores, suggesting that IGT performance is driven increasingly by executive control during the later portion of the task. Potential cognitive mechanisms to be explored in later studies are discussed, including impairment in implicit learning processing.

PTSD risk associated with a functional DRD2 polymorphism in heroin‐dependent cases and controls is limited to amphetamine‐dependent individuals

Posttraumatic stress disorder (PTSD), a pathologic response to severe stress, is a common co-morbid disorder in substance-dependent individuals. Evidence from twin studies suggests that PTSD is moderately heritable. Genetic association studies to date have reported a limited number of replicated findings. We conducted a candidate gene association study in trauma-exposed individuals within the Comorbidity and Trauma Study's sample (1343 heroin-dependent cases and 406 controls from economically disadvantaged neighborhoods). After data cleaning, the 1430 single nucleotide polymorphisms (SNPs) retained for analyses provided coverage of 72 candidate genes and included additional SNPs for which association was previously reported as well as 30 ancestry-informative markers. We found a functional DRD2 promoter polymorphism (rs12364283) to be most highly associated with PTSD liability [odds ratio (OR) 1.65 (1.27-2.15); P = 1.58 × 10(-4) ]; however, this association was not significant, with a stringent Bonferroni correction for multiple comparisons. The top hits include SNPs from other dopaminergic system genes: DRD2 DRD3, TH and DBH. Additional analyses revealed that the association involving rs12364283 is largely limited to amphetamine-dependent individuals. Substantial risk is observed in amphetamine-dependent individuals, with at least one copy of this SNP [OR 2.86 (1.92-4.27); P = 2.6 × 10(-7) ]. Further analyses do not support extensive mediation of PTSD risk via self-reported impulsivity (BIS total score). These findings suggest roles for impairment in inhibitory control in the pathophysiology of PTSD and raise questions about stimulant use in certain populations (e.g. those in combat).

Resting-state activity in the left executive control network is associated with behavioral approach and is increased in substance dependence

BackgroundIndividuals with drug addictions report increased willingness to approach rewards. Approach behaviors are thought to involve executive control processes and are more strongly represented in the left compared to right prefrontal cortex. A direct link between approach tendencies and left hemisphere activity has not been shown in the resting brain. We hypothesized that compared to controls, substance dependent individuals (SDI) would have greater left hemisphere activity in the left executive control network (ECN) at rest. MethodsTwenty-five SDI and 25 controls completed a Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) questionnaire and underwent a resting-state fMRI scan. Group independent component analysis was performed. We used template matching to identify the left and right ECN separately and compared the corresponding components across groups. Across group, BAS scores were correlated with signal fluctuations in the left ECN and BIS scores with right ECN. ResultsBAS scores were higher in SDI compared to controls (p<.003) and correlated with signal fluctuation in the left ECN. SDI showed significantly more activity than controls in the left prefrontal cortex of the left ECN. Conversely, SDI showed less activity than controls in the right prefrontal cortex of the right ECN. ConclusionsResults from this study suggest that approach tendencies are related to the left ECN, even during rest. Higher resting-state signal in the left ECN may play a role in heightened approach tendencies that contribute to drug-seeking behavior.

Alcohol-dependent individuals discount sex at higher rates than controls

BackgroundResearch on delay discounting has expanded our understanding of substance dependence in many ways. Recently, orderly discounting of sexual rewards has been demonstrated in both substance-dependent individuals, and healthy controls. Less clear, however, is if rates of sexual discounting are higher than controls in alcohol-dependent-individuals. Methods20 alcohol-dependent individuals and 21 healthy control participants completed two delay-discounting tasks. One task involved monetary rewards, whereas the other involved the discounting of sexual rewards (i.e., number of sex acts). ResultsAlcohol dependent individuals discounted sexual rewards at significantly higher rates than did controls. There was a trend toward, but not a similarly significant relation for the discounting of monetary rewards. ConclusionsRates of sexual discounting are elevated in alcohol dependent individuals. If this relation is replicated in other at risk populations, the rapid devaluation of sexual rewards may be a laboratory marker of impulsive sexual choices.

Elevated Reward Region Responsivity Predicts Future Substance Use Onset But Not Overweight/Obesity Onset

We tested the hypotheses that adolescents who show elevated reward region responsivity are at increased risk for initial onset of overweight/obesity and substance use, which is important because there have been no such prospective tests of the reward surfeit model of these motivated behaviors. One hundred sixty-two adolescents (mean age = 15.3±1.06 years) with healthy weights (mean body mass index = 20.8±1.90) completed functional magnetic resonance imaging paradigms that assessed neural activation in response to receipt and anticipated receipt of palatable food and monetary reward; body fat and substance use were assessed at baseline and 1-year follow-up. Elevated caudate (r = .31, p<.001) and putamen (r = .28, p<.001) response to monetary reward predicted substance use onset over 1-year follow-up, but reward circuitry responsivity did not predict future overweight/obesity onset. Adolescents who reported substance use versus abstinence at baseline also showed less caudate (r =-.31, p<.001) response to monetary reward. Results show that hyper-responsivity of reward circuitry increases risk for future substance use onset, providing novel support for the reward surfeit model. Results also imply that even a limited substance use history was associated with reduced reward region responsivity, extending results from studies that compared substance-dependent individuals with healthy control subjects and suggesting that substance use downregulates reward circuitry. However, aberrant reward region responsivity did not predict initial unhealthy weight gain.

399 – Psychiatric morbidity and alcohol use among clients seeking treatment in government drug rehabilitation centre, malaysia

Introduction Psychiatric morbidity and concomittant alcohol use are associated with poor outcomes among substance dependent individuals. Objective To investigate the prevalence of psychiatric morbidity and alcohol use among the inmates and their psychosocial correlates. Methods Cross-sectional study involving 201 inmates age 18 years and above with written consent who currently seeking treatment on volunteer basis under the government run rehabilitation centre in sunagi Besi, Kuala Lumpur. The study was conducted in December 2011 with approval from the Ethic committee board from the university hospital. The psychiatric morbidity measured by MINI Neuropsychiatric Inventory (MINI ver 5.0) and alcohol use measured by AUDIT. Results The current prevalence of anxiety and depression are 27.9% and 39.8% respectively. The lifetime prevalence for depression is 21.9%. We also found that lifetime and current prevalence of alcohol use are 77% and 37% respectively. Univariate analysis showed significant association between psychiatric morbidity and alcohol use among this group of inmates (Odd ratio=1.9, P Conclusions There is high prevalence of psychiatric morbidity and alcohol use among the inmates seeking treatment in government run rehabilitation centre on top of receiving methadone treatment. Therefore, this centre need specialised care to cater the dual diagnosis group clients.

Neurocognitive Mechanisms of Impaired Decision Making in Pathological Gambling

Neurocognitive Mechanisms of Impaired Decision Making in Pathological Gambling

12-Step Affiliation and Attendance Following Treatment for Comorbid Substance Dependence and Depression: A Latent Growth Curve Mediation Model

ABSTRACT Among substance-dependent individuals, comorbid major depressive disorder (MDD) is associated with greater severity and poorer treatment outcomes, but little research has examined mediators of posttreatment substance use outcomes within this population. Using latent growth curve models, the authors tested relationships between individual rates of change in 12-step involvement and substance use, utilizing posttreatment follow-up data from a trial of group Twelve-Step Facilitation (TSF) and integrated cognitive-behavioral therapy (ICBT) for veterans with substance dependence and MDD. Although TSF patients were higher on 12-step affiliation and meeting attendance at end-of-treatment as compared with ICBT, they also experienced significantly greater reductions in these variables during the year following treatment, ending at similar levels as ICBT. Veterans in TSF also had significantly greater increases in drinking frequency during follow-up, and this group difference was mediated by their greater reductions in 12-step affiliation and meeting attendance. Patients with comorbid depression appear to have difficulty sustaining high levels of 12-step involvement after the conclusion of formal 12-step interventions, which predicts poorer drinking outcomes over time. Modifications to TSF and other formal 12-step protocols or continued therapeutic contact may be necessary to sustain 12-step involvement and reduced drinking for patients with substance dependence and MDD.

The Relationship Between Impulsivity for Reward and Learning From Reward

Event Abstract Back to Event The Relationship Between Impulsivity for Reward and Learning From Reward Antoinette Poulton1, Kaitlyn Harrington1, Caitlyn Mackenzie1 and Robert Hester1* 1 University of Melbourne, Melbourne School of Psychological Sciences, Australia Background: Although relatively large numbers of Australians are drug users, few individuals transition from low-level occasional use to substance dependence. The specific factors influencing this transition remain unclear. Substance dependent individuals tend to be swayed by the immediate rewards of drug taking, but are often insensitive to the delayed negative consequences of their behaviour. Dependence is consequently associated with impulsivity for reward and atypical learning from feedback. Animal and human studies of drug naïve populations demonstrate impulsivity for reward might precede drug-related problems. Research also suggests dependent individuals are more likely to learn from rewarding (relative to punishing) feedback, which may explain why they fail to modify their behaviour in response to negative outcomes, and may constitute a further pre-existing risk factor for substance dependence. Although impulsivity for reward and preferential learning from rewarding feedback are both underpinned by a compromised dopaminergic system, few studies have examined the relationship between these two mechanisms. Method: Ninety-eight healthy individuals (52 female, M = 23.53, SD = 6.07) undertook 1) An inhibitory control task that quantified ability to inhibit responses in the presence of immediate reward, and 2) A spatial associative learning task that measured capacity to learn from positive and negative feedback (monetary reward and punishment). Results: 1) Compared to the neutral condition, inhibitory control was significantly reduced in the presence of immediate reward, 2) Compared to the punishing feedback condition, recall was significantly better following rewarding feedback, and 3) A reduced ability to inhibit responses in the presence of immediate reward was significantly associated with a preference for learning from rewarding, relative to punishing, feedback. Discussion: Results suggest individual differences in inhibitory control are related to individual differences in learning from feedback in the healthy population. The interplay of these processes may provide evidence explaining why some individuals transition to substance dependence. While our data support an overall relationship, there was a subgroup that was both highly impulsive for, and sensitive to learning from, reward. It is possible these two mechanisms serve as dual pre-existing cognitive markers for vulnerability to the transition from substance use to dependence. Keywords: substance dependence, Inhibitory Control, associative learning, Impulsivity and self-control, Reward sensitivity Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Other Citation: Poulton A, Harrington K, Mackenzie C and Hester R (2013). The Relationship Between Impulsivity for Reward and Learning From Reward. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00049 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Dr. Robert Hester, University of Melbourne, Melbourne School of Psychological Sciences, Melbourne, Victoria, 3010, Australia, hesterr@unimelb.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Antoinette Poulton Kaitlyn Harrington Caitlyn Mackenzie Robert Hester Google Antoinette Poulton Kaitlyn Harrington Caitlyn Mackenzie Robert Hester Google Scholar Antoinette Poulton Kaitlyn Harrington Caitlyn Mackenzie Robert Hester PubMed Antoinette Poulton Kaitlyn Harrington Caitlyn Mackenzie Robert Hester Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

1128 – Methylphenidate for ADHD in adults with substance dependence: A 24-week randomized placebo-controlled trial

There is a lack of evidence for the efficacy of stimulant pharmacotherapy in patients with substance dependence and comorbid attention deficit hyperactivity disorder (ADHD). The aim of the present trial was to test the efficacy and safety of 180 mg extended release methylphenidate for treating ADHD in patients with amphetamine dependence. 54 incarcerated men, mean age 42 years, meeting the DSM-IV criteria for amphetamine dependence and ADHD were randomized to methylphenidate or placebo in a 24-week randomized double-blind, placebo-controlled trial, with parallel groups design. The medication started within 14 days before release from prison and continued in outpatient care with twice weekly visits including once weekly cognitive behaviour therapy. The primary end point was relapse to any drug use measured by urine toxicology. Secondary endpoints included relapse to amphetamine use, retention to treatment, and change in selfrated ADHD symptoms. The methylphenidate group had significantly fewer drug positive urines compared to the placebo group (95% CI -0.31 to -0.05, P=.034), fewer amphetamine positive urines, (95% CI -0.36 to -0.07, P=.019) and better retention to treatment (95% CI 15.64 to 78.58, P=.001). Compared to the placebo group, the methylphenidate group also significantly reduced their selfrated ADHD symptoms (95% CI -21.09 to -3.37, P=.008) during the 24-week treatment. This is the first randomized clinical trial to demonstrate the efficacy of a stimulant treatment for substance dependent individuals with ADHD. The treatment with MPH led to reduction in drug use and a clinically relevant improvement of ADHD symptoms.

Ideação suicida, resolução de problemas, expressão de raiva e impulsividade em dependentes de substâncias psicoativas

This study aimed to compare men with substance use disorders and those who are no addicted/non-dependent on drugs in terms of their executive functions, emotional and behavioral expressions giving particular emphasis on the presence of suicidal ideation. The sample consisted of 25 individuals with substance use disorders and 25 non-dependent individuals. The data collection consisted of a questionnaire including sociodemographic and health data, the Diagnostic Interview (MINI-Plus), the Anger Expression Inventory - State and Trait (STAXI), the Barratt Impulsiveness Scale (I-BIS11), the Wisconsin Card Sorting Test (WCST) and the Beck Scale for Suicide Ideation (BSI). The data revealed that the substance dependent individuals showed no significant cognitive impairment, fact that does not math with the literature. However, they presented alterations with respect to impulsivity and expression of anger.

The nature of coping in treatment for marijuana dependence: latent structure and validation of the Coping Strategies Scale.

The Coping Strategies Scale (CSS) was designed to assess adaptive changes in substance-use specific coping that result from treatment. This study sought to examine the latent structure of the CSS in the hope that it might shed light on the coping processes of drug users and guide the development of a brief version of the CSS. Respondents on the CSS were 751 men and women treated in 3 clinical trials for marijuana dependence. Posttreatment CSS data were analyzed to determine the nature of coping responses in patients who have been trained to use specific strategies to deal with substance use disorders. Exploratory factor analysis yielded 2 factors, categorized as problem-focused and emotion-focused coping, but confirmatory factor analysis did not support this structure. When infrequently endorsed items were removed, however, confirmatory factor analysis revealed a good fit to the data. Contrary to expectations, practical strategies that often form the basis for coping skills training, such as avoiding those who smoke, were not frequently endorsed. Problem-focused items reflected cognitive commitments to change. Emotion-focused items included cognitive reinterpretations of emotions to help manage emotional reactions. Brief versions of the CSS based on these factors showed good convergent and discriminant validity. The CSS, and the brief versions of the CSS, may prove useful in future treatment trials to evaluate effects of treatment on coping skills acquisition and utilization in substance dependent individuals.

Insula and Orbitofrontal Cortical Morphology in Substance Dependence Is Modulated by Sex

Frontolimbic circuits are involved in learning and decision-making processes thought to be affected in substance-dependent individuals. We investigated frontolimbic cortical morphometry in substance-dependent men and women and determined whether morphometric measurements correlated with decision-making performance. Twenty-eight abstinent SDI (17 men/11 women) were compared with 28 controls (13 men/15 women). Cortical thicknesses and volumes were computed by using FreeSurfer. After controlling for age and intracranial volume, group and sex effects were analyzed in 3 a priori regions of interest: the insula, orbitofrontal cortex, and anterior cingulate cortex by using analysis of covariance. A secondary whole-brain analysis was conducted to verify region-of-interest results and to explore potential differences in other brain regions. Region-of-interest analyses revealed a main effect of group on the left insula cortex, which was thinner in SDI compared with controls (P = .02). There was a group by sex interaction on bilateral insula volume (left, P = .02; right, P = .001) and right insula cortical thickness (P = .007). Compared with same-sex controls, female SDI had smaller insulae, whereas male SDI had larger insulae. Neither ACC nor OFC significantly differed across group. Performance on a decision-making task was better in controls than SDI and correlated with OFC measurements in the controls. SDI and controls differed in insula morphology, and those differences were modulated by sex. No group differences in OFC were observed, but OFC measurements correlated with negative-reinforcement learning in controls. These preliminary results are consistent with a hypothesis that frontolimbic pathways may be involved in behaviors related to substance dependence.

Supplemental Material for Decisions During Negatively-Framed Messages Yield Smaller Risk-Aversion-Related Brain Activation in Substance-Dependent Individuals

Supplemental Material for Decisions During Negatively-Framed Messages Yield Smaller Risk-Aversion-Related Brain Activation in Substance-Dependent Individuals

P.3.b.001 Cannabis use and psychotic experiences in UK teenagers – a longitudinal study

Research in adults shows that substance dependent individuals demonstrate attentional bias (AB) for substance-related stimuli. This study investigated the role of AB in adolescents diagnosed with alcohol, cannabis, amphetamine or GHB dependency on entering therapy and six months later, and the role of executive control (EC) as a moderator of the relationship between problem severity and AB.Seventy-eight young substance-dependent (SD) patients (mean age = 19.5), and 64 healthy controls (HC; mean age = 19.0) were tested. Thirty-eight SD patients took part at 6-month follow-up (FU). AB was indexed by a visual probe task, EC by the attention network task, problem severity by the short alcohol (or drug) use disorder identification test and the severity of dependence questionnaire.SD patients demonstrated an AB for substance stimuli presented for 500 ms and 1250 ms, with the latter related to severity of dependence. There was a nonsignificant tendency indicating that EC was higher in HC than SD participants, but EC did not moderate the relationship between AB and dependency. Substance use, dependency, EC and AB remained unchanged in the 6 month FU period.Young SD patients showed a stronger relatively early as well as maintained AB toward substance cues. A stronger maintained attention was related to higher severity of dependence. Further, there were some indications that EC might play a role in adolescent substance use. The finding that at FU AB and problem severity were not decreased, and EC was not increased underlines the persistent character of addiction.

The Assessment of Recovery Capital: Properties and psychometrics of a measure of addiction recovery strengths

Sociological work on social capital and its impact on health behaviours have been translated into the addiction field in the form of 'recovery capital' as the construct for assessing individual progress on a recovery journey. Yet there has been little attempt to quantify recovery capital. The aim of the project was to create a scale that assessed addiction recovery capital. Initial focus group work identified and tested candidate items and domains followed by data collection from multiple sources to enable psychometric assessment of a scale measuring recovery capital. The scale shows moderate test-retest reliability at 1 week and acceptable concurrent validity. Principal component analysis determined single factor structure. The Assessment of Recovery Capital (ARC) is a brief and easy to administer measurement of recovery capital that has acceptable psychometric properties and may be a useful complement to deficit-based assessment and outcome monitoring instruments for substance dependent individuals in and out of treatment.

Neural correlates of hot and cold executive functions in polysubstance addiction: Association between neuropsychological performance and resting brain metabolism as measured by positron emission tomography

The study of substance-abuse-related neuropsychological deficits and brain alterations may provide a better understanding of the neuroadaptations associated with addiction. In this study we investigated the association between performance on neuropsychological tests of cold and hot executive functions and regional brain metabolism. Measured with positron emission tomography (PET), in a sample of 49 substance-dependent individuals (SDI). Neuropsychological performance in the SDI group was compared to that of a non-drug-using control group of 30 participants, and associated with two sets of PET-derived dependent measures: one based on regions of interest (examining mean uptake in selected regions), and a second based on voxel uptake measures (using Statistical Parametric Mapping voxel-based whole-brain analyses). Behavioral analyses showed that SDI had poorer performance than controls across executive function and emotion processing measures. Regression models showed that SDI's performance in “cold” executive tests (i.e., updating, inhibition and flexibility) was associated with regional metabolism in the dorsolateral prefrontal cortex (DLPFC), mid-superior frontal gyrus, superior and inferior temporal gyrus and inferior parietal cortex, whereas performance in “hot” executive functions (i.e., self-regulation, decision-making and emotion perception) was associated with DLPFC, mid-superior frontal gyrus, anterior and mid-posterior cingulate, and temporal and fusiform gyrus. These results are discussed in terms of their relevance for the understanding of cognitive dysfunction and neuroadaptations linked to addiction.

Brain Activation Associated with Attentional Bias in Smokers is Modulated by a Dopamine Antagonist

Attentional bias in substance-dependent individuals is the tendency to automatically direct the attention to substance-related cues in the environment. Attentional bias is known to be associated with clinical measures such as relapse or successful quitting in smokers. It has been suggested that attentional bias emerges as a consequence of dopaminergic activity evoked by substance-related cues. The current functional magnetic resonance imaging study employed a dopaminergic challenge in order to test whether brain activation associated with attentional bias in smokers could be modulated by a dopamine antagonist. A total of 25 smokers were compared with 24 controls. Participants were scanned twice while performing a pictorial attentional bias task. Haloperidol (2 mg), a selective D2/D3 dopamine antagonist, or placebo was orally administered 4 h before each scanning session in a double-blind randomized cross-over design. Imaging analyses were performed in a priori selected regions of interest. Results showed that smokers had enhanced brain activation compared with controls in the dorsal anterior cingulate cortex (dACC), right dorsolateral prefrontal cortex (r-DLPFC), and left superior parietal lobe (I-SPL) after placebo. Group × medication interactions were found in the dACC and r-DLPFC, with no differences between groups in these regions after haloperidol. The current findings suggest that a pharmacologically induced reduction in dopamine normalizes brain activation associated with attentional bias in the dACC and DLPFC in smokers, probably because salience of these cues is no longer detected when dopamine activity is reduced.