Catherine Hanak

Alcohol cues increase cognitive impulsivity in individuals with alcoholism

BackgroundIndividuals 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.MethodsForty 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.ResultsAlcoholics 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.ConclusionsThese 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 deficit is involved in poor decision making under risk in nonamnesic individuals with alcoholism.

Individuals with alcoholism exhibit poor decision making as reflected by their continued alcohol use despite encountering problems and by low performance in laboratory tasks of decision making. Here, the authors investigated the relative contribution of several distinct processes of executive functions in performance on the Iowa Gambling Task (IGT; A. Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994) in recently detoxified individuals with alcoholism. Compared to matched healthy participants, individuals with alcoholism showed below-normal scores in the last 20 trials of the IGT as well as on other tasks of executive functions, specifically those assessing the capacity to manipulate information stored in working memory, detect abstract rules, or inhibit prepotent responses. Prepotent response inhibition best predicted performance in the late trials of the IGT, that is, when participants have likely acquired knowledge about the reward/punishment contingencies of the task. These results underline the important role that response inhibition plays in decision making, especially in risky situations, when knowledge of the probability of a given outcome becomes available (i.e. decisions under risk).

Is the P300 deficit in alcoholism associated with early visual impairments (P100, N170)? An oddball paradigm

OBJECTIVE Studies exploring chronic alcoholism with event-related potentials (ERPs) have shown delayed latency and reduced amplitude of the P300, a long-lasting positive potential reflecting decisional processing. This P300 deficit in alcoholism is generally interpreted as a disturbance in central nervous system inhibition or in memory/attention. The present study aimed at identifying if this electrophysiological deficit is already present on earlier components, and advances a new hypothesis concerning the interpretation of the P300 alteration. METHODS Patients suffering from alcoholism and matched healthy controls had to detect, in an oddball paradigm, emotional faces among a succession of neutral faces. Behavioral performance and ERP data (recorded from 32 electrodes) were analyzed. RESULTS In line with previous studies, data showed that alcoholism led to a P300 deficit. Moreover, we observed for the first time that this deficit begins at earlier visual (P100) and face-processing (N170) stages, and we found high positive correlations between P100, N170 and P300 for amplitude and latency values, suggesting cumulative deficits on the cognitive continuum. CONCLUSIONS We suggest that the P300 deficit observed in chronic alcoholism could be linked to earlier visuo-spatial deficits rather than being an impairment of the specific processes linked to the P300. SIGNIFICANCE These results call for reconsidering the interpretation of P300 impairments at a fundamental and clinical level, and shows that earlier ERP components must be taken into account in future studies.

Dissociation between affective and cognitive empathy in alcoholism : a specific deficit for the emotional dimension.

BACKGROUND Emotional impairments constitute a crucial and widely described dimension of alcoholism, but several affective abilities are still to be thoroughly explored among alcohol-dependent patients. This is particularly true for empathy, which constitutes an essential emotional competence for interpersonal relations and has been shown to be highly impaired in various psychiatric states. The present study aimed at exploring empathic abilities in alcoholism, and notably the hypothesis of a differential deficit between emotional and cognitive empathy. METHODS Empathy abilities were evaluated among 30 recently detoxified inpatients diagnosed with alcohol dependence and 30 paired healthy controls, using highly validated questionnaires (Interpersonal Reactivity Index [J Pers Soc Psychol44:113] and Empathy Quotient [J Autism Dev Disord34:163]). Correlational analyses were performed to evaluate the links between empathy scores and psychopathological measures (i.e., depression, anxiety, interpersonal problems, and alexithymia). RESULTS When psychiatric comorbities are controlled for, alcoholism is not associated with a general empathy deficit, but rather with a dissociated pattern combining impaired emotional empathy and preserved cognitive one. Moreover, this emotional empathy deficit is not associated with depression or anxiety scores, but is negatively correlated with alexithymia and the severity of interpersonal problems. CONCLUSIONS At the theoretical level, this first observation of a specific deficit for emotional empathy in alcoholism, combined with the exact inverse pattern observed in other psychiatric populations, leads to a double-dissociation, which supports the notion that emotional and cognitive empathy are 2 distinct abilities. At the clinical level, this deficit calls for considering emotional empathy rehabilitation as a crucial concern in psychotherapy.

On the predictive validity of automatically activated approach/avoidance tendencies in abstaining alcohol-dependent patients

BACKGROUND Prominent addiction models posit that automatically activated approach/avoidance tendencies play a critical role in addiction. Nevertheless, only a limited number of studies have actually documented the relationship between relapse and automatically activated approach/avoidance tendencies. We compared automatically activated approach/avoidance tendencies towards alcohol in 40 abstaining alcohol-dependent patients and 40 controls. We also examined whether individual differences in automatically activated approach/avoidance tendencies towards alcohol are predictive of relapse in patients. METHODS A Relevant Stimulus Response Compatibility task was used to measure relative approach/avoidance tendencies. In one block of trials, participants were asked to approach alcohol-related pictures and to avoid alcohol-unrelated pictures (i.e., compatible block). In a second block of trials, participants were asked to approach alcohol-unrelated pictures and to move away from alcohol-related pictures (i.e., incompatible block). Patients were tested between 18 and 21 days after they quit drinking. Relapse was assessed 3 months after patients were discharged from the hospital. RESULTS Whereas abstaining alcohol-dependent patients were faster to respond to incompatible trials as compared to compatible trials, participants in the control group showed the exact opposite pattern. Within the patient group, the likelihood of relapse increased as participants were faster to respond to incompatible trials relative to compatible trials. CONCLUSIONS Unlike controls, abstaining alcohol-dependent patients revealed a relative avoidance bias rather than relative approach bias. Moreover, relapse rates were found to increase as the relative tendency to avoid alcohol increased. This finding suggests that an avoidance orientation towards alcohol can potentially be harmful in clinical samples.

Alcoholism leads to early perceptive alterations, independently of comorbid depressed state: an ERP study.

INTRODUCTION Alcoholism is associated with a deficit in the processing of emotional facial expressions (EFE) and with a delayed P3b component, partially mediated by earlier perceptive deficits (P100, N170). Since alcohol dependence often occurs with depression, we aim at investigating whether classical event-related potentials (ERP) alterations observed in alcoholism are modulated or not by depression. METHODS Four groups (controls; alcoholics; depressed; alcoholics-depressed) of 12 participants performed two different discrimination tasks, a gender and an emotional one. They had to decide as quickly as possible about the gender or the emotion displayed by facial stimuli during an ERP recording session (32 channels). Reaction times (RTs), P100, N100, N170 and P3b were recorded. RESULTS At the behavioural level, control participants discriminated EFE (but not gender) more rapidly than the three other groups. At the ERP level, the differences observed on RTs for emotional task were neurophysiologically indexed by a delayed P3b component. This delay was associated with earlier ERP alterations (P100, N100, N170), but only in participants suffering from alcohol dependence, in association or not with depression. DISCUSSION On the one hand, individuals with alcoholism, associated or not with a comorbid depression, were impaired in the processing of EFE. This deficit was neurophysiologically indexed by early perceptive (P100, N100, N170) and decisional (P3b) alterations. On the other hand, non-alcoholic patients with depression only exhibited P3b impairment. These results lead to potential implications concerning the usefulness of the ERP for the differential diagnosis in psychiatry, notably concerning the comorbidities in alcoholism.

Neurocognitive determinants of novelty and sensation-seeking in individuals with alcoholism.

AIM Sober alcoholic abusers exhibit personality traits such as novelty-seeking (NS) and sensation-seeking, which overlap to a limited extent. In parallel, they also show impaired executive and decision-making processes. However, little is known about the specific and common cognitive processes associated with NS and sensation-seeking personality traits in detoxified sober alcoholic abusers. METHODS In these present studies, we have investigated the relationships between executive functioning/central executive of working memory (pre-potent response inhibition, manipulation stored in working memory), and decision-making under uncertainty and NS/sensation-seeking traits in such alcoholics. RESULTS Compared with healthy controls (n = 30, mean age = 40.2), and in agreement with previous studies, alcoholics (n = 30, mean age = 40.4) showed higher levels of both NS and sensation-seeking traits. Alcoholics were also disadvantaged with respect to (a) gambling tasks, as reported previously, and (b) a poor ability to manipulate information stored in working memory and inhibit pre-potent responses. Most importantly, regression analyses and mediation analyses measures showed that poor response inhibition and decision-making were associated with high NS behaviour. In addition, impaired decision-making and manipulation of stored information in working memory were associated with a high sensation-seeking trait. CONCLUSIONS Overall, these results support the existence of specific links between cognitive executive functioning, decision-making under uncertainty and NS/sensation-seeking personality traits in individuals with alcoholism.

Neurophysiological correlates of response inhibition predict relapse in detoxified alcoholic patients: some preliminary evidence from event-related potentials

Background Alcohol dependence is a chronic relapsing disease. The impairment of response inhibition and alcohol-cue reactivity are the main cognitive mechanisms that trigger relapse. Despite the interaction suggested between the two processes, they have long been investigated as two different lines of research. The present study aimed to investigate the interaction between response inhibition and alcohol-cue reactivity and their potential link with relapse. Materials and methods Event-related potentials were recorded during a variant of a “go/no-go” task. Frequent and rare stimuli (to be inhibited) were superimposed on neutral, nonalcohol-related, and alcohol-related contexts. The task was administered following a 3-week detoxification course. Relapse outcome was measured after 3 months, using self-reported abstinence. There were 27 controls (seven females) and 27 patients (seven females), among whom 13 relapsed during the 3-month follow-up period. The no-go N2, no-go P3, and the “difference” wave (P3d) were examined with the aim of linking neural correlates of response inhibition on alcohol-related contexts to the observed relapse rate. Results Results showed that 1) at the behavioral level, alcohol-dependent patients made significantly more commission errors than controls (P<0.001), independently of context; 2) through the subtraction no-go P3 minus go P3, this inhibition deficit was neurophysiologically indexed in patients with greater P3d amplitudes (P=0.034); and 3) within the patient group, increased P3d amplitude enabled us to differentiate between future relapsers and nonrelapsers (P=0.026). Conclusion Our findings suggest that recently detoxified alcoholics are characterized by poorer response-inhibition skills that demand greater neural resources. We propose that event-related potentials can be used in conjunction with behavioral data to predict relapse; this would identify patients that need a higher level of neural resources when suppressing a response is requested.

Reduced processing of alcohol cues predicts abstinence in recently detoxified alcoholic patients in a three-month follow up period: An ERP study

One of the major challenges in alcohol dependence is relapse prevention, as rates of relapse following detoxification are high. Drug-related motivational processes may represent key mechanisms in alcoholic relapse. In the present study, event-related potentials (ERPs) were recorded during a visual oddball task administered to 29 controls (11 females) and 39 patients (9 females). Deviant stimuli were related or unrelated to alcohol. For patients, the task was administered following a 3-week detoxification course. Of these, 19 relapsed during the three months follow-up period. The P3, an ERP component associated with activation of arousal systems in the brain and motivational engagement, was examined with the aim to link the fluctuation of its amplitude in response to alcohol versus non-alcohol cues to the observed relapse rate. Results showed that compared to relapsers, abstainers presented with a decreased P3 amplitude for alcohol related compared to non-alcohol related pictures (p=.009). Microstate analysis and sLORETA topography showed that activation for both types of deviant cues in abstainers originated from the inferior and medial temporal gyrus and the uncus, regions implicated in detection of target stimuli in oddball tasks and of biologically relevant stimuli. Through hierarchical regression, it was found that the P3 amplitude difference between alcohol and non-alcohol related cues was the best predictor of relapse vulnerability (p=.013). Therefore, it seems that a devaluation of the motivational significance of stimuli related to alcohol, measurable through electrophysiology, could protect from a relapse within three months following detoxification in alcohol-dependent patients.

A pharmacological modulation of opiate withdrawal using an up-/down-regulation of the noradrenergic system in opiate-dependent rats

Chronic opioid exposure induces neuroadaptative changes in several brain systems. Amongst others the alpha adrenergic system appears to be extremely sensitive to opioid exposure and has, therefore, been proposed to play a key role in opiate withdrawal symptoms. In order to better understand the influence of the noradrenergic system in opioid withdrawal and be able to develop new therapeutic strategies, we studied the effect of pre-treatment with the alpha2 agonist (clonidine) and alpha2 antagonist (yohimbine) on naloxone-precipitated withdrawal in opiate-dependent rats. As is already known clonidine pre-treatment significantly enhances autonomic and behavioural signs of opioid withdrawal whereas yohimbine significantly attenuates them with dose-related effect. We also tested the effect of clonidine (0.1 mg/kg) during naloxone-precipitated opiate withdrawal in rats pre-treated with yohimbine (5 mg/kg) and we observed that yohimbine pre-treatment potentiates clonidine efficiency in decreasing opiate withdrawal signs. This study supports the possibility of using a noradrenergic antagonist in order to regulate adrenoreceptors chronically exposed to opioids, therefore interfering with the intensity of naloxone-precipitated opiate withdrawal and potentiating later effectiveness of noradrenergic agonists like clonidine. These results may have various applications in clinical opiate detoxification protocols and are discussed through an up-/down- regulation of adrenoreceptors.