The effects of priming restrained versus disinhibited behaviour on alcohol-seeking in social drinkers

The ad-libitum taste test as measure of momentary alcohol use in the laboratory: an investigation of construct validity and confounding factors

RATIONALE

The ad-libitum taste test is a widely used covert measure of motivation to consume alcohol in the laboratory. However, studies on its construct validity and potential confounding factors are scarce.

OBJECTIVES

This study aimed to evaluate the construct validity of the ad-libitum taste test by examining the association of ad-libitum alcohol consumption with typical alcohol use and craving, and investigating potential moderation by trait anxiety, depressiveness, current mood, and drinking motives.

METHODS

A sample of 264 young male individuals were offered two 0.33 l glasses of beer. Participants were instructed to rate the characteristics of each drink, while the percentage of beverages containing alcohol consumed was assessed. Associations of ad-libitum consumption with typical alcohol use and craving were assessed using non-parametric and piecewise regressions. Moreover, moderator analysis with trait anxiety, depressiveness, current mood, and drinking motives was carried out.

RESULTS

Ad-libitum alcohol consumption was associated with typical alcohol use and alcohol craving. However, these associations decreased at high consumption levels. Associations between ad-libitum consumption, typical alcohol use, and craving were stable across several conditions, except that the association between ad-libitum consumption and craving increased with higher social, conformity, and coping drinking motives.

CONCLUSIONS

The ad-libitum taste test appears to be a valid measure of the motivation to drink alcohol in laboratory studies in young male adults, although this validity might be compromised at high levels of ad-libitum consumption. Consideration of these factors can contribute to further refining the ad-libitum taste test as a valuable tool for assessing motivation to consume alcohol in laboratory studies.

In people who drink more, facets of theory of mind may be impaired by alcohol stimuli

BACKGROUND

Theory of mind (ToM) - the ability to understand others' beliefs, mental states, and knowledge - is an important part of successful social interaction. There is a growing (albeit mixed) evidence base suggesting that individuals with substance use disorder or who are intoxicated (relative to sober controls) perform worse on a number of ToM tasks. The aim of this study was to explore the hitherto little explored notion that ToM-related capabilities such as the ability to see the world from another person's perspective (termed Visual Perspective Taking; VPT), may be impacted by alcohol-related stimuli.

METHOD

In this pre-registered study, 108 participants (M age = 25.75, SD age = 5.67) completed a revised version of the director task where they followed the instructions of an avatar to move both alcohol beverages and soft drinks that were mutually visible (target objects) while avoiding those only visible to the participant (distractor items).

RESULTS

Contrary to predictions, accuracy was lower when the target drink was alcohol and the distractor was a soft drink, although higher AUDIT scores were associated with significantly lower accuracy when alcohol drinks were the distractor items.

CONCLUSIONS

There may be some contexts when being able to see alcohol beverages makes it harder to take another person's perspective. It also appears that poorer VPT and perhaps ToM capacity may be evident in individuals who consume more alcohol. Future research is warranted to examine how alcohol beverages, alcohol consumption behaviours, and intoxication interact to impact VPT capacity.

Underlying mechanisms in the relationship between stress and alcohol consumption in regular and risky drinkers (MESA): methods and design of a randomized laboratory study

BACKGROUND

Excessive alcohol consumption and alcohol use disorders (AUD) are among the leading preventable causes of premature morbidity and mortality and are considered a major public health concern. In order to reduce the individual and societal burden of excessive alcohol use, it is crucial to identify high-risk individuals at earlier stages and to provide effective interventions to prevent further progression. Stressful experiences are important risk factors for excessive alcohol consumption and AUDs. However, the underlying biological and psychological mechanisms are still poorly understood.

METHODS

The project "Underlying mechanisms in the relationship between stress and alcohol consumption in regular and risky drinkers (MESA)" is a randomized controlled study that started in December 2018 and is conducted in a laboratory setting, which aims to identify moderators and mediators of the relationship between acute stress and alcohol consumption among regular and risky drinkers. Regular and risky drinkers are randomly assigned to a stress induction or a control condition. Several processes that may mediate (emotional distress, endocrine and autonomic stress reactivity, impulsivity, inhibitory control, motivational sensitization) or moderate (trait impulsivity, childhood maltreatment, basal HPA-axis activity) the relation between stress and alcohol consumption are investigated. As primary dependent variable, the motivation to consume alcohol following psychosocial stress is measured.

DISCUSSION

The results of this study could help to provide valuable targets for future research on tailored interventions to prevent stress-related alcohol consumption.

Nucleation increases the visual appeal of lager but does not alter overall likeability or drinking rate

BACKGROUND

Glassware can be an effective vehicle to recruit customers, revive brands, build profits and increase alcohol consumption by capitalising on the immediacy of glassware to the point of consumption. The design of glassware can also contribute to harm reduction by slowing and reducing consumption. Nucleated bases have been added to lager glasses in recent years which allow carbon dioxide (CO₂) to be more rapidly released and ascend through the solution. The aim of these studies was to investigate the effect of nucleated glasses on the likeability and drinking rate of lager in alcohol drinkers.

METHODS

In Study 1, participants (n = 116) were asked to taste two glasses of lager (280 millilitres (ml) each) in separate 5-min taste tests and fill out a likeability questionnaire after each glass in a within-subjects design with one factor of glass (nucleated, non-nucleated). The primary outcome was the likeability of lager and the secondary outcome was volume consumption during taste tests. In Study 2, participants (n = 160) were asked to consume a pint of lager (568 ml) and fill out a likeability questionnaire in a between-subjects design with one factor of glass (nucleated, non-nucleated). The primary outcome was time taken to consume a pint of lager and secondary outcomes were the likeability of lager, mood and alcohol craving.

RESULTS

There was no clear evidence that likeability of lager differed between nucleated and non-nucleated glasses in either study. In Study 1, a paired-samples t test found strong evidence that lager in nucleated glasses was more visually appealing (single item from likeability measure) than lager in non-nucleated glasses (mean difference (MD) = 10.2, 95% confidence interval (CI) 6.1, 14.2, p < 0.001). In Study 2, a linear regression found no clear evidence that lager was consumed at different rates from nucleated and non-nucleated glasses (nucleated: 16.9 min, non-nucleated: 16.3 min, MD: 0.6 min, 95% CI - 1.5, 2.7, p = 0.57).

CONCLUSIONS

Nucleated lager glasses do not appear to alter the likeability or consumption (volume consumed in Study 1 or drinking rate in Study 2) of lager, although they do seem to increase the visual appeal and refreshment of lager. This may increase the number of drinking episodes by making the drinking experience more enjoyable which may lead to increased alcohol related harm.

Addressing methodological issues in a study of impulsivity and vulnerability for transition to alcohol use disorder

BACKGROUND

Heightened behavioral impulsivity has been advocated as a preexisting risk factor for the development of alcohol use disorder (AUD). Nonetheless, studies investigating impulsivity in adolescent/young adult at-risk drinkers-who are at increased risk of developing AUD-report mixed findings. This may be due to methodological limitations related to definitions of at-risk drinking, the retrospective assessment of alcohol intake, and/or the relatively modest sample size of some studies.

METHODS

Healthy individuals (N = 814, M_age  = 22.50) completed online surveys and a measure of choice impulsivity. Of these, a number of participants also undertook an online measure of response inhibition (n = 627, M_age  = 22.66), and a further subgroup submitted real-time alcohol consumption information for a period of 21 days using an app (n = 543, M_age  = 22.96). Differences in behavioral impulsivity were assessed as a function of various at-risk alcohol intake categories. Hierarchical multiple regression was employed to determine whether impulsivity predicted alcohol use in the form of a continuous index comprising variables related to intake and consequences of use.

RESULTS

Significantly greater impulsivity was not evident in heavy, standard binge, high binge, harmful, or hazardous alcohol drinkers as compared to controls, regardless of the criteria employed to categorize these at-risk drinkers. Neither choice impulsivity nor reduced response inhibition significantly predicted the alcohol use index.

CONCLUSIONS

While results could be attributed to the online nature of this research, it is possible that more sensitive measures of behavioral impulsivity are required when assessing nondependent drinkers.

Intoxication without anticipation: Disentangling pharmacological from expected effects of alcohol

BACKGROUND

The pharmacological effects of alcohol on executive function, craving and subsequent alcohol-seeking have been well documented. Yet, insufficient methodological controls within existing alcohol administration paradigms have meant that the relative importance of alcohol's pharmacological and anticipatory effects remains in need of further elucidation.

AIM

The objective of this study is to disentangle alcohol's pharmacological effects from its anticipatory effects on alcohol-related cognitions and subsequent consumption.

METHODS

Inhibitory control, attentional bias and craving were assessed pre- and post-consumption in 100 participants who were randomly allocated to one of four beverage conditions in a two by two design: (1) alcohol aware (alcohol with participant knowledge (pharmacological/anticipation effects)), (2) alcohol blind (alcohol without participant knowledge; in a novel grain alcohol masking condition (pharmacological/no anticipation effects)), (3) placebo (no alcohol but participants were deceived (anticipation/non-pharmacological effects)) and (4) pure control (no alcohol with participant knowledge (no anticipation/non-pharmacological effects)).

RESULTS

Findings suggest that the pharmacological effects of alcohol result in greater inhibitory control impairments compared with anticipated effects. Anticipatory but not the pharmacological effects of alcohol were found to increase attentional bias. Both pharmacology and anticipation resulted in increased craving, though higher levels of craving were observed due to alcohol's pharmacology. Furthermore, alcohol pharmacology resulted in heightened ad libitum consumption; however, anticipation did not. Changes in craving partially mediated the relationship between initial intoxication and subsequent drinking, while inhibitory control impairments did not.

CONCLUSIONS

Successive alcohol consumption appears driven primarily by the pharmacological effects of alcohol which are exerted via changes in craving.

The Effects of Placebo and Moderate Dose Alcohol on Attentional Bias, Inhibitory Control and Subjective Craving

AIMS

Previous research indicates that acute alcohol intoxication and placebo can inhibit people's control over consumption behaviour and heighten attentional bias (AB) towards alcohol-related stimuli and craving. We designed a study to disentangle anticipated from pharmacological effects of alcohol in order to gain a clearer view of their relative contributions to alcohol consumption.

METHODS

In a within-participants design (moderate alcohol dose, placebo and control), and over a minimum 2-week period, participants completed a battery of questionnaires and cognitive tasks, followed by a bogus taste task to measure ad libitum consumption.

RESULTS

Both alcohol preload and placebo resulted in cognitive and psychological changes, including impaired inhibitory control, heightened AB and craving. However, ad libitum consumption only increased following alcohol and not placebo. Furthermore, inhibitory control impairments did not mediate the relationship between initial intoxication and ad libitum consumption, and findings indicate that increases in craving may mediate this association.

CONCLUSION

Psychological processes such as craving may be more important in driving consummatory behaviour relative to transient changes in cognitive processes, such as inhibitory control.

Boredom proneness is associated with noisy decision-making, not risk-taking

Previous research shows that individuals who tend to get bored frequently and intensely—the highly boredom prone—are more likely to engage in risky behaviors. However, these studies are based largely on self-reports. Here we address this gap and suggest that noisy decision-making (DM) is a potential driver for this relationship between boredom proneness and risk-taking. In Study 1, eighty-six participants completed the Balloon Analogue Risk Task (BART) while EEG was recorded. We found blunted feedback processing with higher boredom proneness, as indexed by reduced feedback-P3 amplitudes. Risk taking, as indexed by the BART, was not higher in the highly boredom prone. In Study 2a (N = 404) we directly tested the noisy DM hypothesis in an online sample using a binary choice task, and found that with higher boredom proneness, participants were more likely to alternate between choices on a trial-to-trial basis, but were not more likely to choose the risky alternative. These findings were replicated in a new sample (Study 2b), and extended to the Iowa Gambling Task (IGT; Study 3). In the IGT we found increased choice switching and reduced feedback sensitivity with higher boredom proneness. Once again, higher risk taking as indexed by the IGT was not evident in the highly boredom prone. Overall, our findings suggest that boredom proneness is associated with noisy decision-making (i.e., a tendency to alternate more between choice options regardless of risk level), and not risk-seeking per se. That is, the highly boredom prone are not necessarily attracted to risks, but rather, may be insensitive to risks due to reduced feedback sensitivity.

The effects of menstrual cycle stage and hormonal contraception on alcohol consumption and craving: A pilot investigation

Background and aims

Although alcohol research often comments on observed sex differences (i.e. patterns of consumption), there is a lack of investigation into the reasons for these differences. For females, the regular hormonal fluctuations across the menstrual cycle are a potential influencing factor for alcohol consumption. In this pilot we aimed to investigate the relationship between menstrual cycle phase (follicular-phase [FP] and luteal-phase [LP]) and status (naturally-cycling [NC] and hormonal-contraception [HC]) on alcohol consumption and craving of casual drinkers, and identify potential influencing factors in this relationship.

Methods

Study One: participants (n ​= ​28; 15 HC, 13 NC) were either NC or HC (between subject factor: hormonal status) and attended two lab-based sessions corresponding with their FP and LP (within factor: cycle phase [NC] or time [HC]). Participants completed a mock alcohol taste-test, in addition to pre- and post-consumption measures of craving, anxiety, stress, and mood. Study Two: participants (n ​= ​262; 144 HC, 118 NC) were either NC or HC (between subject factor) and completed an online study assessing menstrual cycle phase, alcohol use, craving, impulsivity, and stress.

Results

Study One: A significant effect of cycle phase was found on alcohol craving (p ​= ​.019): craving was higher during the FP compared to the LP for NC participants, with HC participants showing no difference across sessions. There was no effect of phase or status on alcohol consumption, stress, or mood (ps ​> ​.05). Study Two: Regression analyses showed that age, craving, impulsivity and stress were significantly associated with alcohol consumption for NC participants (ps ​< ​.05), however only age and craving were associated with consumption for the HC participants (ps ​< ​.001).

Conclusions

Alcohol craving was higher during the follicular, compared to the luteal, phase for the naturally cycling group, and different factors may be associated with drinking behaviour across women who are NC and those using HC. Future alcohol research should consider the menstrual cycle and contraceptive status for females.

Training Inhibitory Control Induced Robust Neural Changes When Behavior Is Affected: A Follow-up Study Using Cognitive Event-Related Potentials

Cognitive training results in significant, albeit modest, improvements in specific cognitive functions across a range of mental illnesses. Inhibitory control, defined as the ability to stop the execution of an automatic reaction or a planned motor behavior, is known to be particularly important for the regulation of health behaviors, including addictive behaviors. For example, several studies have indicated that inhibitory training can lead to reduced alcohol consumption or a loss of weight/reduced energy intake. However, the exact neurocognitive mechanisms that underlie such behavioral changes induced by training are still matter of debate. In the present study, we investigated the long-term impact (ie, at 1 week posttraining) of an inhibitory training program (composed of 4 consecutive daily training sessions of 20 minutes each) on the performance of a Go/No-go task. Healthy participants were randomly assigned to 1 of 3 designated groups: (1) an Inhibition Training (IT) group that received training based on a hybrid flanker Go/No-go task; (2) a group that received a noninhibition-based (ie, episodic memory; EM) training; and (3) a No-Training (NT) group to control for test-retest effects. Each group underwent 3 sessions of a Go/No-go task concomitant with the recording of event-related potentials. Our results revealed a specific impact of the Inhibitory Training on the Go/No-go task, indexed by a faster process compared with the other 2 groups. This effect was neurophysiologically indexed by a faster N2 component on the difference NoGo-Go waveform. Importantly, effects at both the behavioral and at the neural level were still readily discernible 1 week posttraining. Thus, our data clearly corroborate the notion that cognitive training is effective, while also indicating that it may persist over time.

Impaired subjective self-control in alcohol use: An ecological momentary assessment study

BACKGROUND

While both theory and empirical findings have supported impaired self-control as a crucial factor in understanding problem drinking, little is known about the relationship of self-control and drinking in naturalistic settings. The present study uses Ecological Momentary Assessment (EMA) to examine the predictive relationships between impaired subjective self-control, craving and alcohol use in everyday life.

METHODS

A sample of 172 regular drinkers responded on their smartphone to three random prompts each day for seven days in which amount of perceived self-control and craving were measured with self-report. In the meantime, participants were instructed to initiate an EMA report when they started drinking alcohol.

RESULTS

Findings supported the hypotheses that impaired self-control and higher craving levels were prospectively related to the likelihood that people will drink. That is, on random assessments that preceded drinking (i.e., were within two hours of drinking), perceived self-control was lower and craving was higher compared to random assessments that were not followed by drinking. Additionally, during drink consumption, impaired self-control and craving were associated with a higher amount of expected alcohol consumption. Findings further indicated that subjective self-control acted as a moderator of the relationship between craving and alcohol consumption during drinking occasions.

CONCLUSIONS

By using a smartphone mobile application, this study showed that impaired subjective self-control and craving are prospectively related to alcohol use in the real-world. Furthermore, findings are consistent with theories of addiction that substance use might be associated with the interplay of control processes and increased motivation.

Brief Exposure to Pictures Depicting Poor Environments Leads to Increased Consumption of Beer in Adult Social Drinkers

Previous studies have suggested a trait-like association between neighborhood deprivation and alcohol consumption. However, it is not known whether temporarily manipulating poverty and affluence states by exposure to stimuli signifying resource-scarcity or resource-wealth would influence alcohol-seeking behavior. Here, we aimed to investigate whether implicit exposure to affluence and poverty-related pictures would influence beer consumption. Participants in a "poverty" group viewed pictures depicting impoverished environments, and participants in an "affluence" group viewed images of wealthy environments. After priming, participants were provided with nonalcoholic beer (which they were told was alcohol-containing beer) and orange juice under the guise of a bogus taste test, to measure their alcohol-seeking behavior. Results showed that priming participants with a resource-scarce environment led to an increase in beer consumption (as a percentage of total fluid consumed), compared to priming with a resource-rich environment. The same pattern of results was obtained in both a Western European sample (Experiment 1) and a West Indian sample (Experiment 2). In Experiment 2, we also tested whether risk-taking behavior, measured by the Balloon Analogue Risk Task, was influenced by the environmental priming; no differences between groups were observed. These results provide the first experimental evidence that manipulation of poverty-affluence state, by brief exposure to pictures of impoverished or wealthy neighborhoods, can influence alcohol-seeking behavior in adult social drinkers.

A randomized controlled trial of inhibitory control training for the reduction of alcohol consumption in problem drinkers

OBJECTIVE

We conducted a randomized controlled trial to compare the effects of three types of Internet-delivered Inhibitory Control Training (ICT) with each other and with an active control intervention on alcohol consumption in a community sample of problem drinkers.

METHOD

Two hundred and 46 heavy drinkers, who were motivated to reduce their alcohol consumption (mean age 41.32, 130 female) self-monitored their alcohol consumption for 1 week before being randomized to receive 1 of 3 variants of ICT (Associative No-Go, Associative Stop Signal, General Inhibition) or an active control. Participants then completed up to 14 ICT/control sessions on the Internet over a 4-week period, while regularly recording their alcohol consumption.

RESULTS

There were significant reductions in alcohol consumption across all groups over the 4-week training period (main effect of time, F(2, 402) = 77.12, p < .01, ηp2 = .28, BF10 > 99), however there were no differences between ICT groups, or between ICT groups and the active control group (Group × Time interaction, F(6, 402) = 1.10, p = .36, ηp2 = .02, BF10 = 0.03). Contrary to hypotheses, there were no changes in general inhibitory control, the disinhibiting effects of alcohol cues, or alcohol affective associations after ICT.

CONCLUSIONS

In this study, which attempted to translate findings from proof-of-concept laboratory studies into a viable behavior change intervention, we found that multiple sessions of ICT delivered over the Internet did not help heavy drinkers to reduce their alcohol consumption beyond nonspecific effects associated with taking part in a trial. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Gambling, motor cautiousness, and choice impulsivity: An experimental study

BACKGROUND

Impulsivity is currently more commonly regarded as multifaceted, comprising both motor and cognitive subdomains. However, it is less clear how distinct these subdomains are, and the extent to which they interact and draw upon the same psychological resources.

METHODS

The present experiment comprised 70 regular (non-problem) gamblers, and investigated the potential to induce impulsivity transfer effects within an electronic gambling context. Original and existing harm-minimization approaches were tested for their efficacy in inducing motor cautiousness during an electronic slot machine simulation. Participants were exposed to a forced discriminatory motor choice procedure, or pop-up responsible gambling messages that either contained emotive or non-emotive responsible gambling content. The subsequent impact these interventions had on delay discounting and reflection impulsivity was also measured using the 27-item Monetary Choice Questionnaire and Information Sampling Task, respectively.

RESULTS

Findings demonstrated that only original harm-minimization approaches, which force the gambler to engage in discriminatory motor choice procedures during gambling, were successful in inducing motor cautiousness. However, both the discriminatory choice procedure and emotive message harm-minimization approaches were successful in facilitating cognitive choice, even though the emotive message intervention was unsuccessful in facilitating motor response inhibition, suggesting both an indirect motor cautiousness route, and a more direct route to improved cognitive choice during gambling.

CONCLUSION

This study demonstrated that decision-making during gambling can be improved by making simple structural changes to slot machine platforms, by encouraging active engagement in motor processes, which result in a transfer of cautiousness to wider cognitive domains.

Perfect for a Gin and Tonic: How Context Drives Consumption Within a Modified Bogus Taste Test

Aim

To implement a modified bogus taste test (BTT) and to examine the interactive effects of environmental and social contexts on levels of 'alcohol' consumption.

Method

University students (Study 1 n = 38, Study 2 n = 80), recruited via opportunity sampling, completed a modified BTT under the pretence of assessing garnish preference for gin and tonic. All participants were tested alone or as part of an existing friendship group. In Study 1 participants were in a laboratory setting but were exposed to different contextual cues (alcohol-related or neutral) by way of posters displayed on the walls. In Study 2, participants assessed the drinks in either a pub or a library setting.

Results

In Study 1 participants tested in a group consumed significantly more when exposed to pub-related stimuli in contrast to those who were exposed to library-related stimuli. Participants who were alone and exposed to library-related cues consumed significantly more than those in a group and exposed to these cues. In Study 2, as in Study 1, participants tested in a group condition consumed significantly more of what they believed to be alcohol when in the pub compared to those who were tested in the library. Higher group consumption was also evident in the library condition, although the size of this difference was not as large as in the pub testing condition.

Conclusion

In the absence of any pharmacological effects of alcohol, social and environmental context have an interactive impact on shaping consumption.

Cognitive control training for emotion-related impulsivity

Many forms of psychopathology are tied to a heightened tendency to respond impulsively to strong emotions, and this tendency, in turn, is closely tied to problems with cognitive control. The goal of the present study was to test whether a two-week, six-session cognitive control training program is efficacious in reducing emotion-related impulsivity. Participants (N = 52) reporting elevated scores on an emotion-related impulsivity measure completed cognitive control training targeting working memory and response inhibition. A subset of participants were randomized to a waitlist control group. Impulsivity, emotion regulation, and performance on near and far-transfer cognitive tasks were assessed at baseline and after completion of training. Emotion-related impulsivity declined significantly from pre-training to post-training and at two-week follow-up; improvements were not observed in the waitlist control group. A decrease in brooding rumination and an increase in reappraisal were also observed. Participants showed significant improvements on trained versions of the working memory and inhibition tasks as well as improvements on an inhibition transfer task. In sum, these preliminary findings show that cognitive training appears to be well-tolerated for people with significant emotion-driven impulsivity. Results provide preliminary support for the efficacy of cognitive training interventions as a way to reduce emotion-related impulsivity.

Do daily fluctuations in inhibitory control predict alcohol consumption? An ecological momentary assessment study

RATIONALE

Deficient inhibitory control is predictive of increased alcohol consumption in the laboratory; however, little is known about this relationship in naturalistic, real-world settings.

OBJECTIVES

In the present study, we implemented ecological momentary assessment methods to investigate the relationship between inhibitory control and alcohol consumption in the real world.

METHODS

Heavy drinkers who were motivated to reduce their alcohol consumption (N = 100) were loaned a smartphone which administered a stop signal task twice per day at random intervals between 10 a.m. and 6 p.m. for 2 weeks. Each day, participants also recorded their planned and actual alcohol consumption and their subjective craving and mood. We hypothesised that day-to-day fluctuations in inhibitory control (stop signal reaction time) would predict alcohol consumption, over and above planned consumption and craving.

RESULTS

Multilevel modelling demonstrated that daily alcohol consumption was predicted by planned consumption (β = .816; 95% CI .762-.870) and craving (β = .022; 95% CI .013-.031), but inhibitory control did not predict any additional variance in alcohol consumption. However, secondary analyses demonstrated that the magnitude of deterioration in inhibitory control across the day was a significant predictor of increased alcohol consumption on that day (β = .007; 95% CI .004-.011), after controlling for planned consumption and craving.

CONCLUSIONS

These findings demonstrate that short-term fluctuations in inhibitory control predict alcohol consumption, which suggests that transient fluctuations in inhibition may be a risk factor for heavy drinking episodes.

21st century neurobehavioral theories of decision making in addiction: Review and evaluation

This review critically examines neurobehavioral theoretical developments in decision making in addiction in the 21st century. We specifically compare each theory reviewed to seven benchmarks of theoretical robustness, based on their ability to address: why some commodities are addictive; developmental trends in addiction; addiction-related anhedonia; self-defeating patterns of behavior in addiction; why addiction co-occurs with other unhealthy behaviors; and, finally, means for the repair of addiction. We have included only self-contained theories or hypotheses which have been developed or extended in the 21st century to address decision making in addiction. We thus review seven distinct theories of decision making in addiction: learning theories, incentive-sensitization theory, dopamine imbalance and systems models, opponent process theory, strength models of self-control failure, the competing neurobehavioral decision systems theory, and the triadic systems theory of addiction. Finally, we have directly compared the performance of each of these theories based on the aforementioned benchmarks, and highlighted key points at which several theories have coalesced.

Alcohol devaluation has dissociable effects on distinct components of alcohol behaviour

RATIONALE

Substance-related behaviour is often viewed as an appetitive behaviour, motivated by the reinforcing effects of the drug. However, there are various indices of substance motivation (e.g. attentional bias, behavioural economic demand, craving) and it is unclear how these are related or whether they play an important role in all types of substance-related behaviour.

OBJECTIVES

(1) To determine the effect of alcohol devaluation on several indices of alcohol motivation and goal-directed and cue-elicited alcohol behaviour. (2) To investigate which components of motivation mediate any effect of devaluation on behaviour.

METHODS

Sixty-two social drinkers gave baseline measures of alcohol craving, behavioural economic demand and choice for alcohol vs. soft drink. Participants tasted alcohol which was either unadulterated (control) or adulterated with a bitter solution (devaluation) before craving and demand were measured again. Alcohol choice was assessed in several phases: extinction (evaluating goal-directed behaviour), in the presence of drink cues (Pavlovian-to-instrumental transfer (PIT, cue-elicited behaviour)), and reacquisition. Attentional bias (AB) was measured by tracking eye movements towards the drink cues during novel PIT trials where both cues were presented. Finally, consumption was evaluated in a taste test.

RESULTS

Alcohol devaluation reduced alcohol-related demand, AB, alcohol choice in all phases, and consumption. Alcohol cues presented during PIT increased alcohol choice above baseline irrespective of devaluation. AB and demand for alcohol fully mediated the effect of devaluation on alcohol choice during extinction, AB fully mediated the effect on cue-elicited (specific PIT) alcohol choice and alcohol consumption.

CONCLUSIONS

Alcohol behaviour in social drinkers is largely sensitive to devaluation, i.e. governed by current motivational value of the drug (suggesting goal-directed behaviour). However, a dissociable form of stimulus control can also drive alcohol-seeking independently of drug value (specific PIT). Mediation analyses suggests that AB may play a paradoxical role in both forms of alcohol seeking and consumption.

Cognitive training as a potential treatment for overweight and obesity: A critical review of the evidence

The aim of this review is to critically evaluate the effectiveness and candidate mechanisms of action of psychological interventions which aim to either (a) improve the capacity for self-regulatory, reflective processes or (b) reduce the impact of automatic appetitive processes, in an attempt to influence food intake and associated weight-gain. Our aim was to examine three important issues regarding each type of intervention: i) whether the intervention influenced behaviour in the laboratory, ii) whether the intervention influenced behaviour and/or body mass index in the real world, and iii) whether the proposed mechanism of action was supported by evidence. We systematically searched three commonly used databases and identified 32 articles which were relevant to at least one of these issues. The majority of studies attempted to manipulate food intake in the laboratory using associative learning paradigms, in normal-weight female participants. Most of the laboratory studies demonstrated the predicted effects of interventions on behaviour in the laboratory, but studies that attempted to translate these interventions outside of the laboratory yielded more mixed findings. The hypothesised mechanisms of action received inconsistent support across studies. We identified several limitations which may complicate interpretation of findings in this area, including heterogeneity of study methods, small sample sizes, and absence of adequate control groups. We provide recommendations for future studies that aim to develop and evaluate these promising interventions for the reduction of overweight and obesity.

Changes in the Relative Balance of Approach and Avoidance Inclinations to Use Alcohol Following Cue Exposure Vary in Low and High Risk Drinkers

According to the ambivalence model of craving, alcohol craving involves the dynamic interplay of separate approach and avoidance inclinations. Cue-elicited increases in approach inclinations are posited to be more likely to result in alcohol consumption and risky drinking behaviors only if unimpeded by restraint inclinations. Current study aims were (1) to test if changes in the net balance between approach and avoidance inclinations following alcohol cue exposure differentiate between low and high risk drinkers, and (2) if this balance is associated with alcohol consumption on a subsequent taste test. In two experiments (N = 60; N = 79), low and high risk social drinkers were exposed to alcohol cues, and pre- and post- approach and avoidance inclinations measured. An ad libitum alcohol consumption paradigm and a non-alcohol exposure condition were also included in Study 2. Cue-elicited craving was characterized by a predominant approach inclination only in the high risk drinkers. Conversely, approach inclinations were adaptively balanced by equally strong avoidance inclinations when cue-elicited craving was induced in low risk drinkers. For these low risk drinkers with the balanced craving profile, neither approach or avoidance inclinations predicted subsequent alcohol consumption levels during the taste test. Conversely, for high risk drinkers, where the approach inclination predominated, each inclination synergistically predicted subsequent drinking levels during the taste test. In conclusion, results support the importance of assessing both approach and avoidance inclinations, and their relative balance following alcohol cue exposure. Specifically, this more comprehensive assessment reveals changes in craving profiles that are not apparent from examining changes in approach inclinations alone, and it is this shift in the net balance that distinguishes high from low risk drinkers.

Current forms of inhibitory training produce no greater reduction in drinking than simple assessment: A preliminary study

BACKGROUND

Disinhibition is apparent in users of many substances, including heavy drinkers. Previous research has shown that brief training to improve inhibitory control is associated with reduced alcohol consumption. We investigated whether a new form of inhibitory training would produce greater reductions, relative to a carefully designed control condition and a proven method of reducing consumption, the Brief Alcohol Intervention (BAI).

METHODS

One hundred and fourteen regular drinkers were assigned randomly to one of five training conditions: Control (no inhibitory training); Beer-NoGo (inhibit responses linked to task-irrelevant pictures of beer); Restrained-Stop (requiring more urgent inhibition but without pictures of beer); Combined (a previously untested form of training requiring urgent inhibition to pictures of beer); or BAI. The outcome measures were alcohol consumption in the week before and after training, and in a bogus taste test administered immediately post-training.

RESULTS

Participation in the study, regardless of condition, was associated with reductions in weekly consumption. However, only the BAI produced a greater reduction relative to the Control condition. The training tasks were not associated with reductions in taste test consumption.

CONCLUSIONS

Although concerns about low power limit confidence, the current study suggests that three forms of inhibitory training do not have a substantial effect on drinking beyond the effect of simple assessment, in comparison to a control task which does not promote impulsive responding. Future research needs to establish a training protocol that produces greater reductions in consumption not only relative to the effect of assessment but also relative to a BAI.

Do alcohol-dependent patients show different neural activation during response inhibition than healthy controls in an alcohol-related fMRI go/no-go-task?

RATIONALE

Alcohol dependence is associated with impaired response inhibition and heightened cue reactivity towards alcohol-related stimuli. Several brain areas, but mainly prefrontal structures, have been linked to response inhibition in addiction. This study aimed at combining both aspects: salience of drug-associated cues and response inhibition using a go/no-go task with alcohol-associated stimuli during functional magnetic resonance imaging (fMRI).

OBJECTIVES

Nineteen abstinent alcohol-dependent patients (ADP) and 21 healthy control subjects (HC) were compared on blood oxygen level-dependent (BOLD) responses during successful inhibition of no-go stimuli and successful reactions to go stimuli.

RESULTS

ADP and HC did not significantly differ in their behavioural performance in the task. However, both groups performed worse during the inhibition of alcoholic-associated stimuli compared to neutral stimuli. On the neural level, ADP displayed enhanced BOLD activity relative to HC during successful response inhibition in several areas involved in visual processing, cognitive and impulse control, including occipital structures, anterior cingulate gyrus, medial frontal gyrus and medial orbitofrontal cortex.

CONCLUSIONS

We interpret these findings as a possible compensation strategy for impaired cognitive processing. Furthermore, the results underline the impact of salience of alcohol-related stimuli on response inhibition, which seems to affect both ADP and HC.

Training response inhibition to reduce food consumption: Mechanisms, stimulus specificity and appropriate training protocols

Training individuals to inhibit their responses towards unhealthy foods has been shown to reduce food intake relative to a control group. Here we aimed to further explore these effects by investigating the role of stimulus devaluation, training protocol, and choice of control group. Restrained eaters received either inhibition or control training using a modified version of either the stop-signal or go/no-go task. Following training we measured implicit attitudes towards food (Study 1) and food consumption (Studies 1 and 2). In Study 1 we used a modified stop-signal training task with increased demands on top-down control (using a tracking procedure and feedback to maintain competition between the stop and go processes). With this task, we found no evidence for an effect of training on implicit attitudes or food consumption, with Bayesian inferential analyses revealing substantial evidence for the null hypothesis. In Study 2 we removed the feedback in the stop-signal training to increase the rate of successful inhibition and revealed a significant effect of both stop-signal and go/no-go training on food intake (compared to double-response and go training, respectively) with a greater difference in consumption in the go/no-go task, compared with the stop-signal task. However, results from an additional passive control group suggest that training effects could be partly caused by increased consumption in the go control group whereas evidence for reduced consumption in the inhibition groups was inconclusive. Our findings therefore support evidence that inhibition training tasks with higher rates of inhibition accuracy are more effective, but prompt caution for interpreting the efficacy of laboratory-based inhibition training as an intervention for behaviour change.

Cue avoidance training and inhibitory control training for the reduction of alcohol consumption: a comparison of effectiveness and investigation of their mechanisms of action

RATIONALE

Both cue avoidance training (CAT) and inhibitory control training (ICT) reduce alcohol consumption in the laboratory. However, these interventions have never been directly compared and their mechanisms of action are poorly understood.

OBJECTIVES

We compared the effects of both types of training on alcohol consumption and investigated if they led to theoretically predicted changes in alcohol avoidance (CAT) or alcohol inhibition (ICT) associations and changes in evaluation of alcohol cues.

METHODS

Heavy drinking young adults (N = 120) were randomly assigned to one of four groups: (1) CAT (repeatedly pushing alcohol cues away with a joystick), (2) sham (control) CAT; (3) ICT (repeatedly inhibiting behaviour in response to alcohol cues); or (4) sham (control) ICT. Changes in reaction times and automatic evaluations of alcohol cues were assessed before and after training using assessment versions of tasks used in training and the implicit association test (IAT), respectively. Finally, participants completed a bogus taste test as a measure of ad libitum alcohol consumption.

RESULTS

Compared to sham conditions, CAT and ICT both led to reduced alcohol consumption although there was no difference between the two. Neither intervention affected performance on the IAT, and changes in reaction time did not suggest the formation of robust alcohol avoidance (CAT) or alcohol inhibition (ICT) associations after training.

CONCLUSIONS

CAT and ICT yielded equivalent reductions in alcohol consumption in the laboratory. However, these behavioural effects were not accompanied by devaluation of stimuli or the formation of alcohol avoidance or alcohol inhibition associations.

Bibi ergo sum: the effects of a placebo and contextual alcohol cues on motivation to drink alcohol

RATIONALE

Acute 'priming' doses of alcohol reliably increase alcohol-seeking behaviour in social drinkers. However, the effects of the anticipated (rather than pharmacological) effects of alcohol, and their interaction with contextual alcohol cues, are not well understood.

OBJECTIVES

This study aims to determine the extent to which an alcohol-placebo drink increases craving, subjective intoxication and beer consumption, while conjointly investigating the impact of contextual alcohol cues.

METHODS

On a within-subject basis, 64 undergraduate social drinkers consumed both a placebo (which they believed to contain alcohol) and a control drink (which they knew did not contain alcohol) in different sessions. Participants completed the study procedures in a bar laboratory designed to look like a 'pub' or a standard psychology lab containing no alcohol-related cues. Craving (Desires for Alcohol Questionnaire) and subjective intoxication were measured pre- and post-drink, and a bogus taste test to measure ad-lib alcohol consumption was completed at the end of each session.

RESULTS

Compared to the control drink, placebo significantly increased craving, ad-lib consumption and subjective intoxication, regardless of environmental context.

CONCLUSIONS

Increased craving and ad-lib alcohol consumption after consuming a priming dose of alcohol is at least partly attributable to the anticipated rather than the pharmacological effects of the priming dose.

Elevated alcohol consumption following alcohol cue exposure is partially mediated by reduced inhibitory control and increased craving

RATIONALE

Exposure to alcohol-related cues leads to increased alcohol consumption, and this may be partially attributable to momentarily impaired impulse control.

OBJECTIVES

We investigated if exposure to alcohol cues would impair inhibitory control and if the extent of this impairment would partially mediate the effect of alcohol cues on subsequent voluntary alcohol consumption.

METHODS

We recruited 81 heavy drinkers (50 female) who completed baseline measures of inhibitory control (stop-signal task) and subjective craving before random allocation to an alcohol cue exposure or control group. The alcohol cue exposure group then completed a second stop-signal task (with embedded alcohol cues) with concurrent exposure to olfactory alcohol cues, in an alcohol context. The control group completed a second stop-signal task (with embedded water cues), accompanied by exposure to water cues, in a neutral context. Then, subjective craving and ad libitum alcohol consumption were measured in all participants.

RESULTS

Inhibitory control worsened (compared to baseline) to a greater extent in the alcohol cue exposure group compared to the control group. Craving and ad libitum alcohol consumption were elevated in the alcohol cue exposure group compared to the control group, although the group difference in alcohol consumption fell short of statistical significance. In support of our hypotheses, multiple mediation analyses demonstrated that elevated ad libitum alcohol consumption following alcohol cue exposure was partially mediated by both impaired inhibitory control and increased craving.

CONCLUSIONS

These findings suggest that state fluctuations in inhibitory control are a potential mechanism through which alcohol cues increase drinking behaviour.

The effects of social support and stress perception on bulimic behaviors and unhealthy food consumption

Two studies tested a model where perceived stress was the proposed mediator for the relationship between perceived social support and bulimic behaviors, and between perceived social support and unhealthy food consumption among undergraduate students. Study 1 was a longitudinal, online study in which undergraduate students completed the Multidimensional Scale of Perceived Social Support and the Bulimia Test-Revised at the Time 1 assessment, and the Perceived Stress Scale and the Eating Disorder Examination Questionnaire at the Time 2 assessment, approximately four weeks later. Study 2 was an experimental study in which female participants were randomly assigned into a group with or without social support. Stress was induced with a speech task, followed by a bogus taste task paradigm designed to assess unhealthy food consumption. Bootstrap analyses revealed an indirect effect of perceived social support on bulimic behaviors and unhealthy food consumption through perceived stress. Perceived social support was associated with lower perceived stress in both studies. Lower perceived stress was associated with less self-reported bulimic behaviors in Study 1 and greater consumption of unhealthy foods in Study 2. The negative association between perceived stress and calorie consumption in Study 2 was moderated by dietary restraint. Findings suggest that stress perception helps to explain the relationship between perceived social support and bulimic behaviors, and between perceived social support and calorie consumption. Stress perception may be an important treatment target for eating disorder symptoms among undergraduate students.

On the automaticity of response inhibition in individuals with alcoholism

BACKGROUND AND OBJECTIVES

Response inhibition is usually considered a hallmark of executive control. However, recent work indicates that stop performance can become associatively mediated ('automatic') over practice. This study investigated automatic response inhibition in sober and recently detoxified individuals with alcoholism..

METHODS

We administered to forty recently detoxified alcoholics and forty healthy participants a modified stop-signal task that consisted of a training phase in which a subset of the stimuli was consistently associated with stopping or going, and a test phase in which this mapping was reversed.

RESULTS

In the training phase, stop performance improved for the consistent stop stimuli, compared with control stimuli that were not associated with going or stopping. In the test phase, go performance tended to be impaired for old stop stimuli. Combined, these findings support the automatic inhibition hypothesis. Importantly, performance was similar in both groups, which indicates that automatic inhibitory control develops normally in individuals with alcoholism..

LIMITATIONS

This finding is specific to individuals with alcoholism without other psychiatric disorders, which is rather atypical and prevents generalization. Personalized stimuli with a stronger affective content should be used in future studies.

CONCLUSIONS

These results advance our understanding of behavioral inhibition in individuals with alcoholism. Furthermore, intact automatic inhibitory control may be an important element of successful cognitive remediation of addictive behaviors..

Acute stress increases ad-libitum alcohol consumption in heavy drinkers, but not through impaired inhibitory control

RATIONALE

Stress increases alcohol consumption and the risk of relapse, but little is known about the psychological mechanisms that underlie these effects. One candidate mechanism is inhibitory control, which may be impaired by acute stress and is believed to exert a causal influence on alcohol consumption.

OBJECTIVES

We investigated if acute stress would impair inhibitory control and if impaired inhibitory control would be associated with subsequent ad-libitum alcohol consumption in a naturalistic laboratory setting.

MATERIALS AND METHODS

One hundred heavy drinkers took part in an experimental study in a naturalistic 'bar laboratory'. Participants were randomly assigned to an acute stress (n = 50) or control (n = 50) group. In the stress group, participants were exposed to the social evaluative threat of giving a self-critical presentation, whereas the control group completed simple anagrams. Prior to and following the manipulation, participants completed the stop signal task as a measure of inhibitory control. Finally, participants completed a bogus taste test, as a measure of ad-libitum alcohol consumption.

RESULTS

The stress manipulation had no effect on performance on the stop signal task. However, there was a small but significant increase in ad-libitum alcohol consumption in the acute stress group compared to that in the control group.

CONCLUSIONS

Acute stress increased alcohol consumption in heavy drinkers, in a semi-naturalistic setting. However, this was not through the hypothesised mechanism of a transient impairment in inhibitory control.

The ad-libitum alcohol 'taste test': secondary analyses of potential confounds and construct validity

RATIONALE

Motivation to drink alcohol can be measured in the laboratory using an ad-libitum 'taste test', in which participants rate the taste of alcoholic drinks whilst their intake is covertly monitored. Little is known about the construct validity of this paradigm.

OBJECTIVE

The objective of this study was to investigate variables that may compromise the validity of this paradigm and its construct validity.

METHODS

We re-analysed data from 12 studies from our laboratory that incorporated an ad-libitum taste test. We considered time of day and participants' awareness of the purpose of the taste test as potential confounding variables. We examined whether gender, typical alcohol consumption, subjective craving, scores on the Alcohol Use Disorders Identification Test and perceived pleasantness of the drinks predicted ad-libitum consumption (construct validity).

RESULTS

We included 762 participants (462 female). Participant awareness and time of day were not related to ad-libitum alcohol consumption. Males drank significantly more alcohol than females (p < 0.001), and individual differences in typical alcohol consumption (p = 0.04), craving (p < 0.001) and perceived pleasantness of the drinks (p = 0.04) were all significant predictors of ad-libitum consumption.

CONCLUSIONS

We found little evidence that time of day or participant awareness influenced alcohol consumption. The construct validity of the taste test was supported by relationships between ad-libitum consumption and typical alcohol consumption, craving and pleasantness ratings of the drinks. The ad-libitum taste test is a valid method for the assessment of alcohol intake in the laboratory.

Inhibitory control training for appetitive behaviour change: A meta-analytic investigation of mechanisms of action and moderators of effectiveness

Inhibitory control training (ICT) is a novel intervention in which participants learn to associate appetitive cues with inhibition of behaviour. We present a meta-analytic investigation of laboratory studies of ICT for appetitive behaviour change in which we investigate candidate mechanisms of action, individual differences that may moderate its effectiveness, and compare it to other psychological interventions. We conducted random-effects generic inverse variance meta-analysis on data from 14 articles (18 effect sizes in total). Participants who received ICT chose or consumed significantly less food or alcohol compared to control groups (SMD = 0.36, 95% CIs [0.24, 0.47]; Z = 6.18, p < .001; I(2) = 71%). Effect sizes were larger for motor (Go/No-Go and Stop Signal) compared to oculomotor (Antisaccade) ICT. The effects of ICT on behaviour were comparable to those produced by other psychological interventions, and effects of ICT on food intake were greater in participants who were attempting to restrict their food intake. The magnitude of the effect of ICT on behaviour was predicted by the proportion of successful inhibitions but was unrelated to the absolute number of trials in which appetitive cues were paired with the requirement to inhibit, or the contingency between appetitive cues and the requirement to inhibit. The effect of ICT on cue devaluation (primarily assessed with implicit association tests) was not statistically significant. Our analysis confirms the efficacy of ICT for short-term behaviour change in the laboratory, and we have demonstrated that its effectiveness may depend on pairings between appetitive cues and successful inhibition. We highlight the need for further research to translate these findings outside of the laboratory.

The impact of transcranial direct current stimulation on inhibitory control in young adults

BACKGROUND

There is increasing evidence that the dorso-lateral prefrontal cortex (DLPFC), a brain region related to reward and motivational processes, is involved in effective response inhibition and that decreased activity in this region coincides with reduced inhibitory capacity. Using transcranial direct current stimulation (tDCS) to manipulate cortical activation, this study examined whether cross-hemispheric tDCS over the DLPFC affected performance on an inhibitory control task.

METHODS

Neurologically intact participants performed a modified Stroop color-word matching task before and after completing one of two tDCS conditions; (1) anodal stimulation over the left DLPFC or (2) sham tDCS.

RESULTS

There was a statistically significant effect of tDCS condition on Stroop reaction time (RT) pre-post tDCS change scores. Participants who received anodal stimulation over the left DLPFC demonstrated statistically significant faster RT change scores on the Stroop items compared to participants in the sham condition. Although errors on Stroop incongruent items decreased before and after receiving the tDCS treatment, there were no significant differences in errors on Stroop items between the anodal stimulation over left DLPFC and sham tDCS conditions. Anodal tDCS, which is known to elevate neural excitation, may have enhanced activation levels in the left DLPFC and minimized impairment of inhibitory control, resulting in better task performance.

CONCLUSIONS

Current findings provide preliminary evidence that increased excitation of the left DLPFC improves inhibitory control and are a step toward understanding the potential of tDCS for moderating deficits in inhibitory control.

How does response inhibition influence decision making when gambling?

Recent research suggests that response inhibition training can alter impulsive and compulsive behavior. When stop signals are introduced in a gambling task, people not only become more cautious when executing their choice responses, they also prefer lower bets when gambling. Here, we examined how stopping motor responses influences gambling. Experiment 1 showed that the reduced betting in stop-signal blocks was not caused by changes in information sampling styles or changes in arousal. In Experiments 2a and 2b, people preferred lower bets when they occasionally had to stop their response in a secondary decision-making task but not when they were instructed to respond as accurately as possible. Experiment 3 showed that merely introducing trials on which subjects could not gamble did not influence gambling preferences. Experiment 4 demonstrated that the effect of stopping on gambling generalized to different populations. Further, 2 combined analyses suggested that the effect of stopping on gambling preferences was reliable but small. Finally, Experiment 5 showed that the effect of stopping on gambling generalized to a different task. On the basis of our findings and earlier research, we propose that the presence of stop signals influences gambling by reducing approach behavior and altering the motivational value of the gambling outcome.

Deficits in behavioural inhibition in substance abuse and addiction: a meta-analysis

AIMS

Deficits in behavioural inhibitory control are attracting increasing attention as a factor behind the development and maintenance of substance dependence. However, evidence for such a deficit is varied in the literature. Here, we synthesised published results to determine whether inhibitory ability is reliably impaired in substance users compared to controls.

METHODS

The meta-analysis used fixed-effects models to integrate results from 97 studies that compared groups with heavy substance use or addiction-like behaviours with healthy control participants on two experimental paradigms commonly used to assess response inhibition: the Go/NoGo task, and the Stop-Signal Task (SST). The primary measures of interest were commission errors to NoGo stimuli and stop-signal reaction time in the SST. Additionally, we examined omission errors to Go stimuli, and reaction time in both tasks. Because inhibition is more difficult when inhibition is required infrequently, we considered papers with rare and equiprobable NoGo stimuli separately.

RESULTS

Inhibitory deficits were apparent for heavy use/dependence on cocaine, MDMA, methamphetamine, tobacco, and alcohol (and, to a lesser extent, non-dependent heavy drinkers), and in pathological gamblers. On the other hand, no evidence for an inhibitory deficit was observed for opioids or cannabis, and contradictory evidence was observed for internet addiction.

CONCLUSIONS

The results are generally consistent with the view that substance use disorders and addiction-like behavioural disorders are associated with impairments in inhibitory control. Implications for treatment of substance use are discussed, along with suggestions for future research arising from the limitations of the extant literature.

A comparison of three types of web-based inhibition training for the reduction of alcohol consumption in problem drinkers: study protocol

Background

Problem drinkers have poor inhibitory control (disinhibition). Previous studies have demonstrated that various forms of ‘inhibition training’ can reduce alcohol consumption in the laboratory and at short-term follow-up, but their longer-term efficacy and mechanisms of action are unknown. In this phase 2 randomised controlled trial we will contrast the effects of three forms of inhibition training and a control intervention, delivered via the Internet in multiple sessions over four weeks, on alcohol consumption in heavy drinkers.

Methods/design

Heavy drinkers who are interested in reducing their alcohol consumption will receive a brief intervention and will monitor their own alcohol intake for one week before being randomised to one of four treatment groups: 1. General inhibition training; 2. Cue-Specific inhibition training; 3. Alcohol No-Go training; or 4. Control. They will complete up to 14 sessions of training via the Internet over a four-week period, and will be followed-up for a further six weeks after the end of the training period. Primary outcome measures are reductions in alcohol consumption and heavy drinking days. The number of abstinent days is a secondary outcome measure. We will also investigate changes in inhibitory control and automatic alcohol affective associations in response to training.

Discussion

This study will establish if web-based inhibition training can help problem drinkers to reduce their alcohol intake, and it will identify which form(s) of inhibition training are most effective.

Trial registation

Trial Registation number: ISRCTN55671858.

A triadic neurocognitive approach to addiction for clinical interventions

According to the triadic neurocognitive model of addiction to drugs (e.g., cocaine) and non-drugs (e.g., gambling), weakened "willpower" associated with these behaviors is the product of an abnormal functioning in one or more of three key neural and cognitive systems: (1) an amygdala-striatum dependent system mediating automatic, habitual, and salient behaviors; (2) a prefrontal cortex dependent system important for self-regulation and forecasting the future consequences of a behavior; and (3) an insula dependent system for the reception of interoceptive signals and their translation into feeling states (such as urge and craving), which in turn plays a strong influential role in decision-making and impulse control processes related to uncertainty, risk, and reward. The described three-systems account for poor decision-making (i.e., prioritizing short-term consequences of a decisional option) and stimulus-driven actions, thus leading to a more elevated risk for relapse. Finally, this article elaborates on the need for "personalized" clinical model-based interventions targeting interactions between implicit processes, interoceptive signaling, and supervisory function aimed at helping individuals become less governed by immediate situations and automatic pre-potent responses, and more influenced by systems involved in the pursuit of future valued goals.

Why adolescents are at risk of misusing alcohol and gambling

AIMS

The aim of the study was to explore the reasons for alcohol misuse and other risk-taking behaviours in adolescence.

METHODS

Narrative review.

RESULTS

Vulnerable adolescents make suboptimal addictive-related choices in the period of initiation of alcohol use and gambling, which is also a period of cognitive and brain development, and in health behaviours. Hyperactive response to rewards as well as possibly hypoactive responses to punishments combined with weaknesses in the abilities to regulate strong impulses results in greater risk of alcohol and gambling misuse.

CONCLUSION

Abnormal patterns of alcohol consumption (e.g. binge drinking) could dramatically reinforce this disequilibrium by enhancing salience for alcohol and associated information and compromising self-regulatory processes. There are some preventive and therapeutic cognitive training strategies that can strengthen willpower in adolescents.

Fluctuating disinhibition: implications for the understanding and treatment of alcohol and other substance use disorders

Disinhibition is present in various maladaptive behaviors, including substance use disorders. Most previous research has assumed that disinhibition is a psychological construct that is relatively stable within individuals. However, recent evidence suggests that the ability to inhibit behavior fluctuates in response to environmental and psychological triggers. In this review we discuss some of the factors that cause (dis)inhibition to fluctuate, we examine whether these fluctuations contribute to subjective craving and substance consumption, and we ask if they might increase the risk of relapse in those who are attempting to abstain. The research that we discuss has furthered our understanding of the causal relationships between disinhibition and substance use disorders, and it also highlights opportunities to develop novel treatment interventions. We conclude that substance misusers and their therapists should be made aware of the triggers that can cause disinhibition to fluctuate, and we highlight the need for more research to investigate the effectiveness of inhibitory control training in clinical settings.

Testing the Conjoint Influence of Impulsivity and Drinking Restraint on Alcohol Use Consequences in College Student Drinkers

OBJECTIVES

Impulsivity and drinking restraint play a role in excessive drinking patterns and related negative consequences. Two domains of drinking restraint include preoccupation with thoughts of drinking (CEP) and attempts to control drinking (CBC), which differentially predict varying alcohol use outcomes in clinical and non-clinical samples. However, findings do not replicate across clinical, dependent samples and risky drinking young adults. This study examined the moderating role of dispositional impulsivity on the association between drinking restraint and alcohol consequences among college students to help clarify inconsistencies in the literature.

METHODS

Data were collected from a sample of college student drinkers (N = 393) on drinking behavior in the past 90 days, alcohol-related problems, dispositional impulsivity, and drinking restraint.

RESULTS

The association between CBC and alcohol consequences was significantly stronger for those higher than lower in dispositional impulsivity, after controlling for the effects of alcohol consumption. No such relationship was found for those high in trait temptation.

CONCLUSIONS

Alcohol consequences are greater among those who attempt to control their drinking and who act rashly and without consideration of future consequences; those who are high on trait temptation show no such relationship.

Pathological gambling and the loss of willpower: a neurocognitive perspective

The purpose of this review is to gain more insight on the neurocognitive processes involved in the maintenance of pathological gambling. Firstly, we describe structural factors of gambling games that could promote the repetition of gambling experiences to such an extent that some individuals may become unable to control their gambling habits. Secondly, we review findings of neurocognitive studies on pathological gambling. As a whole, poor ability to resist gambling is a product of an imbalance between any one or a combination of three key neural systems: (1) an hyperactive 'impulsive' system, which is fast, automatic, and unconscious and promotes automatic and habitual actions; (2) a hypoactive 'reflective' system, which is slow and deliberative, forecasting the future consequences of a behavior, inhibitory control, and self-awareness; and (3) the interoceptive system, translating bottom-up somatic signals into a subjective state of craving, which in turn potentiates the activity of the impulsive system, and/or weakens or hijacks the goal-driven cognitive resources needed for the normal operation of the reflective system. Based on this theoretical background, we focus on certain clinical interventions that could reduce the risks of both gambling addiction and relapse.

P300 during response inhibition is associated with ad-lib alcohol consumption in social drinkers

Reduced amplitude of the cortical P300 event-related potential (ERP) component during response inhibition is associated with vulnerability to alcohol use disorders. In the current study, we investigated the effect of an experimental manipulation of response conflict on the amplitude of the P300 component during response inhibition, and examined whether individual differences in the amplitude of this P300 component would predict voluntary ad-lib alcohol consumption, in social drinkers. Using a repeated measures design, 16 participants performed a stop-signal task after receiving instructions that either emphasised or de-emphasised response conflict while their electroencephalogram (EEG) was concurrently recorded, before their ad-lib drinking was assessed. Results revealed that task instructions had the predicted effects on behavioural indices of response inhibition and the associated P300 components. Most importantly, individual differences in the amplitude of P300 subcomponents during response inhibition were negatively correlated with ad-lib alcohol consumption. Results provide the first experimental support for theoretical models that posit that reduced amplitude of the P300 during response inhibition is associated with alcohol-seeking behaviour in humans.

Effects of 0.4 g/kg alcohol on attentional bias and alcohol-seeking behaviour in heavy and moderate social drinkers

Alcohol intoxication is known to influence attentional biases for alcohol-related cues and alcohol-seeking behaviour. It is unknown if heavier drinkers are more or less sensitive to these effects of alcohol, or whether the effects of alcohol on attentional bias are associated with subsequent alcohol-seeking behaviour. In the present study, 55 social drinkers were administered either 0.4 g/kg alcohol or placebo in a repeated measures, double-blind experimental design. Participants completed a visual probe task with eye movement monitoring (to measure attentional bias) and a bogus taste test (to measure alcohol-seeking) in both alcohol and placebo sessions. Heavy drinkers showed an attentional bias for alcohol cues that was unaffected by alcohol, whereas in moderate drinkers attentional bias was present after alcohol administration, but was absent after placebo. All participants voluntarily consumed more beer during the taste test after administration of alcohol compared with placebo. The effects of alcohol on attentional bias were unrelated to the effects of alcohol on beer consumption. Results are consistent with the development of tolerance, rather than sensitization, to the acute effects of alcohol on attentional biases in heavy drinkers. However, alcohol-induced increases in attentional bias were not related to the effects of alcohol on the motivation to drink.

Impaired control over alcohol use: An under-addressed risk factor for problem drinking in young adults?

Impaired control over alcohol use may be defined as "a breakdown of an intention to limit consumption in a particular situation" (Heather, Tebbutt, Mattick, & Zamir, 1993, p. 701) and has long been considered an important feature of alcohol dependence. Evidence suggests impaired control is highly relevant to young adult problem drinking. In the natural history of problem drinking, impaired control tends to develop early and may predict alcohol-related problems prospectively in undergraduates. Impaired control over alcohol use may be a facet of generalized behavioral undercontrol specifically related to drinking. In particular, impaired control is theoretically and empirically related to impulsivity. The question of whether impaired control represents a facet of impulsivity or a related but separate construct requires further study. However, theoretical arguments and empirical evidence suggest that there are unique qualities to the constructs. Specifically, existing data suggest that self-report measures of impaired control and impulsivity over alcohol use relate distinctly to problem drinking indices in young adults. Several lines of future research concerning impaired control are suggested, using the impulsivity literature as a guide. We conclude that impaired control is a valuable construct to the study of young adult problem drinking and that measures of impaired control should be included in more young adult alcohol studies. The extent to which impaired control over the use of other substances and impaired control over engagement in other addictive behaviors are clinically relevant constructs requires additional study.

Impulsivity and alcohol consumption in young social drinkers

Impulsivity may have different facets that contribute to drinking patterns in young people. This research examined how aspects of impulse control, especially the ability to inhibit a response, predicted recent alcohol use patterns in young social drinkers. Participants (N=109) between the ages of 18 and 21 performed a cued go/no-go task that required quick responses to go targets and the inhibition of responses to no-go targets. Participants also completed several questionnaires that assessed drinking habits (TLFB) and self-reported impulsivity (BIS-11). Regression analyses revealed that both the impulsivity questionnaire scores and the inhibitory failures observed on the behavioral task predicted various aspects of recent drinking. However, only the inhibitory failures from the behavioral task, and not the impulsivity questionnaire scores, predicted the highest number of drinks consumed on one occasion during the past month. These findings are consistent with the notion that impulsivity may have different components that may be contributing the drinking patterns, and this research suggests that the inability to withhold a response is a strong predictor of the binge use of alcohol.

Components of behavioural impulsivity and automatic cue approach predict unique variance in hazardous drinking

RATIONALE

Hazardous drinking is associated with both increased impulsivity and automatic approach tendencies elicited by alcohol-related cues. However, impulsivity is a multi-factorial construct, and it is currently unclear if all components of impulsivity are associated with heavy drinking. Furthermore, emerging evidence suggests that the relationships between hazardous drinking and automatic alcohol cognitions may be moderated by individual differences in impulsivity.

OBJECTIVES

The aim of this study was to investigate the independence of measures of impulsivity and their association with hazardous drinking, and to examine if the relationship between hazardous drinking and automatic alcohol approach tendencies would be moderated by individual differences in impulsivity.

METHODS

Ninety-seven social drinkers (65 female) completed questionnaire measures of trait impulsivity, alcohol consumption and hazardous drinking. Participants also completed computerised measures of automatic alcohol approach tendencies (stimulus-response compatibility (SRC) task), and two behavioural measures of impulsivity (Go/No-go and delay discounting tasks).

RESULTS

Principal component analysis revealed that the two measures of behavioural impulsivity were distinct from each other and from self-reported trait impulsivity, although self-reported non-planning impulsivity loaded on to two factors (trait impulsivity and delay discounting). Furthermore, all measures of impulsivity predicted unique variance in hazardous drinking as did automatic alcohol approach tendencies, although the latter relationship was not moderated by impulsivity.

CONCLUSIONS

These results indicate that multiple components of impulsivity and automatic alcohol approach tendencies explain unique variance in hazardous drinking.

Priming a restrained mental set reduces alcohol-seeking independently of mood

RATIONALE

Cross-sectional research demonstrates that heavy drinking is associated with elevated impulsivity, including disinhibition. However, causal effects of disinhibition on drinking behaviour are not well established.

OBJECTIVE

To experimentally manipulate disinhibited versus restrained mental sets before exploring their impact on alcohol-seeking behaviour and to investigate if any effects of the manipulation occurred independently of arousal, mood, and craving.

METHODS

The study utilized a between-subjects design in which participants were randomly allocated to experimental groups. Social drinkers (N = 90) attended the laboratory for a single session where they initially completed a stop-signal task. Different mental sets were induced by emphasising either the importance of cautious responding and successful inhibition (Restraint group), the importance of rapid responding (Disinhibition group), or the equal importance of rapid responding and successful inhibition (Control group). Heart rate, blood pressure, and subjective mood were assessed before participants completed a bogus taste test procedure.

RESULTS

The Restraint group consumed less beer than the Disinhibition and Control groups, which did not differ from each other. There were no group differences in heart rate, blood pressure, or self-reported mood after the manipulation. Across the whole sample, cautious responding during the stop-signal task (slower reaction time to 'Go' cues, fewer inhibition errors) was associated with reduced beer consumption.

CONCLUSIONS

These findings suggest that temporary fluctuations in disinhibited/restrained states may play a causal role in drinking behaviour.