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

Identifying the role of (dis)inhibition in the vicious cycle of substance use through ecological momentary assessment and resting-state fMRI

Functional inhibition is known to improve treatment outcomes in substance use disorder (SUD), potentially through craving management enabled by underlying cerebral integrity. Whereas treatment is challenged by a multitude of substances that patients often use, no study has yet unraveled if inhibition and related cerebral integrity could prevent relapse from multiples substances, that is, one's primary drug of choice and secondary ones. Individuals with primary alcohol, cannabis, or tobacco use disorders completed intensive Ecological Momentary Assessment (EMA) coupled with resting-state functional MRI (rs-fMRI) to characterize the extent to which inhibition and cerebral substrates interact with craving and use of primary and any substances. Participants were 64 patients with SUD and 35 healthy controls who completed one week EMA using Smartphones to report 5 times daily their craving intensity and substance use and to complete Stroop inhibition testing twice daily. Subsamples of 40 patients with SUD and 34 control individuals underwent rs-fMRI. Mixed Model Analysis revealed that reported use of any substance by SUD individuals predicted later use of any and primary substance, whereas use of the primary substance only predicted higher use of that same substances. Craving and inhibition level independently predicted later use but did not significantly interact. Preserved inhibition performance additionally influenced use indirectly by mediating the link between subsequent uses and by being linked to rs-fMRI connectivity strength in fronto-frontal and cerebello-occipital connections. As hypothesized, preserved inhibition performance, reinforced by the integrity of inhibitory neurofunctional substrates, may partake in breaking an unhealthy substance use pattern for a primary substance but may not generalize to non-target substances or to craving management.

Cortical paired associative stimulation shows impaired plasticity of inhibition networks as a function of chronic alcohol use

BACKGROUND

Response inhibition - or the ability to withhold a suboptimal response - relies on the efficacy of fronto-striatal networks, and is impaired in neuropsychiatric disorders including addiction. Cortical paired associative stimulation (cPAS) is a form of transcranial magnetic stimulation (TMS) which can strengthen neuronal connections via spike-timing-dependent plasticity mechanisms. Here, we used cPAS targeting the fronto-striatal inhibitory network to modulate performance on a response inhibition measure in chronic alcohol use.

METHODS

Fifty-five participants (20 patients with a formal alcohol use disorder (AUD) diagnosis (26-74 years, 6[30%] females) and 20 matched healthy controls (HCs) (27-73 years, 6[30%] females) within a larger sample of 35 HCs (23-84 years, 11[31.4%] females) underwent two randomized sessions of cPAS 1-week apart: right inferior frontal cortex stimulation preceding right presupplementary motor area stimulation by either 4 ms (excitation condition) or 100 ms (control condition), and were subsequently administered the Stop Signal Task (SST) in both sessions.

RESULTS

HCs showed decreased stop signal reaction time in the excitation condition (t(19) = -3.01, p = 0.007, [CIs]:-35.6 to -6.42); this facilitatory effect was not observed for AUD (F(1,31) = 9.57, p = 0.004, CIs: -68.64 to -14.11). Individually, rates of SST improvement were substantially higher for healthy (72%) relative to AUD (13.6%) groups (OR: 2.33, p = 0.006, CIs:-3.34 to -0.55).

CONCLUSION

In line with previous findings, cPAS improved response inhibition in healthy adults by strengthening the fronto-striatal network through putative long-term potentiation-like plasticity mechanisms. Furthermore, we identified a possible marker of impaired cortical excitability, and, thus, diminished capacity for cPAS-induced neuroplasticity in AUD with direct implications to a disorder-relevant cognitive process.

Self-regulatory control processes in youths: A temporal network analysis approach

Objective

This study aimed to better understand the temporal interrelationships among self-control, response inhibition, and anger (i.e., momentary state and rumination) on both the within- and between-person levels in male adolescents.

Method

We applied temporal network analyses among 62 male adolescents with a wide range of behavioral difficulties. Self-control, momentary anger, and anger rumination were mapped by self-report measures, whereas we measured response inhibition through an ambulatory Go/No-go task (two measures a day-morning and afternoon-over a 9-day period).

Results

Temporal network analysis, at the within-person level, revealed that morning measures of response inhibition, anger rumination, and self-control were related to the corresponding measure in the afternoon. More efficient response inhibition in the morning was associated with higher self-control in the afternoon. Higher anger rumination in the morning led to higher momentary anger in the afternoon. In a concurrent within-person network, higher momentary anger was reciprocally associated with lower self-control. At the between-person level, higher momentary anger was correlated to higher anger rumination, lower response inhibition, and lower self-control.

Discussion

This study provides insight into the dynamic interactions among self-control, response inhibition, and anger (momentary state and rumination) in male adolescents, advancing the understanding of self-regulatory control functioning.

The relationship between inhibitory control and food consumption or choice: A systematic review and meta-analysis

Excess consumption of unhealthy foods has become a major public health problem. Although one potential contributor to unhealthy consumption is poor inhibitory control, findings have been inconsistent. A meta-analysis of 35 studies was conducted to determine whether, and under which conditions, inhibitory control, as measured by the Go/No-Go and Stop-Signal tasks, is associated with food consumption/choice. Moderators included the type of stimuli (neutral or food-specific) used in measuring inhibitory control, sample differences (e.g., age, gender, and weight), and the measure of food consumption or choice. Overall, there was a small positive association between inhibitory control and food consumption/choice, r = .09, CI₉₅ = [0.04, 0.14], p = .001. This held for the Stop-Signal Task in general, and for the Go/No-Go Task for children and when food consumption/choice was measured objectively. The present meta-analysis provides the first comprehensive evidence that inhibitory control, as measured by the Go/No-Go and Stop-Signal tasks, is associated with food consumption or choice, and points to inhibitory control as a potential target for reducing unhealthy food consumption.

Behavioral restriction, lorazepam, and escitalopram uniquely influence the expression of naturalistic stereotypy in deer mice: perspectives on anxiety- and compulsive-like behavior

Introduction: Stereotypical expression in laboratory-housed rodents can be explained by different motivational, coping, and motor dysfunction theories. Here, we aimed to explore the neurocognitive underpinnings of high stereotypical (HS) expression in deer mice (Peromyscus maniculatus bairdii), previously proposed as a model system of compulsive-like behavioral persistence. Specifically, we aimed to establish whether HS behavior is related to an underlying escape-related trigger. Methods: One-hundred and sixteen deer mice were classified as either non-stereotypical (NS) or HS. Mice of each cohort were further subdivided and exposed to either sub-acute (3-day) or chronic (25-day) behavioral restriction (R), and high-dose escitalopram (ESC), lorazepam (LOR), alone and in combination with R (ESC+R and LOR+R, respectively). Mice were reassessed for stereotypical behavior at both time points. Results: Our results indicate that HS behavior is likely not temporally and functionally related to an anxiogenic trigger, i.e., R, but rather that HS is associated with parallel changes in anxiogenic feedback processing. We also show that chronic R alone significantly decreased the time spent in expressing HS behavior in animals of the HS, but not NS phenotype. Discussion: This points to the possibility that HS-expressing mice represent a subgroup of P. maniculatus bairdii in which unique interactions between neurobiology and processes of gradual behavioral organization, may contribute to the expression of the typical behaviors observed in this cohort. Collectively, our findings highlight the value of the deer mouse model system to investigate the potential neurocognitive mechanisms that may underlie the development of persistent phenotypes that can likely not be explained entirely by current theories.

Self-regulatory Processes in Problematic Pornography Use

Purpose of Review

A core symptom of problematic pornography use (PPU) is the repeated failure to control sexual impulses resulting in pornography use; however, the field of self-regulation research has rarely been applied to PPU.

Recent Findings

Various goals can underly the use of online pornography. These goals can conflict with other self-regulatory goals a person holds, which leads to moments of self-control. The outcome of such self-control moments depends on multiple internal factors, including the strength of the desire to use pornography, whether a person perceives a conflict with their behaviour, and the motivation to resist their desire, as well as external, situational factors. Findings on the contribution of volition towards self-regulation in PPU are inconclusive.

Summary

More research is needed to further explore what influences moments of self-control, specifically in PPU. The proposed model of self-control moments can be used to derive research questions for further studies as well as to develop prevention and intervention approaches.

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.

Elevated ad libitum alcohol consumption following continuous theta burst stimulation to the left-dorsolateral prefrontal cortex is partially mediated by changes in craving

Previous research indicates that following alcohol intoxication, activity in prefrontal cortices is reduced, linking to changes in associated cognitive processes, such as inhibitory control, attentional bias (AB), and craving. While these changes have been implicated in alcohol consumption behaviour, it has yet to be fully illuminated how these frontal regions and cognitive processes interact to govern alcohol consumption behaviour. The current preregistered study applied continuous theta burst transcranial magnetic stimulation (cTBS) to examine directly these relationships while removing the wider pharmacological effects of alcohol. A mixed design was implemented, with cTBS stimulation to right and left dorsolateral prefrontal cortex (DLPFC), the medial orbital frontal cortex (mOFC) and Vertex, with measures of inhibitory control, AB, and craving taken both pre- and post-stimulation. Ad libitum consumption was measured using a bogus taste task. Results suggest that rDLPFC stimulation impaired inhibitory control but did not significantly increase ad libitum consumption. However, lDLPFC stimulation heightened craving and increased consumption, with findings indicating that changes in craving partially mediated the relationship between cTBS stimulation of prefrontal regions and ad libitum consumption. Medial OFC stimulation and AB findings were inconclusive. Overall, results implicate the left DLPFC in the regulation of craving, which appears to be a prepotent cognitive mechanism by which alcohol consumption is driven and maintained.

Emotion-Attention Interaction in the Right Hemisphere

Hemispheric asymmetries in affective and cognitive functions have been extensively studied. While both cerebral hemispheres contribute to most affective and cognitive processes, neuroscientific literature and neuropsychological evidence support an overall right hemispheric dominance for emotion, attention and arousal. Emotional stimuli, especially those with survival value such as threat, tend to be prioritized in attentional resource competition. Arousing unpleasant emotional stimuli have prioritized access, especially to right-lateralized attention networks. Interference of task performance may be observed when limited resources are exhausted by task- and emotion-related processing. Tasks that rely on right hemisphere-dependent processing, like attending to the left visual hemifield or global-level visual features, are especially vulnerable to interference due to attention capture by unpleasant emotional stimuli. The aim of this review is to present literature regarding the special role of the right hemisphere in affective and attentional brain processes and their interaction. Furthermore, clinical and technological implications of this interaction will be presented. Initially, the effects of focal right hemisphere lesion or atrophy on emotional functions will be introduced. Neurological right hemisphere syndromes including aprosodia, anosognosia and neglect, which further point to the predominance of the intact right hemisphere in emotion, attention and arousal will be presented. Then there will be a brief review of electrophysiological evidence, as well as evidence from patients with neglect that support attention capture by emotional stimuli in the right hemisphere. Subsequently, experimental work on the interaction of emotion, attention and cognition in the right hemispheres of healthy subjects will be presented. Finally, clinical implications for better understanding and assessment of alterations in emotion-attention interaction due to brain disorder or treatment, such as neuromodulation, that impact affective brain functions will be discussed. It will be suggested that measuring right hemispheric emotion-attention interactions may provide basis for novel biomarkers of brain health. Such biomarkers allow for improved diagnostics in brain damage and disorders and optimized treatments. To conclude, future technological applications will be outlined regarding brain physiology-based measures that reflect engagement of the right hemisphere in affective and attentional processes.

Diagnostic and Classification Considerations Related to Compulsive Sexual Behavior Disorder and Problematic Pornography Use

Purpose of Review

There are ongoing debates about specific features of compulsive sexual behavior disorder (CSBD) relating to classification and diagnoses. We aim to address current discussions relating to potential subtypes of CSBD, the aspect of compulsivity in CSBD, and the aspect of moral incongruence and CSBD.

Recent Findings

CSBD includes multiple specific sexual behaviors that might be related to specific psychological processes. Problematic pornography use may be considered a subtype of CSBD, which may have multiple parallels with addictive behaviors. The feature of compulsivity in CSBD may be different from compulsivity in other disorders and may be differently involved in early versus later stages of CSBD. Moral incongruence is important to consider in the context of CSBD, although moral disapproval is not a general exclusion criterion for diagnosing CSBD.

Summary

Considering the current debates of specific features of CSBD, future research and clinical practice may benefit from a trans-diagnostic approach to contribute to a more fine-grained understanding of the multiple facets of CSBD.

Limited Evidence of Associations Between Executive Functioning and Alcohol Involvement In UK Adolescents

Aims

Deficits in motor inhibitory control and working memory have been hypothesized to be both a cause and consequence of heavy alcohol use. Adolescence is a critical developmental stage for inhibitory control and working memory, and it is also a stage when individuals are most likely to initiate alcohol use. This study aimed to examine whether inhibitory control and working memory would predict alcohol use and involvement in a group of UK adolescents.

Methods

We recruited 220 (N = 178, female) adolescents, aged between 16 and 18, from eight higher education settings in the Merseyside region of the UK. Alcohol use was examined using the Timeline Follow-Back and involvement (and related problems) using the Adolescent Alcohol Involvement Scale. A reward-based inhibitory control task (Go/No-Go) was used to examine the inhibition and reward sensitivity, and a self-ordered pointing task was used to measure working memory.

Results

Multiple regression demonstrated that neither inhibitory control (b = 0.02 (95% confidence interval (CI): −0.21, 0.24)) nor working memory (b = −0.12 (95% CI: −0.30, 0.07)) were significant predictors of alcohol use (units consumed). Inhibitory control (b = 0.61 (95% CI: 0.12, 1.09), specifically, in the no reward condition and school deprivation (b = 0.67 (95% CI: 0.06, 1.28) significantly predicted alcohol-related problems.

Conclusions

Our findings demonstrated limited evidence that deficits in specific mechanisms of executive functioning (i.e. motor inhibition and working memory) were associated with alcohol-related problems in UK adolescents. This study adds to an increasing body of literature suggesting weak or non-existent links between inhibitory control, working memory and alcohol use.

Neurophysiological correlates of alcohol-specific inhibition in alcohol use disorder and its association with craving and relapse

OBJECTIVE

This study investigates neurophysiological correlates of general and alcohol-specific inhibitory control in patients with Alcohol Use Disorder (AUD), focusing on its association with individual craving levels and with relapse at three-month follow-up.

METHODS

59 abstinent AUD patients and 20 healthy controls performed a Go/NoGo task incorporating alcohol-related and neutral stimuli during 64-channel electroencephalography (EEG) recording, yielding four event-related potentials (ERP) per participant (NoGo-Alcohol, Go-Alcohol, NoGo-Neutral, Go-Neutral). Whole-scalp randomization-based statistics assessed effects of the factors group (patients/controls or relapsers/abstainers), craving level, response type (NoGo/Go) and picture type (alcohol/neutral) on topography and signal strength of the ERP components N2 and P3.

RESULTS

No differences on group level were observed between patients and controls. However, analyses incorporating individual craving indicated that the topographic difference between alcohol-related and neutral NoGo-N2 components increased with craving. Moreover, topographic differences in the alcohol-related and neutral NoGo-P3 component allowed for differentiation between relapsers and abstainers.

CONCLUSIONS

In alcohol-related contexts, the response inhibition conflict reflected in the NoGo-N2 seems enhanced in patients with high craving. The inhibition-sensitive NoGo-P3 varies in relapsers but not in abstainers between neutral and alcohol-related contexts.

SIGNIFICANCE

In AUD patients, neurophysiological correlates of inhibition vary with alcohol-related contexts and craving, and might be indicative of relapse risk.

A meta-analytic investigation of the role of reward on inhibitory control

Contemporary theories predict that inhibitory control (IC) can be improved when rewards are available for successfully inhibiting. In non-clinical samples empirical research has demonstrated some support; however, "null" findings have also been published. The aim of this meta-analysis was to clarify the magnitude of the effect of reward on IC and identify potential moderators. A total of 73 articles (contributing k = 80 studies) were identified from PubMed, PsycInfo, and Scopus, published between 1997 and 2020, using a systematic search strategy. A random effects meta-analysis was performed on effect sizes generated from IC tasks, which included rewarded and non-rewarded inhibition trials. Moderator analyses were conducted on clinical samples (vs "healthy controls"), task type (go/no-go vs stop signal vs Flanker vs Simon vs Stroop vs Anti-saccade), reward type (monetary vs points vs other), and age (adults vs children). The prospect of reward for successful inhibition significantly improved IC (SMD = 0.429, 95% CI = 0.288, 0.570, I² = 96.7%) compared with no reward conditions/groups. This finding was robust against influential cases and outliers. The significant effect was present across all IC tasks. There was no evidence of the effect moderated by type of reward, age, or clinical samples. Moderator analyses did not resolve the considerable heterogeneity. The findings suggest that IC is a transient state that fluctuates in response to motivations driven by reward. Future research might examine the potential of improving IC through rewards as a behavioural intervention.

Do the Transmissible Liability Index (TLI) and Adolescent Cannabis Use Predict Paranoid and Schizotypal Symptoms at Young Adulthood?

Background: Adolescent cannabis use is an established risk factor for the development of psychosis, but the premorbid vulnerability factors and specificity versus generality of the psychotic symptom domains affected in cannabis-psychosis relationships remain incompletely understood. To improve our understanding of these relationships, we used longitudinal data to examine the individual and interactive effects of preadolescent transmissible liability to substance use disorders (SUD), measured via the transmissible liability index (TLI), and adolescent cannabis use on the development of two distinct psychotic symptom domains, paranoid and schizotypal personality traits in young adulthood. Methods: We performed secondary analysis of data from the Center for Education and Drug Abuse (CEDAR) study, which longitudinally assessed offspring of men with (N = 211) and without (N = 237) lifetime history of SUD at ages 10-12, and across adolescence as they transitioned to young adulthood. TLI scores were calculated at age 10-12, self-reported cannabis use was assessed at age 16, and paranoid and schizotypal symptoms were assessed at age 19. Results: Cannabis use at age 16 and family history of SUD were significantly associated with paranoid and schizotypal symptoms at age 19, but TLI scores were not. The interactive effect of TLI x cannabis use was also not significant. Paranoid and schizotypal symptoms showed different dose-dependent sensitivities to cannabis exposure at age 16. Conclusions: These findings indicate that adolescent cannabis use and family history of SUD differentially contribute to the development of paranoid and schizotypal personality traits through mechanisms that do not include behavioral disinhibition.

Using Smartphone Sensor Data to Assess Inhibitory Control in the Wild: Longitudinal Study

Background

Inhibitory control, or inhibition, is one of the core executive functions of humans. It contributes to our attention, performance, and physical and mental well-being. Our inhibitory control is modulated by various factors and therefore fluctuates over time. Being able to continuously and unobtrusively assess our inhibitory control and understand the mediating factors may allow us to design intelligent systems that help manage our inhibitory control and ultimately our well-being.

Objective

The aim of this study is to investigate whether we can assess individuals’ inhibitory control using an unobtrusive and scalable approach to identify digital markers that are predictive of changes in inhibitory control.

Methods

We developed InhibiSense, an app that passively collects the following information: users’ behaviors based on their phone use and sensor data, the ground truths of their inhibition control measured with stop-signal tasks (SSTs) and ecological momentary assessments (EMAs), and heart rate information transmitted from a wearable heart rate monitor (Polar H10). We conducted a 4-week in-the-wild study, where participants were asked to install InhibiSense on their phone and wear a Polar H10. We used generalized estimating equation (GEE) and gradient boosting tree models fitted with features extracted from participants’ phone use and sensor data to predict their stop-signal reaction time (SSRT), an objective metric used to measure an individual’s inhibitory control, and identify the predictive digital markers.

Results

A total of 12 participants completed the study, and 2189 EMAs and SST responses were collected. The results from the GEE models suggest that the top digital markers positively associated with an individual’s SSRT include phone use burstiness (P=.005), the mean duration between 2 consecutive phone use sessions (P=.02), the change rate of battery level when the phone was not charged (P=.04), and the frequency of incoming calls (P=.03). The top digital markers negatively associated with SSRT include the standard deviation of acceleration (P<.001), the frequency of short phone use sessions (P<.001), the mean duration of incoming calls (P<.001), the mean decibel level of ambient noise (P=.007), and the percentage of time in which the phone was connected to the internet through a mobile network (P=.001). No significant correlation between the participants’ objective and subjective measurement of inhibitory control was found.

Conclusions

We identified phone-based digital markers that were predictive of changes in inhibitory control and how they were positively or negatively associated with a person’s inhibitory control. The results of this study corroborate the findings of previous studies, which suggest that inhibitory control can be assessed continuously and unobtrusively in the wild. We discussed some potential applications of the system and how technological interventions can be designed to help manage inhibitory control.

The Critical Lack of Data on Alcohol and Marijuana Use by Adolescents on the Autism Spectrum

Alcohol is the most commonly used substance among adolescents, and marijuana is the most commonly used illicit drug. Emerging evidence suggests that at least some autistic individuals may be at increased risk of substance use disorder compared with allistic counterparts, potentially to control social anxiety or facilitate social interaction. However, to the best of our knowledge, U.S. population-based estimates of substance use by autistic youth are limited. The aim of this perspective article was to highlight the lack of data sets that collect information about alcohol and marijuana use by autistic youth in the United States. We used a four-step investigation to identify potential data sources that could provide an estimate of the prevalence of alcohol and/or marijuana use in autistic youth, without regard to whether those estimates would be robust. We identified a total of 19 potential U.S. data sources. Of these, only one included information about both autism and alcohol and/or marijuana by youth. There is too little research on substance use by autistic adolescents, and rigorously collected data would benefit the field. Our recommendations include increased federal funding for data collection from autistic youth on substance use, additional questions on nationally representative surveys that assess autism status in multiple ways, and the use of robust measures of substance use that allow for characterization of substance use according to multiple dimensions. As the number of autistic youth identified increases and these youth transition into adulthood, better understanding of their substance use patterns is critical for developing health promotion efforts that appropriately and fully serve the needs of autistic youth.

Lay summary

Why is this topic important?: Alcohol is the most commonly used substance among adolescents, and marijuana is the most commonly used illicit drug. Previous studies suggest that at least some autistic individuals may be at increased risk of substance use disorder compared with allistic counterparts, potentially to control social anxiety or facilitate social interaction. However, to the best of our knowledge, estimates of substance use by autistic youth in the United States are limited.What is the purpose of this article?: This study was performed to highlight the lack of data sets that collect information about alcohol and/or marijuana use by autistic youth in the United States. We systematically reviewed U.S. data sources on child and/or adolescent health, disability, and/or substance use to identify sources that could generate estimates of the prevalence of substance use among autistic adolescents in the United States, even if those estimates may not be stable due to small sample sizes or other methodological weaknesses.What is the perspective of the authors?: The authors are a team of allistic researchers. M.B.-M. and S.B.-F. are pediatricians. E.F.R. and A.A. are public health researchers. S.B.-F. has an extensive background in providing clinical health care services to children with autism and is an autism researcher. R.A.N.P. and A.C.S.-R. are master's level public health research assistants. E.F.R., A.A., and M.B.-M. are adolescent health research experts. E.F.R. has an adolescent daughter on the autism spectrum. Our collective positionality is that we identify as people who are not autistic and who select to focus on research that we hope will benefit autistic people and society in general.What did the authors find?: Based on our four-step investigation, we identified 19 U.S. data sources that had the potential to generate estimates of the prevalence of alcohol and/or marijuana use in autistic youth. Only one included information about both autism and substance use.What do the authors recommend?: The National Institutes of Health (NIH), and the National Institute of Alcohol Abuse and Alcoholism (NIAAA) and National Institute of Drug Abuse (NIDA), specifically, should prioritize funding data collection from autistic youth and adults on alcohol and marijuana use, misuse, hazardous use, dependence, and use disorders. In addition, it is critical that nationally representative surveys and data sources include robust questions on autism and substance abuse. This includes assessing autism status in multiple ways (e.g., self-report, diagnosis by a clinician, neuropsychology reports). Substance use questions should include age of first drink or use, frequency of use, quantity of use per day or within a certain number of hours, expectancies, consequences of use, and indicators of alcohol use disorder.How will these recommendations help autistic individuals?: These findings highlight a critical gap in the literature on substance use among autistic youth. Substance use is recognized as a pressing adolescent health problem, and autistic youth deserve evidence-based substance use prevention strategies. Without an estimate of substance use by autistic youth, it is difficult to justify to funding entities the expenditure of resources on the development of evidence-based substance use prevention strategies to benefit them.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Does alcohol cue inhibitory control training survive a context shift?

Inhibitory control training (ICT) is a novel psychological intervention that aims to improve inhibitory control in response to alcohol-related cues through associative learning. Laboratory studies have demonstrated reductions in alcohol consumption following ICT compared with control/sham training, but it is unclear if these effects are robust to a change of context. In a preregistered study, we examined whether the effects of ICT would survive a context shift from a neutral context to a seminaturalistic bar setting. In a mixed design, 60 heavy drinkers (40 female) were randomly allocated to receive either ICT or control/sham training in a neutral laboratory over 2 sessions. We developed a novel variation of ICT that used multiple stop signals to establish direct stimulus-stop associations. The effects of ICT/control were measured once in the same context and once following a shift to a novel (alcohol-related) context. Our dependent variables were ad libitum alcohol consumption following training, change in inhibitory control processes, and change in alcohol value. ICT did not reduce alcohol consumption in either context compared with the control group. Furthermore, we demonstrated no effects of ICT on inhibitory control processes or alcohol value. Bayesian analyses demonstrated overall support for the null hypotheses. This study failed to find any effects of ICT on alcohol consumption or candidate psychological mechanisms. These findings illustrate the difficulty in training alcohol-inhibition associations and add to a growing body of literature suggesting that ICT holds little evidential value as a psychological intervention for alcohol use disorders. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Cognitive and emotional predictors of real versus sham repetitive transcranial magnetic stimulation treatment response in methamphetamine use disorder

BACKGROUND AND AIMS

Repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) can effectively reduce cravings in methamphetamine use disorder (MUD). However, a considerable group still fails to respond. Cognitive and emotional disturbance, as well as impulsive features, are widespread in patients with MUD and might mediate the treatment response of rTMS. The purpose of this study is to figure out whether these variables can help predicting patients' responses to rTMS treatment.

METHODS

Ninety-seven patients with severe MUD and thirty-one gender- and age-matched healthy subjects were included. Patients were randomized to receive 20 sessions of real or sham rTMS. Intermittent theta burst protocols (iTBS) or sham iTBS were applied every weekday over the DLPFC for 20 daily sessions. Both groups received regular treatment. Craving induced by drug-related cue was measured before and after stimulation. Cognition was evaluated by using the CogState Battery. Baseline characteristics were collected through the Addiction Severity Index, Patient Health Questionnaire-9, General Anxiety Disorder Scale-7, and Barrett Impulsivity Scale-11.

RESULTS

Results showed that patients with MUD have worse spatial working memory, problem-solving ability, as well as depression and anxiety symptoms compared with healthy controls. Cognition and emotion differed between responders (craving decrease ≥60%) and non-responders in real rTMS group but not in the sham group. Better cognitive and emotional functions means that patients have higher possibility for better response to real rTMS treatment.

CONCLUSIONS

This study suggests that cognitive, emotional and impulsive features could be used to predict the prospective treatment responses of rTMS in patients with MUD.

Inhibitory control and problematic Internet-pornography use - The important balancing role of the insula

BACKGROUND AND AIMS

Diminished control over a specific behavior is a core characteristic in addictive behaviors such as problematic Internet-pornography (IP) use. First studies suggest that a hyperactivity of the impulsive system is one reason for impulsive behaviors in the context of problematic IP use. The tripartite-process theory of addiction explains neurocognitive mechanisms beyond common dual-process theories in addictive behaviors. However, the role of the reflective and interoceptive system is still unresolved.

METHODS

The study comprised a stop-signal task (SST) including neutral and pornographic images during fMRI and questionnaires to investigate associations between symptoms of problematic IP use, craving, and neural activity of the impulsive, reflective, and interoceptive system. We examined 28 heterosexual males with varying symptom severity of problematic IP use.

RESULTS

Data indicates that individuals with more symptoms of problematic IP use showed better performance in the SST which was linked to decreased insula and inferior frontal gyrus activity during pornographic image processing. An increase in craving was associated with lower activity of the ventral striatum during pornographic image processing. The interoceptive system showed varying effects. Increased insula activity during inhibitory control and decreased activity during pornographic image processing were associated with higher inhibitory control performance.

DISCUSSION AND CONCLUSION

Effects of tolerance and motivational aspects may explain the better inhibitory control performance in individuals with higher symptom severity which was associated with differential activity of the interoceptive and reflective system. Diminished control over IP use presumably results from the interaction between the impulsive, reflective, and interoceptive systems.

Random Forest Classification of Alcohol Use Disorder Using EEG Source Functional Connectivity, Neuropsychological Functioning, and Impulsivity Measures

: Individuals with alcohol use disorder (AUD) manifest a variety of impairments that can be attributed to alterations in specific brain networks. The current study aims to identify features of EEG-based functional connectivity, neuropsychological performance, and impulsivity that can classify individuals with AUD (N = 30) from unaffected controls (CTL, N = 30) using random forest classification. The features included were: (i) EEG source functional connectivity (FC) of the default mode network (DMN) derived using eLORETA algorithm, (ii) neuropsychological scores from the Tower of London test (TOLT) and the visual span test (VST), and (iii) impulsivity factors from the Barratt impulsiveness scale (BIS). The random forest model achieved a classification accuracy of 80% and identified 29 FC connections (among 66 connections per frequency band), 3 neuropsychological variables from VST (total number of correctly performed trials in forward and backward sequences and average time for correct trials in forward sequence) and all four impulsivity scores (motor, non-planning, attentional, and total) as significantly contributing to classifying individuals as either AUD or CTL. Although there was a significant age difference between the groups, most of the top variables that contributed to the classification were not significantly correlated with age. The AUD group showed a predominant pattern of hyperconnectivity among 25 of 29 significant connections, indicating aberrant network functioning during resting state suggestive of neural hyperexcitability and impulsivity. Further, parahippocampal hyperconnectivity with other DMN regions was identified as a major hub region dysregulated in AUD (13 connections overall), possibly due to neural damage from chronic drinking, which may give rise to cognitive impairments, including memory deficits and blackouts. Furthermore, hypoconnectivity observed in four connections (prefrontal nodes connecting posterior right-hemispheric regions) may indicate a weaker or fractured prefrontal connectivity with other regions, which may be related to impaired higher cognitive functions. The AUD group also showed poorer memory performance on the VST task and increased impulsivity in all factors compared to controls. Features from all three domains had significant associations with one another. These results indicate that dysregulated neural connectivity across the DMN regions, especially relating to hyperconnected parahippocampal hub as well as hypoconnected prefrontal hub, may potentially represent neurophysiological biomarkers of AUD, while poor visual memory performance and heightened impulsivity may serve as cognitive-behavioral indices of AUD.

Interactions of immediate and long-term action regulation in the course and complications of bipolar disorder

Immediate and long-term mechanisms interact in the regulation of action. We will examine neurobiology and practical clinical consequences of these interactions. Long-term regulation of immediate behavioural control is based on analogous responses to highly rewarding or stressful stimuli: (i) impulsivity is a failure of the balance between activation and inhibition in the immediate regulation of action. (ii) Sensitization is a persistently exaggerated behavioural or physiological response to highly salient stimuli, such as addictive stimuli or inescapable stress. Sensitization can generalize across classes of stimuli. (iii) Impulsivity, possibly related to poor modulation of catecholaminergic and glutamatergic functions, may facilitate development of long-term sensitized responses to stressful or addictive stimuli. In turn, impulsivity is prominent in sensitized behaviour. (iv) While impulsivity and sensitization are general components of behaviour, their interactions are prominent in the course of bipolar disorder, emphasizing roles of substance-use, recurrent course and stressors. (v) Suicide is a complex and severe behaviour that exemplifies the manner in which impulsivity facilitates behavioural sensitization and is, in turn, increased by it, leading to inherently unpredictable behaviour. (vi) Interactions between impulsivity and sensitization can provide targets for complementary preventive and treatment strategies for severe immediate and long-term behavioural disorders. Progress along these lines will be facilitated by predictors of susceptibility to behavioural sensitization. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

High-Risk, but Hidden: Binge Drinking among Men Who Have Sex with Men and Transgender Women in Lima, Peru, 2012-2014

Background: Binge drinking (BD) is common in Peru, but may not be routinely detected by standard assessments of hazardous drinking. Objectives: We describe prevalence and risk behaviors of men who have sex with men (MSM) and transgender women (TW) in Peru who met criteria for BD as compared with those who met criteria for hazardous drinking. Methods: In a cross-sectional sample of MSM and TW from Lima (2012-2014), we calculated prevalence of BD (consuming ≥6 alcoholic drinks per occasion by AUDIT-3 criteria), conducted bivariate analyses of associations of BD with demographic and behavioral characteristics, and compared prevalence and behaviors of BD to those of hazardous drinkers (identified by AUDIT-10 criteria). Results: Of 1,520 MSM (n = 1,384) and TW (n = 137) with median age 27 years, 74.4% of MSM and 86.9% of TW met criteria for BD. Among MSM, BD was associated with a greater likelihood of using alcohol (41.6% vs. 13.8%; p < .01) or drugs (7.8% vs. 2.8%; p < .01) prior to a recent sexual contact. Among TW, BD was associated with greater frequency of alcohol use (44.9% vs. 11.1%; p < .01) or unprotected anal intercourse (58.8% vs. 33.3%; p = .04) during ≥1 of their three most recent sexual contacts. There was a higher prevalence of BD (75.5%) than hazardous drinking (53.2%) in our sample, with binge drinkers exhibiting similar sexual risk behaviors to hazardous drinkers. Conclusions: Binge drinking is common among MSM and TW in Lima, associated with risky sexual behavior, and may not be adequately captured by AUDIT-10 criteria.

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.

Continuous Theta Burst Transcranial Magnetic Stimulation of the Right Dorsolateral Prefrontal Cortex Impairs Inhibitory Control and Increases Alcohol Consumption

Previous research indicates that alcohol intoxication impairs inhibitory control and that the right dorsolateral prefrontal cortex (rDLPFC) is a functional brain region important for exercising control over thoughts and behaviour. At the same time, the extent to which changes in inhibitory control following initial intoxication mediate subsequent drinking behaviours has not been elucidated fully. Ascertaining the extent to which inhibitory control impairments drive alcohol consumption, we applied continuous theta burst transcranial magnetic stimulation (rDLPFC cTBS vs. control) to isolate how inhibitory control impairments (measured using the Stop-Signal task) shape ad libitum alcohol consumption in a pseudo taste test. Twenty participants (13 males) took part in a within-participants design; their age ranged between 18 and 27 years (M = 20.95, SD = 2.74). Results indicate that following rDLPFC cTBS participants' inhibitory control was impaired, and ad libitum consumption increased. The relationship between stimulation and consumption did not appear to be mediated by inhibitory control in the present study. Overall, findings suggest that applying TMS to the rDLPFC may inhibit neural activity and increase alcohol consumption. Future research with greater power is recommended to determine the extent to which inhibitory control is the primary mechanism by which the rDLPFC exerts influence over alcohol consumption, and the degree to which other cognitive processes may play a role.

The role of neuropsychological mechanisms in implementation intentions to reduce alcohol consumption among heavy drinkers: a randomized trial

Implementation intention formation, which involves identifying triggers and linking them with coping strategies, has proven effective at reducing alcohol consumption in general populations. For the first time, the present study tested the ability of implementation intentions to reduce alcohol consumption among heavy drinkers and to explore potential neuropsychological mechanisms. At baseline, participants were randomized to form implementation intentions or to an active control group. There was a 5.7 unit (1 unit = 10 ml or 8 g ethanol) per week reduction ([95%CI 0.15, 11.19], p = 0.048) in alcohol consumption at 1 month follow-up among participants who formed implementation intentions, which was significantly more than controls F(1, 91) = 3.95, p = 0.048, a medium effect size (d = 0.47, Cohen, 1992). No significant differences in performance on the neuropsychological tasks were found between groups. The present study demonstrates for the first time that implementation intentions reduce alcohol consumption among heavy drinkers.

Alcohol-Specific Computerized Interventions to Alter Cognitive Biases: A Systematic Review of Effects on Experimental Tasks, Drinking Behavior, and Neuronal Activation

Background: In patients with alcohol use disorder, novel interventions to increase abstinence have attracted growing attention. Interventions aimed at modifying cognitive biases linked to alcohol use [i.e. cognitive bias modification (CBM)] may serve as an add-on to standard therapy. This systematic review thoroughly aggregates existing data on the effects of three alcohol-specific computerized interventions, namely attentional bias modification (AtBM), approach bias modification (ApBM), and inhibition training (IT). In doing so, each CBM's effects on experimental tasks assessing the relevant biases, drinking behavior, and neurophysiology are summarized. Also, the influence of drinking behavior severity and motivation to change drinking behavior are discussed. Methods: A literature search was conducted in four databases for original research articles published between 2000 and May 2019. Studies were eligible if investigating the effects of alcohol-specific computerized interventions (AtBM, ApBM, IT) on drinking behavior, bias change, and/or neurophysiology. Forty eligible articles were classified as being either a non-clinical experimental lab study (ELS) or clinical randomized-controlled trial (RCT) and summarized. Results: While AtBM seems to influence attentional bias, its effects on drinking behavior are inconsistent. As for ApBM, the best effects on drinking behavior are obtained in clinical samples. Effects of ApBM on approach bias are mixed. Interestingly, those clinical RCTs which investigated ApBM effects on bias change as well as on drinking outcome, reported consistent effects in both measures (i.e. either effects on bias and drinking or no effects). Studies on IT are limited to non-clinical samples and show inconsistent effects on drinking behavior. Considering ITs effects on implicit semantic associations, most studies do not support the conceptualization of IT as a form of memory bias modification, while reports on IT's effects on inhibitory control are still incomplete. Conclusions about the overall influence of drinking behavior severity are hampered by the non-uniform use of sample descriptions. Conclusions: In clinical samples, ApBM has shown more consistent beneficial effects, while evidence on AtBM is more inconsistent, and data on IT still lacks important information. Conclusions about the influence of drinking behavior severity would be facilitated by a uniform use of clearly defined sample descriptions.

Transdiagnostic Investigation of Impulsivity in Alcohol Use Disorder and Binge Eating Disorder With Eye-Tracking Methodology-A Pilot Study

Objective: Patients with alcohol use disorder (AUD) and patients with binge eating disorder (BED) are characterized by increased impulsivity, i.e. increased reward sensitivity and diminished response inhibition. In this pilot study, we compare both disorders directly concerning impulsivity using disorder-specific stimuli to gain insight into the relationship of both disorders and underlying mechanisms. Methods: We compared eye movements of 23 women with BED (age M = 40.9), 21 participants with AUD (13 females, 8 males, age M = 46.6), and age- and sex-matched control groups (BED-CG and AUD-CG, respectively). We measured reward sensitivity with the free exploration paradigm and response inhibition with the modified antisaccade paradigm. We presented disorder-specific stimuli vs. neutral stimuli, i.e. food stimuli in the BED and BED-CG and alcohol stimuli in the AUD and AUD-CG. Results: BED and BED-CG initially fixated more often on food stimuli vs. neutral stimuli, whereas AUD and AUD-CG initially fixated more often on neutral stimuli vs. alcohol stimuli. AUD showed shorter dwell times on both stimulus categories in comparison with the other groups. When saccades towards stimuli should be inhibited, BED made more errors in first saccades for both stimulus categories in comparison with AUD-CG and in second saccades particularly for food stimuli in comparison with all other groups, whereas AUD did not differ from the control groups. Conclusions: This pilot study indicates that food and alcohol stimuli are at the first sight differently processed. Moreover, patients with BED and with AUD seem to process disorder-specific stimuli differently. Whereas patients with AUD avoid stimuli generally, patients with BED predominantly show deficits in inhibitory control.

The effect of alcohol cue exposure and acute intoxication on inhibitory control processes and ad libitum alcohol consumption

RATIONALE

Alcohol intoxication and alcohol cue exposure impair 'reactive' inhibitory control and increase motivation to drink. However, inhibitory control is a multi-component process that also comprises signal detection and proactive control. It is unknown whether intoxication and cue exposure selectively influence these subprocesses in heavy drinkers.

OBJECTIVES

In two pre-registered studies, we investigated whether exposure to alcohol-related cues (study 1) and alcohol priming (study 2) impair each of these subprocesses of inhibitory control and increase motivation to drink.

METHODS

In study 1, 64 heavy drinkers completed a modified stop-signal task in an alcohol context (with embedded alcohol cues) and a neutral context (with embedded neutral cues) followed by a subjective measure of craving and a bogus taste test to measure ad libitum alcohol consumption. In study 2, 36 heavy drinkers consumed an alcoholic beverage (0.6 g/kg body weight), an alcohol-placebo beverage, and water on a within-subjects basis, followed by the modified stop-signal task and a bogus taste test.

RESULTS

In study 1, alcohol cue exposure did not impair inhibitory control subprocesses. Reactive control was unexpectedly better following alcohol cue exposure (compared to neutral cue exposure). However, craving and ad libitum consumption increased as expected. In study 2, reactive control was significantly impaired following the alcohol and control primes, relative to the placebo, but there was no effect on proactive slowing or signal detection. As expected, intoxication increased motivation to drink and ad libitum consumption (compared to placebo and control).

CONCLUSIONS

Alcohol intoxication and cue exposure increase motivation to drink in the absence of impairments in subcomponents of inhibitory control.

Marijuana use is associated with alcohol use and consequences across the first 2 years of college

College entry is associated with marijuana initiation, and co-use of alcohol and marijuana is associated with problematic outcomes, including alcohol-related consequences. The present study explored if: (a) use of marijuana on a given day would be associated with greater alcohol use within the same day; (b) use of marijuana within a given week would be associated with increased alcohol-related consequences in that same week; and (c) the association between marijuana use and alcohol consumption and consequences varies across time or by precollege level of problematic alcohol use. Participants (N = 488 college student drinkers, 59% female) completed assessments of marijuana use, alcohol use, and alcohol consequences across 2 years. Analyses revealed: (a) daily marijuana use predicted greater number of daily drinks and estimated breath alcohol concentration; (b) weekly marijuana use predicted more weekly positive and negative alcohol consequences; (c) the effect of daily marijuana use on alcohol use strengthened over time, while the effect of weekly marijuana use on positive alcohol consequences reduced over time; and (d) precollege level of problematic alcohol use moderated the association between daily marijuana and alcohol use and weekly marijuana use and negative consequences. This study provides the first longitudinal evidence of the association between marijuana use and greater alcohol use and consequences in college students. Future research examining event-level measurement of alcohol and marijuana co-use is important for the prevention of alcohol-related consequences. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

PTSD symptoms and alcohol-related problems among veterans: Temporal associations and vulnerability

Posttraumatic stress disorder (PTSD) is associated with elevated risk of both alcohol use disorder (AUD) and related conduct problems, which are associated with behavioral and emotional dysregulation. We conducted an intensive longitudinal burst design study with 10 weeks of experience sampling over the course of 1.5 years with 250 veterans of recent conflicts. We tested time-series models of daily associations between posttraumatic stress symptoms (PTSS), alcohol dependence syndrome, and conduct problems. Exacerbations of PTSS predicted higher dependence syndrome and conduct problems the next day. This effect was significant after controlling for both concurrent (i.e., same-day) associations between drinking and the outcomes as well as the strength of associations between the outcomes from one day to the next (i.e., autoregression). Affect lability and disinhibition were hypothesized vulnerability factors increasing the strength of within-person predictors of dependence syndrome and conduct problems. Lability and disinhibition were associated with greater dependence syndrome symptoms and conduct problems over the follow-up period. Consistent with expectation, lability rather than disinhibition increased the association between drinking and dependence syndrome as well as the strength of association between dependence syndrome symptoms from one day to the next. Moderating effects of disinhibition in the conduct problems model were not significant. Importantly, results indicated reciprocal associations over time. Lability potentiated the association between dependence syndrome symptoms and next day PTSS, whereas disinhibition potentiated the association between conduct problems and next day PTSS. Results demonstrate complex dynamic associations between PTSS, AUD symptoms, and conduct problems over time indicative of broad regulatory impairments. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A latent class analysis of alcohol and drug use immediately before or during sex among women

BACKGROUND

Alcohol and drug use by women is related to high-risk sexual practices and protective behaviors.

OBJECTIVES

To determine sexual risk and protective behaviors using information about women's drug use immediately before or during sex.

METHODS

Latent class analysis using PROC LCA in SAS software was used to determine classes of women using both past 30-day drug use and before or during sex. Participants were recruited from a community-based research site located in a low socio-economic area of Los Angeles County and completed the Risk Behavior Assessment, which elicits information on drug and sex risk behaviors.

RESULTS

The Risk Behavior Assessment and HIV and sexually transmitted infections testing was obtained on 812 women. Five distinct groups were identified by PROC LCA: An Abstinent group comprised of 26% of participants; an Alcohol and Marijuana group (16%); an Amphetamine group (11%); a No Sex-with-Alcohol group (37%); and a Poly Drug group (11%). Multinomial logistic regression revealed that sexual behaviors and condom use were different across the five groups: The Alcohol and Marijuana group had a higher odds of vaginal intercourse, while the No Sex-with-Alcohol group was most likely to use condoms for vaginal intercourse. The Poly Drug group had the highest risk for anal intercourse while the Amphetamine and Poly Drug groups had high proportions of women with injection-drug using and men-who-have-sex-with-men sexual partners.

CONCLUSION

Identifying women based on drug use immediately before or during sex can help providers understand prevention and risk-reduction practices and interventions for drug-using women.

Competing Motivations: Proactive Response Inhibition Toward Addiction-Related Stimuli in Quitting-Motivated Individuals

We examined whether addiction-related cues impact proactive inhibition (the restraint of actions in preparation for stopping) in individuals who are motivated to quit gambling or cannabis use. In Study 1, treatment-seeking individuals with cannabis use disorder and matched controls performed a stop-signal task that required them to inhibit categorizing cannabis or neutral pictures, and within varying levels of stop-signal probability. In Study 2, two groups of individuals, who applied to a voluntary self-exclusion program toward gambling, performed the stop-task following relaxation or gambling craving induction, with results compared to non-gamblers. Study 1 showed that despite being less efficient in proactive inhibition, individuals with cannabis use disorder exhibited heightened proactive inhibition toward cannabis cues. In Study 2, proactive inhibition toward gambling cues was heightened in gamblers after craving, but the degree of proactive adjustment decreased as a function of induced changes in gambling-related motivation. Present findings demonstrate that exposure to addiction-related cues can modulate proactive inhibition in individuals who are motivated to restrict their addictive behaviors.

Deficient inhibition in alcohol-dependence: let's consider the role of the motor system!

Impaired inhibitory control contributes to the development, maintenance, and relapse of alcohol-dependence, but the neural correlates of this deficit are still unclear. Because inhibitory control has been labeled as an executive function, most studies have focused on prefrontal areas, overlooking the contribution of more "primary" structures, such as the motor system. Yet, appropriate neural inhibition of the motor output pathway has emerged as a central aspect of healthy behavior. Here, we tested the hypothesis that this motor inhibition is altered in alcohol-dependence. Neural inhibitory measures of motor activity were obtained in 20 detoxified alcohol-dependent (AD) patients and 20 matched healthy subjects, using a standard transcranial magnetic stimulation procedure whereby motor-evoked potentials (MEPs) are elicited in a choice reaction time task. Moreover, behavioral inhibition and trait impulsivity were evaluated in all participants. Finally, the relapse status of patients was assessed 1 year after the experiment. As expected, AD patients displayed poorer behavioral inhibition and higher trait impulsivity than controls. More importantly, the MEP data revealed a considerable shortage of neural motor inhibition in AD patients. Interestingly, this neural defect was strongest in the patients who ended up relapsing during the year following the experiment. Our data suggest a strong motor component in the neural correlates of altered inhibitory control in AD patients. They also highlight an intriguing relationship with relapse and the perspective of a new biomarker to follow strategies aiming at reducing relapse in AD patients.

Momentary assessment of impulsive choice and impulsive action: Reliability, stability, and correlates

Impulsivity is associated with substance use, including tobacco use. The degree to which impulsivity fluctuates over time within persons, and the degree to which such intra-individual changes can be measured reliably and validly in ambulatory assessments is not known, however. The current study evaluated two novel ambulatory measures of impulsive choice and impulsive action. Impulsive choice was measured with an eight-item delay discounting task designed to estimate the subjective value of delayed monetary rewards. Impulsive action was measured with a two-minute performance test to assess behavioral disinhibition (the inability to inhibit a motor response when signaled that such a response will not be rewarded). Valid data on impulsive choice were collected at 70% of scheduled reports and valid data on impulsive action were collected on 55% of scheduled reports, on average. Impulsive choice and action data were not normally distributed, but models of relations of these measures with within- and between-person covariates were robust across distributional assumptions. Intra-class correlations were substantial for both impulsive choice and action measures. Between persons, random intercepts in impulsive choice and action were significantly related to laboratory levels of their respective facets of impulsivity, but not self-reported or other facets of impulsivity. Validity of the ambulatory measures is supported by associations between abstinence from smoking and increased impulsivity, but challenged by an association between strong temptations to smoke and reduced impulsive choice. Results suggest that meaningful variance in impulsive choice and action can be captured using ambulatory methods, but that additional measure refinement is needed.

Daily Patterns of Marijuana and Alcohol Co-Use Among Individuals with Alcohol and Cannabis Use Disorders

BACKGROUND

The study aims were to examine daily associations between marijuana and alcohol use and the extent to which the association differs as a function of cannabis use disorder (CUD) and/or alcohol use disorder (AUD) diagnosis.

METHODS

Timeline Followback interview data was collected in a study of veterans (N = 127) recruited from a Veterans Affairs hospital who reported at least 1 day of co-use of marijuana and alcohol in the past 180 days (22,860 observations). Participants reported 40% marijuana use days, 28% drinking days, with 37% meeting DSM-5 criteria for CUD, 40% for AUD, and 15% for both. Use of marijuana on a given day was used to predict a 3-level gender-adjusted drinking variable (heavy: ≥5 (men)/4 (women) drinks; moderate: 1 to 4/3 drinks; or none: 0 drinks). A categorical 4-level variable (no diagnosis, AUD, CUD, or both) was tested as a moderator of the marijuana-alcohol relationship.

RESULTS

Multilevel modeling analyses demonstrated that participants were more likely to drink heavily compared to moderately (OR = 2.34) and moderately compared to not drinking (OR = 1.61) on marijuana use days relative to nonuse days. On marijuana use days, those with AUD and those with AUD + CUD were more likely to drink heavily (OR = 1.91; OR = 2.51, respectively), but those with CUD were less likely to drink heavily (OR = 0.32) compared to moderately, nonsignificant differences between any versus moderate drinking in interaction models.

CONCLUSIONS

Heavy drinking occurs on days when marijuana is also used. This association is particularly evident in individuals diagnosed with both AUD and CUD and AUDs alone but not in those with only CUDs. Findings suggest that alcohol interventions may need to specifically address marijuana use as a risk factor for heavy drinking and AUD.

From neuroscience to evidence based psychological treatments - The promise and the challenge, ECNP March 2016, Nice, France

This ECNP meeting was designed to build bridges between different constituencies of mental illness treatment researchers from a range of backgrounds with a specific focus on enhancing the development of novel, evidence based, psychological treatments. In particular we wished to explore the potential for basic neuroscience to support the development of more effective psychological treatments, just as this approach is starting to illuminate the actions of drugs. To fulfil this aim, a selection of clinical psychologists, psychiatrists and neuroscientists were invited to sit at the same table. The starting point of the meeting was the proposition that we know certain psychological treatments work, but we have only an approximate understanding of why they work. The first task in developing a coherent mental health science would therefore be to uncover the mechanisms (at all levels of analysis) of effective psychological treatments. Delineating these mechanisms, a task that will require input from both the clinic and the laboratory, will provide a key foundation for the rational optimisation of psychological treatments. As reviewed in this paper, the speakers at the meeting reviewed recent advances in the understanding of clinical and cognitive psychology, neuroscience, experimental psychopathology, and treatment delivery technology focussed primarily on anxiety disorders and depression. We started by asking three rhetorical questions: What has psychology done for treatment? What has technology done for psychology? What has neuroscience done for psychology? We then addressed how research in five broad research areas could inform the future development of better treatments: Attention, Conditioning, Compulsions and addiction, Emotional Memory, and Reward and emotional bias. Research in all these areas (and more) can be harnessed to neuroscience since psychological therapies are a learning process with a biological basis in the brain. Because current treatment approaches are not fully satisfactory, there is an imperative to understand why not. And when psychological therapies do work we need to understand why this is the case, and how we can improve them. We may be able to improve accessibility to treatment without understanding mechanisms. But for treatment innovation and improvement, mechanistic insights may actually help. Applying neuroscience in this way will become an additional mission for ECNP.

Does self-control modify the impact of interventions to change alcohol, tobacco, and food consumption? A systematic review

Low self-control is associated with increased consumption of alcohol, tobacco, and unhealthy food. This systematic review aimed to assess whether individual differences in self-control modify the effectiveness of interventions to reduce consumption of these products, and hence their potential to reduce consumption amongst those whose consumption is generally greater. Searches of six databases were supplemented with snowball searches and forward citation tracking. Narrative synthesis summarised findings by: consumption behaviour (alcohol, tobacco, food); psychological processes targeted by the intervention (reflective, non-reflective, or both); and study design (experiment, cohort, or cross-sectional). Of 54 eligible studies, 22 reported no evidence of modification, 18 reported interventions to be less effective in those with low self-control, and 14 reported interventions to be more effective in those with low self-control. This pattern did not differ from chance. Whilst self-control often influenced intervention outcomes, there was no consistent pattern of effects, even when stratifying studies by consumption behaviour, intervention type, or study design. There was a notable absence of evidence regarding interventions that restructure physical or economic environments. In summary, a heterogeneous, low-quality evidence base suggests an inconsistent moderating effect of low self-control on the effectiveness of interventions to change consumption behaviours.

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.

Optogenetic activation of amygdala projections to nucleus accumbens can arrest conditioned and unconditioned alcohol consummatory behavior

Following a Pavlovian pairing procedure, alcohol-paired cues come to elicit behavioral responses that lead to alcohol consumption. Here we used an optogenetic approach to activate basolateral amygdala (BLA) axonal terminals targeting the shell of nucleus accumbens (AcbSh) and investigated a possible influence over cue-conditioned alcohol seeking and alcohol drinking, based on the demonstrated roles of these areas in behavioral responding to Pavlovian cues and in feeding behavior. Rats were trained to anticipate alcohol or sucrose following the onset of a discrete conditioned stimulus (CS). Channelrhodopsin-mediated activation of the BLA-to-AcbSh pathway concurrent with each CS disrupted cued alcohol seeking. Activation of the same pathway caused rapid cessation of alcohol drinking from a sipper tube. Neither effect was accompanied by an overall change in locomotion. Finally, the suppressive effect of photoactivation on cued-triggered seeking was also evidenced in animals trained with sucrose. Together these findings suggest that photoactivation of BLA terminals in the AcbSh can override the conditioned motivational properties of reward-predictive cues as well as unconditioned consummatory responses necessary for alcohol drinking. The findings provide evidence for a limbic-striatal influence over motivated behavior for orally consumed rewards, including alcohol.

Neural correlates of proactive and reactive motor response inhibition of gambling stimuli in frequent gamblers

We used functional magnetic resonance imaging to examine whether motivational-salient cues could exert a differential impact on proactive (the restrain of actions in preparation for stopping) and reactive (outright stopping) inhibition. Fourteen high-frequency poker players, and 14 matched non-gambler controls, performed a modified version of the stop-signal paradigm, which required participants to inhibit categorization of poker or neutral pictures. The probability that a stop-signal occurs (0%, 17%, 25%, 33%) was manipulated across blocks of trials, as indicated by the color of the computer screen. Behavioral analyses revealed that poker players were faster than controls in categorizing pictures across all levels of proactive motor response inhibition (go trials). Brain imaging analyses highlighted higher dorsal anterior cingulate cortex activation in poker players, as compared to controls, during reactive inhibition. These findings suggest that, due to their faster rates of stimulus discrimination, poker players might have recruited more cognitive resources than controls when required to stop their response (reactive inhibition). Nevertheless, no main effect of stimulus type was found, on either proactive or reactive inhibition. Additional studies are, therefore, needed in order to confirm that investigating the dynamics between reactive and proactive inhibition offers a discriminative analysis of inhibitory control toward motivational-salient cues.

Executive functions in alcohol-dependence: A theoretically grounded and integrative exploration

BACKGROUND

Alcohol-dependence is related to large-scale cognitive impairments, particularly for executive functions (EF). These deficits persist even after long-term abstinence and have a major impact on patients' everyday life and relapse risk. Earlier studies, based on multi-determined tasks, mostly focused on inhibition and did not offer a theoretically-grounded and exhaustive view of the differential deficit across EF. The present paper proposes a model-based exploration of EF in alcohol-dependent individuals (ALC), to precisely compare the specific deficit related to each executive subcomponent.

METHODS

Forty-seven recently detoxified ALC were compared to 47 matched healthy participants on a nine-tasks validated neuropsychological battery, simultaneously exploring and comparing the three main executive subcomponents (shifting, updating, and inhibition). Psychopathological comorbidities were also controlled for.

RESULTS

Reaction time indexes revealed a global slowing down among ALC, whatever the EF explored. Accuracy indexes revealed a moderate deficit for inhibition tasks but a massive impairment for shifting and updating ones. Complementary analyses indicated that the executive deficits observed were centrally related to alcohol-dependence, while comorbid depressive symptoms appeared to intensify the deficits observed.

CONCLUSIONS

By offering a direct comparison between the three major EF, these results showed that alcohol-related executive deficits extend beyond the classically described inhibition impairment. This impairment encompasses each EF subcomponent, as ALC actually presented stronger deficits for updating and shifting abilities. This first observation of a multifaceted EF deficit stresses the need for an individualized evaluation and rehabilitation of EF during and/or after the detoxification process.

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.

A Serious Game to Increase Healthy Food Consumption in Overweight or Obese Adults: Randomized Controlled Trial

BACKGROUND

Obesity is a growing global issue that is linked to cognitive and psychological deficits.

OBJECTIVE

This preliminary study investigated the efficacy of training to improve inhibitory control (IC), a process linked to overeating, on consumption and cognitive control factors.

METHODS

This study utilized a multisession mobile phone-based intervention to train IC in an overweight and obese population using a randomized waitlist-control design. A combination of self-assessment questionnaires and psychophysiological measures was used to assess the efficacy of the intervention in terms of improved general IC and modified food consumption after training. Attitudes toward food were also assessed to determine their mediating role in food choices. A total of 58 participants (47 female) completed 2 assessment sessions 3 weeks apart, with 2 weeks of intervention training for the training group during this time. The groups did not differ in baseline demographics including age, body mass index, and inhibitory control.

RESULTS

Inhibitory control ability improved across the training sessions, with increases in P3 amplitude implying increased cognitive control over responses. Inhibitory control training was associated with increased healthy and reduced unhealthy food consumption in a taste test and in the week following training, as measured by the Healthy Eating Quiz and the food consumption test. Cognitive restraint was enhanced after training for the training but not the waitlist condition in the Three-Factor Eating Questionnaire, implying that attempts to avoid unhealthy foods in the future will be easier for the training group participants.

CONCLUSIONS

Inhibitory control training delivered via a purpose-designed mobile phone app is easy to complete, is convenient, and can increase cognitive restraint and reduce unhealthy food consumption.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12616000263493; http://www.ANZCTR.org.au/ACTRN12616000263493.aspx (Archived by WebCite at http://www.webcitation.org/6ioHjGING).

The impact of cognitive impairment and impulsivity on relapse of alcohol-dependent patients: implications for psychotherapeutic treatment

Recent models of the development of addiction propose a transition from a pleasure-driven to a heavily automatized behaviour, marked by a loss of cognitive control. This study investigated the deficits in different components of cognitive functions including behavioural inhibition in response to alcohol-related stimuli in alcohol-dependent patients (ADP) and healthy controls (HC). The aims of the study were to identify which particular cognitive functions are impaired in ADP. Furthermore, we analysed the association between cognitive deficits and relapse rates and the reversibility of cognitive deficits under abstinence in a 6-month follow-up period. Ninety-four recently detoxified ADP and 71 HC completed the cognitive tasks as well as questionnaire measures assessing drinking behaviour and personality traits. Compared with HC, ADP showed poorer performance in response initiation, response inhibition, complex-sustained attention and executive functions. Impairment in response inhibition was a significant predictor for relapse, yet the strongest predictor was the interaction between the number of previous detoxifications and response-inhibition deficits. The results of a moderation analysis showed that patients with many previous detoxifications and large deficits in response inhibition showed the highest relapse risk. These findings indicate that interventions should take into account inhibitory deficits especially in ADP with a high number of previous detoxifications.

The Dynamics of Addiction: Craving versus Self-Control

This study deals with addictive acts that exhibit a stable pattern not intervening with the normal routine of daily life. Nevertheless, in the long term such behaviour may result in health damage. Alcohol consumption is an example of such addictive habit. The aim is to describe the process of addiction as a dynamical system in the way this is done in the natural and technological sciences. The dynamics of the addictive behaviour is described by a mathematical model consisting of two coupled difference equations. They determine the change in time of two state variables, craving and self-control. The model equations contain terms that represent external forces such as societal rules, peer influences and cues. The latter are formulated as events that are Poisson distributed in time. With the model it is shown how a person can get addicted when changing lifestyle. Although craving is the dominant variable in the process of addiction, the moment of getting dependent is clearly marked by a switch in a variable that fits the definition of addiction vulnerability in the literature. Furthermore, the way chance affects a therapeutic addiction intervention is analysed by carrying out a Monte Carlo simulation. Essential in the dynamical model is a nonlinear component which determines the configuration of the two stable states of the system: being dependent or not dependent. Under identical external conditions both may be stable (hysteresis). With the dynamical systems approach possible switches between the two states are explored (repeated relapses).

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.