The relationship between impulsivity and craving in alcohol dependent patients

Development and Initial Validation of a Momentary Cannabis Craving Scale Within a Homogeneous Sample of U.S. Emerging Adults

Given the popularity and ease of single-item craving assessments, we developed a multi-item measure and compared it to common single-item assessments in an ecological momentary assessment (EMA) context. Two weeks of EMA data were collected from 48 emerging adults (56.25% female, 85.42% White) who frequently used cannabis. Eight craving items were administered, and multilevel factor analyses were used to identify the best fitting model. The resulting scale's factors represented purposefulness/general desire and emotionality/negative affect craving. Convergent validity was examined using measures of craving, cannabis use disorder symptoms, frequency of use, cannabis cue reactivity, cannabis use, negative affect, and impulsivity. The scale factors were associated with cue-reactivity craving, negative affect, impulsivity, and subfactors of existing craving measures. For researchers interested in using a single item to capture craving, one item performed particularly well. However, the new scale may provide a more nuanced assessment of mechanisms underlying craving.

Music therapy, neural processing, and craving reduction: an RCT protocol for a mixed methods feasibility study in a Community Substance Misuse Treatment Service

BACKGROUND

Music therapy has been shown to be effective for multiple clinical endpoints associated with substance use disorder such as craving reduction, emotion regulation, depression, and anxiety, but there are a lack of studies investigating those effects in UK Community Substance Misuse Treatment Services (CSMTSs). Furthermore, there is a demand for identifying music therapy mechanisms of change and related brain processes for substance use disorder treatment. The present study aims to evaluate the feasibility and acceptability of music therapy and a pre-test, post-test, and in-session measurement battery in a CSMTS.

METHODS

Fifteen participants, from a community service based in London, will take part in a mixed-methods non-blind randomized-controlled trial. Ten participants will receive six-weekly sessions of music therapy in addition to the standard treatment offered by the CSMTS-five of them will receive individual music therapy and five of them will receive group music therapy-while a further five participants will act as a control group receiving standard treatment only. Satisfaction and acceptability will be evaluated in focus groups with service users and staff members following the final treatment session. Moreover, attendance and completion rates will be monitored throughout the intervention. Subjective and behavioral indexes will be assessed before and after the interventions to explore the effects of music therapy on craving, substance use, symptoms of depression and anxiety, inhibitory control, and will be correlated with associated neurophysiological signatures. In-session analysis of two individual music therapy sessions will serve to explore how music and emotion are processed in the brain within the therapy. The data collected at each step will be included in an intention-to-treat analysis basis.

DISCUSSION

This study will provide a first report on the feasibility of music therapy as an intervention for participants with substance use disorder engaged within a community service. It will also provide valuable information regarding the implementation of a multifaceted methodology that includes neurophysiological, questionnaire-based, and behavioral assessments in this cohort. Notwithstanding the limitation of a small sample size, the present study will provide novel preliminary data regarding neurophysiological outcomes in participants with substance use disorder that received music therapy.

TRIAL REGISTRATION

ClinicalTrails.gov, NCT0518061, Registered 6 January 2022, https://clinicaltrials.gov/ct2/show/NCT05180617.

Validity of the DSM-5 craving criterion for alcohol, tobacco, cannabis, cocaine, heroin, and non-prescription use of prescription painkillers (opioids)

BACKGROUND

Although the DSM-5 was adopted in 2013, the validity of the new substance use disorder (SUD) diagnosis and craving criterion has not been investigated systematically across substances.

METHODS

Adults (N = 588) who engaged in binge drinking or illicit drug use and endorsed at least one DSM-5 SUD criterion were included. DSM-5 SUD criteria were assessed for alcohol, tobacco, cannabis, cocaine, heroin, and opioids. Craving was considered positive if "wanted to use so badly that could not think of anything else" (severe craving) or "felt a very strong desire or urge to use" (moderate craving) was endorsed. Baseline information on substance-related variables and psychopathology was collected, and electronic daily assessment queried substance use for the following 90 days. For each substance, logistic regression estimated the association between craving and validators, i.e. variables expected to be related to craving/SUD, and whether association with the validators differed for DSM-5 SUD diagnosed with craving as a criterion v. without.

RESULTS

Across substances, craving was associated with most baseline validators (p values<0.05); neither moderate nor severe craving consistently showed greater associations. Baseline craving predicted subsequent use [odds ratios (OR): 4.2 (alcohol) - 234.3 (heroin); p's ⩽ 0.0001], with stronger associations for moderate than severe craving (p's < 0.05). Baseline DSM-5 SUD showed stronger associations with subsequent use when diagnosed with craving than without (p's < 0.05).

CONCLUSION

The DSM-5 craving criterion as operationalized in this study is valid. Including craving improves the validity of DSM-5 SUD diagnoses, and clinical relevance, since craving may cause impaired control over use and development and maintenance of SUD.

The Lack of Influence of Homozygous Long Allele of the 5-HTTLPR Gene on the Severity of Alcohol Craving During 6 Weeks of Rehab Hospitalisation in Comparison to Not Homozygous and Homozygous Short Alleles - Preliminary Report

Purpose

The aim of this study was to assess changes in the severity of alcohol craving according to allelic variants of the 5-HTTLPR gene polymorphism during hospitalisation and their association with selected clinical variables in alcohol-dependent patients.

Patients and Methods

The study is exploratory. Participants were investigated at the 2nd and 6th week of alcohol-dependence therapy in the addiction treatment unit. Recruitment was conducted among alcohol-dependent patients from several Polish drug treatment centres. The total sample size was 130 persons (12 females and 118 males). Study subjects' mean age was 43.0 years. Patients were investigated twice by using the Penn Alcohol Craving Scale (PACS) and Beck Depression Inventory (BDI), and once by using Short Alcohol Dependence Data Questionnaire (SADD) and taking a swab for genetic testing. The polymorphism of the gene encoding the serotonin transporter 5-HTTLPR (SLC6A4) was determined from isolated DNA and its homozygous variants of short/short or long/long alleles and heterozygous short/long alleles were analysed.

Results

At 6th week of the follow-up, there was a decrease in the severity of alcohol craving in half of subjects with the short/short allele (p = 0.033) and in one-fifth of subjects with the long/short allele (p = 0.002) of the 5-HTTLPR gene. In subjects with long/long allele of the 5-HTTLPR gene, there was no change in the severity of alcohol craving between 2nd and 6th weeks of the study (p = 0.242).

Conclusion

There was no statistical influence of the homozygous long allele of the 5-HTTLPR gene on severity of alcohol craving during 6 weeks of rehab hospitalisation in comparison to not homozygous and homozygous short alleles. The s-allele was associated with decrease of alcohol craving. It may point on the potential need for differentiated rehabilitation methods depending on the genetic diversity of addicted patients and its role in the severity of alcohol craving.

Testing the validity and reliability of the Matching Familiar Figures Test-2021: An updated behavioral measure of reflection–impulsivity

The Matching Familiar Figures Test (MFFT) is a well-known and extensively used behavioral measure of reflection-impulsivity. However, the instrument has several deficiencies, including images designed for school-age children in the United States during the 1960s. Most importantly, an adult version of the instrument is currently unavailable and the lack of a single repository for the images raises questions regarding the MFFT’s validity and reliability. We developed a 21st century version of the MFFT using images that are familiar to adults and reside in a freely accessible repository. We conducted two studies examining validity and reliability issues. In Study 1, participants interacting with the MFFT-2021, versus those interacting with the original MFFT20, spent more time on the task, took more time in making their first response, and were more likely to complete the task without errors, even though the average number of errors was higher than the comparison group. The coherence of these results is evidence of convergent validity. Regarding predictive validity, the MFFT-2021 remained a reliable predictor of rational thinking, such that participants who demonstrated more reflection (less impulsivity) tended to avoid rational thinking errors. Also, performance on the MFFT-2021 predicted higher quality judgments in processing job characteristic cues with embedded interactions, a form of configural information processing. We also found evidence of concurrent validity: performance on the MFFT-2021 differed in a predictable manner for participants grouped by their performance on the Cognitive Reflection Test. In Study 2, we tested discriminant validity by comparing participant performance on the MFFT-2021 to their performance on the Information Sampling Task (IST), another behavioral measure of reflection-impulsivity used in studies of psychopharmacological and addiction behaviors. For our participants (undergraduate business students), we found that the MFFT was a stronger predictor of performance on rational thinking tasks, and, contrary to prior studies, our exploratory factor analysis identified separate factors for the MFFT-2021 and the IST, supporting discriminant validity, indicating that these two instruments measure different subtypes of reflection-impulsivity.

Lower Emotion Regulation Competencies Mediate the Association between Impulsivity and Craving during Alcohol Withdrawal Treatment

There is evidence that craving mediates the relationship between Impulsive Personality Traits (IPTs) and relapse during the treatment of an Alcohol Use Disorder (AUD). To provide tailored interventions, a deeper understanding of the relation between IPTs and craving, namely mediating processes, is important. Based on previous literature, we proposed that lower emotion regulation competencies mediate the relation between attentional as well as non-planning IPTs and craving. To investigate these interrelations, we used data from the baseline assessment (n = 320) of the SmartAssistEntz project (pre-registered in the German Clinical Trials Register [DRKS00017700]). Inpatients with a primary AUD diagnosis were interviewed using standardized self-report measures (IPTs: BIS-15, emotion regulation competencies: ERSQ, craving: OCDS-G short version) during their withdrawal treatment. Indirect effects were calculated using the SPSS macro PROCESS v3.5. Attentional as well as non-planning, but not motor, IPTs were associated with craving. Emotion regulation competencies mediated the relationship between attentional as well as non-planning IPTs and craving. Given their mediating role in the present study, it is interesting to investigate if addressing emotion regulation competencies can mitigate the negative influences of attentional and non-planning IPTs. The direct effect of attentional IPTs implicates alternate mediating processes, which should also be investigated in future research.

Cognitive boosting interventions for impulsivity in addiction: a systematic review and meta-analysis of cognitive training, remediation and pharmacological enhancement

AIMS

To evaluate and compare the effects of three cognitive boosting intervention approaches (computerised cognitive training, cognitive remediation and pharmacological cognitive enhancers) on measures of impulsive action and impulsive choice.

DESIGN

Systematic review and meta-analysis of publications that reported original controlled trials of cognitive boosting interventions.

SETTING

Studies conducted anywhere in the world. No language restrictions were applied.

PARTICIPANTS

Treatment-seeking adults with substance use disorder or gambling disorder.

MEASUREMENTS

Our primary outcome was a reduction in impulsive action or choice on a validated cognitive measure post-intervention. We assessed risk of bias using the Cochrane Collaboration tool and determined pooled estimates from published reports. We performed random-effects analyses for impulsive action and impulsive choice outcomes and planned moderator analyses.

FINDINGS

Of 2204 unique studies identified, 60 were included in the full-text review. Twenty-three articles were considered eligible for inclusion in the qualitative synthesis and 16 articles were included in our meta-analysis. Articles eligible for pooled analyses included five working memory training (computerised cognitive training) studies with 236 participants, three goal management training (cognitive remediation) studies with 99 participants, four modafinil (cognitive enhancer) studies with 160 participants and four galantamine (cognitive enhancer) studies with 131 participants. Study duration ranged from 5 days to 13 weeks, with immediate follow-up assessments. There were no studies identified that specifically targeted gambling disorder. We only found evidence for a benefit on impulsive choice of goal management training, although only in two studies involving 66 participants (standardised mean difference (SMD) = 0.86; 95% CI = 0.49-1.23; P = 0.02; I²  = 0%, P = 0.95).

CONCLUSION

Cognitive remediation, and specifically goal management training, may be an effective treatment for addressing impulsive choice in addiction. Preliminary evidence does not support the use of computerised cognitive training or pharmacological enhancers to boost impulse control in addiction.

The Association Between Impulsivity and Relapse in Patients With Alcohol Use Disorder: A Literature Review

AIM

Impulsivity has been identified as a key relapse risk factor in patients with alcohol use disorder (AUD); however, the inherent characteristics of this relationship have been largely understudied. The heterogeneity of AUD and variation in impulsivity constructs require careful consideration to inform future work examining the relationship. This study sought to review empirical findings examining facets of impulsivity and AUD relapse.

METHODS

A systematic search strategy was employed to capture studies on impulsivity measures related to AUD relapse. Impulsivity measures were qualitatively organized in terms of 'trait impulsivity'-typically measured by self-report questionnaires-and 'behavioural impulsivity', i.e. 'motor impulsivity', 'impulsive choice' and 'reflection impulsivity, assessed with cognitive-behavioural tasks.

RESULTS

Seventeen peer-reviewed papers were identified. Relapse outcomes varied substantially in relation to impulsivity measures. Twelve papers included aspects of 'trait impulsivity', and nine studies included 'behavioural impulsivity' measures, from which five studies dealt with the 'impulsive choice' subcategory. The Barratt Impulsivity Scale was the self-report questionnaire that was most frequently used.

CONCLUSIONS

All three included facets of impulsivity ('trait-, motor- and impulsive choice impulsivity') were associated with AUD relapse, but none seemed to be superior to another. This study confirmed that research on the relation between impulsivity and AUD relapse is relatively scarce. Future research and treatment options are proposed.

Impulsivity Scale-12 and its utilization in alcohol use disorder

INTRODUCTION

One of the core symptoms of alcohol use disorder (AUD) is impulsivity. The recently published study on the Impulsivity Scale 12 (IS-12) offers a promising tool to use in clinics working with clients with AUD due to its simplicity. IS-12 includes subscales related tocognitive impulsivity and behavioral impulsivity, which are related to different aspects of AUD symptomatology. The aim of the study was to adapt IS-12 to polish and test its utility in a sample of patients diagnosed with AUD.

METHODS

Using a Confirmatory Factor Analysis, we compared the two-factor model of the Polish adaptation of the BIS-11 and the IS-12 on a sample of 615 patients diagnosed with AUD. Additionally, we explored the association between the IS-12's cognitive impulsivity and behavioral impulsivity subscales and depressive symptoms, AUD severity, and suicidal ideation using Structural Equation Modeling on a subsample of 450 patients with AUD.

RESULTS

The IS-12 demonstrated a better model fit and good reliability compared to the BIS-11. Moreover, cognitive impulsivity predicted suicidal ideation, but not AUD severity, while behavioral impulsivity predicted AUD severity, but not suicidal ideation. Both subscales of IS-12 predicted depressive symptoms.

CONCLUSION

Consistent with prior work, findings indicate that the second-order factor model of the BIS-11 had reliability issues and evidenced poor model fit. In contrast, the IS-12 demonstrated a satisfactory model fit and was predictive of clinical symptomatology. Thus, utilizing an easy tool, such as IS-12, might be beneficial for researchers and clinicians working with patients with AUD.

Bilateral transcranial direct current stimulation attenuated symptoms of alcohol use disorder: A systematic review and meta-analysis

BACKGROUND

Alcohol use disorder is one of the common substance use disorders leading to mental and health problems. Despite the potential positive effects of transcranial direct current stimulation (tDCS) on symptoms of various substance use disorder, how specific tDCS protocols effectively influence on individuals with alcohol use disorder is still controversial. This systematic review and meta-analysis investigated beneficial effects of tDCS on symptoms of alcohol use disorder.

METHOD

Eighteen total studies met our inclusion criteria, and we used 25 total comparisons from the qualified studies for the data synthesis. We estimated effect sizes by quantifying changes in alcohol craving and consumption between active tDCS protocol and sham groups. In addition, three moderator variable analyses determined whether tDCS effects on symptoms of alcohol use disorder were different based on (a) bilateral versus unilateral tDCS protocols, (b) specific targeted regions, and (c) multiple sessions versus single session of tDCS protocols.

RESULTS

Random-effects model meta-analysis revealed small positive tDCS effects on alcohol craving and consumption. Specifically, bilateral tDCS protocols significantly reduced alcohol craving, and further anodal tDCS on right dorsolateral prefrontal cortex (DLPFC) and cathodal tDCS on left DLPFC revealed significant positive effects. The multiple sessions of tDCS protocols showed better effects on reducing alcohol craving.

CONCLUSIONS

The current findings suggested that bilateral tDCS protocols including anodal tDCS on right DLPFC and cathodal tDCS on left DLPFC with multiple sessions may effectively improve tDCS effects on symptoms of alcohol use disorder.

Drawing alcohol craving process: A systematic review of its association with thought suppression, inhibition and impulsivity

Alcohol Use Disorder (AUD) is a worldwide public health problem. In recent years, there has been growing evidence supporting craving, the irrepressible desire to drink, as a major mechanism implicated in AUD. Impulsivity is identified as playing a significant role in craving in many studies. However, relationships with inhibition and thought suppression remain unclear in the existing literature. A systematic review was conducted to evaluate their associations in order to better understand the cognitive processes involved in craving.

Studies were identified by searching PubMed, PsycINFO and Web of Science using PRISMA procedure and PICOTS framework. There were included if they assessed craving and thought suppression or inhibition or impulsivity, and sample was composed of AUD participants.

Thirteen studies were included and were categorized in accordance with the evaluated cognitive process. The first part dealt with thought suppression and the second with impulsivity and inhibition. Four studies showed a positive association between thought suppression and increased craving. Two studies showed that poorer inhibition was associated with increased craving and four studies showed that impulsivity was positively associated with craving. Three studies showed a negative association between impulsivity and inhibition and higher craving.

Our review highlights the association of alcohol craving with poorer inhibition and greater impulsivity. Further investigations are needed to give support to different theories and lead to propose an integrative model involving the cognitive process of inhibition in alcohol craving.

Higher Trait Impulsivity and Altered Frontostriatal Connectivity in Betel-Quid Dependent Individuals

Objective: Betel quid dependency (BQD) is characterized by functional and structural brain alterations. Trait impulsivity may influence substance dependence by impacting its neurobiological underpinnings in the frontostriatal circuit. However, little is known about the trait impulsivity and its neural correlates in individuals with BQD.

Methods: Forty-eight participants with BQD and 22 normal controls (NCs) were recruited and scanned on a 3T MRI scanner. Barratt impulsiveness scale (BIS) was used to measure trait impulsivity: motor, attention, and no plan impulsivity. We used voxel-based morphometry (VBM) to assess the relationship between trait impulsivity and gray matter volumes. The relevant clusters identified were served as regions of interest (ROI) seeds. The whole-volume psycho-physiological interactions (PPI) analysis was used to investigate the changes of functional connectivity related to ROI seeds in the cue-reactivity task condition (BQ and control images).

Results: Behaviorally, the BQD group showed significantly higher trait impulsivity including motor and no plan impulsivity than the NCs group. VBM analyses showed that motor impulsivity was negatively associated with gray matter volume of right caudate in the whole sample. No difference in gray matter volume between the two groups was observed. PPI analyses showed that there was a significantly decreased functional connectivity between the right caudate and right dorsolateral prefrontal cortex (DLPFC) when watching BQ related images than control images in individuals with BQD. Furthermore, functional connectivity between the right caudate and right DLPFC was negatively correlated with BQ dependency scores.

Conclusions: Our study demonstrated the structural basis of trait impulsivity in the caudate and provided evidence for abnormal interactions within frontostriatal circuitsin individuals with BQD, which may provide insight into the selection of potential novel therapeutic targets for the treatment of BQ dependency.

Alcohol Craving and Psychiatric Disorders Among Current Drinkers

BACKGROUND AND OBJECTIVES

Previous research has shown that alcohol craving is associated with psychiatric comorbidities. However, no population studies have examined the odds of psychiatric disorders in cravers and noncravers. The purpose of this study was to investigate current prevalence rates and odds ratios of psychiatric disorders among alcohol drinkers with and without alcohol craving in a population-based sample. We also compared four craving groups (cravers with and without alcohol use disorder [AUD], noncravers with and without AUD) for psychiatric comorbidities.

METHODS

The study data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). A subset of the NESARC sample (N = 22 000) who reported alcohol use during the past 12 months was included. Prevalence rates of psychiatric disorders were compared among current drinkers with alcohol craving (N = 900) and without alcohol craving (N = 21 500).

RESULTS

Cravers had higher prevalence rates of current psychiatric disorders than noncravers. Even after adjustment for other psychiatric disorders including AUD, cravers had significantly higher odds of any substance use disorder (adjusted odds ratio [AOR], 9.01), any mood disorder (AOR, 1.78), any anxiety disorder (AOR, 1.86), and any personality disorder (AOR, 1.92) than noncravers. Interestingly, cravers without AUD had even higher rates of any anxiety disorder and any personality disorder than noncravers with AUD.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Alcohol craving is associated with a higher prevalence of various psychiatric disorders. These findings suggest that alcohol craving may be related to transdiagnostic features that are present across various psychiatric disorders. (Am J Addict 2021;30:34-42).

Personality driven alcohol and drug abuse: New mechanisms revealed

While the majority of the regular consumers of alcohol controls their consumption well over life span and even takes instrumentalization benefits from it, a minority, but yet high total number of users develops an alcohol addiction. It has long been known that particular personality types are more addiction prone than others. Here we review recent progress in the understanding of neurobiological pathways that determine personality and facilitate drug abuse. Novel approaches to characterize personality traits leading to addiction proneness in social settings in mice are discussed. A common genetic and neurobiological base for the behavioural traits of sensation seeking or a depressed phenotype and escalating alcohol consumption are reviewed. Furthermore, recent progress on how social and cognitive factors, including impulsivity and decision making, act at brain level to make an individual more vulnerable to alcohol abuse, are discussed. Altogether, this review provides an update on brain mechanisms underlying a broad spectrum of personality traits that make an individual more prone to alcohol and drug abuse and addiction.

Craving mediates the effect of impulsivity on lapse-risk during alcohol use disorder treatment

Rash impulsiveness, the propensity for approach behaviour despite potential negative consequences, is associated with stronger alcohol craving in patients with Alcohol Use Disorder (AUD). This relationship is poorly understood and implications for treatment response are unexamined. This study explored the relationship between rash impulsiveness, craving, and treatment response among 304 outpatients enrolled in a 12-week abstinence-based Cognitive-Behavioural Therapy (CBT) program for AUD. Assessments were completed pre-and-post treatment, with craving and alcohol consumption monitored at each treatment session. Higher rash impulsiveness predicted more frequent craving over treatment (b = 0.95, 95% CI = 0.40, 1.50). Higher craving was associated with greater lapse-risk (b = 0.04, 95% CI = 0.03, 0.05), with the association between craving and lapse-risk increasing as treatment progressed (b = 0.01, 95% CI = 0.01, 0.02). Craving positively mediated the relationship between rash impulsiveness and lapse-risk (µ = 0.38, 95% CI = 0.10, 0.70). Contrary to hypotheses, the risk of lapse in response to craving was not moderated by rash-impulsiveness. These results suggest that AUD patients with a predisposition for rash impulsiveness are more vulnerable to alcohol craving, and subsequently, poorer treatment outcomes.

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.

GABAAR α2-activated neuroimmune signal controls binge drinking and impulsivity through regulation of the CCL2/CX3CL1 balance

BACKGROUND AND PURPOSE

Toll-like receptors (TLRs) are a family of innate immune system receptors that respond to pathogen-derived and tissue damage-related ligands and are increasingly recognized for their impact on homeostasis and its dysregulation in the nervous system. TLR signaling participates in brain injury and addiction, but its role in the alcohol-seeking behavior, which initiates alcohol drinking, is still poorly understood. In this review, we discuss our findings designed to elucidate the potential contribution of the activated TLR4 signal located in neurons, on impulsivity and the predisposition to initiate alcohol drinking (binge drinking).

RESULTS

Our findings indicate that the TLR4 signal is innately activated in neurons from alcohol-preferring subjects, identifying a genetic contribution to the regulation of impulsivity and the alcohol-seeking propensity. Signal activation is through the non-canonical, previously unknown, binding of TLR4 to the α2 subunit of the γ-aminobutyric 2 acid A receptor (GABAAR α2). Activation is sustained by the stress hormone corticotrophin-releasing factor (CRF) and additional still poorly recognized ligand/scaffold proteins. Focus is on the effect of TLR4 signal activation on the balance between pro- and anti-inflammatory chemokines [chemokine (C-C motif) ligand 2 (CCL2)/chemokine (C-X3-C motif) ligand 1 (CX3CL1)] and its effect on binge drinking.

CONCLUSION

The results are discussed within the context of current findings on the distinct activation and functions of TLR signals located in neurons, as opposed to immune cells. They indicate that the balance between pro- and anti-inflammatory TLR4 signaling plays a major role in binge drinking. These findings have major impact on future basic and translational research, including the development of potential therapeutic and preventative strategies.

Transcranial Direct Current Stimulation Reduces Craving in Substance Use Disorders: A Double-blind, Placebo-Controlled Study

OBJECTIVES

The use of transcranial direct current stimulation (tDCS) in addiction disorders is still on its rise in comparison with pharmacological and psychotherapeutic strategies that still show low level of evidence. In this study, we aimed to evaluate the efficacy of the anodic tDCS for the short-term treatment of substance craving and other psychiatric symptoms.

METHODS

In this randomized, double-blind, sham-controlled trial, inclusion criteria included the diagnosis of substance use disorder and/or gambling disorder. The protocol includes 5 consecutive days of active or sham tDCS session. Cathode was placed over the left dorsolateral prefrontal cortex. Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Young Mania Rating Scale, Barratt Impulsiveness Scale, South Oaks Gambling Screen, and visual analog scale (VAS) 1 to 10 for craving were administered at the baseline (T0) and after 5 days of treatment (T1).

RESULTS

Thirty-four treatment-seeking subjects were randomized to sham (n = 16) and active stimulation (n = 18) groups. A statistically significant reduction of values at T1 was found in all subjects considering VAS (P < 0.001), Hamilton Depression Rating Scale (P < 0.001), Hamilton Anxiety Rating Scale (P < 0.001), and Barratt Impulsiveness Scale 11 (P = 0.032). A significant reduction for VAS craving in favor of the active stimulation (P = 0.011) was found.

CONCLUSIONS

Our findings reveal a statistically significant rapid reduction of craving in the active tDCS group on the right dorsolateral prefrontal cortex with respect to sham group, confirming the scientific literature trend. Large samples, with maintenance tDCS therapy and long-term follow-up, are required to establish the potential of this noninvasive and easily delivered brain stimulation strategy.

A multi-dimensional evaluation of craving and impulsivity among people admitted for alcohol-related problems in emergency department

Craving and impulsivity are key psychological dimensions involved in the development and maintenance of severe alcohol-use disorders. This study proposes an integrative evaluation of craving (Visual Analogue Scale, VAS and Obsessive Compulsive Drinking Scale, OCDS) and impulsivity (UPPS Scale and Barratt Impulsiveness Scale) among patients admitted in emergency department for alcohol misuse. Ninety-eight patients were included. Regression analyses showed that the scores obtained at the compulsive subscale of the OCDS, at the VAS and at the Urgency subscale of impulsivity constitute the main predictors of the severity of alcohol-use disorders (indexed by the AUDIT). These results suggest that specific sub-dimensions of craving and impulsivity may play a critical and joint role in the maintenance of excessive alcohol consumption.

Innately activated TLR4 signal in the nucleus accumbens is sustained by CRF amplification loop and regulates impulsivity

Cognitive impulsivity is a heritable trait believed to represent the behavior that defines the volition to initiate alcohol drinking. We have previously shown that a neuronal Toll-like receptor 4 (TLR4) signal located in the central amygdala (CeA) and ventral tegmental area (VTA) controls the initiation of binge drinking in alcohol-preferring P rats, and TLR4 expression is upregulated by alcohol-induced corticotropin-releasing factor (CRF) at these sites. However, the function of the TLR4 signal in the nucleus accumbens shell (NAc-shell), a site implicated in the control of reward, drug-seeking behavior and impulsivity and the contribution of other signal-associated genes, are still poorly understood. Here we report that P rats have an innately activated TLR4 signal in NAc-shell neurons that co-express the α2 GABAA receptor subunit and CRF prior to alcohol exposure. This signal is not present in non-alcohol drinking NP rats. The TLR4 signal is sustained by a CRF amplification loop, which includes TLR4-mediated CRF upregulation through PKA/CREB activation and CRF-mediated TLR4 upregulation through the CRF type 1 receptor (CRFR1) and the MAPK/ERK pathway. NAc-shell Infusion of a neurotropic, non-replicating herpes simplex virus vector for TLR4-specific small interfering RNA (pHSVsiTLR4) inhibits TLR4 expression and cognitive impulsivity, implicating the CRF-amplified TLR4 signal in impulsivity regulation.

Neurofeedback as a Treatment for Impulsivity in a Forensic Psychiatric Population With Substance Use Disorder: Study Protocol of a Randomized Controlled Trial Combined With an N-of-1 Clinical Trial

BACKGROUND

Impulsivity and substance use disorder (SUD) are strongly interconnected, with persons scoring high on impulsivity being more vulnerable to develop substance abuse, facing more challenges for successful treatment, and being more prone to engage in criminal behavior. Studies have shown that impulsivity and craving for substances are strongly correlated. Neurofeedback is an effective treatment to reduce impulsive behavior. This study intends to determine to what extent a neurofeedback-intervention that is aimed at reducing impulsivity can also reduce levels of craving in forensic patients with SUD and comorbid Axis I and/or II diagnoses.

OBJECTIVE

The main objective of this study is to investigate to what extent a reduction in impulsivity by a sensorimotor rhythm (SMR)-neurofeedback intervention will lead to a reduction in craving in a population of forensic psychiatric patients with a diagnosis of SUD.

METHODS

Participants will be male SUD patients with various comorbidities residing in an inpatient forensic treatment facility approached through treatment supervisors for participation. Participants have tested positive for drug use in the past 24 months. The study consists of 2 parts: a randomized controlled trial (RCT) and a n-of-1 clinical series. In the RCT, 50 patients will be randomly assigned to an intervention (n=25) or a control (n=25) condition. Patients in the intervention group will receive 20 SMR neurofeedback sessions aimed at reducing impulsivity; participants in the control group receive treatment-as-usual (TAU). Additionally, 4 in depth n-of-1 clinical trials will be conducted where effects of an SMR neurofeedback intervention will be compared to effects of sham neurofeedback.

RESULTS

Results of this study are expected by the end of 2017.

CONCLUSIONS

This protocol describes the design of a study testing the effects of an impulsivity-based neurofeedback protocol among forensic patients with SUD and various comorbidities. We expect a significant reduction in impulsive behavior, level of craving, and actual drug-use for participants receiving the SMR neurofeedback protocol. The n-of-1 approach might help to explain effects possibly found in the RCT study since it allows for a more direct focus on treatment effects by following participants more closely and thereby being able to directly attribute behavioral and neurophysiological change to the SMR neurofeedback protocol employed.

CLINICALTRIAL

Dutch National Trial Register NTR5386; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5386 (Archived by WebCite at http://www.webcitation.org/6nXLQuoLl).

Motivational factors and negative affectivity as predictors of alcohol craving

Craving is thought to play an important role in alcohol use disorders. The recent inclusion of "craving" as a formal diagnostic symptom calls for further investigation of this subjective phenomenon with multiple dimensions. Considering that alcohol-dependent patients compensate negative physical/emotional states with alcohol, the aim of this study is to investigate alcohol craving and its correlation with drinking measures and affective personality dimensions. A sample of 135 alcohol-dependent patients (104 males and 31 females) was collected from a clinical setting. Subjects self-rated their cravings (Penn Alcohol Craving Scale) and the stage of change. Several personality scales were also administered. Craving was related to drinking status, abstinence time, age, and taking steps. After controlling for these conditions, psychological characteristics related to low self-concept, neuroticism, cyclothymic affective temperament, depression, and hostility were found to be predictors of craving in sober alcohol-dependent patients. Our results support craving as a component of the phenomenology of alcohol dependence and highlight the presence of unpleasant feelings as predictors of craving in sober alcohol-dependent patients without co-occurring psychiatric conditions. The predisposition to experience negative emotions may induce a stronger craving response and increase the likelihood of a first drink and a subsequent loss of control.

TLR4 signaling in VTA dopaminergic neurons regulates impulsivity through tyrosine hydroxylase modulation

Alcohol dependence is a complex disorder that initiates with episodes of excessive alcohol drinking known as binge drinking, and has a 50-60% risk contribution from inherited susceptibility genes. Cognitive impulsivity is a heritable trait that may set the stage for transition to alcohol dependence but its role in the ethanol-seeking behavior and the involved genes are still poorly understood. We have previously shown that alcohol-preferring P rats have innately elevated levels of a neuronal Toll-like receptor 4 (TLR4) signal in the ventral tegmental area (VTA) that controls the initiation of excessive alcohol drinking. Here we report that TLR4 is localized in dopaminergic (TH+) neurons and it upregulates the expression of tyrosine hydroxylase (TH) through a cAMP-dependent protein kinase (PKA)/cyclic AMP response element binding protein (CREB) signal. P rats have higher impulsivity than wild-type (WT) rats and VTA infusion of a non-replicating Herpes simplex virus (HSV) vector for TLR4-specific small interfering RNA (siRNA; pHSVsiTLR4) inhibits both impulsivity and TLR4/TH expression. A scrambled siRNA vector does not affect gene expression or impulsivity. The data suggest that TLR4 signaling in VTA dopaminergic neurons controls impulsivity related to the regulation of TH expression, likely contributing to the initiation of alcohol drinking and its transition to alcohol dependence.

Alcohol Craving and Consumption in Borderline Personality Disorder: When, Where, and with Whom

Substance use is highly prevalent in our society, and substance use disorders are comorbid with most psychiatric disorders, including borderline personality disorder (BPD; Grant et al., 2006, 2008). Craving is a fundamental feature of addiction and disorder, yet the contexts in which craving occurs and is associated with substance use is still under-researched. We examined alcohol craving and consumption in a sample of 56 BPD individuals and a comparison group of community drinkers (COM; n = 60) who carried electronic diaries for approximately 21 days. BPD individuals reported more craving than COM individuals in most contexts. Compared to COM individuals, elevated craving in BPD individuals was paralleled by more drinking when at work, at home, and with romantic partners, coworkers, and children. These findings identify contexts of particular relevance to those with BPD and other mood/anxiety disorders in which craving may lead to risky and maladaptive alcohol use.

Exercise training - A beneficial intervention in the treatment of alcohol use disorders?

BACKGROUND

A growing body of evidence suggests that exercise training may have multiple beneficial effects in individuals with mental health or substance use disorders. Yet, relatively little knowledge exists regarding the benefits of exercise training to augment treatment for alcohol use disorders (AUDs).

PURPOSE

The purpose of this narrative review is to present a summary of the growing body of published literature supporting exercise training as a treatment strategy for individuals with AUDs. We will provide evidence on the myriad of ways in which exercise may exert a positive effect on AUD outcomes including stress, anxiety, impulsivity, and depression. Further, we will explore how these mechanisms share common neurobiological pathways. The role of exercise in enhancing the social environment and increasing individual self-efficacy to reduce excess and/or inappropriate alcohol consumption will also be discussed.

DISCUSSION

We will conclude with a description of completed investigations involving exercise training and provide suggestions for next steps in this innovative field of study.

The analysis of BDNF gene polymorphism haplotypes and impulsivity in methamphetamine abusers

An increasing number of evidence showed that genetic factors might contribute to drug abuse vulnerability. Data from genetic scans in humans suggest that brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family, may be associated with substance abuse or dependence. To test the hypothesis that the BDNF gene polymorphism is involved in methamphetamine abuse, we compared three single nucleotide polymorphisms (SNPs, rs16917204, rs16917234, and rs2030324) of the BDNF gene in 200 methamphetamine abusers and 219 healthy individuals. We also considered the association of these polymorphisms with impulsivity in methamphetamine abusers using Barratt Impulsivity Scale-11(BIS-11) Chinese version. Individual SNP analysis showed no significant differences in genotype and allele distributions between the methamphetamine abusers and controls. Haplotype analysis of rs16917204-rs16917234-rs2030324 revealed that a major C-C-T haplotype was significantly associated a lower odds of methamphetamine abuse, even after Bonferroni correction. Within the methamphetamine-abuse group, subjects carrying the T allele of rs2030324 genotype had significantly higher motor impulsivity scores of BIS compared to those with the C/C genotype. Our findings suggest that the BDNF gene polymorphism may contribute to the impulsivity in methamphetamine abusers.

Impulse control in the dorsolateral prefrontal cortex counteracts post-diet weight regain in obesity

A variety of studies suggest that efficient treatments to induce short-term dietary success in obesity exist. However, sustained maintenance of reduced weight is rare as a large proportion of patients start to regain weight when treatment is discontinued. Thus, from a clinical perspective, it would be desirable to identify factors that counteract post-diet weight regain across longer time-scales. To address this question, we extended our previous work on neural impulse control mechanisms of short-term dietary success in obesity and now investigated the mechanisms counteracting long-term weight regain after a diet. Specifically, we measured neural impulse control during a delay discounting task with fMRI at two time points, i.e. the beginning ('T0') and the end ('T12') of a one-year follow-up interval after a 12-week diet. Then, we tested whether activity in the dorsolateral prefrontal cortex (DLPFC) at T0 and whether activity changes across the follow-up period (T0-T12) are linked to success in weight maintenance. The analyses conducted show that control-related DLPFC activity at T0 was coupled to the degree of success in weight maintenance. Consistently, also behavioral measures of control were linked to the degree of success in maintenance. A direct comparison of neural and behavioral control parameters for prognostic weight change modeling revealed that neural signals were more informative. Taken together, neural impulse control in the DLPFC measured with fMRI directly after a diet predicts real-world diet success in obese patients across extended time periods.

Cigarette Cravings, Impulsivity, and the Brain

Craving is a core feature of tobacco use disorder as well as a significant predictor of smoking relapse. Studies have shown that appetitive smoking-related stimuli (e.g., someone smoking) trigger significant cravings in smokers impede their self-control capacities and promote drug seeking behavior. In this review, we begin by an overview of functional magnetic resonance imaging (fMRI) studies investigating the neural correlates of smokers to appetitive smoking cues. The literature reveals a complex and vastly distributed neuronal network underlying smokers' craving response that recruits regions involved in self-referential processing, planning/regulatory processes, emotional responding, attentional biases, and automatic conducts. We then selectively review important factors contributing to the heterogeneity of results that significantly limit the implications of these findings, namely between- (abstinence, smoking expectancies, and self-regulation) and within-studies factors (severity of smoking dependence, sex-differences, motivation to quit, and genetic factors). Remarkably, we found that little to no attention has been devoted to examine the influence of personality traits on the neural correlates of cigarette cravings in fMRI studies. Impulsivity has been linked with craving and relapse in substance and tobacco use, which prompted our research team to examine the influence of impulsivity on cigarette cravings in an fMRI study. We found that the influence of impulsivity on cigarette cravings was mediated by fronto-cingulate mechanisms. Given the high prevalence of cigarette smoking in several psychiatric disorders that are characterized by significant levels of impulsivity, we conclude by identifying psychiatric patients as a target population whose tobacco-smoking habits deserve further behavioral and neuro-imaging investigation.

Delay discounting and the use of mindful attention versus distraction in the treatment of drug addiction: a conceptual review

In recent decades, researchers have integrated measurements of delay discounting, how the subjective valuation of a reward changes as a function of time, into their study of addiction. Research has begun to explore the idea that delay discounting may serve as both a marker for the effectiveness of existing treatments for addiction and a potential target for novel intervention strategies. As this work is in its infancy, many potentially significant connections between the construct of delay discounting and the treatment of addiction have yet to be explored. Here, we present a conceptual review highlighting novel points of intersection between delay discounting and two approaches to treating addiction that have become increasingly popular in recent years: those that focus on the development of mindfulness skills and those that emphasize the use of distraction techniques. Viewing these two techniques through the lens of delay discounting is particularly intriguing because of the very different way that they address the experience of drug cravings in the present moment (nonjudgmentally attending to vs. shifting attention away from subjective cravings, respectively). We propose that these opposing strategies for dealing with cravings may interact with delay discounting in ways that have important implications for treatment effectiveness.

Impulsivity as a predictor of treatment outcome in substance use disorders: review and synthesis

ISSUES

Impulsivity is a widely studied personality trait and research construct that has been implicated as a risk factor for substance use, including initiating and continuing use. However, relatively few studies have examined impulsivity as a predictor of treatment outcome. Because impulsivity has been operationalised in many different ways, cross-comparisons of empirical studies have been difficult.

APPROACH

The PubMed database was searched in September 2013. Reference lists of papers retrieved from this search were also manually scanned for additional resources. Studies were included if they presented data that assessed impulsivity as a predictor of treatment outcomes.

KEY FINDINGS

The body of literature reviewed in this paper suggests that higher pretreatment impulsivity, regardless of how it is measured, usually is associated with poorer treatment outcomes. Recent data indicate that some psychosocial and pharmacological treatments may directly impact impulsivity and thus represent an interesting avenue for further research.

CONCLUSIONS

Impulsivity appears to be a key predictor of substance use treatment outcomes and warrants more attention in the improvement of treatment outcomes. Suggestions for future research on the role of impulsivity in substance use treatment are provided.

"Killing Two Birds with One Stone": Alcohol Use Reduction Interventions with Potential Efficacy in Enhancing Self-Control

We review interventions with empirical support for reducing alcohol use and enhancing self-control. While any intervention that decreases drinking could improve self-control, we focus here on interventions with evidence of direct benefit for both indications. Although no intervention yet shows strong evidence for dual efficacy, multiple interventions have strong evidence for one indication and solid or suggestive evidence for the other. Among pharmacotherapies, opioid antagonists currently have the best evidence for reducing alcohol use and enhancing self-control. Nicotinic partial agonist varenicline also appears to be efficacious for alcohol use and self-control. Many psychosocial and behavioral interventions (e.g., cognitive behavioral therapy, contingency management, mindfulness training) may have efficacy for both indications based on purported mechanisms of action and empirical evidence. Cognitive bias modification and neurophysiological interventions have promise for alcohol use and self-control as well and warrant further research. We offer several other suggestions for future research directions.

Alcohol-induced risk taking on the BART mediates alcohol priming

RATIONALE

Hazardous drinking has been associated with risk taking and alcohol priming effects. However, the potential relationship between risk taking and priming has not been investigated. The Balloon Analogue Risk Task (BART) is a behavioural measure of risk taking which appears to be associated with drinking behaviour. However, alcohol's acute effects on BART performance are not clear, and the potentially mediating effect of alcohol-induced risk taking on priming has not been tested.

OBJECTIVES

To assess the effects of a priming dose of alcohol on BART performance; to determine the predictive utility of the BART on drinking habits; and to identify whether alcohol-induced risk taking mediates alcohol priming (urge to drink).

METHODS

A total of 142 participants provided data on drinking habits and trait-like impulsivity and sensation seeking. The BART was then completed after consuming alcohol (0.6 g/kg) or placebo (between-subjects design). Baseline and post-drink measures of alcohol urge were also taken.

RESULTS

Alcohol consumption increased urge to drink (priming) and risk taking on the BART. In the alcohol group only, risk taking on the BART predicted unique variance in weekly alcohol consumption and bingeing. Mediation analysis showed that risk taking following alcohol consumption mediated alcohol priming.

CONCLUSIONS

This is the first study to show that alcohol acutely increases risk taking on the BART. Results suggest that social drinkers susceptible to alcohol-induced risk taking may be more likely to drink excessively, perhaps due to increased urge to drink (priming).

Gender, history of alcohol use and number of drinks consumed predict craving among drinkers in a field setting

To the extent that craving serves to compel excessive drinking, it would be important to predict the intensity of an individual's craving over the course of a drinking episode. Previous research indicates that regular alcohol use (measured by the AUDIT) and the number of drinks individuals have already consumed that evening independently predict craving to drink (Schoenmakers & Wiers, 2010). The current study aims to replicate those findings by testing whether these same variables predict craving to drink in a sample of 1320 bar patrons in a naturalistic setting. In addition, we extend those findings by testing whether regular alcohol use and self-reported number of drinks consumed interact to predict craving, and whether gender independently predicts craving or interacts with other variables to predict craving. Results indicate that for men, AUDIT score alone predicted craving, whereas for women, AUDIT score and number of drinks consumed interacted to predict craving, with craving highest among women with either high AUDIT scores or relatively high consumption levels. Our findings have implications for targeted intervention and prevention efforts, as women who have a history of harmful alcohol use and consume several drinks in an evening might be at the greatest risk for continued alcohol consumption.

Neural circuitry of impulsivity in a cigarette craving paradigm

Impulsivity has been shown to play a pivotal role in the onset, pattern of consumption, relapse and, most notably, craving of illicit and licit drugs such as cigarette smoking. The goal of this study was to examine the neurobiological influence of trait impulsivity during cue-induced cigarette craving. Thirty-one chronic smokers passively viewed appetitive smoking-related and neutral images while being scanned and reported their feelings of craving. They completed the Barratt Impulsiveness Scale, a measure of trait impulsivity. We conducted functional connectivity analyses using the psycho-physiological interaction method. During the processing of smoking stimuli, participants presented increased activations in the cingulate and prefrontal cortices. We observed a significant positive relationship between impulsivity scores and reported craving. A negative correlation was observed between the impulsivity score and activity in the posterior cingulate cortex (PCC). The insula, dorsal anterior cingulate cortex (dACC) as well as the dorsolateral prefrontal cortex (DLPFC) presented a negative connectivity with the PCC. Consistent with the view that the PCC is related to the ability to resist cigarette craving, our results suggest that high impulsive smokers have greater difficulty in controlling their cravings, and that this weakness may be mediated by lower PCC activity. Moreover, we argue that the less PCC activity, the greater the probability of a stronger emotional, physiological, and biased attentional response to smoking cues mediated by insula, dACC, and DLPFC activity. This is the first study on this topic, and so, results will need to be replicated in both licit and illicit drug abusers. Our findings also highlight a need for more emphasis on the PCC in drug addiction research, as it is one of the most consistently activated regions in functional magnetic resonance imaging studies examining the neural correlates of cue-induced alcohol, drug, and tobacco cravings.