Cravings as a mediator and moderator of drinking outcomes in the COMBINE study

From alcohol and other drug treatment mediator to mechanism to implementation: A systematic review and the cases of self-efficacy, social support, and craving

Research designed to establish alcohol and other drug (AOD) mechanisms of behavioral change (MOBC) has centered on what variables mediate the relation between AOD treatment and outcomes. The purpose of this paper was to review this research evidence to identify empirically supported mediators of alcohol and other drug use and related outcomes and then to evaluate their potential as being AOD treatment MOBC. The first phase was a systematic review of reviews (2008-2023) to identify the variables with the strongest empirical support as mediators of AOD treatment effects. Eligible reviews focused on AOD treatment modalities, included empirically tested mediators, and targeted adult samples. The second phase was a systematic review of empirical studies (1990-2023) testing the hypothesis that variables identified in phase one were AOD treatment mediators/mechanisms and then evaluating each eligible stage two study according to the Kazdin and Nock (Journal of Child Psychology and Psychiatry, 44, 1116) criteria. Eligible articles included empirical studies with adult samples attending AOD treatment and empirically tested one of the three treatment mechanisms as a mediator of an AOD-related outcome. Databases were searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. This systematic review was not preregistered. The first review of 11 eligible review articles identified self-efficacy, social support, and craving as having the strongest empirical support. The second review captured 48 individual studies. An evaluation of each of these studies by the Kazdin and Nock criteria suggested that they likely are MOBC and therefore are ready for implementation. The implementation of self-efficacy, social support, and craving into clinical practice and training is warranted. Six directions for future research to solidify and generalize empirical support for the case that self-efficacy, social support, and craving are MOBC are presented, as are five implications for clinical practice and training.

Molecular mechanisms involved in alcohol craving, IRF3, and endoplasmic reticulum stress: a multi-omics study

Alcohol use disorder (AUD) is the most prevalent substance use disorder worldwide. Acamprosate and naltrexone are anti-craving drugs used in AUD pharmacotherapy. However, molecular mechanisms underlying their anti-craving effect remain unclear. This study utilized a patient-derived induced pluripotent stem cell (iPSC)-based model system and anti-craving drugs that are used to treat AUD as "molecular probes" to identify possible mechanisms associated with alcohol craving. We examined the pathophysiology of craving and anti-craving drugs by performing functional genomics studies using iPSC-derived astrocytes and next-generation sequencing. Specifically, RNA sequencing performed using peripheral blood mononuclear cells from AUD patients with extreme values for alcohol craving intensity prior to treatment showed that inflammation-related pathways were highly associated with alcohol cravings. We then performed a genome-wide assessment of chromatin accessibility and gene expression profiles of induced iPSC-derived astrocytes in response to ethanol or anti-craving drugs. Those experiments identified drug-dependent epigenomic signatures, with IRF3 as the most significantly enriched motif in chromatin accessible regions. Furthermore, the activation of IRF3 was associated with ethanol-induced endoplasmic reticulum (ER) stress which could be attenuated by anti-craving drugs, suggesting that ER stress attenuation might be a target for anti-craving agents. In conclusion, we found that craving intensity was associated with alcohol consumption and treatment outcomes. Our functional genomic studies suggest possible relationships among craving, ER stress, IRF3 and the actions of anti-craving drugs.

Evidence of subgroup differences in meta-analyses evaluating medications for alcohol use disorder: An umbrella review

Randomized controlled trials (RCTs) evaluating medications for alcohol use disorder (AUD) often examine heterogeneity of treatment effects through subgroup analyses that contrast effect estimates in groups of patients across individual demographic, clinical, and study design-related characteristics. However, these analyses are often not prespecified or adequately powered, highlighting the potential role of subgroup analyses in meta-analysis. Here, we conducted an umbrella review (i.e., a systematic review of meta-analyses) to determine the range and characteristics of reported subgroup analyses in meta-analyses of AUD medications. We searched PubMed to identify meta-analyses of RCTs evaluating medications for the management of AUD, alcohol abuse, or alcohol dependence in adults. We sought studies that measured drinking-related outcomes; quality of life, function, and rates of mortality; adverse events; and dropout. We considered meta-analyses that reported the results from formal subgroup analyses (comparing the summary effects across subgroup levels); summary effect estimates stratified across subgroup levels; and meta-regression, regression, or correlation-based subgroup analyses. We analyzed nine meta-analyses that included 61 formal subgroup analyses (median = 6 per meta-analysis), of which 33 (54%) were based on baseline participant-level and 28 (46%) were based on trial-level characteristics. Of the 58 subgroup analyses with either a p-value from a subgroup test or a statement by the authors that the subgroup analyses were not statistically significant, eight (14%) were statistically significant at the p < 0.05 level. Twelve meta-analyses reported the results of 102 meta-regression analyses, of which 25 (25%) identified statistically significant predictors of the relevant outcome of interest; nine (9%) were based on baseline participant-level and 93 (91%) were based on trial characteristics. Subgroup analyses across meta-analyses of AUD medications often focus on study-level characteristics, which may not be as clinically informative as subgroup analyses based on participant-level characteristics. Opportunities exist for future meta-analyses to standardize their subgroup methodology, focus on more clinically informative participant-level characteristics, and use predictive approaches to account for multiple relevant variables.

Trajectories of change in subclinical anxiety and alcohol use during alcohol treatment: A parallel process growth model

BACKGROUND

Anxiety is implicated in the course and prognosis of alcohol use disorder (AUD); however, it is unclear how current AUD treatments affect the joint trajectories of anxiety and alcohol use. We used data from the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) study to examine the longitudinal relationship between subclinical anxiety symptoms and alcohol use during and following AUD treatment in adults with AUD and no comorbid anxiety disorders.

METHODS

Univariate and parallel process growth models using five waves of COMBINE study data were analyzed from 865 adults randomized to medication (n = 429) or medication plus psychotherapy (n = 436). Weekly drinking quantity and average weekly anxiety symptoms were measured at baseline, mid-treatment, end-of-treatment, and three follow-up periods.

RESULTS

Significant positive associations of anxiety symptoms and drinking were found at mid-treatment and over time. Temporal associations revealed that higher mid-treatment anxiety predicted decreases in drinking over time. Baseline anxiety and drinking predicted mid-treatment anxiety and drinking. Only baseline anxiety predicted increases in drinking over time. Group differences revealed mid-treatment drinking predicted decreases in anxiety over time in the medication group.

CONCLUSIONS

Findings demonstrate the influence of subclinical anxiety on alcohol use during and up to one year after AUD treatment. Baseline anxiety symptoms may influence drinking behavior over the course of treatment. Findings suggest that greater attention to negative affect in AUD treatment is warranted even for those individuals who do have a comorbid anxiety disorder.

Desire to get drunk partially mediates effects of a combined text message-based alcohol intervention for young adults

BACKGROUND

This study aimed to test the causal effect of different text message interventions on reducing alcohol consumption indirectly by altering desire to get drunk.

METHODS

Participants were young adults randomized to interventions with different behavior change techniques: self-monitoring alone (TRACK); pre-drinking plan feedback (PLAN); post-drinking alcohol consumption feedback (USE); pre- and post-drinking goal feedback (GOAL); and a combination of techniques (COMBO) who completed at least 2 days of both pre- and post-drinking assessments over 12 weeks of intervention exposure. On the two days per week they planned to drank alcohol, participants were asked to report desire to get drunk (0 "none" to 8 "completely"). The next day, participants reported drinking quantity. Outcomes included binge drinking (defined as 4+ drinks for a woman and 5+ drinks for a man) and drinks per drinking day. Mediation was tested using path models of simultaneous between-person and within-person effects using maximum likelihood estimation.

RESULTS

At the between-person level, controlling for race and baseline AUDIT-C and within-person associations, 35.9 % of the effects of USE and 34.4 % of the effects of COMBO on reducing binge drinking were mediated through desire to get drunk. 60.8 % of the effects of COMBO on reducing drinks per drinking day were mediated through desire to get drunk. We did not find significant indirect effects for any other text-message intervention.

DISCUSSION

Findings support the hypothesized mediation model where desire to get drunk partially mediates the effects of a text message intervention using a combination of behavior change techniques on reducing alcohol consumption.

The effect of approach bias modification during alcohol withdrawal treatment on craving, and its relationship to post-treatment alcohol use in a randomised controlled trial

BACKGROUND

Approach bias modification (ApBM) for alcohol use disorder helps prevent relapse, yet the psychological mechanisms underlying its efficacy remain unclear. Alcohol craving predicts relapse and appears to be related to the biased processing of alcohol stimuli which is reduced by ApBM. However, there is little research examining whether ApBM reduces alcohol craving.

METHODS

In a randomised controlled trial testing the effect of 4 ApBM sessions (vs. sham training) on post-treatment alcohol use in 300 alcohol withdrawal inpatients, we administered the Alcohol Craving Questionnaire - Short Form - Revised (ACQ-SF-R) pre and post-training and at 2-week, 3, 6 and 12-month follow ups; and a cue-induced craving measure pre and post training.

RESULTS

Groups did not significantly differ in terms of declines in ACQ-SF-R total scores (p = .712) or cue-induced craving (p = .841) between the first and last training session, nor in terms of ACQ-SF-R scores at follow-ups (p = .509). However, the ACQ-SF-R Expectancy subscale, which assesses craving based on anticipated positive reinforcement from alcohol, was significantly lower in the ApBM group than in controls following training (p = .030), although the group x time interaction for this subscale was non-significant (p = .062). Post-intervention Expectancy scores mediated only a small portion of ApBM's effect on post-discharge alcohol use (14% in intention-to-treat analysis, p = .046; 15% in per-protocol analysis, p = .020).

CONCLUSIONS

ApBM does not appear to have robust, sustained effects on alcohol craving. Reduced craving is unlikely to account for ApBM's relapse prevention effects. However, further research on whether ApBM's effects are related to devaluation of alcohol reward expectancy is warranted.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry Identifier: ACTRN12617001241325.

Genetic Variants Associated with Acamprosate Treatment Response in Alcohol Use Disorder Patients: A Multiple Omics Study

Background and Purpose

Acamprosate is an anti‐craving drug used for the pharmacotherapy of alcohol use disorder (AUD). However, only some patients achieve optimal therapeutic outcomes. This study was designed to explore differences in metabolomic profiles between patients who maintained sobriety and those who relapsed, to determine whether those differences provide insight into variation in acamprosate treatment response phenotypes.

Experimental Approach

We previously conducted an acamprosate trial involving 442 AUD patients, and 267 of these subjects presented themselves for a 3‐month follow‐up. The primary outcome was abstinence. Clinical information, genomic data and metabolomics data were collected. Baseline plasma samples were assayed using targeted metabolomics.

Key Results

Baseline plasma arginine, threonine, α‐aminoadipic acid and ethanolamine concentrations were associated with acamprosate treatment outcomes and baseline craving intensity, a measure that has been associated with acamprosate treatment response. We next applied a pharmacometabolomics‐informed genome‐wide association study (GWAS) strategy to identify genetic variants that might contribute to variations in plasma metabolomic profiles that were associated with craving and/or acamprosate treatment outcome. Gene expression data for induced pluripotent stem cell‐derived forebrain astrocytes showed that a series of genes identified during the metabolomics‐informed GWAS were ethanol responsive. Furthermore, a large number of those genes could be regulated by acamprosate. Finally, we identified a series of single nucleotide polymorphisms that were associated with acamprosate treatment outcomes.

Conclusion and Implications

These results serve as an important step towards advancing our understanding of disease pathophysiology and drug action responsible for variation in acamprosate response and alcohol craving in AUD patients.

Effects of couple conflict on alcohol craving: Does intimate partner violence play a role?

OBJECTIVE

Social stress in the form of maladaptive relationship conflict is a common precipitant to alcohol misuse and problems. Research has also established a clear causal association between alcohol misuse and relationship conflict in the form of intimate partner violence (IPV). Despite the robust literature linking relationship conflict and problematic drinking using survey methodology, no laboratory studies have examined the proximal association between relationship conflict and alcohol craving among couples, or the influence of IPV perpetration and victimization on this association.

METHOD

As part of a larger randomized controlled trial, 30 different-sex community couples with substance misuse completed a laboratory conflict resolution task. Participants reported subjective alcohol craving on a Likert-type scale immediately, before, and after the task. Conflict behaviors were coded by trained observers. Analyses were conducted using a multilevel modeling framework to account for the dyadic nature of the data.

RESULTS

Findings indicate that psychological and physical IPV perpetration and victimization strengthened the associations between negative and positive conflict behaviors and alcohol craving among men only. Contrary to our hypotheses, no main or moderating effects of conflict behaviors, IPV perpetration, or IPV victimization were found for women.

CONCLUSIONS

Findings from this exploratory study suggest that in this sample, relationship conflict and IPV in one's current relationship played a more impactful role on acute alcohol craving among men compared to women. Future studies should examine the role of specific conflict behaviors on alcohol craving and relapse risk, and patterns of communication that might increase or reduce risk for exacerbated alcohol craving.

Differences in Sociodemographic and Alcohol-Related Clinical Characteristics Between Treatment Seekers and Nontreatment Seekers and Their Role in Predicting Outcomes in the COMBINE Study for Alcohol Use Disorder

BACKGROUND

One of the challenges in early-stage clinical research aimed at developing novel treatments for alcohol use disorder (AUD) is that the enrolled participants are heavy drinkers, but do not seek treatment for AUD.

AIMS

To compare nontreatment seekers with alcohol dependence (AD) from 4 human laboratory studies conducted at Brown University (N = 240; 65.4% male) to treatment seekers with AD from the multisite COMBINE study (N = 1,383; 69.1% male) across sociodemographic and alcohol-related clinical variables and to evaluate whether the variables that significantly differentiate the 2 samples predict the 3 main COMBINE clinical outcomes: time to relapse, percent days abstinent (PDA), and good clinical outcome.

METHODS

Sample characteristics were assessed by parametric and nonparametric testing. Three regression models measured the association between the differing variables and the 3 main COMBINE clinical outcomes.

RESULTS

The nontreatment seekers, compared to the treatment seekers, were more ethnically diverse, less educated, single, and working part-time or unemployed (p's < 0.05); they met fewer DSM-IV AD criteria and had significantly lower scores on alcohol-related scales (p's < 0.05); they were less likely to have a father with alcohol problems (p < 0.0001) and had a significantly earlier age of onset and longer duration of AD (p's < 0.05); they also had significantly more total drinks, drinks per drinking day, heavy drinking days (HDD), and lower PDA in the 30 days prior to baseline (p's < 0.0001 to <0.05). Having more HDD in the 30 days prior to baseline predicted all of the 3 COMBINE clinical outcomes. All the other characteristics mentioned above that differed significantly between the 2 groups predicted at least 1 of the 3 COMBINE clinical outcomes, except for level of education, age of onset, and duration of AD.

CONCLUSIONS

The observed differences between groups should be considered in efforts across participant recruitment at different stages of the development of new treatments for AUD.

The search for mechanisms of cognitive behavioral therapy for alcohol or other drug use disorders: A systematic review

The emphasis in addictions research has shifted toward a greater interest in identifying the mechanisms involved in patient behavior change. This systematic review investigated nearly 30 years of mediation research on cognitive behavioral therapy (CBT) for alcohol or other drug use disorders (AUD/SUD).

METHOD

Study inclusion criteria targeted analyses occurring in the context of a randomized clinical trial where both intervention/intervention ingredient to mediator (a path) and mediator to outcome (b path) paths were reported. Between- and within-condition analyses were eligible, as were studies that formally tested mediation and those that conducted path analysis only.

RESULTS

The review sample included K = 15 reports of primarily between-condition analyses. Almost half of these reports utilized Project MATCH (k = 2) or COMBINE (k = 4) samples. Among the mediator candidates, support for changes in coping skills was strongest, although the specificity of this process to CBT or CBT-based treatment remains unclear. Similarly, support for self-efficacy as a statistical mediator was found in within-, but not between-condition analyses.

CONCLUSIONS

A coherent body of literature on CBT mechanisms is significantly lacking. Adopting methodological guidelines from the Science of Behavior Change Framework, we provide recommendations for future research in this area of study.

Drink goal difficulty effect on outcomes in moderation-based alcohol treatment for sexual minority men

Sexual minority men (SMM) who drink heavily are at a greater risk for developing alcohol use disorders (AUD) and associated negative consequences. Barriers to treatment prevent SMM from accessing traditional care, and moderation-based alcohol treatment is a more desirable alternative. As such, investigating effective goal setting in moderation-based alcohol treatment, particularly, which goals yield the most effective outcomes, is warranted. Applying the tenets of Goal Setting Theory, this study explored the relationship between goal difficulty and goal achievement. In a secondary data analysis of a randomized controlled trial that delivered a combination of medication (i.e., naltrexone) and behavioral (i.e., Modified Behavioral Self-Control Training) treatment for SMM with AUD (N = 178), generalized estimating equations tested the effect of goal difficulty (defined as the proposed magnitude of change from current drinking in number of drinking days and number of heavy drinking days) on goal achievement at Months 0, 3, 6, and 9. Goal importance, self-efficacy, and AUD severity were tested as moderators. Findings yielded a significant positive relationship between goal difficulty and goal achievement for number of drinking days but a negative relationship for the number of heavy drinking days. Moderators of these relationships were not found. In order to increase the likelihood of achieving their goals in moderation-based alcohol treatment, SMM should initially consider setting more difficult goals for reducing drinking days. Additionally, goals of more conservative difficulty should be set for reducing heavy drinking days.

Topiramate Pharmacotherapy for Alcohol Use Disorder and Other Addictions: A Narrative Review

: Topiramate is a non-benzodiazepine anticonvulsant medication with multi-faceted pharmacologic action. It has emerged as an efficacious pharmacotherapeutic option for the treatment of addiction, especially alcohol use disorder (AUD). We present a broad narrative review of the putative mechanism of action and clinical utility of topiramate with regard to AUD and other substance use disorders. Collective evidence suggests topiramate is an effective treatment option in AUD, with notable efficacy in reducing harmful drinking patterns in AUD. Though not currently approved by the United States Food and Drug Administration for the indication of AUD, topiramate should be considered as a pharmacological treatment option with high utility among AUD patients. Early pharmacogenetic studies raise the intriguing possibility of identifying patients likely to respond to topiramate using genetic testing, and initial studies show that topiramate may also be useful in treating cocaine use disorder, smoking cessation and behavioral addictions. However, further research is needed in all these areas.

Effects of Initiating Abstinence from Alcohol on Daily Craving and Negative Affect: Results from a Pharmacotherapy Clinical Trial

BACKGROUND

Craving and negative affect are distressing and commonly experienced during alcohol use disorder (AUD) treatment. Patients may assume that initiating abstinence will intensify their cravings and negative affect despite limited empirical data to support this assumption. This study extends and replicates, under improved methodological conditions, previous work that found reductions in daily craving associated with initiating abstinence.

METHODS

Seventy-eight adults (80.8% male, 57.1% Caucasian) in a clinical trial testing prazosin for AUD provided daily reports of drinking, craving, and negative affect for up to 12 weeks (mean = 64.77 daily reports). Participants were classified into 3 subgroups based on whether and when they initiated 14 days of continuous abstinence, including (i) "abstinence initiators" who quit drinking during treatment (n = 17), (ii) "already abstainers" who were abstinent at the start of treatment (n = 20), and (iii) "continued drinkers" who never initiated abstinence (n = 41). The timing and degree of change in craving and negative affect were compared across these groups using multivariate growth curve modeling.

RESULTS

All participant subgroups reported gradual reductions in craving over the course of treatment, with "abstinence initiators" reporting additional sudden reductions in craving upon initiating abstinence from alcohol. "Continued drinkers" reported higher levels of craving than "already abstainers" throughout the full course of treatment. Negative affect followed a different pattern of change, with "abstinence initiators" experiencing gradual reductions in negative affect after initiating abstinence but no changes prior to or immediately upon initiating abstinence, and with "already abstainers" and "continued drinkers" experiencing no changes in negative affect over time.

CONCLUSIONS

Initiating abstinence is associated with immediate reductions in craving, followed by gradual reductions in both craving and negative affect. Results provide insight into the timing and magnitude of changes in theoretically and clinically important variables and may help patients anticipate when to expect improvement in craving and negative effect.

Reasons for Testing Mediation in the Absence of an Intervention Effect: A Research Imperative in Prevention and Intervention Research

OBJECTIVE

Mediation models are used in prevention and intervention research to assess the mechanisms by which interventions influence outcomes. However, researchers may not investigate mediators in the absence of intervention effects on the primary outcome variable. There is emerging evidence that in some situations, tests of mediated effects can be statistically significant when the total intervention effect is not statistically significant. In addition, there are important conceptual and practical reasons for investigating mediation when the intervention effect is nonsignificant.

METHOD

This article discusses the conditions under which mediation may be present when an intervention effect does not have a statistically significant effect and why mediation should always be considered important.

RESULTS

Mediation may be present in the following conditions: when the total and mediated effects are equal in value, when the mediated and direct effects have opposing signs, when mediated effects are equal across single and multiple-mediator models, and when specific mediated effects have opposing signs. Mediation should be conducted in every study because it provides the opportunity to test known and replicable mediators, to use mediators as an intervention manipulation check, and to address action and conceptual theory in intervention models.

CONCLUSIONS

Mediators are central to intervention programs, and mediators should be investigated for the valuable information they provide about the success or failure of interventions.

Difficulties in emotion regulation mediate negative and positive affects and craving in alcoholic patients

The aim of this study was to assess the mediating effects of difficulties in emotion regulation (DER) on the relations of negative and positive affects to craving in alcoholic patients. 205 treatment-seeking alcoholic outpatients were included. DER, positive and negative affects as well as craving were evaluated by the Difficulties in Emotion Regulation Scale (DERS), the Positive/Negative Affect Scales, and the Obsessive Compulsive Drinking Scale (OCDS) respectively. Clinical factors including depression and severity of alcohol dependence were investigated by the Alcohol Use Disorders Identification Test (AUDIT) and the Beck Depression Inventory-II (BDI-II) respectively. Results revealed that both increased negative affect and decreased positive affect indirectly influenced craving through limited access to emotion regulation strategies. It was concluded that limited access to emotion regulation strategies may be important in predicting craving for alcoholics who experience both increased negative affect and decreased positive affect. This suggests that treatment and prevention efforts focused on increasing positive affect, decreasing negative affect and teaching effective regulation strategies may be critical in reducing craving in alcoholic patients.

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

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

Differences between treatment-seeking and non-treatment-seeking participants in medication studies for alcoholism: do they matter?

BACKGROUND

Medication development for alcoholism typically includes experimental pharmacology studies with non-treatment-seeking individuals with alcohol use disorder (AUD) paving the way for randomized controlled trials in treatment-seekers with AUD.

OBJECTIVES

The goal of this study is to provide a direct comparison between AUD treatment-seeking research participants and non-treatment-seeking participants on demographic and clinical variables and to test whether variables that differentiate the two groups are associated with clinical outcomes.

METHOD

Non-treatment-seeking AUD participants (n = 213; 76.3% male) who completed behavioral pharmacology studies were compared to treatment-seekers who completed the COMBINE Study (n = 1383; 69.1% male) on demographic and clinical variables. Analyses examined whether the variables that differentiated the two groups predicted treatment outcomes in the COMBINE Study.

RESULTS

Analyses revealed that treatment-seeking participants were older, had more years of education, higher Alcohol Dependence Scale scores, higher Drinker Inventory of Consequences scores, higher Obsessive Compulsive Drinking Scale scores, a greater number of DSM-IV symptoms of AUD, longer duration of AUD, and consumed more standard drinks and more drinks per drinking day (i.e., in the past 30 days) compared to non-treatment-seeking participants. Nearly all characteristics that differed between the groups predicted at least one of the primary clinical outcomes of the COMBINE Study.

CONCLUSIONS

This study highlights a host of clinical and demographic factors that differ between non-treatment-seeking and treatment-seeking research participants and the clinical significance of these variables. Differences between samples should be considered and addressed in order to promote greater consilience across stages of medication development.

Craving Behavior Intervention in Ameliorating College Students' Internet Game Disorder: A Longitudinal Study

Craving, as a central feature of addiction and a precursor of relapse, is targeted recently in addiction intervention. While Internet gaming disorder (IGD), conceptualized as a behavioral addiction, is lack of effective treatment practice and exploration of its mechanism. This research aims to test the effectiveness and detect the active ingredients of craving behavior intervention (CBI) in mitigation of IGD among young adults. A total of 63 male college students with IGD were assigned into the intervention group (six-session CBI intervention) or the waiting-list control group. Structured questionnaires were administered at pre-intervention (T1), post-intervention (T2), 3-month follow-up (T3), and 6-month follow-up (T4). Compared to the control group, a significant decrease in the severity of IGD in intervention group was found at post-intervention and lasting to 6 months after intervention. The value changes of craving could partially mediate the relationship between intervention and changes of IGD among all effects tests (immediate, T2-T1; short-term, T3-T1; and long-term effects, T4-T1). Further, explorations of the active ingredients of intervention found depression relief and shift of psychological needs from Internet to real life significantly predict craving amelioration at both post-intervention and 6-month follow-up. Although preliminary, the current study provides evidence for the value of craving-aimed intervention practice in IGD treatment and identifies two potential active ingredients for mitigation of craving, and the long-term therapeutic benefits are further conferred.

Registry name: The behavioral and brain mechanism of IGD;

URL: https://www.clinicaltrials.gov/ct2/show/NCT02550405;

Registration number: NCT02550405.

Exploration of Core Symptoms for the Diagnosis of Alcohol Dependence in the ICD-10

BACKGROUND

The classification of alcohol use disorder has changed over the past century. Now, the conceptualization of alcohol dependence is still controversial. Accumulating evidence has shown the reliability and validity for the diagnosis of alcohol dependence in the ICD-10 and DSM-IV. However, the meaning and association of the respective diagnostic items, which are descriptive of representative symptoms, have hardly been examined. The core symptom of substance use disorder has been debated in various situations, but has never been elucidated logically.

METHODS

We consecutively registered 192 patients with alcohol-related problems who visited our hospital for the first time during a certain period. The relations and principal components among the checked items of the ICD-10 diagnostic criteria were examined statistically.

RESULTS

Three diagnostic items in the ICD-10 were strongly correlated with each other and were thought to form the core symptoms of alcohol dependence: "strong desire," "difficulties in controlling," and "neglect of pleasures." One major physical phenomenon, "withdrawal," seemed to complement the core symptoms in the diagnosis of alcohol dependence. Another physical phenomenon, "tolerance," was demonstrated to be a relatively independent item. The principal component analysis also demonstrated that the diagnostic item "difficulties in controlling" had the maximum component loading value, followed by 2 items, "neglect of pleasures" and "strong desire."

CONCLUSIONS

The core symptomatic elements in the diagnosis of alcohol dependence were statistically suggested in this study. Knowledge of the relations and components among the diagnostic items of alcohol dependence might also be applicable to other forms of substance use dependence and behavioral addiction.

Continuous Abstinence During Early Alcohol Treatment is Significantly Associated with Positive Treatment Outcomes, Independent of Duration of Abstinence

AIMS

Neither the predictive value of early continuous abstinence in alcohol use disorder (AUD) or the point at which this effect may emerge has been evaluated. This analysis of the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) clinical trial evaluated whether abstinence early in treatment was a predictor of longer term abstinence.

METHODS

Participants who stated a goal of total abstinence (N = 954) were dichotomized into Early Abstainer vs. Nonabstainers and were compared on a variety of drinking outcome measures that are frequently used in clinical trial evaluations of alcohol treatment strategies, as a function of duration of early continuous abstinence.

RESULTS

Significant differences existed for every outcome. Early Abstinence was significantly associated with fewer drinks per drinking day, number of drinking and number of heavy drinking days, and longer time to first drinking and first heavy drinking day. Effects were evident within the first week. The magnitude of all effects increased as the duration of early abstinence (1-4 weeks) increased, though the size of increase varied across the outcomes.

CONCLUSIONS

These data provide evidence that drinking at the beginning of alcohol treatment is significantly and robustly associated with drinking throughout and at the end of a clinical trial treatment for AUD. Early drinking may be a useful early index to identify whether patients are responding positively to a treatment strategy, and provides a useful method for tailoring treatment to patients that is consistent with a personalized medicine approach.

Association between a brief alcohol craving measure and drinking in the following week

BACKGROUND AND AIMS

Craving for alcohol is thought to be a predictor of alcohol use, particularly in the near future. The assessment of craving in clinical practice requires brief, simple measures that can be implemented routinely. This study tested whether greater alcohol craving was associated with a higher likelihood of alcohol use in the subsequent week.

DESIGN

The COMBINE Study (Combining Medications and Behavioral Interventions for Alcohol Dependence) was a large, multi-site clinical trial of treatment for alcohol dependence. Participants were randomized (stratified by site) to one of nine treatment conditions involving combinations of pharmacotherapy and psychotherapy. Craving was assessed every other week throughout the treatment period.

SETTING

Substance use disorder treatment settings at 11 academic sites across the United States.

PARTICIPANTS

Participants from the COMBINE Study (n = 1370) with available craving data.

MEASUREMENTS

Craving was assessed using the three-item self-report Craving Scale. Drinking was assessed using the Timeline Followback method, and was defined as alcohol use in each study week.

FINDINGS

There was an average of 5.8 (of a possible seven) observation pairs per participant. Craving was associated strongly with alcohol use in the following week [B = 0.27, standard error (SEB ) = 0.06, Wald χ(2)  = 43.34, odds ratio (OR) = 1.31, 95% confidence interval (CI) = 1.16, 1.47, P < 0.001]. For each 1-unit increase in the Craving Scale, the likelihood of drinking in the next week was 31% higher.

CONCLUSIONS

Craving for alcohol is associated strongly with alcohol use in the following week. Clinicians can measure alcohol craving effectively using a brief self-report craving scale.

Social network moderators of naltrexone and behavioral treatment effects on heavy drinking in the COMBINE study

BACKGROUND

Oral naltrexone is an efficacious medication for treatment of alcohol dependence, but small effect sizes and variability in outcomes suggest the presence of person-level moderators of naltrexone response. Identification of contextual or psychosocial moderators may assist in guiding clinical recommendations. Given the established importance of social networks in drinking outcomes, as well as the potential effects of naltrexone in reducing cue reactivity which may be especially important among those with more heavy drinkers and more alcohol cues in their networks, we examined pretreatment social network variables as potential moderators of naltrexone treatment effects in the COMBINE study.

METHODS

The sample included all COMBINE study participants in medication conditions with full data on the Important People Inventory (IPI) and covariates at intake (N = 1,197). The intake IPI assessed whether participants had any frequent drinkers in their network and the average frequency of contact with these drinkers. The effects of treatment condition, pretreatment network variables, and their interactions on percent heavy drinking days were tested in hierarchical linear models, controlling for demographics and baseline clinical covariates.

RESULTS

In treatment conditions involving medical management and combined behavioral intervention (CBI), the effects of active naltrexone on heavy drinking were significantly greater for individuals with frequent drinkers in their network (z = -2.66, p < 0.01) and greater frequency of contact with those drinkers (z = -3.19, p < 0.01). These network variables did not moderate the effects of active naltrexone without CBI.

CONCLUSIONS

When delivered in conjunction with behavioral interventions, naltrexone can be more potent for alcohol-dependent adults who have greater contact with frequent drinkers prior to treatment, which may indicate patterns of environmental exposure to alcohol. Contextual, social risk factors are a potential avenue to guide personalized treatment of alcohol dependence.

Trajectories of drinking urges and the initiation of abstinence during cognitive-behavioral alcohol treatment

BACKGROUND AND AIMS

Drinking urges during treatment for alcohol use disorders (AUDs) are common, can cause distress and predict relapse. Clients may have little awareness of how their drinking urges might be expected to change during AUD treatment in general and in response to initiating abstinence. The aim of the present study was to test whether drinking urges change on a daily level during treatment and after initiating abstinence.

DESIGN

Secondary data analysis was performed using daily drinking urge ratings from two randomized clinical trials.

SETTING AND PARTICIPANTS

Women (n = 98) and men (n = 79) with AUDs in separate clinical trials of out-patient AUD-focused cognitive-behavioral therapy.

MEASUREMENTS

Daily dichotomous indicators of any drinking urges or acute escalations in urges (i.e. at least two more urges compared with the previous day) were examined using generalized linear mixed growth-curve modeling.

FINDINGS

Participants who initiated abstinence reported reductions in urges immediately thereafter (log odds ratios: women B = -0.701, P < 0.001; men B = -0.628, P = 0.018), followed by additional, gradual reductions over time (women B = -0.118, P < 0.001; men B = -0.141, P < 0.001). Participants who entered treatment abstaining from alcohol also reported significant reductions in urges over time (women B = -0.147, P < 0.001; men B = -0.142, P < 0.001). Participants who drank throughout treatment had smaller (women B = -0.042, P = 0.012) or no reductions in urges (men B = 0.015, P = 0.545). There was no evidence that urges increased systematically in response to initiating abstinence.

CONCLUSIONS

Drinking urges during out-patient behavioral treatment for alcohol use disorders may be maintained in part by alcohol consumption. Initiating abstinence is associated with reductions in drinking urges immediately and then more gradually over time.

Opioid antagonists in broadly defined behavioral addictions: a narrative review

INTRODUCTION

Naltrexone (NTX), a mu-opioid receptor antagonist, has been approved for the treatment of alcoholism and opioid dependence. More recently, however, NTX and a related drug, nalmefene (NMF), have also shown positive results for the treatment of gambling disorders.

AREAS COVERED

In this study, we reviewed the trials testing the effect of opioid antagonists (OA) in gambling disorders and in other broadly defined behavioral addictions, including selected DSM-5 disruptive, impulse-control, and conduct disorders, obsessive-compulsive and related disorders, eating disorders, and other conditions not currently recognized by official classification schemes. We found six randomized controlled trials (RCTs) of OA in gambling disorder, two RCTs of OA in trichotillomania (hair pulling disorder), two RCTs of OA in binge eating disorder, and one RCT of OA for kleptomania. We also reviewed case reports on hypersexual disorder, compulsive buying and skin picking disorders.

EXPERT OPINION

The reviewed data supported the use of OA, namely NTX and NMF, in gambling disorder (both) and kleptomania (NTX). We did not find enough evidence to support the use of NTX or NMF in trichotillomania (hair pulling disorder), excoriation (skin-picking) disorder, compulsive buying disorder, hypersexual disorder, or binge eating disorder.

Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention

We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation of risk-difference- and risk-ratio-based effects (RDs, RRs) using the ML, WLSMV and Bayes estimators in Mplus. Across most variations in path-coefficient and mediator-residual-correlation signs and strengths, and confounding situations investigated, the method performs well with all estimators, but favors ML/WLSMV for RDs with continuous mediators, and Bayes for RRs with ordinal mediators. Bayes outperforms WLSMV/ML regardless of mediator type when estimating RRs with small potential outcome probabilities and in two other special cases. An adolescent alcohol prevention study is used for illustration.

An analysis of moderators in the COMBINE study: Identifying subgroups of patients who benefit from acamprosate

The goal of the current study was to use tree-based methods to identify moderators of acamprosate effect on abstinence from heavy drinking in COMBINE, the largest study of pharmacotherapy for alcoholism in the United States to date. We used three different tree-based methods for identification of subgroups with enhanced treatment response on acamprosate based on over 100 predictors measured at baseline in COMBINE. No heavy drinking during the last two months of treatment was the considered outcome. All three methods identified consecutive days of abstinence prior to treatment as the most important moderator of treatment effect. Acamprosate was beneficial for participants with shorter abstinence (1 week or less) especially when body mass index was low or normal. In this group, 46% of participants receiving active acamprosate abstained from heavy drinking compared to 23% of those receiving placebo acamprosate. Prior treatment, age, drinking goal and cognitive inefficiency were identified as moderators of acamprosate effects by one of the three methods. In conclusion, acamprosate may be beneficial for participants with shorter abstinence who are not overweight or obese. One hypothesis for this finding is that this subgroup may have greater glutamatergic hyperactivity, a target of acamprosate, and may achieve better drug plasma levels based on their lower BMI. In contrast, those with extended pretreatment abstinence who have an otherwise good prognosis did not benefit from acamprosate. Further validation of the results in independent data sets is necessary.

Trajectories of Drinking Urges During Individual- and Couple-based Cognitive-Behavioral Treatment for Alcohol Use Disorders

Individuals receiving treatment for alcohol use disorders (AUDs) often experience urges to drink, and reductions in drinking urges during cognitive-behavioral therapy (CBT) predict better treatment outcomes. However, little previous work has examined patterns of daily drinking urges during treatment. The present study examined patterns of change in daily drinking urges among participants in two randomized clinical trials of males (N = 80 with 4401 daily recordings) and females (N = 101 with 8011 daily recordings) receiving individual- or couples-based CBT. Drinking urges were common during treatment, occurring on 45.1% percent of days for men and 44.8% for women. Drinking urges and alcohol use for both genders decreased substantially during the course of treatment. Both genders had increases in drinking urges as more time elapsed since attending a treatment session. For men, this increase was most pronounced at the beginning of treatment, but for women it was most pronounced near the end of treatment. Alcohol use and drinking urges were both more likely to occur on weekends. The results suggest that these times may lead to higher risk for drinking, and clients may benefit from high-risk planning that is focused on these times.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Entering the Era of Data Science: Targeted Learning and the Integration of Statistics and Computational Data Analysis

This outlook paper reviews the research of van der Laan’s group on Targeted Learning, a subfield of statistics that is concerned with the construction of data adaptive estimators of user-supplied target parameters of the probability distribution of the data and corresponding confidence intervals, aiming at only relying on realistic statistical assumptions. Targeted Learning fully utilizes the state of the art in machine learning tools, while still preserving the important identity of statistics as a field that is concerned with both accurate estimation of the true target parameter value and assessment of uncertainty in order to make sound statistical conclusions. We also provide a philosophical historical perspective on Targeted Learning, also relating it to the new developments in Big Data. We conclude with some remarks explaining the immediate relevance of Targeted Learning to the current Big Data movement.

Mediation misgivings: ambiguous clinical and public health interpretations of natural direct and indirect effects

Recent methodological innovation is giving rise to an increasing number of applied papers in medical and epidemiological journals in which natural direct and indirect effects are estimated. However, there is a longstanding debate on whether such effects are relevant targets of inference in population health. In light of the repeated calls for a more pragmatic and consequential epidemiology, we review three issues often raised in this debate: (i) the use of composite cross-world counterfactuals and the need for cross-world independence assumptions; (ii) interventional vs non-interventional identifiability; and (iii) the interpretational ambiguity of natural direct and indirect effect estimates. We use potential outcomes notation and directed acyclic graphs to explain 'cross-world' assumptions, illustrate implications of this assumption via regression models and discuss ensuing issues of interpretation. We argue that the debate on the relevance of natural direct and indirect effects rests on whether one takes as a target of inference the mathematical object per se, or the change in the world that the mathematical object represents. We further note that public health questions may be better served by estimating controlled direct effects.

Pharmacological approaches to reducing craving in patients with alcohol use disorders

Research on the concept of craving may lead to better understanding of the biobehavioural circuitries that contribute to the complexity of alcohol use disorders (AUDs). The experiences described as craving or desire to drink are often associated with physical responses such as increased salivation and heart rate, and alteration of stress hormones, as well as psychological responses such as anxiety and depression. Greater craving has been associated with an increased probability of alcohol relapse. Reversal of craving, which is understood as a symptom of protracted abstinence, offers the possibility of preventing relapses and treating alcoholism. Various medications have been studied to establish whether they are able to reduce craving; however, the results obtained from clinical studies have been inconsistent. Here, we review the interdisciplinary models developed to evaluate craving, then the different approaches used to assess and measure craving and, finally, the medications utilized and tested to lessen craving in patients suffering from AUDs.