Neurofunctional Domains Derived From Deep Behavioral Phenotyping in Alcohol Use Disorder

Neuropsychosocial markers of binge drinking in young adults

Binge drinking is associated with disease and death, and developing tools to identify risky drinkers could mitigate its damage. Brain processes underlie risky drinking, so we examined whether neural and psychosocial markers could identify binge drinkers. Reward is the most widely studied neural process in addiction, but processes such as emotion, social cognition, and self-regulation are also involved. Here we examined whether neural processes apart from reward contribute to predicting risky drinking behaviors. From the Human Connectome Project, we identified 177 young adults who binged weekly and 309 nonbingers. We divided the sample into a training and a testing set and used machine-learning algorithms to classify participants based on psychosocial, neural, or both (neuropsychosocial) data. We also developed separate models for each of the seven fMRI tasks used in the study. An ensemble model developed in the training dataset was then applied to the testing dataset. Model performance was assessed by the area under the receiver operating characteristic curve (AUC) and differences between models were assessed using DeLong's test. The three models performed better than chance in the test sample with the neuropsychosocial (AUC = 0.86) and psychosocial (AUC = 0.84) performing better than the neural model (AUC = 0.64). Two fMRI-based models predicted binge drinking status better than chance, corresponding to the social and language tasks. Models developed with psychosocial and neural variables could contribute as diagnostic tools to help classify risky drinkers. Since social and language fMRI tasks performed best among the neural discriminators (including those from gambling and emotion tasks), it suggests the involvement of a broader range of brain processes than those traditionally associated with binge drinking in young adults.

Addiction treatment in the postpartum period: an opportunity for evidence-based personalized medicine

Substance use disorders (SUD) are becoming rapidly more prevalent in women and a leading cause of pregnancy associated deaths, with most deaths occurring during the 12 months after pregnancy. The postpartum period can be quite intense, especially for women seeking addiction recovery. There is a call to reconceptualize the obstetrical postpartum care model into one that extends specialised care and is tailored to an individual's specific needs. Although SUD treatment improves maternal and infant outcomes as well as decreases overdose risk, many women do not receive consistent SUD treatment during the postpartum period. Thus, SUD treatments should consider following the same guidance as obstetrics to reconceptualize how SUD treatment is delivered postpartum. Clinically, this translates into substantially modifying traditional siloed SUD treatment structures to meet the unique needs of this vulnerable patient population. At the same time, more research is urgently needed to inform these advancements in clinical care to ensure they are evidence-based and effective. In this article, we review the existing evidence as well as highlight opportunities for both clinicians and researchers to advance the integration of tailored approaches for postpartum women into personalised SUD medical and behavioural treatments.

A Longitudinal Mediation Model of Negative Emotionality, Coping Motives and Drinking Intensity Among Individuals Receiving Community Treatment for Alcohol Use Disorder

AIMS

Negative emotionality is a key domain in frameworks measuring heterogeneity in alcohol use disorder (AUD), such as the Addictions Neuroclinical Assessment (ANA). Recent research has examined the construct validity of the ANA negative emotionality domain, but has not examined whether this domain demonstrates predictive validity for drinking outcomes. In this study, we examined the association between self-reported negative emotionality at baseline and drinking intensity 1 year following AUD treatment initiation. We also assessed whether coping motives for alcohol use at 6 months following treatment initiation and changes in coping motives mediated this association.

METHODS

This was a secondary data analysis of a multisite prospective study of individuals entering AUD treatment (n = 263; 61.6% male; mean age = 33.8). Measures of coping motives and drinking intensity captured those who experienced a lapse to drinking. The associations between the ANA negative emotionality domain, coping motives and drinking intensity over time were assessed using a latent growth curve mediation model.

RESULTS

The ANA negative emotionality domain at baseline was indirectly associated with greater 7-12-month drinking intensity through higher coping motives at 6 months. Negative emotionality was not related to change in coping motives over the assessment period and change in coping motives was not related to 7-12-month drinking intensity.

CONCLUSIONS

This analysis provides evidence for the predictive validity of the ANA negative emotionality domain for coping motives and drinking intensity among treatment seekers who experienced a lapse to drinking. Coping motives may be an important target in AUD treatment among those high in negative emotionality.

The profound heterogeneity of substance use disorders: Implications for treatment development

A single treatment approach will never be sufficient to address the diversity of individuals with substance use disorders (SUDs). SUDs have historically defied definition through simple characterizations or models, and no single characterization has led to the development of broadly effective interventions. The range of dimensions of heterogeneity among individuals with SUDs, including severity, type of substance, and issues that frequently co-occur underscore that highly tailored approaches are needed. To approach personalized medicine for individuals with SUDs; two major developments are needed. First, given the diversity of individuals with SUDs, multivariate phenotyping approaches are needed to identify the particular features driving addictive processes in any individual. Second, a wider range of interventions that directly target core mechanisms of addiction and the problems that co-occur with them are needed. As clinicians cannot be expected to master the full range of interventions that may target these core processes, developing these so that they can be delivered easily, flexibly, and systematically via technology will facilitate our ability to truly tailor interventions to this highly complex and challenging population. One such technology-delivered intervention, computer-based training for cognitive behavioral therapy (CBT4CBT), is used as an example to illustrate a vision for the future of highly-tailored interventions for individuals with SUDs.

A neural substrate of compulsive alcohol use

Alcohol intake remains controlled in a majority of users but becomes "compulsive," i.e., continues despite adverse consequences, in a minority who develop alcohol addiction. Here, using a footshock-punished alcohol self-administration procedure, we screened a large population of outbred rats to identify those showing compulsivity operationalized as punishment-resistant self-administration. Using unsupervised clustering, we found that this behavior emerged as a stable trait in a subpopulation of rats and was associated with activity of a brain network that included central nucleus of the amygdala (CeA). Activity of PKCδ+ inhibitory neurons in the lateral subdivision of CeA (CeL) accounted for ~75% of variance in punishment-resistant alcohol taking. Activity-dependent tagging, followed by chemogenetic inhibition of neurons activated during punishment-resistant self-administration, suppressed alcohol taking, as did a virally mediated shRNA knockdown of PKCδ in CeA. These findings identify a previously unknown mechanism for a core element of alcohol addiction and point to a novel candidate therapeutic target.

Sex-specific associations between subcortical morphometry in childhood and adult alcohol consumption: A 17-year follow-up study

Men and women tend to differ in the age of first alcohol consumption, transition into disordered drinking, and the prevalence of alcohol use disorder. Here, we use a unique longitudinal dataset to test for potentially predispositonal sex-biases in brain organization prior to initial alcohol exposure. Our study combines measures of subcortical morphometry gathered in alcohol naive individuals during childhood (mean age: 9.43 years, SD = 2.06) with self-report measures of alcohol use in the same individuals an average of 17 years later (N = 81, 46 males, 35 females). We observe that pediatric amygdala and hippocampus volume both show sex-biased relationships with adult drinking. Specifically, females show a stronger association between subcortical volumetric reductions in childhood and peak drinking in adulthood as compared to males. Detailed analysis of subcortical shape localizes these effects to the rostro-medial hippocampus and basolateral amygdala subnuclei. In contrast, we did not observe sex-specific associations between striatal anatomy and peak alcohol consumption. These results are consistent with a model in which organization of the amygdala and hippocampus in childhood is more relevant for subsequent patterns of peak alcohol use in females as compared to males. Differential neuroanatomical precursors of alcohol use in males and females could provide a potential developmental basis for well recognized sex-differences in alcohol use behaviors.. Thus, our findings not only indicate that brain correlates of human alcohol consumption are manifest long before alcohol initiation, but that some of these correlates are not equivalent between males and females.

Altered effective connectivity of the reward network during an incentive-processing task in adults with alcohol use disorder

BACKGROUND

Abnormalities of reward sensitivity and impulsivity are known to be correlated with each other and alcohol use disorder (AUD) risk, but the underlying aberrant neural circuitry involved is not clearly defined. We sought to extend the current knowledge of AUD pathophysiology by studying incentive processing in persons with AUD using functional neuroimaging data.

METHODS

We utilized functional MRI data from the Human Connectome Project Database obtained during performance of a number-guessing incentive-processing task with win, loss, and neutral feedback conditions in 78 participants with either DSM-IV alcohol abuse or dependence (combined as the AUD group) and 78 age- and sex-matched control (CON) participants. Within a network consisting of anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), insula, ventral striatum, and dorsal striatum (DS) in the right hemisphere, we performed dynamic causal modeling analysis to test group-level differences (AUD vs. CON) in effective directional connectivity (EC) as modulated by "win" and "loss" conditions. We used linear regression analyses to characterize the relations between each EC outcome and measures of cumulative alcohol exposure and impulsivity.

RESULTS

During wins, AUD participants had lower ECs from ACC to the other four nodes, greater ECs from insula to the other four nodes, greater ECs from DLPFC to the other four nodes, and greater DS to DS self-connection EC than CON participants. In the total sample, EC from the insula to the DLPFC (insula → DLPFC) during wins was positively correlated with both impulsivity (as measured by the delay-discounting task) and cumulative alcohol exposure. The DS to DS self-connection EC during wins was positively correlated with impulsivity. Many of the altered ECs from the ACC and insula to other nodes were correlated with cumulative alcohol exposure.

CONCLUSIONS

Individuals with AUD have disrupted EC in both instrumentally driven and automatized corticostriatal reward circuits during non-alcohol reward feedback. These results point to disrupted corticostriatal EC in both "top-down" and "bottom-up" pathways among individuals with AUD.

Protocol for the Project SAVE randomised controlled trial examining CBT for insomnia among veterans in treatment for alcohol use disorder

INTRODUCTION

As many as 74% of veterans with alcohol use disorders (AUDS) report symptoms of insomnia. Insomnia represents a barrier to alcohol treatment because insomnia symptoms (1) may lead to relapse among those who use alcohol to help them sleep and may negatively impact (2) executive functions and (3) emotion regulation skills. Cognitive-behavioural therapy for insomnia (CBT-I) is an efficacious first-line treatment for insomnia; however, no research has examined the impact of CBT-I on individuals' response to alcohol treatment. In the Sleep and Alcohol for Veterans (Project SAVE) randomised controlled trial, we hypothesise that CBT-I will enhance the efficacy of alcohol treatment among Veterans with insomnia by enhancing their abilities to attend to treatment, regulate emotions and initiate sleep without alcohol.

METHODS AND ANALYSIS

Eighty Veterans enrolled in alcohol treatment at the Veterans Administration (VA) hospital will be randomly assigned to receive either CBT-I or single-session sleep hygiene (SH) education. Individuals will be eligible to participate if they meet Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for moderate to severe AUD and Insomnia Disorder of at least 1-month duration. Participants will complete assessments at baseline, post-treatment and 6-week follow-up. Preliminary process outcomes include retention/recruitment rates and treatment satisfaction (feasibility and acceptability, respectively). Primary outcomes are insomnia severity, percentage of heavy-drinking days and alcohol-related problems. We will assess a variety of secondary clinical and mechanistic outcomes (eg, post-traumatic stress disorder (PTSD) symptoms, attention and working memory).

ETHICS AND DISSEMINATION

Ethics approval was obtained in October 2018. Data collection began in July 2019 and is planned for completion by July 2021. Trial results will be disseminated at local and national conferences, in peer-reviewed publications and through media outlets, as available. Results will also be shared with interested participants and clinical collaborators at the end of the trial.

TRIAL REGISTRATION NUMBER

clinicaltrials.gov identifier NCT03806491 (pre-results).

Evaluation of the Addictions Neuroclinical Assessment (ANA) framework through deep phenotyping of problem drinkers

BACKGROUND

To advance the development of a neuroscience-informed understanding of alcohol use disorder (AUD) through the Addictions Neuroclinical Assessment (ANA) framework, the present study reports on deep phenotyping of a large sample of problem drinkers.

METHODS

Participants (n = 1679) were primarily heavy drinkers with and without AUD, who completed a phenotypic battery of well-validated scales and behavioral measures of alcohol use and problems, mood, attention, and impulsivity. These scales were subjected to sequential factor analytic work in order to derive a factor solution that explains biobehavioral variation in the sample. To assess the construct validity of the resulting factor solution, scores on each factor were associated with demographic and clinical indicators.

RESULTS

Factor analysis techniques using indicators of alcohol use and problems, mood, attention, and impulsivity implicated four functional domains that compliment and extend the proposed ANA domains: negative alcohol-related consequences, incentive salience, negative emotionality, and executive function. Demographic and clinical variables significantly predicted scores on all ANA domains.

CONCLUSIONS

This study provides an independent test of the recently proposed neuroscience-based ANA framework. Results largely support the novel approach in identifying four core constructs in problem drinkers. Future studies can deepen our understanding of how these domains are relevant to AUD by incorporating biomarkers.

An integrated multimodal model of alcohol use disorder generated by data-driven causal discovery analysis

Alcohol use disorder (AUD) has high prevalence and adverse societal impacts, but our understanding of the factors driving AUD is hampered by a lack of studies that describe the complex neurobehavioral mechanisms driving AUD. We analyzed causal pathways to AUD severity using Causal Discovery Analysis (CDA) with data from the Human Connectome Project (HCP; n = 926 [54% female], 22% AUD [37% female]). We applied exploratory factor analysis to parse the wide HCP phenotypic space (100 measures) into 18 underlying domains, and we assessed functional connectivity within 12 resting-state brain networks. We then employed data-driven CDA to generate a causal model relating phenotypic factors, fMRI network connectivity, and AUD symptom severity, which highlighted a limited set of causes of AUD. The model proposed a hierarchy with causal influence propagating from brain connectivity to cognition (fluid/crystalized cognition, language/math ability, & working memory) to social (agreeableness/social support) to affective/psychiatric function (negative affect, low conscientiousness/attention, externalizing symptoms) and ultimately AUD severity. Our data-driven model confirmed hypothesized influences of cognitive and affective factors on AUD, while underscoring that addiction models need to be expanded to highlight the importance of social factors, amongst others.

Insomnia treatment effects among young adult drinkers: Secondary outcomes of a randomized pilot trial

BACKGROUND

Cognitive behavioral therapy for insomnia (CBT-I) has moderate-to-large effects on insomnia among young adult drinkers, with preliminary data indicating that improvements in insomnia may have downstream effects on alcohol-related consequences. However, the mechanism(s) by which insomnia treatment may facilitate reductions in alcohol-related problems is unclear. Secondary outcome data from a randomized pilot trial were used to examine CBT-I effects on four proposed mediators of the insomnia/alcohol link: alcohol craving, delay discounting, negative affect, and difficulties with emotion regulation.

METHODS

Young adults (ages 18 to 30 years) with insomnia who reported 1+ binge drinking episode (4/5+ drinks for women/men) in the past month were randomized to receive CBT-I (n = 28) or to a sleep hygiene control (n = 28). Outcomes were assessed at baseline, after 5 weeks of treatment, and at 1-month posttreatment.

RESULTS

Relative to those in sleep hygiene, CBT-I participants reported greater decreases in alcohol craving (d = 0.33) at the end of treatment and greater 1-month posttreatment decreases in delay discounting of large rewards (d = 0.42). CBT-I did not have a significant effect on delay discounting of smaller rewards or momentary negative affect. There was also no significant treatment effect on difficulties with emotion regulation, although findings were confounded by a significant group difference at baseline in difficulties with emotion regulation.

CONCLUSIONS

Treatment of insomnia may lead to improvements in alcohol craving and delay discounting of large rewards among young adult drinkers with insomnia. Additional research examining whether improvement in insomnia is a mechanism for improvement in addiction domains is warranted.

The future of translational research on alcohol use disorder

In March 2019, a scientific meeting was held at the University of California, Los Angeles (UCLA) Luskin Center to discuss approaches to expedite the translation of neurobiological insights to advances in the treatment of alcohol use disorder (AUD). A guiding theme that emerged was that while translational research in AUD is clearly a challenge, it is also a field ripe with opportunities. Herein, we seek to summarize and disseminate the recommendations for the future of translational AUD research using four sections. First, we briefly review the current landscape of AUD treatment including the available evidence-based treatments and their uptake in clinical settings. Second, we discuss AUD treatment development efforts from a translational science viewpoint. We review current hurdles to treatment development as well as opportunities for mechanism-informed treatment. Third, we consider models of translational science and public health impact. Together, these critical insights serve as the bases for a series of recommendations and future directions. Towards the goal of improving clinical care and population health for AUD, scientists are tasked with bolstering the clinical applicability of their research findings so as to expedite the translation of knowledge into patient care.

Mapping data-driven individualized neurobehavioral phenotypes in heavy alcohol drinkers

OBJECTIVE

Recent studies have examined the factor structure and associated correlates of three neurofunctional domains, executive function, incentive salience, and negative emotionality in the development and maintenance of alcohol use disorders in clinical samples. The current study sought to replicate and extend prior work by testing this 3-factor model, utilizing both exact and similar phenotypic measures, as well as novel measures, in a non-treatment-seeking sample.

METHODS

Self-report measures of alcohol addiction, impulsivity, behavior, and exposure to early-life stress were collected as part of baseline assessments for alcohol imaging and pharmacotherapy studies in 335 individuals. Confirmatory factor analysis (CFA) was used to examine model structure and fit. A multiple indicators, multiple causes (MIMIC) model identified predictors of latent factors identified by CFA.

RESULTS

Results supported an intercorrelated model with three factors: executive function, incentive salience, and emotionality. All factors were associated with current AUD, and incentive salience was uniquely associated with past 30-day drinking frequency. MIMIC results identified multiple significant predictors of these latent factors, including history of alcohol use disorder, positive family history of alcohol dependence, earlier age of first drink, and a history of childhood emotional abuse and physical neglect.

CONCLUSIONS

Our results support an intercorrelated 3-factor model of neurofunctional domains in alcohol use models, consistent with published findings. Because childhood physical neglect was a significant predictor of all latent factors, these results also highlight the significant negative impact of childhood neglect on later addiction development.

Validity and measurement invariance of the Addictions Neuroclinical Assessment incentive salience domain among treatment-seekers with alcohol use disorder

Incentive salience, or the attribution of motivational value to stimuli, is a biopsychological process that is disrupted in alcohol use disorder (AUD). The Addictions Neuroclinical Assessment (ANA) is a framework to characterize heterogeneity in addiction and establish a common assessment battery for research and clinical use. The ANA framework hypothesizes three constructs that correspond to processes in the etiology, course, and treatment of addiction: incentive salience, negative emotionality, and executive function. The current study extends prior findings on the ANA by validating the incentive salience construct among participants (n = 563) in a multisite prospective study of individuals entering treatment for AUD. We used confirmatory factor analysis to test a one-factor model of incentive salience. Indicators included items assessing perception of urges to drink from the Alcohol Dependence Scale, Impaired Control Scale, and Marlatt Relapse Interview. Results indicated the one-factor model fit the data well (χ² (12) = 19.42, p = .08; RMSEA = 0.034 [90% CI: 0.000, 0.060], CFI = 0.992) and was measurement invariant across sex. Incentive salience was associated with drinking patterns (e.g., drinks per day, r = 0.447 [95% CI: 0.379, 0.514]); reasons for drinking (urges/temptation r = 0.529 [95% CI: 0.460, 0.599]); testing personal control, r = 0.384 (95% CI: 0.308, 0.461); social pressure, r = 0.549 (95% CI: 0.481, 0.617); and family history of AUD, r = 0.134. The incentive salience factor demonstrated greater predictive validity for drinking outcomes compared to alternative preexisting scales. Overall, this study provides support for the construct validity and measurement invariance of the ANA incentive salience construct in a sample of individuals seeking AUD treatment.

Clinical Neuroscience of Addiction: What Clinical Psychologists Need to Know and Why

The last three decades in psychological research have been marked by interdisciplinary science. Addiction represents a prime example of a disorder marked by a complex interaction among psychosocial and biological factors. This review highlights critical findings in the basic neuroscience of addiction and translates them into clinical language that can inform clinical psychologists in their research, teaching, and practice. From mechanisms of reward processing, learning and memory, allostasis, incentive-sensitization, withdrawal, tolerance, goal-directed decision making, habit learning, genetics, inflammation, and the microbiome, the common theme of this review is to illustrate the clinical utility of basic neuroscience research and to identify opportunities for clinical science. The thoughtful integration of basic and clinical science provides a powerful tool to fulfill the scientific mission of improving health care. Clinical psychologists have a crucial role to play in the translational science of addiction.

Prevalence of alcohol use disorder among individuals who binge eat: a systematic review and meta-analysis

BACKGROUND AND AIMS

Binge eating disorder (BED) is correlated with substance use. This study aimed to estimate the life-time prevalence of alcohol use disorder (AUD) among individuals with non-compensatory binge eating and determine whether their life-time prevalence of AUD is higher than in non-bingeing controls.

DESIGN

A systematic search of databases (PubMed, Embase and Web of Science) for studies of adults diagnosed with BED or a related behavior that also reported the life-time prevalence of AUD was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was followed. The protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO).

SETTING

Studies originating in Canada, Sweden, the United Kingdom and the United States.

PARTICIPANTS

Eighteen studies meeting the inclusion criteria were found, representing 69 233 individuals.

MEASUREMENTS

Life-time prevalence of AUD among individuals with binge eating disorder and their life-time relative risk of AUD compared with individuals without this disorder.

RESULTS

The pooled life-time prevalence of AUD in individuals with binge eating disorder was 19.9% [95% confidence interval (CI) = 13.7-27.9]. The risk of life-time AUD incidence among individuals with binge eating disorder was more than 1.5 times higher than controls (relative risk = 1.59, 95% CI = 1.41-1.79). Life-time AUD prevalence was higher in community samples than in clinical samples (27.45 versus 14.45%, P = 0.041) and in studies with a lower proportion of women (β = -2.2773, P = 0.044).

CONCLUSIONS

Life-time alcohol use disorder appears to be more prevalent with binge eating disorder than among those without.

Drug Addiction: Hyperkatifeia/Negative Reinforcement as a Framework for Medications Development

Compulsive drug seeking that is associated with addiction is hypothesized to follow a heuristic framework that involves three stages (binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation) and three domains of dysfunction (incentive salience/pathologic habits, negative emotional states, and executive function, respectively) via changes in the basal ganglia, extended amygdala/habenula, and frontal cortex, respectively. This review focuses on neurochemical/neurocircuitry dysregulations that contribute to hyperkatifeia, defined as a greater intensity of negative emotional/motivational signs and symptoms during withdrawal from drugs of abuse in the withdrawal/negative affect stage of the addiction cycle. Hyperkatifeia provides an additional source of motivation for compulsive drug seeking via negative reinforcement. Negative reinforcement reflects an increase in the probability of a response to remove an aversive stimulus or drug seeking to remove hyperkatifeia that is augmented by genetic/epigenetic vulnerability, environmental trauma, and psychiatric comorbidity. Neurobiological targets for hyperkatifeia in addiction involve neurocircuitry of the extended amygdala and its connections via within-system neuroadaptations in dopamine, enkephalin/endorphin opioid peptide, and γ-aminobutyric acid/glutamate systems and between-system neuroadaptations in prostress corticotropin-releasing factor, norepinephrine, glucocorticoid, dynorphin, hypocretin, and neuroimmune systems and antistress neuropeptide Y, nociceptin, endocannabinoid, and oxytocin systems. Such neurochemical/neurocircuitry dysregulations are hypothesized to mediate a negative hedonic set point that gradually gains allostatic load and shifts from a homeostatic hedonic state to an allostatic hedonic state. Based on preclinical studies and translational studies to date, medications and behavioral therapies that reset brain stress, antistress, and emotional pain systems and return them to homeostasis would be promising new targets for medication development. SIGNIFICANCE STATEMENT: The focus of this review is on neurochemical/neurocircuitry dysregulations that contribute to hyperkatifeia, defined as a greater intensity of negative emotional/motivational signs and symptoms during withdrawal from drugs of abuse in the withdrawal/negative affect stage of the drug addiction cycle and a driving force for negative reinforcement in addiction. Medications and behavioral therapies that reverse hyperkatifeia by resetting brain stress, antistress, and emotional pain systems and returning them to homeostasis would be promising new targets for medication development.

Alcohol Binge Drinking: Negative and Positive Valence System Abnormalities

BACKGROUND

Each year, 3 million deaths occur owing to alcohol misuse. Translational studies are crucial to translate preclinical findings to patients. Preclinical studies have highlighted abnormalities in specific brain systems, with these forming the basis of allostasis theory. However, few studies have tested predictions in humans using neuroimaging.

METHODS

We used a Research Domain Criteria approach to test allostasis theory predictions of blunted positive valence system (PVS) and abnormally increased negative valence system (NVS) responses in 57 binge alcohol drinking subjects and healthy control subjects who completed an instrumental task during functional magnetic resonance imaging.

RESULTS

As hypothesized, binge alcohol drinkers showed abnormally increased activity in NVS-linked regions, such as the hippocampus and dorsal cingulate, and abnormally blunted activity in PVS-linked regions, such as the striatum, compared with control subjects. Higher measures of problematic alcohol use were associated with more abnormal brain activity only for binge drinkers who had been most recently drinking.

CONCLUSIONS

These results support allostasis theory predictions of abnormally increased NVS and blunted PVS responses in binge alcohol drinkers. Further similar translational neuroimaging studies are indicated, particularly focusing on the NVS.

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.

Risk for Substance Use Disorders in young adulthood: Associations with developmental experiences of homelessness, foster care, and adverse childhood experiences

BACKGROUND

Multiple developmental risk factors for Substance Use Disorders (SUDs) during young adulthood have been identified. In this investigation, we examined the impact of homelessness, foster care, and adverse childhood experiences (ACEs) prior to 12th grade on the development of three common SUDs during young adulthood-Alcohol Use Disorder (AUD), Tobacco Use Disorder (TUD) and Cannabis Use Disorder (CUD). Our hypothesis was that while both homelessness and ACEs are significant risk factors for young adult SUDs, foster care involvement might convey protection.

METHODS

Using nationally representative data from the National Longitudinal Study of Adolescent to Adult Health, measures of ACEs were derived from the CDC-Kaiser ACE study, and DSM-V SUD diagnoses were derived from items originally based on DSM-IV. SUD diagnoses were binned into "mild", "moderate", and "severe" groupings. Survey-based logistic models were used to estimate risks of SUDs while controlling for demographics.

RESULTS

The results suggest that the experience of homelessness prior to 12th grade in addition to ACEs were significantly associated with the development in young adulthood of the most severe forms of AUD and TUD and all severity levels of CUD. Foster care was not associated with either risk or protection from SUDs.

CONCLUSIONS

The experience of homelessness during development may be viewed as another detrimental ACE that is a risk factor for the most common SUDs in young adulthood. Given the magnitude of the current epidemic of homelessness in the U.S., these results should raise substantial concern.

Cognition and addiction

In this targeted review, we summarize current knowledge on substance-use disorder (SUD)-related cognitive deficits, the link between these deficits and clinical outcomes, and the cognitive training, remediation, and pharmacological approaches that have the potential to rescue cognition. We conclude that: (i) people with SUDs have moderate deficits in memory, attention, executive functions, and decision-making (including reward expectancy, valuation, and learning); (ii) deficits in higher-order executive functions and decision-making are significant predictors of relapse; (iii) cognitive training programs targeting reward-related appetitive biases, cognitive remediation strategies targeting goal-based decision-making, and pharmacotherapies targeting memory, attention, and impulsivity have potential to rescue SUD-related cognitive deficits. We suggest avenues for future research, including developing brief, clinically oriented harmonized cognitive testing suites to improve individualized prediction of treatment outcomes; computational modeling that can achieve deep phenotyping of cognitive subtypes likely to respond to different interventions; and phenotype-targeted cognitive, pharmacological, and combined interventions. We conclude with a tentative model of neuroscience-informed precision medicine.


The Addictions Neuroclinical Assessment Negative Emotionality Domain Among Treatment-Seekers with Alcohol Use Disorder: Construct Validity and Measurement Invariance

BACKGROUND

The Addictions Neuroclinical Assessment (ANA), a framework for measuring heterogeneity in alcohol use disorder (AUD), focuses on 3 domains that reflect neurobiological dysfunction in addiction and correspond to the cycles of addiction: executive function, incentive salience, and negative emotionality. Kwako and colleagues (Am J Psychiatry 176:744, 2019) validated a 3-factor model of the ANA with neuropsychological and self-report indicators among treatment-seekers and non-treatment-seekers with and without AUD. The present analysis replicated and extended these findings in a treatment-seeking sample, focusing on the negative emotionality domain.

METHODS

Participants (n = 563; 58.8% male; mean age = 34.3) were part of a multisite prospective study of individuals entering AUD treatment. We examined the factor structure of the negative emotionality domain at the baseline, 6-month follow-up, and 12-month follow-up assessments. The Beck Depression Inventory, Beck Anxiety Inventory, State-Trait Anger Expression Inventory-Trait Anger Subscale, and 3 Drinker Inventory of Consequences items assessing negative affective consequences were indicators in the model.

RESULTS

Results indicated that a 1-factor model was an excellent fit at all assessments and that the negative emotionality domain was time and gender invariant. Furthermore, negative emotionality was associated with drinking patterns and reasons for alcohol use (i.e., drinking because of negative emotions and urges/withdrawal) at all assessments.

CONCLUSIONS

This analysis provides evidence for the construct validity and measurement invariance of the ANA negative emotionality domain among AUD treatment-seekers. Future studies are needed to evaluate prospective associations between negative emotionality and specific treatment modalities, and whether individuals with greater negative emotionality are more likely to respond to treatment that targets drinking to relieve negative affective states.

Alcohol Use Disorder Interventions Targeting Brain Sites for Both Conditioned Reward and Delayed Gratification

Alcohol use disorder is a destructive compulsion characterized by chronic relapse and poor recovery outcomes. Heightened reactivity to alcohol-associated stimuli and compromised executive function are hallmarks of alcohol use disorder. Interventions targeting these two interacting domains are thought to ameliorate these altered states, but the mutual brain sites of action are yet unknown. Although interventions on alcohol cue reactivity affect reward area responses, how treatments alter brain responses when subjects exert executive effort to delay gratification is not as well-characterized. Focusing on interventions that could be developed into effective clinical treatments, we review and identify brain sites of action for these two categories of potential therapies. Using activation likelihood estimation (ALE) meta-analysis, we find that interventions on alcohol cue reactivity localize to ventral prefrontal cortex, dorsal anterior cingulate, and temporal, striatal, and thalamic regions. Interventions for increasing delayed reward preference elicit changes mostly in midline default mode network regions, including posterior cingulate, precuneus, and ventromedial prefrontal cortex-in addition to temporal and parietal regions. Anatomical co-localization of effects appears in the ventromedial prefrontal cortex, whereas effects specific to delay-of-gratification appear in the posterior cingulate and precuneus. Thus, the current available literature suggests that interventions in the domains of cue reactivity and delay discounting alter brain activity along midline default mode regions, specifically in the ventromedial prefrontal cortex for both domains, and the posterior cingulate/precuneus for delay-of-gratification. We believe that these findings could facilitate targeting and development of new interventions, and ultimately treatments of this challenging disorder.

Alcohol use disorder and sleep disturbances: a feed-forward allostatic framework

The development of alcohol use disorder (AUD) involves binge or heavy drinking to high levels of intoxication that leads to compulsive intake, the loss of control in limiting intake, and a negative emotional state when alcohol is removed. This cascade of events occurs over an extended period within a three-stage cycle: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These three heuristic stages map onto the dysregulation of functional domains of incentive salience/habits, negative emotional states, and executive function, mediated by the basal ganglia, extended amygdala, and frontal cortex, respectively. Sleep disturbances, alterations of sleep architecture, and the development of insomnia are ubiquitous in AUD and also map onto the three stages of the addiction cycle. During the binge/intoxication stage, alcohol intoxication leads to a faster sleep onset, but sleep quality is poor relative to nights when no alcohol is consumed. The reduction of sleep onset latency and increase in wakefulness later in the night may be related to the acute effects of alcohol on GABAergic systems that are associated with sleep regulation and the effects on brain incentive salience systems, such as dopamine. During the withdrawal/negative affect stage, there is a decrease in slow-wave sleep and some limited recovery in REM sleep when individuals with AUD stop drinking. Limited recovery of sleep disturbances is seen in AUD within the first 30 days of abstinence. The effects of withdrawal on sleep may be related to the loss of alcohol as a positive allosteric modulator of GABAA receptors, a decrease in dopamine function, and the overactivation of stress neuromodulators, including hypocretin/orexin, norepinephrine, corticotropin-releasing factor, and cytokines. During the preoccupation/anticipation stage, individuals with AUD who are abstinent long-term present persistent sleep disturbances, including a longer latency to fall asleep, more time awake during the night, a decrease in slow-wave sleep, decreases in delta electroencephalogram power and evoked delta activity, and an increase in REM sleep. Glutamatergic system dysregulation that is observed in AUD is a likely substrate for some of these persistent sleep disturbances. Sleep pathology contributes to AUD pathology, and vice versa, possibly as a feed-forward drive to an unrecognized allostatic load that drives the addiction process.

Using Machine Learning to Classify Individuals With Alcohol Use Disorder Based on Treatment Seeking Status

OBJECTIVE

The authors used a decision tree classifier to reduce neuropsychological, behavioral and laboratory measures to a subset of measures that best predicted whether an individual with alcohol use disorder (AUD) seeks treatment.

METHOD

Clinical measures (N = 178) from 778 individuals with AUD were used to construct an alternating decision tree (ADT) with 10 measures that best classified individuals as treatment or not treatment-seeking for AUD. ADT's were validated by two methods: using cross-validation and an independent dataset (N = 236). For comparison, two other machine learning techniques were used as well as two linear models.

RESULTS

The 10 measures in the ADT classifier were drinking behavior, depression and drinking-related psychological problems, as well as substance dependence. With cross-validation, the ADT classified 86% of individuals correctly. The ADT classified 78% of the independent dataset correctly. Only the simple logistic model was similar in accuracy; however, this model needed more than twice as many measures as ADT to classify at comparable accuracy.

INTERPRETATION

While there has been emphasis on understanding differences between those with AUD and controls, it is also important to understand, within those with AUD, the features associated with clinically important outcomes. Since the majority of individuals with AUD do not receive treatment, it is important to understand the clinical features associated with treatment utilization; the ADT reported here correctly classified the majority of individuals with AUD with 10 clinically relevant measures, misclassifying < 7% of treatment seekers, while misclassifying 38% of non-treatment seekers. These individual clinically relevant measures can serve, potentially, as separate targets for treatment.

FUNDING

Funding for this work was provided by the Intramural Research Programs of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), National Institute on Drug Abuse (NIDA) and the Center for Information Technology (CIT).

RESEARCH IN CONTEXT

Evidence Before This Study: Less than 10% of persons who meet lifetime criteria for Alcohol Use Disorder (AUD) receive treatment. As the etiology of AUD represents a complex interaction between neurobiological, social, environmental and psychological factors, low treatment utilization likely stems from barriers on multiple levels. Given this issue, it is important from both a research and clinical standpoint to determine what characteristics are associated with treatment utilization in addition to merely asking individuals if they wish to enter treatment. At the level of clinical research, if there are phenotypic differences between treatment and nontreatment-seekers that directly influence outcomes of early-phase studies, these phenotypic differences are a potential confound in assessing the utility of an experimental treatment for AUD. At the level of clinical practice, distinguishing between treatment- and nontreatment-seekers may help facilitate a targeted treatment approach. Previous efforts to understand the differences between these populations of individuals with AUD leveraged the multidimensional data collected in clinical research settings for AUD that are not well suited to traditional regression methods.Added Value of This Study: Alternating decision trees are well suited to deep-phenotyping data collected in clinical research settings as this approach handles nonparametric, skewed, and missing data whose relationships are nonlinear. This approach has proved to be superior in some cases to conventional clinical methods to solve diagnostic problems in medicine. We used a decision tree classifier to understand treatment- and non-treatment seeking group differences. The decision tree classifier approach chose a subset of factors arranged in an alternating decision tree that best predicts a given outcome. Assuming that the input measures are clinically relevant, the alternating decision tree that is generated has clinical value. Unlike other machine learning approaches, in addition to its predictive value, the nodes in the tree and their arrangement in a hierarchy have clinical utility. With the "if-then" logic of the tree, the clinician can learn what features become important and which recede in importance as the logic of the tree is followed. The decision tree classifier approach reduced 178 characterization measures (both categorical and continuous) in multiple domains to a decision tree comprised of 10 measures that together best classified subjects by treatment seeking status (yes/no).Implications After All the Available Evidence: We leveraged a large data set comprised of 178 clinical measures and using the decision tree approach, we have reduced these to a subset of 10 measures that accurately classified individuals with alcohol dependence by treatment utilization. From this analysis, drinking behavior variables and depression measures are strong treatment seeking predictors. Having identified a cluster of factors that predicts treatment seeking, we can assess the influence of these factors directly on the clinical study outcome measures themselves. In clinical practice these factors can be separate targets for treatment. In clinical research, the group differences my directly influence research outcomes for treatment of AUD.

Impulsivity Derived From the Dark Side: Neurocircuits That Contribute to Negative Urgency

Negative urgency is a unique dimension of impulsivity that involves acting rashly when in extreme distress and impairments in inhibitory control. It has been hypothesized to derive from stress that is related to negative emotional states that are experienced during the withdrawal/negative affect stage of the addiction cycle. Classically, a transition to compulsive drug use prevents or relieves negative emotional states that result from abstinence or stressful environmental circumstances. Recent work suggests that this shift to the "dark side" is also implicated in impulsive use that derives from negative urgency. Stress and anxious, depressed, and irritable mood have high comorbidity with addiction. They may trigger bouts of drug seeking in humans via both negative reinforcement and negative urgency. The neurocircuitry that has been identified in the "dark side" of addiction involves key neuropeptides in the central extended amygdala, including corticotropin-releasing factor. The present review article summarizes empirical and conceptual advances in the field to understand the role of the "dark side" in driving the risky and detrimental substance use that is associated with negative urgency in addiction.

A Roadmap for Integrating Neuroscience Into Addiction Treatment: A Consensus of the Neuroscience Interest Group of the International Society of Addiction Medicine

Although there is general consensus that altered brain structure and function underpins addictive disorders, clinicians working in addiction treatment rarely incorporate neuroscience-informed approaches into their practice. We recently launched the Neuroscience Interest Group within the International Society of Addiction Medicine (ISAM-NIG) to promote initiatives to bridge this gap. This article summarizes the ISAM-NIG key priorities and strategies to achieve implementation of addiction neuroscience knowledge and tools for the assessment and treatment of substance use disorders. We cover two assessment areas: cognitive assessment and neuroimaging, and two interventional areas: cognitive training/remediation and neuromodulation, where we identify key challenges and proposed solutions. We reason that incorporating cognitive assessment into clinical settings requires the identification of constructs that predict meaningful clinical outcomes. Other requirements are the development of measures that are easily-administered, reliable, and ecologically-valid. Translation of neuroimaging techniques requires the development of diagnostic and prognostic biomarkers and testing the cost-effectiveness of these biomarkers in individualized prediction algorithms for relapse prevention and treatment selection. Integration of cognitive assessments with neuroimaging can provide multilevel targets including neural, cognitive, and behavioral outcomes for neuroscience-informed interventions. Application of neuroscience-informed interventions including cognitive training/remediation and neuromodulation requires clear pathways to design treatments based on multilevel targets, additional evidence from randomized trials and subsequent clinical implementation, including evaluation of cost-effectiveness. We propose to address these challenges by promoting international collaboration between researchers and clinicians, developing harmonized protocols and data management systems, and prioritizing multi-site research that focuses on improving clinical outcomes.