Delay Discounting, Treatment Motivation and Treatment Retention Among Substance-Dependent Individuals Attending an in Inpatient Detoxification Program

Gender disparities in neuropsychological assessment research in drug abuse populations: A systematic review

Objective: To systematically review the literature on the neurocognitive effects of drug use to determine if there are significant gender differences. Methods: In April 2023, we conducted a broad search in MEDLINE (via PubMed), PsycINFO, and Embase for original research studies that used objective neuropsychological assessment to evaluate neurocognition in persons with drug use. Data extraction was performed in a masked, duplicate fashion. Results: Our initial search returned 22,430 records, of which 273 articles were included in our analysis. We found significant underrepresentation of women as participants in the studies. Twenty-one percent of studies had exclusively male participants; when women were included, they averaged only 23% of the sample. Only 49 studies sufficiently documented an analysis of their results by gender; due to the heterogeneity in study characteristics, no conclusions about cognitive differences between women and men could be made. Conclusions: Women are significantly underrepresented in the research on cognition in drug use. Increased efforts to include more women participants and consistent analysis and reporting of data for potential gender differences will be required to close this gap in knowledge, which may lead to improved substance abuse treatment approaches for women.

The phenotype of recovery XI: associations of sleep quality and perceived stress with discounting and quality of life in substance use recovery

PURPOSE

Sleep and stress show an interdependent relationship in physiology, and both are known risk factors for relapse in substance use disorder (SUD) recovery. However, sleep and stress are often investigated independently in addiction research. In this exploratory study, the associations of sleep quality and perceived stress with delay discounting (DD), effort discounting (ED), and quality of life (QOL) were examined concomitantly to determine their role in addiction recovery. DD has been proposed as a prognostic indicator of SUD treatment response, ED is hypothesized to be relevant to the effort to overcome addiction, and QOL is an important component in addiction recovery.

METHOD

An online sample of 118 individuals recovering from SUDs was collected through the International Quit and Recovery Registry. Exhaustive model selection, using the Bayesian Information Criterion to determine the optimal multiple linear model, was conducted to identify variables (i.e., sleep quality, perceived stress, and demographics) contributing to the total variance in DD, ED, and QOL.

RESULTS

After model selection, sleep was found to be significantly associated with DD. Stress was found to be significantly associated with psychological health, social relationships, and environment QOL. Both sleep and stress were found to be significantly associated with physical health QOL. Neither sleep nor stress was supported as an explanatory variable of ED.

CONCLUSION

Together, these findings suggest sleep and stress contribute uniquely to the process of addiction recovery. Considering both factors when designing interventions and planning for future research is recommended.

Impulsivity Dimensions Predict Treatment Dropout Among Women in Residential Treatment for Substance Use Disorders

Residential treatment for substance use disorders (SUDs) is effective at reducing substance use, dependence, and other related problems. However, dropout from treatment against medical advice (AMA) is common in residential treatment settings. Studies have shown that impulsivity is associated with substance misuse and treatment dropout in predominately male samples, but less is known regarding whether impulsivity dimensions predict treatment dropout among women. This study examined impulsivity dimensions (ie, negative urgency, positive urgency, lack of perseverance, lack of premeditation, and sensation seeking) as predictors of dropout AMA among women in a residential substance use treatment facility (N = 229). Logistic regression results demonstrated that elevations in lack of perseverance and sensation seeking were associated with an increased odds of treatment dropout AMA and that lack of premeditation was associated with a decreased odds of treatment dropout AMA. Study findings suggest that early evidence-based interventions for sensation seeking and lack of perseverance may improve retention of women in residential treatment.

The hidden-zero effect in male individuals with opioid use disorder

Background: Explicitly expressing the hidden opportunity cost in intertemporal choice significantly reduces healthy participants' delay discounting - a phenomenon named the "hidden-zero effect," which is undetermined in individuals with substance use disorder (SUD).Objectives: This study aimed to determine whether the hidden-zero effect occurs among individuals with opioid use disorder (OUD) and the degree to which this effect differs between the OUD group and healthy controls.Methods: In two different experiments, Exp#1) 29 male individuals with OUD (13.5 ± 6.0 months abstinence) and 29 male controls performed an intertemporal choice task (ICT); Exp#2) 28 male individuals with OUD (17.5 ± 5.6 months abstinence) and 27 male controls performed a delay discounting task (DDT). The OUD group was recruited from a mandatory treatment, and controls from WeChat. There were two choice conditions in both two tasks: the hidden-zero (H0) condition (standard), and the explicit-zero (E0) condition (explicitly expressing opportunity cost).Results: Compared with the H0 condition, all participants' delay discounting was significantly decreased in the E0 condition (ps < .05, ηp2 = 0.254, 0.110). There was no significant difference in the changed degree between these two groups in either experiment (ps > .05). The delay discounting of the OUD group was significantly higher than that of controls only in Experiment 2 (p < .001, ηp2 = 0.376).Conclusion: This study extended the population in which the hidden-zero effect occurs to individuals with OUD. With respect to delay discounting, the hidden-zero effect benefit did not differ in OUD and control participants.

Rate-dependent effects of narrative interventions in a longitudinal study of individuals who use alcohol

BACKGROUND

Delay discounting (DD), the decrease in reward valuation as a function of delay to receipt, is a key process undergirding alcohol use. Narrative interventions, including episodic future thinking (EFT), have decreased delay discounting and demand for alcohol. Rate dependence, the relationship between a baseline rate and change in that rate after an intervention, has been evidenced as a marker of efficacious substance use treatment, but whether narrative interventions have rate-dependent effects needs to be better understood. We investigated the effects of narrative interventions on delay discounting and hypothetical demand for alcohol in this longitudinal, online study.

METHODS

Individuals (n = 696) reporting high- or low-risk alcohol use were recruited for a longitudinal 3-week survey via Amazon Mechanical Turk. Delay discounting and alcohol demand breakpoint were assessed at baseline. Individuals returned at weeks 2 and 3 and were randomized into the EFT or scarcity narrative interventions and again completed the delay discounting tasks and alcohol breakpoint task. Oldham's correlation was used to explore the rate-dependent effects of narrative interventions. Study attrition as a function of delay discounting was assessed.

RESULTS

Episodic future thinking significantly decreased, while scarcity significantly increased delay discounting relative to baseline. No effects of EFT or scarcity on the alcohol demand breakpoint were observed. Significant rate-dependent effects were observed for both narrative intervention types. Higher delay discounting rates were associated with a greater likelihood of attrition from the study.

CONCLUSION

The evidence of a rate-dependent effect of EFT on delay discounting rates offers a more nuanced, mechanistic understanding of this novel therapeutic intervention and can allow more precise treatment targeting by demonstrating who is likely to receive the most benefit from it.

A narrative review of outcome measures used in drug and alcohol inpatient withdrawal treatment research

ISSUES

Assessing drug and alcohol inpatient withdrawal treatment programs is important, as these represent a first step of treatment among people with alcohol and drug problems. However, there are many ways of measuring outcomes making it difficult for service providers to decide which domains and methods to use. This narrative review aims to clarify frequencies of the domains and methods used to assess withdrawal treatment outcomes.

APPROACH

We reviewed published studies that examined outcomes of inpatient drug and alcohol withdrawal treatment. The types of outcome measures used and the frequency of use were summarised.

KEY FINDINGS

The review showed that assessment of withdrawal treatment outcomes goes beyond traditional abstinence measures. Outcomes mainly focus on biological and psychological outcomes, with social outcomes rarely measured. Even within outcome domains (e.g., cravings), there were many assessment methods.

IMPLICATIONS

The review provides service providers with an outline of common outcome domains and measures. Given the importance of social functioning to recovery from alcohol and drug problems, greater emphasis on such measures is desirable. Future research could develop greater consensus on outcome measures for use in withdrawal management services to facilitate clarity around factors associated with treatment success.

CONCLUSION

Outcome assessment in withdrawal treatment goes beyond abstinence to include holistic measurement of biological, psychological and some social outcomes; but more work needs to be done to cohere the different assessment methods and broaden the scope to include social functioning.

Social vulnerability, COVID-19 impact, and decision making among adults in a low-resource community

Socially vulnerable individuals, including those with greater exposure to adversity and social instability, are at greater risk for a variety of negative outcomes following exposure to public health crises. One hypothesized mechanism linking social vulnerability to poor health outcomes is delay discounting, the behavioral tendency to select smaller immediately available rewards relative to larger delayed rewards. However, little research has examined the impact of real-world disease outbreaks, such as the COVID-19 pandemic, on the relation between social vulnerability and delay discounting. This study examined whether the severity of COVID-19 impact moderated the association between social vulnerability and delay discounting in a diverse sample of 72 human adults (Mage = 42.4; 69% Black; 87% female) drawn from two low-resource urban areas. Contrary to hypotheses, results indicated that exposure to more severe COVID-19 impacts did not affect decision making among individuals with higher levels of social vulnerability. Conversely, findings suggest that individuals with lower levels of social vulnerability who reported more significant impacts of COVID-19 evidenced a greater tendency to select larger, delayed rewards relative to individuals with greater social vulnerability. Findings suggest the recent pandemic may influence the relation between social vulnerability and behavioral processes underlying health decision-making.

Borderline Personality Disorder With Versus Without Alcohol Use Disorder: Comparing Impulsivity and Schema Modes

Substance use disorders (SUDs) and borderline personality disorder (BPD) are highly comorbid. In the present study, an attempt was made to understand the differences between BPD and BPD with comorbid SUD (BPD + alcohol use disorder [AUD]), by studying impulsivity and schema modes (i.e., maladaptive moment-to-moment emotional states and coping responses). BPD patients, BPD+AUD patients, and nonpatients (NP) were compared regarding behavioral impulsivity (motor impulsivity, risk taking, delay discounting), and schema modes. The two patient groups displayed greater delay discounting than the NP group. Further, BPD and BPD+AUD groups were different from the NP group regarding all schema modes investigated. However, no differences were found on any of the dependent variables between the two patient groups. It is suggested that although BPD patients are in general more impulsive and have more maladaptive moment-to-moment emotional states and coping responses, BPD patients with and without AUD seem not to be different in this respect.

Predictors of and reasons for early discharge from inpatient withdrawal management settings: A scoping review

ISSUES

Early discharges, also known as 'against medical advice' discharges, frequently occur in inpatient withdrawal management settings and can result in negative outcomes for patients. The purpose of this scoping review is to identify what is known about predictors of and reasons for the early discharge among adults accessing inpatient withdrawal management settings.

APPROACH

MEDLINE, CINAHL, PsycINFO, ASSIA and EMBASE were searched, resulting in 2587 articles for screening. Title and abstract screening and full-text review were completed by two independent reviewers. Results were synthesised in quantitative and qualitative formats.

KEY FINDINGS

Sixty-two studies were included in this scoping review. All studies focused on predictors of early discharge, except one which only described reasons for the early discharge. Forty-eight percent of studies involved retrospective review of health records data. The most frequently examined variables were demographics. Variables related to the treatment setting, such as referral source and treatment received, were examined less frequently but were more consistently associated with early discharge compared to demographics. Only six studies described patient reasons for the early discharge, which were retrieved via clinical documentation. The most common reasons for early discharge were dissatisfaction with treatment and family issues.

IMPLICATIONS AND CONCLUSIONS

Most demographic variables do not consistently predict early discharge, and reasons for early discharge are not well understood. Future studies should focus on the predictive value of non-patient-level variables, or conduct analyses to account for predictors of early discharge among different subgroups of people (e.g. by gender or ethnicity). Qualitative research exploring patient perspectives is needed.

Reward-related decision-making deficits in internet gaming disorder: a systematic review and meta-analysis

AIMS

To estimate the aggregated effect sizes of reward-related decision-making deficits in internet gaming disorder (IGD) and to explore potential moderators on the variability of effect sizes across studies.

DESIGN

Review of peer-reviewed studies comparing reward-related decision-making performance between IGD and control participants identified via PubMed, Web of Science and ProQuest databases. Random-effects modeling was conducted using Hedge's g as the effect size (ES). The effects of decision-making situation, valence, sample type, testing environment, IGD severity and self-reported impulsivity on decision-making differences were examined by moderator analyses.

SETTING

No restrictions on location.

PARTICIPANTS

Twenty-four studies (20 independent samples) were included in the meta-analysis, resulting in 604 IGD and 641 control participants and 35 ESs.

MEASURES

Reward-related decision-making differences between IGD and control groups.

FINDINGS

The overall ES for decision-making deficits in IGD was small (g = -0.45, P < 0.01). The effects were comparable across risky, ambiguous and inter-temporal decision-making. Larger aggregate ESs were identified for pure-gain and mixed compared with pure-loss decision-making. Studies based on clinical and community samples showed similar effects. No significant difference between behavioral studies and those with extra measurements was observed. Decision-making alterations were not closely associated with IGD severity or self-reported impulsivity differences at the study level.

CONCLUSIONS

Internet gaming disorder appears to be consistently associated with reward-related decision-making deficits.

Delayed Reward Discounting as a Prognostic Factor for Smoking Cessation Treatment Outcome: A Systematic Review

INTRODUCTION

While large proportions of smokers attempt to quit, rates of relapse remain high and identification of valid prognostic markers is of high priority. Delayed reward discounting (DRD) is a behavioral economic index of impulsivity that has been associated with smoking cessation, albeit inconsistently. This systematic review sought to synthesize the empirical findings on DRD as a predictor of smoking cessation treatment outcome, to critically appraise the quality of the literature, and to propose directions for future research.

AIMS AND METHODS

A total of 734 articles were identified, yielding k = 14 studies that met the eligibility criteria. The Quality in Prognosis Studies (QUIPS) tool was used to assess methodological quality of the included studies.

RESULTS

Individual study methods were highly heterogeneous, including substantial variation in research design, DRD task, clinical subpopulation, and treatment format. The predominant finding was that steeper DRD (higher impulsivity) was associated with significantly worse smoking cessation outcomes (10/14 studies). Negative results tended to be in pregnant and adolescent subpopulations. The QUIPS results suggested low risk of bias across studies; 11/14 studies were rated as low risk of bias for 5/6 QUIPS domains.

CONCLUSIONS

This review revealed consistent low-bias evidence for impulsive DRD as a negative prognostic predictor of smoking cessation treatment outcome in adults. However, methodological heterogeneity was high, precluding meta-analysis and formal tests of small study bias. The prospects of targeting impulsive DRD as a potentially modifiable risk factor or providing targeted treatment for smokers exhibiting high levels of discounting are discussed.

IMPLICATIONS

These findings indicate consistent evidence for DRD as a negative prognostic factor for smoking cessation outcome in adults. As such, DRD may be a useful as a novel treatment target or for identifying high-risk populations requiring more intensive treatment.

Perceived appropriateness of medication adherence incentives

BACKGROUND: 50% of prescriptions dispensed in the United States are not taken as prescribed, leading to approximately 125,000 deaths and 10% of hospitalizations per year. Incentives are effective in improving medication adherence; however, information about patient perceptions regarding incentives is lacking. OBJECTIVES: To (1) explore perceived appropriateness of incentives among patients prescribed at least 1 medication for chronic hypertension, hyperlipidemia, heart disease, diabetes, and/or asthma/chronic obstructive pulmonary disease and (2) examine associations between perceived appropriateness and patient characteristics. METHODS: A cross-sectional online survey was administered via Qualtrics Panels to US adults taking at least 1 prescription medication for a chronic condition. The results describe patient preference for financial or social recognition-based incentive, perceived appropriateness of adherence incentives (5-point Likert scale), self-reported adherence (Medometer), and demographics. Analyses included descriptive statistics with chi-square and independent t-tests comparing characteristics between participants who perceived incentives as being appropriate or inappropriate and logistic regression to determine predictors of perceived appropriateness. RESULTS: 1,009 individuals completed the survey. Of the 1,009 total survey participants, 933 (92.5%) preferred to receive a financial (eg, cash, gift card, or voucher) rather than a social recognition-based incentive (eg, encouraging messages, feedback, individual recognition, or team competition) for medication adherence. 740 participants (73%) perceived medication adherence incentives as being appropriate or acceptable as a reward given for taking medications at the right time each day, whereas 95 (9%) perceived incentives as being inappropriate. Remaining participants were neutral. Hispanic ethnicity (OR = 0.57; 95% CI = 0.37-0.89); income under $75,000 (OR = 0.48; 95% CI = 0.28-0.84); no college degree (OR = 0.60; 95% CI = 0.37-0.96); and adherence (OR = 0.99; 95% CI = 0.98-0.99) were significant predictors. CONCLUSIONS: The majority of patients perceived incentives as appropriate and preferred financial incentives over social recognition-based incentives. Perceived appropriateness for medication adherence incentives was less likely among certain groups of patients, such as those with Hispanic ethnicity, lower annual income, no college degree, and higher levels of adherence. These characteristics should be taken into account when structuring incentives. DISCLOSURES: This study was funded by the Auburn University's Intramural Grants Program. Hansen, Qian, and Garza are affiliated with Auburn University. Hansen has provided expert testimony for Daiichi Sankyo and Takeda on unrelated matters. The other authors have no potential conflicts of interest to declare. This study was presented as a poster presentation at the American Association of Colleges of Pharmacy Annual Meeting held July 2018 in Boston, MA.

Patient preferences for medication adherence financial incentive structures: A discrete choice experiment

BACKGROUND

Medication adherence for chronic conditions continues to be a challenge for patients. Patient incentives for medication adherence may help. Financial incentives delivered at the point of care may act as cues for medication-taking behavior.

OBJECTIVES

The purpose of this study was to investigate patient preferences for specific structures of financial medication adherence incentives that could feasibly be delivered at the point of care.

METHODS

A discrete choice experiment (DCE) was performed using a national online survey. Study participants were adults who self-reported taking at least one prescription medication for one or more chronic conditions. Following an orthogonal design generated in SAS, the DCE included 32 paired-choice tasks. Data were analyzed using mixed logit models and stratified on participants' income level.

RESULTS

In the full cohort (n = 933), form of financial reward (such as gift-card or cash) was 1.02 times as important to participants as the probability of incentive receipt, 1.58 times as important as monetary value, and 1.93 times as important as timing of receipt. Participants were willing to give up $31.04 of an incentive's monetary value (95% CI = $27.11-$34.98) to receive the incentive 5 months sooner (1-month vs. 6-month time-lag); $60.79 (95% CI = $53.19-$68.39) for probability of receipt to increase from a 1 out of 100 chance to a 1 out of 20 chance; and $10.52 (95% CI = $6.46-$14.58) to receive an incentive in the form of a Visa® gift-card instead of grocery store voucher. These patterns of trade-offs between attributes were generally consistent among participants with lower and higher income.

CONCLUSIONS

Regardless of socioeconomic status, patient preferences for financial medication adherence incentives delivered at the point of care may be most heavily influenced by incentive form and probability of receipt. This has implications for designing medication adherence programs in terms of incentive sustainability, patient engagement, plan star ratings, and patient outcomes.

Envisioning a future: Values clarification in early recovery from opioid use disorder

High rates of relapse and overdose during early recovery from opioid use disorder (OUD) highlight the importance of providing effective treatment during this crucial phase. While early treatment often focuses on managing urges and withdrawal symptoms, eliciting personally salient motivators may help to target predictors of treatment outcomes such as motivation and self-efficacy. This experimental study examined the effect of a brief values clarification exercise on motivation and self-efficacy for abstinence in a sample of n = 93 individuals in brief residential treatment for OUD. Participants were randomly assigned to values clarification or a time management control condition exercise. Self-efficacy for abstinence as measured by a validated single-item measure was higher for participants in the values condition (M = 8.7) compared to control (M = 7.8, p = .013), while motivation for abstinence as measured by the commitment to sobriety scale was similarly high for both the values clarification (M = 28.0) and control (M = 27.8, p = .642) groups. There were no group differences in delay discounting, the theorized mediator of these relationships. Taken together, these results suggest that even a brief values clarification exercise may increase self-efficacy for abstinence when added to early residential treatment for OUD.

Cognitive deficits in methamphetamine addiction: Independent contributions of dependence and intelligence

BACKGROUND

Methamphetamine's effects on brain function have been associated with cognitive deficits, which have a negative impact on clinical outcomes. However, it remains unclear if cognitive deficits relate to methamphetamine dependence (potentially amenable to abstinence and retraining) or background characteristics, mental health and other drug use. We tested the association between methamphetamine dependence and cognitive performance, while factoring in the impact of background characteristics, depressive symptoms and tobacco, alcohol and cannabis use.

METHOD

The sample comprised 108 treatment-seeking participants who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV TR) criteria for methamphetamine dependence and 50 socio-demographically matched controls. We administered a comprehensive neuropsychological test battery (delay discounting, decision making, disinhibition, episodic and working memory) and examined cognitive deficits in methamphetamine users after taking into account socio-demographic characteristics, tobacco, alcohol and cannabis use, and depressive symptoms.

RESULTS

Hierarchical multiple regression analyses showed that methamphetamine dependence was associated with poorer performance in decision-making and disinhibition over and above other predictors, while IQ better explained performance in episodic and working memory. Although duration of methamphetamine use was linked to disinhibition, other patterns of methamphetamine use (including dose and frequency) were not consistently related to performance.

CONCLUSIONS

Methamphetamine dependence impacts inhibitory control and decision-making, whereas lower IQ associates with memory/working memory deficits among methamphetamine users. Findings suggest the need to target disinhibition and impulsive decision-making as part of methamphetamine dependence treatment, while buffering the impact of IQ on memory systems.

Denial of Alcohol Treatment Need among Baby Boomers across Time: Implications for Social Work

As baby boomers continue to enter older adulthood in the coming decades, research suggests that this cohort is expected to exhibit changes in alcohol usage and treatment need patterns compared to previous older-adult cohorts. The literature suggests that unmet alcohol treatment need may be related to denial of treatment need among baby boomers who possess a diagnosable alcohol-use disorder (AUD). Therefore, this study explores potential risk and protective factors predicting alcohol-use among baby boomers who d\eny treatment need at two time periods. Data was obtained from the National Survey of Drug and Health (NSDUH). Variable selection procedures were performed at each time period, resulting in two predictive models for baby boomers who denied alcohol treatment need when treatment was indicated by a concurrent diagnosable alcohol-use disorder. The primary findings suggest that generalized, nonspecific alcohol treatment may be ineffective for treating AUD baby boomers who deny alcohol treatment need. Rather, as baby boomers continue to enter older adulthood, individualized specialty treatments may be needed in order to provide effective alcohol treatment for this unprecedentedly large birth cohort.

The Role of Impulsivity Facets on the Incidence and Development of Alcohol Use Disorders

Alcohol Use Disorder (AUD) is a chronic relapsing disorder defined according to the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5; American Psychiatric Association 2013), "by a cluster of behavioural and physical symptoms, which can include, withdrawal, tolerance and craving". Social, emotional, behavioural and cognitive factors are important contributors to AUD. Impulsivity, a multifaceted behavioural concept, defined as a predisposition for rapid and unplanned actions, without considering potential negative consequences of these actions, represents an important such factor. In this chapter, research on the role of distinct impulsivity dimensions in different severity stages of alcohol use is presented.Increased self-reported (trait) impulsivity and an inability to wait, as well as difficulty to adjust behaviour appropriately following a failure to withhold a response are observed across the spectrum of alcohol-use severities. Research on temporal impulsivity (inability to delay gratification) consistently shows deficits in more severe alcohol users. Data on temporal impulsivity in early stages of alcohol use are less consistent, with some studies showing no differences between high and moderate drinkers, while others indicating increased impulsivity in high alcohol users. Data on reflexion impulsivity are currently limited to draw conclusions. Recent research is also presented suggesting the importance of perception and interpretation of physiological and emotional signals on alcohol use behaviour highlighting the necessity of comprehensive integration of the field of the study of emotion and interoception with impulsivity research.

Neural correlates of reward magnitude and delay during a probabilistic delay discounting task in alcohol use disorder

RATIONALE

Alcohol-use disorder (AUD) is associated with the propensity to choose smaller sooner options on the delay discounting task. It is unclear, however, how inherent risk underlies delay discounting behavior. As impulsive choice is a hallmark feature in AUD, it is important to understand the neural response to reward and delay while accounting for risk in impulsive decision-making.

OBJECTIVE

This study examined activation associated with delay and reward magnitude, while controlling for risk in a probabilistic delay discounting task in AUD and examined if differences in activation were associated with treatment outcomes.

METHODS

Thirty-nine recently abstinent alcohol-dependent volunteers and 46 controls completed a probabilistic delay discounting task paired with functional magnetic resonance imaging. Alcohol use was collected using a self-report journal for 3 months following baseline scan.

RESULTS

During delay stimulus presentations, Controls exhibited greater activation compared to the Alcohol group notably in the anterior insula, middle/dorsal anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (PFC), and inferior parietal lobule. For magnitude, the Alcohol group exhibited greater activation than Controls primarily in medial PFC, rostral ACC, left posterior parietal cortex, and right precuneus. Within the Alcohol group, alcohol craving severity negatively correlated with right lateral PFC activation during reward magnitude in individuals who completed the 3-month study without relapse, while non-completers showed the opposite relationship.

CONCLUSIONS

The results of this study extend previous findings that alcohol use disorder is associated with differences in activation during an immediate or delayed choice by delineating activation associated with the parameters of impulsive choice.

The myeloarchitecture of impulsivity: premature responding in youth is associated with decreased myelination of ventral putamen

Impulsivity has been suggested as a neurocognitive endophenotype conferring risk across a number of neuropsychiatric conditions, including substance and behavioural addictions, eating disorders, and attention deficit/hyperactivity disorder. We used a paradigm with interspecies translation validity (the four-choice serial reaction time task, 4CSRTT) to assess 'waiting' impulsivity in a youth sample (N = 99, aged 16-26 years). We collected magnetization prepared two rapid acquisition gradient echo (MP2RAGE) scans, which enabled us to measure R1, the longitudinal relaxation rate, a parameter closely related to tissue myelin content, as well as quantify grey matter volume. We also assessed inhibitory control (commission errors) on a Go/NoGo task and measured decisional impulsivity (delay discounting) using the Monetary Choice Questionnaire (MCQ). We found R1 of the bilateral ventral putamen was negatively correlated with premature responding, the index of waiting impulsivity on the 4CSRTT. Heightened impulsivity in youth was significantly and specifically associated with lower levels of myelination in the ventral putamen. Impulsivity was not associated with grey matter volume. The association with myelination was specific to waiting impulsivity: R1 was not associated with decisional impulsivity on the MCQ or inhibitory control on the Go/NoGo task. We report that heightened waiting impulsivity, measured as premature responding on the 4CSRTT, is specifically associated with lower levels of ventral putaminal myelination, measured using R1. This may represent a neural signature of vulnerability to diseases associated with excessive impulsivity and demonstrates the added explanatory power of quantifying the mesoscopic organization of the human brain, over and above macroscopic volumetric measurements.

Working memory predicts methamphetamine hair concentration over the course of treatment: moderating effect of impulsivity and implications for dual-systems model

High impulsivity and poor executive function are characteristic of methamphetamine use disorder. High arousal in the impulsive system has been proposed to compromise the executive system's regulating ability (i.e. the dual-systems model). While interaction between these variables may partly explain poor treatment outcomes associated with methamphetamine use disorder, previous research has tended to examine each factor separately. We investigated whether high impulsivity (measured with an impulsive choice task) and poor executive function (measured with a working memory task) predict methamphetamine use (determined by hair sample) in the 6 weeks following treatment commencement. We also investigated whether impulsive choice moderates the relationship between working memory and methamphetamine use. One hundred and eight individuals with methamphetamine use disorder (75 percent male) were tested within 3 weeks of commencing treatment; 80 (74 percent) were followed up 6 weeks following baseline testing. Cognitive measures significantly predicted drug use after controlling for nuisance variables. Working memory was a significant predictor, while impulsive choice was not. The interaction model included working memory as a predictor and impulsive choice as a moderator. This model was significant, as was the interaction term. Working memory significantly predicted levels of methamphetamine use in early treatment, and impulsive choice moderated this relationship. Those with working memory deficits are particularly vulnerable to using greater amounts of methamphetamine. As working memory increased methamphetamine use decreased among individuals with low/medium delay discounting. Pre-treatment cognitive testing may identify patients at high risk, while remediation of working memory function may be a treatment target for reducing methamphetamine use.

Brain and Cognition for Addiction Medicine: From Prevention to Recovery Neural Substrates for Treatment of Psychostimulant-Induced Cognitive Deficits

Addiction to psychostimulants like cocaine, methamphetamine, and nicotine poses a continuing medical and social challenge both in the United States and all over the world. Despite a desire to quit drug use, return to drug use after a period of abstinence is a common problem among individuals dependent on psychostimulants. Recovery for psychostimulant drug-dependent individuals is particularly challenging because psychostimulant drugs induce significant changes in brain regions associated with cognitive functions leading to cognitive deficits. These cognitive deficits include impairments in learning/memory, poor decision making, and impaired control of behavioral output. Importantly, these drug-induced cognitive deficits often impact adherence to addiction treatment programs and predispose abstinent addicts to drug use relapse. Additionally, these cognitive deficits impact effective social and professional rehabilitation of abstinent addicts. The goal of this paper is to review neural substrates based on animal studies that could be pharmacologically targeted to reverse psychostimulant-induced cognitive deficits such as impulsivity and impairment in learning and memory. Further, the review will discuss neural substrates that could be used to facilitate extinction learning and thus reduce emotional and behavioral responses to drug-associated cues. Moreover, the review will discuss some non-pharmacological approaches that could be used either alone or in combination with pharmacological compounds to treat the above-mentioned cognitive deficits. Psychostimulant addiction treatment, which includes treatment for cognitive deficits, will help promote abstinence and allow for better rehabilitation and integration of abstinent individuals into society.

Self-awareness deficits associated with lower treatment motivation in cocaine addiction

BACKGROUND

Individuals with cocaine use disorder (CUD) often display behaviours that are paradoxically misaligned with their situation. Typical examples include poor treatment motivation and inconsistent self-reported craving. These behaviours may reflect impairments in the awareness of one's own behaviour.

OBJECTIVES

We examined whether impaired self-awareness of addiction-related frontostriatal dysfunction (i.e., symptoms of apathy, disinhibition, and executive dysfunction) was associated with treatment motivation and craving.

METHODS

Sixty-five outpatients with CUD (57 male) and their informants (those who knew the patient well) completed parallel self and informant versions of the Frontal Systems Behaviour Scale. Self-awareness was indexed through the discrepancy between self and informant scores in the three sub-scales; apathy, disinhibition and executive dysfunction. The University Rhode Island Change Assessment Scale assessed treatment motivation. Self-reported craving was assessed using a visual analogue scale. Multiple linear regression models examined associations between self-awareness and treatment motivation and craving, adjusting for sociodemographic factors and lifetime drug use.

RESULTS

We found an inverse relationship between self-awareness of symptoms of disinhibition and treatment motivation maintenance. Although impaired awareness of disinhibition was also correlated with craving, this association was not significant after adjusting for sociodemographic factors and drug use. The apathy and executive dysfunction awareness scores were not associated with treatment motivation or craving.

CONCLUSION

We show that people with lower insight into their disinhibition problems (e.g., impulsivity, mood instability) have more problems maintaining motivation when initiating treatment. Findings suggest that self-awareness interventions could be useful to prevent premature treatment dropout and improve addiction treatment outcomes.

A review of contingency management for the treatment of substance-use disorders: adaptation for underserved populations, use of experimental technologies, and personalized optimization strategies

This review of contingency management (CM; the behavior-modification method of providing reinforcement in exchange for objective evidence of a desired behavior) for the treatment of substance-use disorders (SUDs) begins by describing the origins of CM and how it has come to be most commonly used during the treatment of SUDs. Our core objective is to review, describe, and discuss three ongoing critical advancements in CM. We review key emerging areas wherein CM will likely have an impact. In total, we qualitatively reviewed 31 studies in a systematic fashion after searching PubMed and Google Scholar. We then describe and highlight CM investigations across three broad themes: adapting CM for underserved populations, CM with experimental technologies, and optimizing CM for personalized interventions. Technological innovations that allow for mobile delivery of reinforcers in exchange for objective evidence of a desired behavior will likely expand the possible applications of CM throughout the SUD-treatment domain and into therapeutically related areas (eg, serious mental illness). When this mobile technology is coupled with new, easy-to-utilize biomarkers, the adaptation for individual goal setting and delivery of CM-based SUD treatment in hard-to-reach places (eg, rural locations) can have a sustained impact on communities most affected by these disorders. In conclusion, there is still much to be done, not only technologically but also in convincing policy makers to adopt this well-established, cost-effective, and evidence-based method of behavior modification.

Attention and memory deficits in crack-cocaine users persist over four weeks of abstinence

BACKGROUND

Crack-cocaine addiction is an important public health problem worldwide. Although there is not a consensus, preliminary evidence has suggested that cognitive impairments in patients with crack-cocaine dependence persist during abstinence, affecting different neuropsychological domains. However, few studies have prospectively evaluated those deficits in different phases of abstinence.

OBJECTIVES

The main aim of present study was to examine neuropsychological performance of patients with crack-cocaine dependence during early abstinence and after four weeks, comparing with matched controls.

METHODS

Thirty-five males with crack-cocaine dependence, aged 18 to 50years, who met DSM-IV criteria for cocaine dependence and a control group of 33 healthy men were enrolled. They were assessed through Block Design, Digit Span and Vocabulary of Wechsler Adult Intelligence Scale (WAIS-III), the Rey Auditory Learning Test (RAVLT) and the Verbal Fluency (FAS) between 3 and 10days (mean of 6.1±2.0days) and after 4weeks of abstinence.

RESULTS

Compared to controls, the crack-cocaine dependent group exhibited deficits in cognitive performance affecting attention, verbal memory and learning tasks in early withdrawal. Most of the cognitive deficits persisted after four weeks of abstinence.

CONCLUSION

Present results observed that the group of patients with crack-cocaine dependence presented persistent deficits affecting memory and attention even after four weeks of abstinence, confirming previous studies that had disclosed such cognitive impairments.

Dropout in clinical trials of pharmacological treatment for methamphetamine dependence: the role of initial abstinence

BACKGROUND AND AIMS

High rates of loss to follow-up represent a significant challenge to clinical trials of pharmacological treatments for methamphetamine (MA) use disorder. We aimed to estimate and test the relationship between achieving and maintaining abstinence in the initial weeks of study participation and subsequent retention in such trials, hypothesizing that participants able to achieve early abstinence would be less likely to drop out.

DESIGN

Data from four randomized controlled trials (RCTs) of pharmacological treatments for MA use disorder were pooled and analyzed using a random-effects approach.

SETTING

All trials were conducted in the greater Los Angeles, CA, USA area.

PARTICIPANTS

A total of 440 participants were included; trials were conducted between 2004 and 2014.

MEASUREMENTS

Participants' ability to achieve a brief period of initial abstinence was measured as the number of MA-negative urine screens completed in the first 2 weeks of the trials. Outcomes were the likelihood of dropout, i.e. missing two consecutive weeks of scheduled urine drug screens, and the number of days participants were retained in the trials.

FINDINGS

Study participants achieved an average of three (of six possible) negative urine screens during the first 2 weeks of the trials, 51% dropped out and the average number of days retained was 60 (of 90 maximum). Each additional negative urine screen achieved during the first 2 weeks of the study reduced multiplicatively the odds of dropout by 41% [odds ratio (OR) = 0.59, 95% confidence interval (CI) = 0.53, 0.66]. Abstinence was also a significant predictor of retention time; the hazard ratio for non-completion was 0.75 per additional negative urine screen (95% CI = 0.71, 0.80).

CONCLUSIONS

Participants in randomized controlled trials of pharmacological treatments for methamphetamine use disorder who are able to achieve a brief period of early abstinence are retained longer in the trials and are less likely to drop out overall.

Predictors of induction onto extended-release naltrexone among unemployed heroin-dependent adults

BACKGROUND AND AIM

Extended-release naltrexone (XR-NTX) blocks the effects of opioids for 4weeks; however, starting treatment can be challenging because it requires 7 to 10days of abstinence from all opioids. In the present study we identified patient and treatment characteristics that were associated with successful induction onto XR-NTX.

METHODS

144 unemployed heroin-dependent adults who had recently undergone opioid detoxification completed self-report measures and behavioral tasks before starting an outpatient XR-NTX induction procedure. Employment-based reinforcement was used to promote opioid abstinence and adherence to oral naltrexone during the induction. Participants were invited to attend a therapeutic workplace where they earned wages for completing jobs skills training. Participants who had used opioids recently were initially invited to attend the workplace for a 7-day washout period. Then those participants were required to provide opioid-negative urine samples and then take scheduled doses of oral naltrexone to work and earn wages. Participants who had not recently used opioids could begin oral naltrexone immediately. After stabilization on oral naltrexone, participants were eligible to receive XR-NTX and were randomized into one of four treatment groups, two of which were offered XR-NTX. Binary and multiple logistic regressions were used to identify characteristics at intake that were associated with successfully completing the XR-NTX induction.

RESULTS

58.3% of participants completed the XR-NTX induction. Those who could begin oral naltrexone immediately were more likely to complete the induction than those who could not (79.5% vs. 25.0%). Of 15 characteristics, 2 were independently associated with XR-NTX induction success: legal status and recent opioid detoxification type. Participants who were not on parole or probation (vs. on parole or probation) were more likely to complete the induction (OR [95% CI]=2.5 [1.1-5.7], p=0.034), as were those who had come from a longer-term detoxification program (≥21days) (vs. a shorter-term [<21days]) (OR [95% CI]=7.0 [3.0-16.6], p<0.001).

CONCLUSIONS

Our analyses suggest that individuals recently leaving longer-term opioid detoxification programs are more likely to complete XR-NTX induction. Individuals on parole or probation are less likely to complete XR-NTX induction and may need additional supports or modifications to induction procedures to be successful.

Addiction Vulnerability and Binge Eating in Women: Exploring Reward Sensitivity, Affect Regulation, Impulsivity & Weight/Shape Concerns

Almost 40% of individuals with eating disorders have a comorbid addiction. The current study examined weight/shape concerns as a potential moderator of the relation between the hypothesized latent factor "addiction vulnerability" (i.e., impairments in reward sensitivity, affect regulation and impulsivity) and binge eating. Undergraduate women (n=272) with either high or low weight/shape concerns completed self-report measures examining reward sensitivity, emotion regulation, impulsivity and disordered (binge) eating. Results showed that (1) reward sensitivity, affect regulation and impulsivity all loaded onto a latent "addiction vulnerability" factor for both women with high and with low weight/shape concerns, (2) women with higher weight/shape concerns reported more impairment in these areas, and (3) weight/shape concerns moderated the relation between addiction vulnerability and binge eating. These findings suggest that underlying processes identified in addiction are present in individuals who binge eat, though weight/shape concerns may be a unique characteristic of disordered eating.

Machine-learning identifies substance-specific behavioral markers for opiate and stimulant dependence

BACKGROUND

Recent animal and human studies reveal distinct cognitive and neurobiological differences between opiate and stimulant addictions; however, our understanding of the common and specific effects of these two classes of drugs remains limited due to the high rates of polysubstance-dependence among drug users.

METHODS

The goal of the current study was to identify multivariate substance-specific markers classifying heroin dependence (HD) and amphetamine dependence (AD), by using machine-learning approaches. Participants included 39 amphetamine mono-dependent, 44 heroin mono-dependent, 58 polysubstance dependent, and 81 non-substance dependent individuals. The majority of substance dependent participants were in protracted abstinence. We used demographic, personality (trait impulsivity, trait psychopathy, aggression, sensation seeking), psychiatric (attention deficit hyperactivity disorder, conduct disorder, antisocial personality disorder, psychopathy, anxiety, depression), and neurocognitive impulsivity measures (Delay Discounting, Go/No-Go, Stop Signal, Immediate Memory, Balloon Analogue Risk, Cambridge Gambling, and Iowa Gambling tasks) as predictors in a machine-learning algorithm.

RESULTS

The machine-learning approach revealed substance-specific multivariate profiles that classified HD and AD in new samples with high degree of accuracy. Out of 54 predictors, psychopathy was the only classifier common to both types of addiction. Important dissociations emerged between factors classifying HD and AD, which often showed opposite patterns among individuals with HD and AD.

CONCLUSIONS

These results suggest that different mechanisms may underlie HD and AD, challenging the unitary account of drug addiction. This line of work may shed light on the development of standardized and cost-efficient clinical diagnostic tests and facilitate the development of individualized prevention and intervention programs for HD and AD.

Cocaine-specific neuroplasticity in the ventral striatum network is linked to delay discounting and drug relapse

AIMS

To contrast functional connectivity on ventral and dorsal striatum networks in cocaine dependence relative to pathological gambling, via a resting-state functional connectivity approach; and to determine the association between cocaine dependence-related neuroadaptations indexed by functional connectivity and impulsivity, compulsivity and drug relapse.

DESIGN

Cross-sectional study of 20 individuals with cocaine dependence (CD), 19 individuals with pathological gambling (PG) and 21 healthy controls (HC), and a prospective cohort study of 20 CD followed-up for 12 weeks to measure drug relapse.

SETTING AND PARTICIPANTS

CD and PG were recruited through consecutive admissions to a public clinic specialized in substance addiction treatment (Centro Provincial de Drogodependencias) and a public clinic specialized in gambling treatment (AGRAJER), respectively; HC were recruited through community advertisement in the same area in Granada (Spain).

MEASUREMENTS

Seed-based functional connectivity in the ventral striatum (ventral caudate and ventral putamen) and dorsal striatum (dorsal caudate and dorsal putamen), the Kirby delay-discounting questionnaire, the reversal-learning task and a dichotomous measure of cocaine relapse indicated with self-report and urine tests.

FINDINGS

CD relative to PG exhibit enhanced connectivity between the ventral caudate seed and subgenual anterior cingulate cortex, the ventral putamen seed and dorsomedial pre-frontal cortex and the dorsal putamen seed and insula (P≤0.001, kE=108). Connectivity between the ventral caudate seed and subgenual anterior cingulate cortex is associated with steeper delay discounting (P≤0.001, kE=108) and cocaine relapse (P≤0.005, kE=34).

CONCLUSIONS

Cocaine dependence-related neuroadaptations in the ventral striatum of the brain network are associated with increased impulsivity and higher rate of cocaine relapse.