Cocaine craving and use during daily life

Trend-analysis reveals real and placebo rtms effects on addiction craving: a case-control observational study

Background and aims

Repetitive transcranial magnetic stimulation (rTMS) can be a potential therapeutic tool for the treatment of addiction, thanks to its ability to non-invasively modulate cortical excitability. In the present study, we investigated the short- and the long-term rTMS effects on craving behaviour and psychopathological symptoms in a sample of individuals suffering from gambling and cocaine use disorder.

Methods

42 individuals (age: 40.7 ± 9.5 years; 40 M) underwent an initial screening testing craving behaviour, by means of visual analogue scales, and psychopathological symptoms, by means of Symptom Checklist-90-R. Participants were subsequently assigned to a real or sham (placebo) rTMS treatment of 2 weeks delivered over the left dorso-lateral prefrontal cortex. To assess the short- and long-term effects of rTMS, participants were evaluated again after 1, 2, 4, 8, 12, 16, 20 and 24 weeks.

Results

After an initial similar trend in the craving behaviour of the two groups, our trend analysis showed a long-lasting decrease (until 24 weeks) in the real-rTMS group, following a linear trend (p<0.001); whereas the sham-rTMS group progressively returned to the initial level after about 12 weeks, following a quadratic trend (p<0.001). In addition, we observed moderate-to-strong correlations (0.4

Conclusions

Our results supported a long-term rTMS efficacy for cocaine and gambling craving, for which evidence was still lacking, and the correlation of short-lasting placebo effects and psychopathological symptoms.

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Key Words

• DLPFC
• addiction
• cocaine
• craving
• gambling
• mixed models
• rTMS
• trend analysis

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MESH Headings Collapse

Grants

• Ministero dell'Università e della Ricerca

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Affiliation(s)

Elias Paolo Casula Department of System Medicine, University of Tor Vergata, Rome, Italy
Francesca Chieco Servizio Dipendenze (SER.D.), Local Public Care Services (ULSS 6), Padua, Italy
Magdalini Maria Papaioannou Servizio Dipendenze (SER.D.), Local Public Care Services (ULSS 6), Padua, Italy
Fabio Frizzarin Servizio Dipendenze (SER.D.), Local Public Care Services (ULSS 6), Padua, Italy
Lorenzo Rocchi Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
Arianna Camporese Servizio Dipendenze (SER.D.), Local Public Care Services (ULSS 6), Padua, Italy

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Network state dynamics underpin basal craving in a transdiagnostic population

Emerging fMRI methods quantifying brain dynamics present an opportunity to capture how fluctuations in brain responses give rise to individual variations in affective and motivation states. Although the experience and regulation of affective states affect psychopathology, their underlying time-varying brain responses remain unclear. Here, we present a novel framework to identify network states matched to an affective experience and examine how the dynamic engagement of these network states contributes to this experience. We apply this framework to investigate network state dynamics underlying basal craving, an affective experience with important clinical implications. In a transdiagnostic sample of healthy controls and individuals diagnosed with or at risk for craving-related disorders (total N = 252), we utilized connectome-based predictive modeling (CPM) to identify brain networks predictive of basal craving. An edge-centric timeseries approach was leveraged to quantify the moment-to-moment engagement of the craving-positive and craving-negative subnetworks during independent scan runs. We found that dynamic markers of network engagement, namely more persistence in a craving-positive network state and less dwelling in a craving-negative network state, characterized individuals with higher craving. We replicated the latter results in a separate dataset, incorporating distinct participants (N = 173) and experimental stimuli. The associations between basal craving and network state dynamics were consistently observed even when craving-predictive networks were defined in the replication dataset. These robust findings suggest that network state dynamics underpin individual differences in basal craving. Our framework additionally presents a new avenue to explore how the moment-to-moment engagement of behaviorally meaningful network states supports our affective experiences.

Improvement in coping skills from culturally-adapted digital CBT for Spanish-speaking Hispanics with substance use disorder: Secondary analysis of a randomized clinical trial

INTRODUCTION

Developing adaptive coping skills for avoiding substance use is a proposed treatment mechanism of cognitive behavioral therapy (CBT) for substance use disorder (SUD). However, the generalizability of research on treatment mechanisms of CBT for SUD is limited by the underrepresentation of racial/ethnic minorities in clinical trials. In a secondary analysis of clinical trial data, we tested whether a culturally-adapted digital CBT program for Hispanics ("Spanish CBT4CBT") improved the quality of coping skills for avoiding substance use. We also tested whether coping skills' quality was associated with reductions in primary substance use.

METHODS

Participants were Spanish-speaking Hispanic adults seeking outpatient treatment for SUD (n = 85; 68 % male; primary substance type: 36 % cannabis, 33 % alcohol, 26 % cocaine, 5 % other). They were randomized to 8 weeks of outpatient treatment as usual (TAU) or TAU + Spanish CBT4CBT and assessed for 6 months after treatment. The study conducted separate analyses for the full sample (n = 85) and for those who engaged in at least 5 treatment sessions ("treatment exposed"; n = 64). Daily substance use and coping skills' quality were assessed repeatedly during the treatment and follow-up periods. Bayesian mixed models for repeated measures tested hypotheses.

RESULTS

Among treatment-exposed participants, those receiving TAU + Spanish CBT4CBT improved the quality of coping skills more than TAU alone during the treatment period (b = 0.77; 95 % CI[0.08, 1.47]), but this difference was not detected during the follow-up period. In the full sample and treatment exposed subsample, participants with higher quality coping skills during the study reported less primary substance use (b = -0.67; 95 % CI[-1.08, -0.26]). Among treatment-exposed participants only, within-person increases in the quality of coping skills were associated with reductions in future primary substance use (b = -0.18; 95 % CI[-0.36, -0.01]).

CONCLUSIONS

Spanish-speaking Hispanics with SUD may improve the quality of their coping skills more when they are sufficiently exposed to a culturally-adapted digital CBT program during outpatient treatment. Coping skills' quality may be a mechanism of CBT for SUD among Hispanic populations. Spanish-speaking Hispanics' access to treatments that target mechanisms of behavior change may be expanded by digital therapeutics.

The Incentive-Sensitization Theory of Addiction 30 Years On

The incentive-sensitization theory (IST) of addiction was first published in 1993, proposing that (a) brain mesolimbic dopamine systems mediate incentive motivation ("wanting") for addictive drugs and other rewards, but not their hedonic impact (liking) when consumed; and (b) some individuals are vulnerable to drug-induced long-lasting sensitization of mesolimbic systems, which selectively amplifies their "wanting" for drugs without increasing their liking of the same drugs. Here we describe the origins of IST and evaluate its status 30 years on. We compare IST to other theories of addiction, including opponent-process theories, habit theories of addiction, and prefrontal cortical dysfunction theories of impaired impulse control. We also address critiques of IST that have been raised over the years, such as whether craving is important in addiction and whether addiction can ever be characterized as compulsive. Finally, we discuss several contemporary phenomena, including the potential role of incentive sensitization in behavioral addictions, the emergence of addiction-like dopamine dysregulation syndrome in medicated Parkinson's patients, the role of attentional capture and approach tendencies, and the role of uncertainty in incentive motivation.

Measurement invariance of the Perceived Stress Scale across race, sex, and time, and differential impacts on cocaine use treatment outcomes

INTRODUCTION

To understand the influence of phenotypic characteristics, such as stress, on substance use treatment outcomes, measures must function equivalently across groups to allow for interpretable comparisons of effects. The present study evaluated measurement invariance of the Perceived Stress Scale (PSS) across race, sex, and time, examined its association with cocaine use disorder (CUD) treatment outcomes, and tested whether associations were moderated by race and/or sex.

METHODS

Data from four clinical trials evaluating behavioral and/or pharmacological treatments for cocaine use were combined providing a total sample of 302 participants with DSM-IV cocaine abuse/dependence (57.6 % Black, 42.4 % White, 43.7 % females, Mage = 40.22 years, SD = 9.26).

RESULTS

Factor analyses support a two-factor model (i.e., general stress, self-efficacy to cope with stressors) that demonstrated configural, metric, and scalar invariance across race and sex and configural and metric invariance across time. End-of-treatment stress and coping were both related to treatment outcomes, but not treatment retention. Interactions between baseline and end-of-treatment stress and coping self-efficacy with race and sex predicting treatment retention and outcomes were not significant.

CONCLUSIONS

Results support the utility of the PSS to examine between-group differences among individuals with CUD and suggest that sociodemographic groups differ in the extent to which stress and self-efficacy to cope influence treatment outcomes.

Trajectories of craving in the course of pharmacotherapy trials for methamphetamine use disorder

AIMS

The aim of this study was to measure trajectories of craving for methamphetamine during the course of pharmacotherapy trials for methamphetamine use disorder.

DESIGN, SETTING AND PARTICIPANTS

Craving trajectories were identified using Group-Based Trajectory Modeling. The association of craving trajectories with drug use trajectories was examined using a dual trajectory model. Association of craving trajectories with other health and social outcomes was also examined. The study used pooled data from five randomized controlled pharmacotherapy trials for methamphetamine use disorder. A total of 866 adults with methamphetamine use disorder participated in randomized controlled pharmacotherapy trials.

MEASUREMENT

Craving was assessed weekly using the Brief Substance Craving Scale. Drug use was assessed using urine toxicology. Alcohol- and drug-related problems, as well as psychiatric, medical, legal, employment and relationship problems, were measured using the Addiction Severity Index.

FINDINGS

A three-trajectory model with high, medium and low craving trajectories was selected as the most parsimonious model. Craving trajectories were associated with methamphetamine use trajectories in the course of trial; 88.4% of those in the high craving trajectory group had a consistently high frequency of methamphetamine use compared with 18.7% of those in the low craving group. High craving was also associated with less improvement in most other outcomes and higher rate of dropout from treatment. In turn, low craving was associated with a rapidly decreasing frequency of methamphetamine use, greater improvement in most other outcomes and a lower rate of dropout. Participants on modafinil daily and ondansetron 1 mg twice daily were less likely to be in the high craving group compared with those on placebo.

CONCLUSIONS

Trajectories of methamphetamine craving in the course of clinical trials for methamphetamine use disorder appear to be both highly variable and strongly associated with greater frequency of drug use, other drug-related outcomes and dropout from trials. Two medications, modafinil daily and ondansetron at a dose of 1 mg two times daily, appear to be associated with greater reduction in craving in the course of treatment compared with placebo. A decrease in methamphetamine craving shows promise as an early indicator of recovery from methamphetamine use disorder.

Laboratory method to induce state boredom increases impulsive choice in people who use cocaine and controls

Background: Impulsive choice is associated with both cocaine use and relapse. Little is known about the influence of transient states on impulsive choice in people who use cocaine (PWUC).Objective: This study investigated the direct effects of induced boredom on impulsive choice (i.e., temporal discounting) in PWUC relative to well-matched community controls.Methods: Forty-one PWUC (≥1× cocaine use in past 3 months; 7 females) and 38 demographically matched controls (5 females) underwent two experimental conditions in counterbalanced order. Temporal discounting was assessed immediately after a standardized boredom induction task (peg-turning) and a self-selected video watched for the same duration (non-boredom). Subjective mood state and perceived task characteristics were assessed at baseline, during experimental manipulations, and after the choice task.Results: PWUC and controls were well matched on sex, age, and socioeconomic status. Groups were also similar in reported use of drugs other than cocaine, except for recent cigarette and alcohol use (PWUC > controls). As expected, peg-turning increased boredom in the sample overall, with higher boredom reported during peg-turning than the video (p < .001, η2p = .20). Participants overall exhibited greater impulsive choice after boredom than non-boredom (p = .028, η2p = .07), with no preferential effects in PWUC (p > .05, BF01 = 2.9).Conclusion: Experimentally induced boredom increased state impulsivity irrespective of cocaine use status - in PWUC and carefully matched controls - suggesting a broad link between boredom and impulsive choice. This is the first study to show that transient boredom directly increases impulsive choice. Data support a viable laboratory method to further parse the effects of boredom on impulsive choice.

Network state dynamics underpin craving in a transdiagnostic population

Emerging fMRI brain dynamic methods present a unique opportunity to capture how brain region interactions across time give rise to evolving affective and motivational states. As the unfolding experience and regulation of affective states affect psychopathology and well-being, it is important to elucidate their underlying time-varying brain responses. Here, we developed a novel framework to identify network states specific to an affective state of interest and examine how their instantaneous engagement contributed to its experience. This framework investigated network state dynamics underlying craving, a clinically meaningful and changeable state. In a transdiagnostic sample of healthy controls and individuals diagnosed with or at risk for craving-related disorders (N=252), we utilized connectome-based predictive modeling (CPM) to identify craving-predictive edges. An edge-centric timeseries approach was leveraged to quantify the instantaneous engagement of the craving-positive and craving-negative networks during independent scan runs. Individuals with higher craving persisted longer in a craving-positive network state while dwelling less in a craving-negative network state. We replicated the latter results externally in an independent group of healthy controls and individuals with alcohol use disorder exposed to different stimuli during the scan (N=173). The associations between craving and network state dynamics can still be consistently observed even when craving-predictive edges were instead identified in the replication dataset. These robust findings suggest that variations in craving-specific network state recruitment underpin individual differences in craving. Our framework additionally presents a new avenue to explore how the moment-to-moment engagement of behaviorally meaningful network states supports our changing affective experiences.

Discriminating cocaine use from other sympathomimetics using wearable electrocardiographic (ECG) sensors

BACKGROUND

Our group has established the feasibility of using on-body electrocardiographic (ECG) sensors to detect cocaine use in the human laboratory. The purpose of the current study was to test whether ECG sensors and features are capable of discriminating cocaine use from other non-cocaine sympathomimetics.

METHODS

Eleven subjects with cocaine use disorder wore the Zephyr BioHarness™ 3 chest band under six experimental (drug and non-drug) conditions, including 1) laboratory, intravenous cocaine self-administration, 2) after a single oral dose of methylphenidate, 3) during aerobic exercise, 4) during tobacco use (N=7 who smoked tobacco), and 5) during routine activities of daily inpatient living (unit activity). Three ECG-derived feature sets served as primary outcome measures, including 1) the RR interval (i.e., heart rate), 2) a group of ECG interval proxies (i.e., PR, QS, QT and QTc intervals), and 3) the full ECG waveform. Discriminatory power between cocaine and non-cocaine conditions for each of the three outcomes measures was expressed as the area under the receiver operating characteristics (AUROC) curve.

RESULTS

All three outcomes successfully discriminated cocaine use from unit activity, exercise, tobacco, and methylphenidate conditions with a mean AUROC values ranging from 0.66 to 0.99 and with least squares means values all statistically different/higher than 0.5 among all subjects [F(3, 99) = 3.38, p =0.02] and among those with tobacco use [F(4, 84) = 5.39, p = 0.0007].

CONCLUSIONS

These preliminary results support discriminatory power of wearable ECG sensors for detecting cocaine use.

Clinical management of psychostimulant withdrawal: review of the evidence

It is estimated that a majority of people who use psychostimulants, particularly methamphetamine (MA) and cocaine, experience withdrawal upon abstinence from sustained use. This review of clinical research reports the evidence regarding biomedical and behavioral treatments for psychostimulant withdrawal symptoms. It provides a framework for clinicians and scientists to increase impact on attenuating MA and cocaine withdrawal during initial and sustained abstinence. Articles reviewed included reports of controlled clinical trials (randomized or non-randomized) reporting at least one withdrawal symptom among the outcomes or specifically studying patients in withdrawal. Potential efficacy for MA withdrawal is noted for a few medications (mirtazapine, naltrexone, bupropion) and repetitive transcranial magnetic stimulation during acute (first week), early protracted (weeks 2-4) and late protracted (> 4 weeks) withdrawal phases. Topiramate shows mixed evidence of efficacy for cocaine withdrawal. In general, there is inconsistent signal for biomedical and behavioral treatments on MA and cocaine withdrawal.

Alcohol availability during withdrawal gates the impact of alcohol vapor exposure on responses to alcohol cues

RATIONALE

Chronic intermittent ethanol (CIE) vapor inhalation is a widely used model of alcohol dependence, but the impact of CIE on cue-elicited alcohol seeking is poorly understood.

OBJECTIVE

Here, we assessed the effects of CIE on alcohol-seeking elicited by cues paired with alcohol before or after CIE vapor inhalation.

METHODS

In experiment 1, male and female Long-Evans rats were trained in a discriminative stimulus (DS) task, in which one auditory cue (the DS) predicts the availability of 15% ethanol and a control cue (the NS) predicts no ethanol. Rats then underwent CIE or served as controls. Subsets of each group received access to oral ethanol twice a week during acute withdrawal. After CIE, rats were presented with the DS and NS cues under extinction and retraining conditions to determine whether they would alter their responses to these cues. In experiment 2, rats underwent CIE prior to training in the DS task.

RESULTS

CIE enhanced behavioral responses to cues previously paired with alcohol, but only in rats that received access to alcohol during acute withdrawal. When CIE occurred before task training, male rats were slower to develop cue responses and less likely to enter the alcohol port, even though they had received alcohol during acute withdrawal.

CONCLUSIONS

These results suggest that CIE vapor inhalation alone does not potentiate the motivational value of alcohol cues but that an increase in cue responses requires alcohol experience during acute withdrawal. Furthermore, under some conditions, CIE may disrupt responses to alcohol-paired cues.

Impaired control in addiction involves cognitive distortions and unreliable self-control, not compulsive desires and overwhelmed self-control

Impaired control in addiction involves a characteristic but obscure kind of partial control. Certain aspects of control over drug use are clearly reduced, reflected in difficulty cutting back and relapse. However, other aspects of control are clearly preserved, as reflected in substantial sensitivity to situational incentives-for example, the ability to defer use when needed. This juxtaposition is puzzling, and a clear mechanistically precise understanding of impaired control has yet to emerge. In this article, a Distortion model of impaired control is put forward. The key insight of the model is that the puzzling pattern of partial control seen in addiction can be understood in terms of unreliable control. The model posits large populations of distorted automatic thoughts (e.g., about drugs, one's self, one's circumstances, and one's abilities to cope), coupled with unreliable control over these distorted thoughts. These distorted thoughts, typically gradually and cumulatively, lead to illusion-like misvaluation of costs and benefits of drug use, in turn eventually leading to decisions to use. The model captures an elusive middle ground in addiction in which substantially preserved control over drug use for briefer intervals coexists with difficulty maintaining sobriety over the long-term. Moreover, the model explains a range of clinical findings in addiction that are not easily accommodated on leading alternative views.

Sex Differences in Opioid and Psychostimulant Craving and Relapse: A Critical Review

A widely held dogma in the preclinical addiction field is that females are more vulnerable than males to drug craving and relapse. Here, we first review clinical studies on sex differences in psychostimulant and opioid craving and relapse. Next, we review preclinical studies on sex differences in psychostimulant and opioid reinstatement of drug seeking after extinction of drug self-administration, and incubation of drug craving (time-dependent increase in drug seeking during abstinence). We also discuss ovarian hormones' role in relapse and craving in humans and animal models and speculate on brain mechanisms underlying their role in cocaine craving and relapse in rodent models. Finally, we discuss imaging studies on brain responses to cocaine cues and stress in men and women.The results of the clinical studies reviewed do not appear to support the notion that women are more vulnerable to psychostimulant and opioid craving and relapse. However, this conclusion is tentative because most of the studies reviewed were correlational, not sufficiently powered, and not a priori designed to detect sex differences. Additionally, imaging studies suggest sex differences in brain responses to cocaine cues and stress. The results of the preclinical studies reviewed provide evidence for sex differences in stress-induced reinstatement and incubation of cocaine craving but not cue- or cocaine-induced reinstatement of cocaine seeking. These sex differences are modulated in part by ovarian hormones. In contrast, the available data do not support the notion of sex differences in craving and relapse/reinstatement for methamphetamine or opioids in rodent models. SIGNIFICANCE STATEMENT: This systematic review summarizes clinical and preclinical studies on sex differences in psychostimulant and opioid craving and relapse. Results of the clinical studies reviewed do not appear to support the notion that women are more vulnerable to psychostimulant and opioid craving and relapse. Results of preclinical studies reviewed provide evidence for sex differences in reinstatement and incubation of cocaine seeking but not for reinstatement or incubation of methamphetamine or opioid seeking.

Beyond abstinence and relapse II: momentary relationships between stress, craving, and lapse within clusters of patients with similar patterns of drug use

RATIONALE

Given that many patients being treated for opioid-use disorder continue to use drugs, identifying clusters of patients who share similar patterns of use might provide insight into the disorder, the processes that affect it, and ways that treatment can be personalized.

OBJECTIVES AND METHODS

We applied hierarchical clustering to identify patterns of opioid and cocaine use in 309 participants being treated with methadone or buprenorphine (in a buprenorphine-naloxone formulation) for up to 16 weeks. A smartphone app was used to assess stress and craving at three random times per day over the course of the study.

RESULTS

Five basic patterns of use were identified: frequent opioid use, frequent cocaine use, frequent dual use (opioids and cocaine), sporadic use, and infrequent use. These patterns were differentially associated with medication (methadone vs. buprenorphine), race, age, drug-use history, drug-related problems prior to the study, stress-coping strategies, specific triggers of use events, and levels of cue exposure, craving, and negative mood. Craving tended to increase before use in all except those who used sporadically. Craving was sharply higher during the 90 min following moderate-to-severe stress in those with frequent use, but only moderately higher in those with infrequent or sporadic use.

CONCLUSIONS

People who share similar patterns of drug-use during treatment also tend to share similarities with respect to psychological processes that surround instances of use, such as stress-induced craving. Cluster analysis combined with smartphone-based experience sampling provides an effective strategy for studying how drug use is related to personal and environmental factors.

Validation of the craving scale in a large sample of adults with substance use disorders

Valid and reliable measures of craving are essential for both clinical practice and research. Brief measures are particularly valuable for clinical and research settings in which assessment burden needs to be minimized. The Craving Scale is a 3-item measure of craving that has been previously validated in cocaine-dependent samples. This brief measure has also demonstrated predictive validity in both alcohol and opioid use disorder; however, its psychometric properties in these disorders are not well characterized. The aim of this paper was to extend prior psychometric analyses of the Craving Scale to a large sample of adults seeking treatment for substance use disorders (N = 1,283). Analyses of readability indicated that the Craving Scale was written between a 7-8th grade reading level and had minimal grammatical complexity. The Craving Scale demonstrated strong internal consistency reliability (omega = 0.81), a single-factor latent structure, and adequate concurrent and discriminant validity. Importantly, results were similar when analyses were run separately for alcohol and opioid craving and in men and women, supporting measure invariance across these key groups. Our results provide further support for the reliability and validity of the Craving Scale for use in people with substance use disorders.

Ambulatory Assessment Methods to Examine Momentary State-Based Predictors of Opioid Use Behaviors

PURPOSE OF REVIEW

Addiction scientists have begun using ambulatory assessment methods-including ecological momentary assessment (EMA), experience sampling, and daily diaries-to collect real-time or near-real-time reports of participants' internal states in their natural environments. The goal of this short review is to synthesize EMA findings from our research group, which has studied several hundred outpatients during treatment for opioid-use disorder (OUD). (We cite pertinent findings from other groups, but have not tried to be comprehensive.) One of our main goals in using EMA is to examine momentary changes in internal states that proximally predict, or concurrently mark, events such as lapses to opioid use.

RECENT FINDINGS

We summarize findings evaluating several classes of momentary markers or predictors (craving, stress, negative and positive moods, and physical pain/discomfort) of lapses and other states/behaviors. Craving and some negatively valenced mood states are concurrently and prospectively associated with lapses to opioid use during treatment. Craving is also concurrently and prospectively associated with momentary changes in stress and mood. Convincing evidence has not yet emerged for stress as a robust redictor of lapse to opioid use; it appears to be contributory, but neither necessary nor sufficient.

SUMMARY

Ambulatory assessment can capture changes in internal states and drug-related behaviors in situ and at high temporal resolution. We recommend research strategies that may increase the clinical and prognostic utility of ambulatory assessment, including denser sampling (i.e., more assessments per day) and more attention to heterogeneity across people and across populations.

Is there a 24-hour rhythm in alcohol craving and does it vary by sleep/circadian timing?

Increasing evidence implicates sleep/circadian factors in alcohol use; however, the role of such factors in alcohol craving has received scant attention. Prior research suggests a 24-hour rhythm in related processes (e.g., reward motivation), but more research directly investigating a rhythm in craving is needed. Moreover, prior evidence is ambiguous whether such a rhythm in alcohol craving may vary by sleep/circadian timing. To examine these possibilities, 36 late adolescents (18-22 years of age; 61% female) with regular alcohol use but without a current alcohol use disorder were recruited to complete smartphone reports of alcohol craving intensity six times a day for two weeks. During these two weeks, participants wore wrist actigraphs and completed two in-lab assessments (on Thursday and Sunday) of dim light melatonin onset (DLMO). Average actigraphically derived midpoint of sleep on weekends and average DLMO were used as indicators of sleep and circadian timing, respectively. Multilevel cosinor analysis revealed a 24-hour rhythm in alcohol craving. Findings across the sleep and circadian timing variables converged to suggest that sleep/circadian timing moderated the 24-hour rhythm in alcohol craving. Specifically, people with later sleep/circadian timing had later timing of peak alcohol craving. These findings add to the growing evidence of potential circadian influences on reward-related phenomena and suggest that greater consideration of sleep and circadian influences on alcohol craving may be useful for understanding alcohol use patterns and advancing related interventions.

I can't get it off my mind: Attentional bias in former and current cocaine addiction

BACKGROUND

Cocaine addiction is a global health issue with limited therapeutic options and a high relapse rate. Attentional bias towards substance-related cues may be an important factor for relapse. However, it has never been compared in former and current cocaine-dependent patients.

METHODS

Attentional bias towards cocaine-related words was assessed using an emotional Stroop task in cocaine-dependent patients (N = 40), long-term abstinent former cocaine-dependent patients (N = 24; mean abstinence: 2 years) and control subjects (N = 28). Participants had to name the colour of cocaine-related words, neutral words and colour names. We assessed response times using an automatic voice-onset detection method we developed and we measured attentional bias as the difference in response times between cocaine-related and neutral conditions.

RESULTS

There was an overall group effect on attentional bias towards cocaine, but no group effect on the colour Stroop effect. Two-by-two comparison showed a difference in attentional bias between cocaine-dependent patients and controls, whereas long-term abstinent former cocaine-dependent patients were not different from either. Although cocaine-dependent patients showed a significant attentional bias, consistent with the literature, neither long-term abstinent former cocaine-dependent patients nor controls showed a significant attentional bias towards cocaine-related words. We found no link between attentional bias size and either addiction severity or craving.

CONCLUSIONS

Cocaine abstinence was associated with an absence of significant attentional bias towards cocaine-related words, which may be interpreted either as an absence of attentional bias predicting success in maintaining abstinence, or as attentional bias being able to disappear with long-term cocaine abstinence. Further research is needed to distinguish the role of attentional bias in maintaining abstinence.

What We're Not Talking about When We Talk about Addiction

The landscape of addiction is dominated by two rival models: a moral model and a model that characterizes addiction as a neurobiological disease of compulsion. Against both, I offer a scientifically and clinically informed alternative. Addiction is a highly heterogenous condition that is ill-characterized as involving compulsive use. On the whole, drug consumption in addiction remains goal directed: people take drugs because drugs have tremendous value. This view has potential implications for the claim that addiction is, in all cases, a brain disease. But more importantly, it has implications for clinical and policy interventions. To help someone overcome addiction, you need to understand and address why they persist in using drugs despite negative consequences. If they are not compelled, then the explanation must advert to the value of drugs for them as an individual. What blocks us from acknowledging this reality is not science but fear: that it will ignite moralism about drugs and condemnation of drug users. The solution is not to cleave to the concept of compulsion but to fight moralism directly.

Intensive longitudinal methods for studying the role of self-regulation strategies in substance use behavior change

Purpose of review

Many psychosocial interventions for substance use disorders (SUDs) focus on teaching self-regulation strategies. Research using intensive longitudinal methods (ILM), such as ecological momentary assessment and daily diaries, is critical for elucidating if and how these strategies function as mechanisms of change among individuals with SUDs. We review this emerging area of research.

Recent findings

We found a small number of studies using ILM to study self-regulation strategies in SUD (n=18 studies), with most conducted among college student drinkers (n=9) and cigarette smokers (n=7), and few among treatment-engaged individuals, and those with other drug use disorders. There is preliminary evidence that the use of specific self-regulation strategies commonly taught in psychosocial interventions for SUDs (i.e., cognitive reappraisal, problem solving, stimulus control, harm reduction) is associated with decreased momentary or daily substance use, at the within-person level.

Summary

There is a need for further ILM research on self-regulation strategies as mechanisms of substance use behavior change. Such research can inform the development, refinement, and personalization of interventions that teach self-regulation strategies, including mobile interventions that facilitate strategy use in the moment. One key next step is developing psychometrically validated ILM assessments of self-regulation strategy use.

Is craving a risk factor for substance use among treatment-seeking individuals with alcohol and other drugs use disorders? A meta-analytic review

BACKGROUND

It is still unclear whether craving should be considered a key risk factor for substance-use behaviors (SUB) among treatment-seeking individuals with alcohol (AUD) and other drugs use disorders. Therefore, this study aims at clarifying this topic using a meta-analytic approach.

METHODS

Cohen's d was computed as effect size (ES) measure. Heterogeneity of ESs was computed using the Q statistic and I² index. The analyses also evaluated the impact assessment length on ESs. Furthermore, proximal effects of craving on SUB were compared to distal ones. The diagnoses of specific substance use disorders (SUDs), together with assessment instruments and research design were considered as additional moderators.

RESULTS

Thirty-six independent studies were included for a total of 4868 treatment-seeking individuals with SUDs. Patients who used substances showed slightly higher levels of craving than abstinent ones. The heterogeneity of results was large and significant. The length of period of assessment was positively related to ESs. The analyses highlighted no differences between pooled ESs of proximal and distal impacts of craving on SUB. The diagnoses of SUDs were significant moderators. Considering AUD, assessment instruments and research design were additional moderators.

CONCLUSIONS

Craving is a modest time-dependent proximal and distal risk factor for SUB among individuals with SUDs. Both the frequency of craving episodes and a heightened reactivity to craving cues are largely associated to SUB among individuals with AUD. Future studies should evaluate the mediating and moderating roles of self-regulatory mechanisms on the relationship between craving and SUB.

"Chasing the first high": memory sampling in drug choice

Although vivid memories of drug experiences are prevalent within clinical contexts and addiction folklore ("chasing the first high"), little is known about the relevance of cognitive processes governing memory retrieval to substance use disorder. Drawing on recent work that identifies episodic memory's influence on decisions for reward, we propose a framework in which drug choices are biased by selective sampling of individual memories during two phases of addiction: (i) downward spiral into persistent use and (ii) relapse. Consideration of how memory retrieval influences the addiction process suggests novel treatment strategies. Rather than try to break learned associations between drug cues and drug rewards, treatment should aim to strengthen existing and/or create new associations between drug cues and drug-inconsistent rewards.

Evaluating a longitudinal mediation model of perceived stress, depressive symptoms, and substance use treatment outcomes

The allostatic model of addiction suggests that negative affect, such as depressive symptoms, mediates the effect of stress on outcomes among individuals with substance use disorders. However, few longitudinal treatment studies have demonstrated this effect. We analyzed data from a 12-week randomized trial of galantamine and/or computerized cognitive-behavioral therapy (CBT4CBT) for individuals (N = 120) with cocaine use disorder in methadone treatment for opioid use disorder. We evaluated baseline perceived stress as a predictor of end-of-treatment (EOT) substance use outcomes, and EOT perceived stress as a predictor of month 6 posttreatment outcomes. We conducted mediation models with intervening depressive symptoms as a mediator. We also explored whether CBT4CBT moderated the effects of perceived stress. Baseline perceived stress did not predict EOT outcomes (i.e., total effect). However, in mediation models, we found indirect effects of baseline perceived stress on EOT cocaine and illicit opioid use, via midtreatment depressive symptoms. EOT perceived stress had significant total effects on month 6 cocaine and illicit opioid use, and an indirect effect on month 6 illicit opioid use (but not cocaine use), via month 3 depressive symptoms. Alternative models with depressive symptoms as the predictor and perceived stress as a mediator revealed no indirect effects. The addition of CBT4CBT to standard methadone treatment did not moderate total or indirect effects of perceived stress on substance use. Depressive symptoms may play a mediating role in the prospective indirect effect of perceived stress on substance use outcomes, particularly illicit opioid use. Further research is needed on therapies targeting stress. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Sexual dimorphism in the neural impact of stress and alcohol

Alcohol use disorder is a widespread mental illness characterized by periods of abstinence followed by recidivism, and stress is the primary trigger of relapse. Despite the higher prevalence of alcohol use disorder in males, the relationship between stress and behavioral features of relapse, such as craving, is stronger in females. Given the greater susceptibility of females to stress-related psychiatric disorders, understanding sexual dimorphism in the relationship between stress and alcohol use is essential to identifying better treatments for both male and female alcoholics. This review addresses sex differences in the impact of stressors on alcohol drinking and seeking in rodents and humans. As these behavioral differences in alcohol use and relapse originate from sexual dimorphism in neuronal function, the impact of stressors and alcohol, and their interaction, on molecular adaptations and neural activity in males and females will also be discussed. Together, the data reviewed herein, arising from a symposium titled "Sex matters in stress-alcohol interactions" presented at the Fourth Volterra Conference on Stress and Alcohol, will highlight the importance of identifying sex differences to improve treatments for comorbid stress and alcohol use disorder in both sexes.

Before and after: craving, mood, and background stress in the hours surrounding drug use and stressful events in patients with opioid-use disorder

RATIONALE

Ecological momentary assessment (EMA) of specific events usually focuses more on antecedents and concomitants than on aftermaths.

OBJECTIVES

To examine mental state both before and after discrete episodes of stress and drug use.

METHODS

For up to 16 weeks, outpatients on opioid-agonist treatment carried smartphones on which they initiated entries for stressful events (SEs) or lapses to drug use (DUs), and thrice daily when randomly prompted (RPs). Participants rated their stress, opioid craving, cocaine craving, and moods. RP entries within 5 h of an event were analyzed and compared to other RPs.

RESULTS

Stress, negative mood, and craving were generally higher before and after DUs and SEs compared to background levels in participants with at least one DU (n = 149) or SE (n = 158). Before DUs, there were increases in negative mood, opioid craving, and cocaine craving, but not background stress. Before SEs, there were increases in background stress, opioid craving, and cocaine craving, but not negative mood. These changes were more variable after events than before. Neither DUs nor SEs were significantly related to positive mood.

CONCLUSIONS

Stress increased before stressful-event entries, but was less evident before drug use. Craving increased in the hours before drug use and stressful events-and remained elevated in the hours after either event. These results suggest a stronger link between drug use and craving than between drug use and stress. Lapses to drug use did not improve mood or reduce stress, at least not at our 1-h-bin time resolution, suggesting that if such benefits exist, they are brief.

The hot 'n' cold of cue-induced drug relapse

Environmental cues associated with rewards can acquire motivational properties. However, there is considerable variation in the extent to which a reward cue gains motivational control over behavior, depending on the individual and the form of the cue. When a discrete cue is paired with food reward, it acquires greater control over motivated behavior in some rats (sign-trackers, STs) than others (goal-trackers, GTs) as indicated by the propensity to approach the cue, the willingness to work to obtain it, and its ability to reinstate reward-seeking behavior. Here, we review studies that employ this ST/GT animal model to investigate characteristics of individuals that are especially susceptible to reward cue-elicited behavior and the involvement of dopamine and acetylcholine neuromodulator systems in the susceptibility to cue-induced drug relapse. First, we discuss individual differences in the attribution of incentive salience to different forms of reward cues and the involvement of the mesolimbic dopamine system. We then discuss individual differences in cognitive/attentional control and the contributions of the cholinergic system in processing reward cues. It is suggested that in STs a propensity to attribute motivational properties to a drug cue is combined with poor attentional control in the face of these cues, making them particularly vulnerable to transition from casual/experimental patterns of drug use to addiction and to cue-induced relapse.

Differences in the subjective and motivational properties of alcohol across alcohol use severity: application of a novel translational human laboratory paradigm

The Allostatic Model proposes that Alcohol Use Disorder (AUD) is associated with a transition in the motivational structure of alcohol drinking: from positive reinforcement in early-stage drinking to negative reinforcement in late-stage dependence. However, direct empirical support for this preclinical model from human experiments is limited. This study tests predictions derived from the Allostatic Model in humans. Specifically, this study tested whether alcohol use severity (1) independently predicts subjective responses to alcohol (SR; comprised of stimulation/hedonia, negative affect, sedation and craving domains), and alcohol self-administration and 2) moderates associations between domains of SR and alcohol self-administration. Heavy drinking participants ranging in severity of alcohol use and problems (N = 67) completed an intravenous alcohol administration paradigm combining an alcohol challenge (target BrAC = 60 mg%), with progressive ratio self-administration. Alcohol use severity was associated with greater baseline negative affect, sedation, and craving but did not predict changes in any SR domain during the alcohol challenge. Alcohol use severity also predicted greater self-administration. Craving during the alcohol challenge strongly predicted self-administration and sedation predicted lower self-administration. Neither stimulation, nor negative affect predicted self-administration. This study represents a novel approach to translating preclinical neuroscientific theories to the human laboratory. As expected, craving predicted self-administration and sedation was protective. Contrary to the predictions of the Allostatic Model, however, these results were inconsistent with a transition from positively to negatively reinforced alcohol consumption in severe AUD. Future studies that assess negative reinforcement in the context of an acute stressor are warranted.

Stress Promotes Drug Seeking Through Glucocorticoid-Dependent Endocannabinoid Mobilization in the Prelimbic Cortex

BACKGROUND

Clinical reports suggest that rather than directly driving cocaine use, stress may create a biological context within which other triggers for drug use become more potent. We hypothesize that stress-induced increases in corticosterone "set the stage" for relapse by promoting endocannabinoid-induced attenuation of inhibitory transmission in the prelimbic cortex (PL).

METHODS

We have established a rat model for these stage-setting effects of stress. In this model, neither a stressor (electric footshock) nor stress-level corticosterone treatment alone reinstates cocaine seeking following self-administration and extinction, but each treatment potentiates reinstatement in response to an otherwise subthreshold cocaine priming dose (2.5 mg/kg, intraperitoneal). The contributions of endocannabinoid signaling in the PL to the effects of stress-level corticosterone on PL neurotransmission and cocaine seeking were determined using intra-PL microinfusions. Endocannabinoid-dependent effects of corticosterone on inhibitory synaptic transmission in the rat PL were determined using whole-cell recordings in layer V pyramidal neurons.

RESULTS

Corticosterone application attenuated inhibitory synaptic transmission in the PL via cannabinoid receptor type 1 (CB₁R)- and 2-arachidonoylglycerol-dependent inhibition of gamma-aminobutyric acid release without altering postsynaptic responses. The ability of systemic stress-level corticosterone treatment to potentiate cocaine-primed reinstatement was recapitulated by intra-PL injection of corticosterone, the CB₁R agonist WIN 55,212-2, or the monoacylglycerol lipase inhibitor URB602. Corticosterone effects on reinstatement were attenuated by intra-PL injections of either the CB₁R antagonist, AM251, or the diacylglycerol lipase inhibitor, DO34.

CONCLUSIONS

These findings suggest that stress-induced increases in corticosterone promote cocaine seeking by mobilizing 2-arachidonoylglycerol in the PL, resulting in CB₁R-mediated attenuation of inhibitory transmission in this brain region.

What does the Fos say? Using Fos-based approaches to understand the contribution of stress to substance use disorders

Despite extensive research efforts, drug addiction persists as a largely unmet medical need. Perhaps the biggest challenge for treating addiction is the high rate of recidivism. While many factors can promote relapse in abstinent drug users, the contribution of stress is particularly problematic, as stress is uncontrollable and pervasive in the lives of those struggling with addiction. Thus, understanding the neurocircuitry that underlies the influence of stress on drug seeking is critical for guiding treatment. Preclinical research aimed at defining this neurocircuitry has, in part, relied upon the use of experimental approaches that allow visualization of cellular and circuit activity that corresponds to stressor-induced drug seeking in rodent relapse models. Much of what we have learned about the mechanisms that mediate stressor-induced relapse has been informed by studies that have used the expression of the immediate early gene, cfos, or its protein product, Fos, as post-mortem activity markers. In this review we provide an overview of the rodent models used to study stressor-induced relapse and briefly summarize what is known about the underlying neurocircuitry before describing the use of cfos/Fos-based approaches. In addition to reviewing findings obtained using this approach, its advantages and limitations are considered. Moreover, new techniques that leverage the expression profile of cfos to tag and manipulate cells based on their activity patterns are discussed. The intent of the review is to guide the interpretation of old and design of new studies that utilize cfos/Fos-based strategies to study the neurocircuitry that contributes to stress-related drug use.

Racing the clock: The role of circadian rhythmicity in addiction across the lifespan

Although potent effects of psychoactive drugs on circadian rhythms were first described over 30 years ago, research into the reciprocal relationship between the reward system and the circadian system - and the impact of this relationship on addiction - has only become a focus in the last decade. Nonetheless, great progress has been made in that short time toward understanding how drugs of abuse impact the molecular and physiological circadian clocks, as well as how disruption of normal circadian rhythm biology may contribute to addiction and ameliorate the efficacy of treatments for addiction. In particular, data have emerged demonstrating that disrupted circadian rhythms, such as those observed in shift workers and adolescents, increase susceptibility to addiction. Furthermore, circadian rhythms and addiction impact one another longitudinally - specifically from adolescence to the elderly. In this review, the current understanding of how the circadian clock interacts with substances of abuse within the context of age-dependent changes in rhythmicity, including the potential existence of a drug-sensitive clock, the correlation between chronotype and addiction vulnerability, and the importance of rhythmicity in the mesocorticolimbic dopamine system, is discussed. The primary focus is on alcohol addiction, as the preponderance of research is in this area, with references to other addictions as warranted. The implications of clock-drug interactions for the treatment of addiction will also be reviewed, and the potential of therapeutics that reset the circadian rhythm will be highlighted.

Exacerbated Craving in the Presence of Stress and Drug Cues in Drug-Dependent Patients

In addiction, risk factors for craving and use include stress and drug-related cues. Stress and cues have additive or more-than-additive effects on drug seeking in laboratory animals, but, surprisingly, seem to compete with one another (ie, exert less-than-additive effects) in human laboratory studies of craving. We sought heretofore elusive evidence that human drug users could show additive (or more-than-additive) effects of stress and cues on craving, using ecological momentary assessment (EMA). Outpatients (N=182) maintained on daily buprenorphine or methadone provided self-reports of stress, craving, mood, and behavior on electronic diaries for up to 16 weeks. In three randomly prompted entries (RPs) per day, participants reported the severity of stress and craving and whether they had seen or been offered opioids, cocaine, cannabis, methamphetamine, alcohol, or tobacco. In random-effects models controlling for between-person differences, we tested effects of momentary drug-cue exposure and stress (and their interaction) on momentary ratings of cocaine and heroin craving. For cocaine craving, the Stress × Cue interaction term had a positive mean effect across participants (M=0.019; CL95 0.001-0.036), denoting a more-than-additive effect. For heroin, the mean was not significantly greater than 0, but the confidence interval was predominantly positive (M=0.019; CL95 -0.007-0.044), suggesting at least an additive effect. Heterogeneity was substantial; qualitatively, the Stress × Cue effect appeared additive for most participants, more than additive for a sizeable minority, and competitive in very few. In the field, unlike in human laboratory studies to date, craving for cocaine and heroin is greater with the combination of drug cues and stress than with either alone. For a substantial minority of users, the combined effect may be more than additive.

Posterior hippocampal regional cerebral blood flow predicts abstinence: a replication study

The posterior hippocampus (pHp) plays a major role in the processing and storage of drug-related cues and is linked to striatal-limbic brain circuits involved with craving and drug salience. We have recently reported that increased basal regional cerebral blood flow (rCBF) in a pHp loci, as measured by pseudo-continuous arterial spin labeling magnetic resonance imaging, predicted days to cocaine relapse following residential treatment. In this secondary analysis, we explored whether rCBF in this same pHp region would successfully predict 30-day point prevalence abstinence 60 days following residential treatment in an independent group of previously studied participants with cocaine dependence. rCBF was assessed with single photon emission computerized tomography during a saline infusion in 21 cocaine dependence and 22 healthy control participants. pHp rCBF was significantly higher in those endorsing substance use (n = 10) relative to both abstinent (n = 11) (p < 0.001) and control (p < 0.05) participants. There were no significant differences in measured demographic or clinical variables between the actively using and non-using participants. This replicative finding suggests that heightened pHp activation is a significant predictor of substance use in cocaine-dependent individuals, possibly reflecting a neural susceptibility to continued drug cues.

Extended exposure to environmental cues, but not to sucrose, reduces sucrose cue reactivity in rats

In the present study, we examined the effects of extinction of sucrose-predictive contextual cues and/or sucrose satiation on the expression of sucrose cue reactivity in a rat model of relapse. Context extinction was imposed by housing rats in their home cage or in the operant conditioning chamber for 17 h prior to testing. For sucrose satiation, rats were allowed unlimited access to water or sucrose for 17 h prior to testing. Cue reactivity was assessed after either one (Day 1) or 30 (Day 30) days of forced abstinence from sucrose self-administration. An abstinence-dependent increase in sucrose cue reactivity was observed in all conditions ("incubation of craving"). Context extinction dramatically reduced lever responding on both Day 1 and Day 30. Sucrose satiation had no significant effect on cue reactivity in any condition. These results demonstrate that the context in which self-administration occurs maintains a powerful influence over cue reactivity, even after extended forced abstinence. In contrast, the primary reinforcer has little control over cue reactivity. These findings highlight the important role of conditioned contextual cues in driving relapse behavior.

Spatio-temporal determinants of mental health and well-being: advances in geographically-explicit ecological momentary assessment (GEMA)

PURPOSE

Overview of geographically explicit momentary assessment research, applied to the study of mental health and well-being, which allows for cross-validation, extension, and enrichment of research on place and health.

METHODS

Building on the historical foundations of both ecological momentary assessment and geographic momentary assessment research, this review explores their emerging synergy into a more generalized and powerful research framework.

RESULTS

Geographically explicit momentary assessment methods are rapidly advancing across a number of complimentary literatures that intersect but have not yet converged. Key contributions from these areas reveal tremendous potential for transdisciplinary and translational science.

CONCLUSIONS

Mobile communication devices are revolutionizing research on mental health and well-being by physically linking momentary experience sampling to objective measures of socio-ecological context in time and place. Methodological standards are not well-established and will be required for transdisciplinary collaboration and scientific inference moving forward.

Magnitude and duration of cue-induced craving for marijuana in volunteers with cannabis use disorder

AIMS

Evaluate magnitude and duration of subjective and physiologic responses to neutral and marijuana (MJ)-related cues in cannabis dependent volunteers.

METHODS

33 volunteers (17 male) who met DSM-IV criteria for Cannabis Abuse or Dependence were exposed to neutral (first) then MJ-related visual, auditory, olfactory and tactile cues. Mood, drug craving and physiology were assessed at baseline, post-neutral, post-MJ and 15-min post MJ cue exposure to determine magnitude of cue- responses. For a subset of participants (n=15; 9 male), measures of craving and physiology were collected also at 30-, 90-, and 150-min post-MJ cue to examine duration of cue-effects.

RESULTS

In cue-response magnitude analyses, visual analog scale (VAS) items craving for, urge to use, and desire to smoke MJ, Total and Compulsivity subscale scores of the Marijuana Craving Questionnaire, anxiety ratings, and diastolic blood pressure (BP) were significantly elevated following MJ vs. neutral cue exposure. In cue-response duration analyses, desire and urge to use MJ remained significantly elevated at 30-, 90- and 150-min post MJ-cue exposure, relative to baseline and neutral cues.

CONCLUSIONS

Presentation of polysensory MJ cues increased MJ craving, anxiety and diastolic BP relative to baseline and neutral cues. MJ craving remained elevated up to 150-min after MJ cue presentation. This finding confirms that carry-over effects from drug cue presentation must be considered in cue reactivity studies.

Pilot RCT of bidirectional text messaging for ART adherence among nonurban substance users with HIV

OBJECTIVE

This pilot study tested the preliminary efficacy of a theory-based bidirectional text messaging intervention (TEXT) on antiretroviral (ART) adherence, missed care visits, and substance use among people with HIV.

METHOD

Participants with recent substance use and ART nonadherence from 2 nonurban HIV clinics were randomized to TEXT or to usual care (UC). The TEXT intervention included daily queries of ART adherence, mood, and substance use. The system sent contingent intervention messages created by participants for reports of adherence/nonadherence, good mood/poor mood, and no substance use/use. Assessments were at preintervention, postintervention, and 3-month postintervention follow-up. Objective primary outcomes were adherence, measured by past 3-month pharmacy refill rate, and proportion of missed visits (PMV), measured by medical records. The rate of substance-using days from the timeline follow-back was a secondary outcome.

RESULTS

Sixty-three patients participated, with 33 randomized to TEXT and 30 to UC. At preintervention, adherence was 64.0%, PMV was 26.9%, and proportion of days using substances was 53.0%. At postintervention, adherence in the TEXT condition improved from 66% to 85%, compared with 62% to 71% in UC participants (p = .04). PMV improved from 23% to 9% for TEXT participants and 31% to 28% in UC participants (p = .12). There were no significant differences between conditions in substance-using days at postintervention. At 3-month follow-up, differences were not significant.

CONCLUSIONS

Personalized bidirectional text messaging improved adherence and shows promise to improve visit attendance, but did not reduce substance using days. This intervention merits further testing and may be cost-efficient given its automation.

Gender-related Differences in Food Craving and Obesity

Food craving is often defined as a strong desire to eat. Much work has shown that it consistently and prospectively predicts eating and weight-related outcomes, contributing to the growing obesity epidemic. Although there are clear gender differences in the prevalence and health consequences of obesity, relatively little recent work has investigated gender differences in craving, or any sex-hormone-based differences as they relate to phases of the menstrual cycle. Here, we propose that gender-related differences in food craving contribute to gender-related differences in obesity. Drawing on findings in the addiction literature, we highlight ways to incorporate gender-based differences in food craving into treatment approaches, potentially improving the efficacy of obesity and weight loss treatment. Overall, this review aims to emphasize the importance of investigating gender differences in food craving, with a view towards informing the development of more effective treatments for obesity and weight loss.

Ecological Momentary Assessment of Illicit Drug Use Compared to Biological and Self-Reported Methods

BACKGROUND

The use of mHealth methods for capturing illicit drug use and associated behaviors have become more widely used in research settings, yet there is little research as to how valid these methods are compared to known measures of capturing and quantifying drug use.

OBJECTIVE

We examined the concordance of ecological momentary assessment (EMA) of drug use to previously validated biological and audio-computer assisted self-interview (ACASI) methods.

METHODS

The Exposure Assessment in Current Time (EXACT) study utilized EMA methods to assess drug use in real-time in participants' natural environments. Utilizing mobile devices, participants self-reported each time they used heroin or cocaine over a 4-week period. Each week, PharmChek sweat patch samples were collected for measurement of heroin and cocaine and participants answered an ACASI-based questionnaire to report behaviors and drug using events during the prior week. Reports of cocaine and heroin use captured through EMA were compared to weekly biological or self-report measures through percent agreement and concordance correlation coefficients to account for repeated measures. Correlates of discordance were obtained from logistic regression models.

RESULTS

A total of 109 participants were a median of 48.5 years old, 90% African American, and 52% male. During 436 person-weeks of observation, we recorded 212 (49%) cocaine and 103 (24%) heroin sweat patches, 192 (44%) cocaine and 161 (37%) heroin ACASI surveys, and 163 (37%) cocaine and 145 (33%) heroin EMA reports. The percent agreement between EMA and sweat patch methods was 70% for cocaine use and 72% for heroin use, while the percent agreement between EMA and ACASI methods was 77% for cocaine use and 79% for heroin use. Misreporting of drug use by EMA compared to sweat patch and ACASI methods were different by illicit drug type.

CONCLUSIONS

Our work demonstrates moderate to good agreement of EMA to biological and standard self-report methods in capturing illicit drug use. Limitations occur with each method and accuracy may differ by type of illicit drugs used.

The coupling of nicotine and stimulant craving during treatment for stimulant dependence

OBJECTIVE

Smoking prevalence is high among substance abusers, making it important to understand when nicotine abstinence will aid, impair, or not affect abstinence from other substances. This study tested novel hypotheses about the coupling of nicotine and stimulant craving over time during stimulant dependence treatment.

METHOD

Adults (N = 538) with cocaine and/or methamphetamine dependence completed a 10-week randomized controlled trial of substance use treatment with or without smoking cessation treatment. Participants reported nicotine and stimulant craving weekly and use twice per week.

RESULTS

Latent change score modeling tested the association between weekly increases in nicotine craving and subsequent weekly changes in stimulant craving. Interestingly, results revealed a "substitution" effect: increases in nicotine craving predicted subsequent decreases in stimulant craving, γ = -.37, p = .001. Additionally, increases in nicotine craving predicted subsequent increases in nicotine use, γ = 1.26, p = .04, and decreases in stimulant use, γ = -.07, p = .03. As expected, the substitution effect between nicotine and stimulant craving was stronger when stimulants were administered through the same route as nicotine (i.e., smoking), γ = -.56, p = .005, versus other routes, γ = -.32, p = .06. Finally, smoking cessation treatment eliminated the coupling between nicotine craving and stimulant craving, γ = -.07, p = .39.

CONCLUSIONS

Contrary to concerns about nicotine abstinence during substance dependence treatment, increases in nicotine craving may be associated with later reductions in stimulant craving and use, and unrelated when smoking cessation treatment is introduced. Weekly changes in nicotine craving convey information that can help clinicians to predict and understand shifts in stimulant craving and use during substance use disorder treatment.

Boundary conditions of methamphetamine craving

Methamphetamine use has increased significantly and become a global health concern. Craving is known to predict methamphetamine use and relapse following abstinence. Some have suggested that cravings are automatic, generalized, and uncontrollable, but experimental work addressing these claims is lacking. In 2 exploratory studies, we tested the boundary conditions of methamphetamine craving by asking: (a) is craving specific to users' preferred route of administration?, and (b) can craving be regulated by cognitive strategies? Two groups of methamphetamine users were recruited. In Study 1, participants were grouped by their preferred route of administration (intranasal vs. smoking), and rated their craving in response to photographs and movies depicting methamphetamine use (via the intranasal vs. smoking route). In Study 2, methamphetamine smokers implemented cognitive regulation strategies while viewing photographs depicting methamphetamine smoking. Strategies involved either focusing on the positive aspects of smoking methamphetamine or the negative consequences of doing so-the latter strategy based on treatment protocols for addiction. In Study 1, we found a significant interaction between group and route of administration, such that participants who preferred to smoke methamphetamine reported significantly stronger craving for smoking stimuli, whereas those who preferred the intranasal route reported stronger craving for intranasal stimuli. In Study 2, participants reported significantly lower craving when focusing on the negative consequences associated with methamphetamine use. Taken together, these findings suggest that strength of craving for methamphetamine is moderated by users' route of administration and can be reduced by cognitive strategies. This has important theoretical, methodological, and clinical implications.

Alcohol Consumption, Craving, and Craving Control Efforts Assessed Daily in the Context of Readiness to Change Among Individuals with Alcohol Dependence and PTSD

Research has demonstrated the positive association between alcohol craving and alcohol use and has identified craving as a central component of alcohol use disorders (AUD). Despite potential clinical implications, few studies have examined the relationship between craving and alcohol use in individuals with AUD and common psychiatric comorbidities or explored possible moderators of the craving-alcohol use relationship. The current study used daily monitoring data to: 1) replicate previous findings detecting a positive relationship between craving and alcohol use in individuals with AUD and co-occurring posttraumatic stress disorder (PTSD) and 2) extend these findings by examining the influence of initial change motivation on the craving-use relationship and within-day associations among craving, efforts to control craving, and alcohol consumption. Participants were 84 individuals with alcohol dependence and PTSD enrolled in an intervention study. Generalized estimating equations using pre-treatment baseline daily data revealed significant main effects for craving, craving control, and motivation to change alcohol use. Daily craving was positively related to alcohol use. Greater change motivation and craving control (i.e., efforts to resist craving, avoidance of thoughts and feelings related to craving) were negatively related to alcohol use. A significant interaction was detected between baseline change motivation and daily craving indicating that the association between craving and alcohol use was significantly stronger for those with low baseline change motivation. A significant interaction was also detected between craving control and daily craving, suggesting that participants were more likely to consume alcohol when experiencing high levels of craving if they reported low levels of craving control. Findings bolster the idea that efforts to prevent or ameliorate craving are critical to treatment success for individuals with AUD and PTSD who are seeking to reduce or quit drinking.

Early Phase in the Development of Cannabidiol as a Treatment for Addiction: Opioid Relapse Takes Initial Center Stage

Multiple cannabinoids derived from the marijuana plant have potential therapeutic benefits but most have not been well investigated, despite the widespread legalization of medical marijuana in the USA and other countries. Therapeutic indications will depend on determinations as to which of the multiple cannabinoids, and other biologically active chemicals that are present in the marijuana plant, can be developed to treat specific symptoms and/or diseases. Such insights are particularly critical for addiction disorders, where different phytocannabinoids appear to induce opposing actions that can confound the development of treatment interventions. Whereas Δ(9)-tetracannabinol has been well documented to be rewarding and to enhance sensitivity to other drugs, cannabidiol (CBD), in contrast, appears to have low reinforcing properties with limited abuse potential and to inhibit drug-seeking behavior. Other considerations such as CBD's anxiolytic properties and minimal adverse side effects also support its potential viability as a treatment option for a variety of symptoms associated with drug addiction. However, significant research is still needed as CBD investigations published to date primarily relate to its effects on opioid drugs, and CBD's efficacy at different phases of the abuse cycle for different classes of addictive substances remain largely understudied. Our paper provides an overview of preclinical animal and human clinical investigations, and presents preliminary clinical data that collectively sets a strong foundation in support of the further exploration of CBD as a therapeutic intervention against opioid relapse. As the legal landscape for medical marijuana unfolds, it is important to distinguish it from "medical CBD" and other specific cannabinoids, that can more appropriately be used to maximize the medicinal potential of the marijuana plant.

Dyadic social interaction inhibits cocaine-conditioned place preference and the associated activation of the accumbens corridor

Impaired social interaction is a hallmark symptom of many psychiatric disorders. In substance use disorders, impaired social interaction is triply harmful (a) because addicts increasingly prefer the drug of abuse to the natural reward of drug-free social interaction, thus worsening the progression of the disease by increasing their drug consumption, (b) because treatment adherence and, consequently, treatment success itself depends on the ability of the recovering addict to maintain social interaction and adhere to treatment, and (c) because socially interacting with an individual suffering from a substance use disorder may be harmful for others. Helping the addict reorient his/her behavior away from the drug of abuse toward social interaction would therefore be of considerable therapeutic benefit. This article reviews our work on the neural basis of such a reorientation from cocaine, as a prototypical drug of abuse, toward dyadic (i.e. one-to-one) social interaction and compares our findings with the effects of other potentially beneficial interventions, that is, environmental enrichment or paired housing, on the activation of the accumbens and other brain regions involved in behavior motivated by drugs of abuse or nondrug stimuli. Our experimental models are based on the conditioned place preference paradigm. As the therapeutically most promising finding, only four 15 min episodes of dyadic social interaction were able to inhibit both the subsequent reacquisition/re-expression of preference for cocaine and the neural activation associated with this behavior, that is, an increase in the expression of the immediate early gene Early Growth Response protein 1 (EGR1, Zif268) in the nucleus accumbens, basolateral and central amygdala, and the ventral tegmental area. The time spent in the cocaine-associated conditioning compartment was correlated with the density of EGR1-activated neurons not only in the medial core (AcbCm) and medial shell (AcbShm) of the nucleus accumbens, but was observed in all regions medial to the anterior commissure ('accumbens corridor'), including (from medial to lateral), the vertical limb of the diagonal band and the medial septum (VDB+MS), the major island of Calleja and the intermediate nucleus of the lateral septum (ICjM+LSI), the AcbShm, and the AcbCm. All effects were limited to GABAergic projection neurons (called 'medium spiny neurons', in the accumbens), encompassing both dopamine D1 receptor-expressing and D2 receptor-expressing medium spiny neuron subtypes. Our EGR1 expression findings were mirrored in multielectrode array recordings. Finally, we have validated our paradigm in C57BL/6 mice to make use of the plethora of transgenic models available in this genus.

The Imperial College Cambridge Manchester (ICCAM) platform study: An experimental medicine platform for evaluating new drugs for relapse prevention in addiction. Part A: Study description

Drug and alcohol dependence are global problems with substantial societal costs. There are few treatments for relapse prevention and therefore a pressing need for further study of brain mechanisms underpinning relapse circuitry. The Imperial College Cambridge Manchester (ICCAM) platform study is an experimental medicine approach to this problem: using functional magnetic resonance imaging (fMRI) techniques and selective pharmacological tools, it aims to explore the neuropharmacology of putative relapse pathways in cocaine, alcohol, opiate dependent, and healthy individuals to inform future drug development. Addiction studies typically involve small samples because of recruitment difficulties and attrition. We established the platform in three centres to assess the feasibility of a multisite approach to address these issues. Pharmacological modulation of reward, impulsivity and emotional reactivity were investigated in a monetary incentive delay task, an inhibitory control task, and an evocative images task, using selective antagonists for µ-opioid, dopamine D3 receptor (DRD3) and neurokinin 1 (NK1) receptors (naltrexone, GSK598809, vofopitant/aprepitant), in a placebo-controlled, randomised, crossover design. In two years, 609 scans were performed, with 155 individuals scanned at baseline. Attrition was low and the majority of individuals were sufficiently motivated to complete all five sessions (n=87). We describe herein the study design, main aims, recruitment numbers, sample characteristics, and explain the test hypotheses and anticipated study outputs.

Cue-induced craving in patients with cocaine use disorder predicts cognitive control deficits toward cocaine cues

INTRODUCTION

Cue-induced craving is a clinically important aspect of cocaine addiction influencing ongoing use and sobriety. However, little is known about the relationship between cue-induced craving and cognitive control toward cocaine cues. While studies suggest that cocaine users have an attentional bias toward cocaine cues, the present study extends this research by testing if cocaine use disorder patients (CDPs) can control their eye movements toward cocaine cues and whether their response varied by cue-induced craving intensity.

METHODS

Thirty CDPs underwent a cue exposure procedure to dichotomize them into high and low craving groups followed by a modified antisaccade task in which subjects were asked to control their eye movements toward either a cocaine or neutral drug cue by looking away from the suddenly presented cue. The relationship between breakdowns in cognitive control (as measured by eye errors) and cue-induced craving (changes in self-reported craving following cocaine cue exposure) was investigated.

RESULTS

CDPs overall made significantly more errors toward cocaine cues compared to neutral cues, with higher cravers making significantly more errors than lower cravers even though they did not differ significantly in addiction severity, impulsivity, anxiety, or depression levels. Cue-induced craving was the only specific and significant predictor of subsequent errors toward cocaine cues.

CONCLUSION

Cue-induced craving directly and specifically relates to breakdowns of cognitive control toward cocaine cues in CDPs, with higher cravers being more susceptible. Hence, it may be useful identifying high cravers and target treatment toward curbing craving to decrease the likelihood of a subsequent breakdown in control.

Pilot study of the effects of lisdexamfetamine on cocaine use: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Amphetamine analogs have been demonstrated to have some efficacy in reducing use in cocaine dependent individuals. However, these agents also have potential for abuse. Lisdexamfetamine (LDX), a lysine+dextroamphetamine formulation, has been approved for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) and as a prodrug, has less abuse potential.

OBJECTIVE

This pilot study sought to evaluate the safety, tolerability, and efficacy of LDX as a candidate treatment for cocaine dependence.

METHODS

A randomized, double-blind, placebo-controlled parallel group study served to evaluate LDX in 43 cocaine-dependent individuals: (1) placebo (PBO; 0mg, n=21), (2) LDX (70mg, n=22). Participants received medication for 14 weeks. Cocaine use was determined based on urine analysis for benzoylecgonine (BE; a cocaine metabolite).

RESULTS

Retention rates were higher though not significantly different in the PBO (71.4%) than the LDX condition (57.1%). Compared to those in the PBO condition, those receiving LDX were more likely to report experiencing (ps<0.05) diarrhea (45.5% vs. 14.3%), headaches (45.5% vs. 9.5%), and anxiety (31.8% vs. 4.8%). No differences in medication conditions were observed for blood pressure, heart rate, or body weight. In the randomized sample, no differences in cocaine use were seen. Those receiving LDX reported significantly less craving for cocaine than participants receiving PBO.

CONCLUSIONS

LDX did not significantly reduce cocaine use compared to PBO in the randomized sample.

Utilizing mHealth methods to identify patterns of high risk illicit drug use

INTRODUCTION

We assessed patterns of illicit drug use using mobile health (mHealth) methods and subsequent health care indicators among drug users in Baltimore, MD.

METHODS

Participants of the EXposure Assessment in Current Time (EXACT) study were provided a mobile device for assessment of their daily drug use (heroin, cocaine or both), mood and social context for 30 days from November 2008 through May 2013. Real-time, self-reported drug use events were summed for individuals by day. Drug use risk was assessed through growth mixture modeling. Latent class regression examined the association of mHealth-defined risk groups with indicators of healthcare access and utilization.

RESULTS

109 participants were a median of 48.5 years old, 90% African American, 52% male and 59% HIV-infected. Growth mixture modeling identified three distinct classes: low intensity drug use (25%), moderate intensity drug use (65%) and high intensity drug use (10%). Compared to low intensity drug users, high intensity users were younger, injected greater than once per day, and shared needles. At the subsequent study visit, high intensity drug users were nine times less likely to be medically insured (adjusted OR: 0.10, 95%CI: 0.01-0.88) and at greater risk for failing to attend any outpatient appointments (aOR: 0.13, 95%CI: 0.02-0.85) relative to low intensity drug users.

CONCLUSIONS

Real-time assessment of drug use and novel methods of describing sub-classes of drug users uncovered individuals with higher-risk behavior who were poorly utilizing healthcare services. mHealth holds promise for identifying individuals engaging in high-risk behaviors and delivering real-time interventions to improve care outcomes.

Continuous in-the-field measurement of heart rate: Correlates of drug use, craving, stress, and mood in polydrug users

BACKGROUND

Ambulatory physiological monitoring could clarify antecedents and consequences of drug use and could contribute to a sensor-triggered mobile intervention that automatically detects behaviorally risky situations. Our goal was to show that such monitoring is feasible and can produce meaningful data.

METHODS

We assessed heart rate (HR) with AutoSense, a suite of biosensors that wirelessly transmits data to a smartphone, for up to 4 weeks in 40 polydrug users in opioid-agonist maintenance as they went about their daily lives. Participants also self-reported drug use, mood, and activities on electronic diaries. We compared HR with self-report using multilevel modeling (SAS Proc Mixed).

RESULTS

Compliance with AutoSense was good; the data yield from the wireless electrocardiographs was 85.7%. HR was higher when participants reported cocaine use than when they reported heroin use (F(2,9)=250.3, p<.0001) and was also higher as a function of the dose of cocaine reported (F(1,8)=207.7, p<.0001). HR was higher when participants reported craving heroin (F(1,16)=230.9, p<.0001) or cocaine (F(1,14)=157.2, p<.0001) than when they reported of not craving. HR was lower (p<.05) in randomly prompted entries in which participants reported feeling relaxed, feeling happy, or watching TV, and was higher when they reported feeling stressed, being hassled, or walking.

CONCLUSIONS

High-yield, high-quality heart-rate data can be obtained from drug users in their natural environment as they go about their daily lives, and the resultant data robustly reflect episodes of cocaine and heroin use and other mental and behavioral events of interest.