The clinical neurobiology of drug craving

Stress and substance use disorders: risk, relapse, and treatment outcomes

Stress has long been associated with substance misuse and substance use disorders (SUDs). The past two decades have seen a surge in research aimed at understanding the underlying mechanisms driving this association. This Review introduces a multilevel "adaptive stress response" framework, encompassing a stress baseline, acute reaction, and recovery with return-to-homeostasis phase that occurs at varying response times and across domains of analysis. It also discusses evidence showing the disruption of this adaptive stress response in the context of chronic and repeated stressors, trauma, adverse social and drug-related environments, as well as with acute and chronic drug misuse and with drug withdrawal and abstinence sequelae. Subjective, cognitive, peripheral, and neurobiological disruptions in the adaptive stress response phases and their link to inflexible, maladaptive coping; increased craving; relapse risk; and maintenance of drug intake are also presented. Finally, the prevention and treatment implications of targeting this "stress pathophysiology of addiction" are discussed, along with specific aspects that may be targeted in intervention development to rescue stress-related alterations in drug motivation and to improve SUD treatment outcomes.

Chronic ethanol exposure produces long-lasting, subregion-specific physiological adaptations in RMTg-projecting mPFC neurons

Chronic ethanol exposure produces neuroadaptations in the medial prefrontal cortex (mPFC) that are thought to facilitate maladaptive behaviors that interfere with recovery from alcohol use disorder. Despite evidence that different cortico-subcortical projections play distinct roles in behavior, few studies have examined the physiological effects of chronic ethanol at the circuit level. The rostromedial tegmental nucleus (RMTg) is functionally altered by chronic ethanol exposure. Our recent work identified dense input from the mPFC to the RMTg, yet the effects of chronic ethanol exposure on this circuitry is unknown. In the current study, we examined physiological changes after chronic ethanol exposure in prelimbic (PL) and infralimbic (IL) mPFC neurons projecting to the RMTg. Adult male Long-Evans rats were injected with fluorescent retrobeads into the RMTg and rendered dependent using a 14-day chronic intermittent ethanol (CIE) vapor exposure paradigm. Whole-cell patch-clamp electrophysiological recordings were performed in fluorescently-labeled (RMTg-projecting) and -unlabeled (projection-undefined) layer 5 pyramidal neurons 7-10 days following ethanol exposure. CIE exposure significantly increased intrinsic excitability as well as spontaneous excitatory and inhibitory postsynaptic currents (sE/IPSCs) in RMTg-projecting IL neurons. In contrast, no lasting changes in excitability were observed in RMTg-projecting PL neurons, although a CIE-induced reduction in excitability was observed in projection-undefined PL neurons. CIE exposure also increased the frequency of sEPSCs in RMTg-projecting PL neurons. These data uncover novel subregion- and circuit-specific neuroadaptations in the mPFC following chronic ethanol exposure and reveal that the IL mPFC-RMTg projection is uniquely vulnerable to long-lasting effects of chronic ethanol exposure.

Habitual behavioural control moderates the relation between daily perceived stress and purging

OBJECTIVE

Evidence suggests that interpersonal stress plays a role in maintaining binge eating and purging (e.g., self-induced vomiting, misuse of laxatives). Stress is especially likely to promote engagement in maladaptive behaviour if the behaviour is habitual; therefore, individuals whose binge eating and/or purging are habitual may be particularly likely to engage in these behaviours in the context of interpersonal stress. We aimed to investigate this hypothesis in a sample of women with binge eating and/or purging using ecological momentary assessment (EMA).

METHOD

Women (N = 81) with binge-eating and/or purging symptoms completed a self-report measure assessing habit strength of binge eating and purging followed by a 14-day EMA protocol assessing daily perceived interpersonal stress and binge-eating and purging episodes.

RESULTS

Habit strength of purging moderated the within-person effect of interpersonal stress on purging frequency, such that higher daily stress was associated with greater same-day purging frequency when purging was more habitual. Contrary to expectations, the interactive effect of habit strength of binge eating and daily interpersonal stress on same-day binge-eating frequency was non-significant.

CONCLUSIONS

Findings suggest that individuals with habitual purging may be vulnerable to engaging in purging when they are experiencing high levels of interpersonal stress.

Hypocretin-1 receptor antagonism improves inhibitory control during the Go/No-Go task in highly motivated, impulsive male mice

RATIONALE

Motivation and inhibitory control are dominantly regulated by the dopaminergic (DA) and noradrenergic (NA) systems, respectively. Hypothalamic hypocretin (orexin) neurons provide afferent inputs to DA and NA nuclei and hypocretin-1 receptors (HcrtR1) are implicated in reward and addiction. However, the role of the HcrtR1 in inhibitory control is not well understood.

OBJECTIVES

To determine the effects of HcrtR1 antagonism and motivational state in inhibitory control using the go/no-go task in mice.

METHODS

n = 23 male C57Bl/6JArc mice were trained in a go/no-go task. Decision tree dendrogram analysis of training data identified more and less impulsive clusters of animals. A HcrtR1 antagonist (BI001, 12.5 mg/kg, per os) or vehicle were then administered 30 min before go/no-go testing, once daily for 5 days, under high (food-restricted) and low (free-feeding) motivational states in a latin-square crossover design. Compound exposure levels were assessed in a satellite group of animals.

RESULTS

HcrtR1 antagonism increased go accuracy and decreased no-go accuracy in free-feeding animals overall, whereas it decreased go accuracy and increased no-go accuracy only in more impulsive, food restricted mice. HcrtR1 antagonism also showed differential effects in premature responding, which was increased in response to the antagonist in free-feeding, less impulsive animals, and decreased in food restricted, more impulsive animals. HcrtR1 receptor occupancy by BI001 was estimated at ~ 66% during the task.

CONCLUSIONS

These data indicate that hypocretin signalling plays roles in goal-directed behaviour and inhibitory control in a motivational state-dependant manner. While likely not useful in all settings, HcrtR1 antagonism may be beneficial in improving inhibitory control in impulsive subpopulations.

Tobacco Images Choice and Its Association with Craving and Dependence in People who Smoke Cigarettes

INTRODUCTION

Increased salience of drug-related cues over non-drug reinforcers can drive drug use and contribute to tobacco use disorder (TUD). An important scientific and clinical goal is to effectively measure this elevated drug-seeking behavior in TUD. However, most TUD assessments rely on self-reported cravings and cigarette consumption, not providing an objective measure of the impact of drug-cues on biasing behavior towards drugs. The probabilistic image choice (PIC) task investigates the choice of viewing drug-related pictures as compared to other salient pictures (e.g., pleasant and unpleasant). This study aimed to develop and validate the PIC task for TUD and evaluate the associations between behavioral choice and tobacco craving, daily cigarette consumption, quit attempts and motivation to quit, and nicotine dependence (the Fagerström score).

METHODS

We recruited 468 smokers and 121 nonsmokers using the Prolific online platform. Participants performed the PIC task twice (at a one-month interval) and completed other measures relevant to TUD.

RESULTS

compared to nonsmokers, tobacco smokers selected to view significantly more tobacco images and less pleasant (non-drug reinforcer) images, a profile that remained stable at retest. Individual differences in choice of tobacco as compared to pleasant images on the PIC task were associated with craving but not with the other tobacco dependence measures, suggesting that the task may serve as a behavioral proxy measure of drug "wanting" rather than of cumulative nicotine exposure or physical dependence.

CONCLUSIONS

these results suggest that the PIC task can be a valuable tool for objectively assessing craving-associated tobacco seeking in TUD.

IMPLICATIONS SECTION

which should provide a brief description about what the study addsMost of the current measures of tobacco use disorder (TUD) rely on self-reports of consumption, dependence and craving and do not take into consideration the role of drug-related cues in driving tobacco seeking. This study shows that the probabilistic image choice (PIC) task provides an objective, reliable proxy measure of tobacco image seeking behavior in people who smoke cigarettes that is linked to craving (desire) for smoking but not to other measures of TUD. Therefore, the PIC task may be a useful complementary tool for the classification, diagnosis, and prognosis of TUD.

Moroccan version of the short Tobacco Craving Questionnaire (MTCQ-12)

INTRODUCTION

Craving is a key clinical dimension in the assessment and management of substance use disorders. It is also a recognized predictor of relapse in addictology. To date, no scale for measuring tobacco craving is available to Moroccan clinicians. This work proposes a cross-cultural validation of the Tobacco Craving Questionnaire (TCQ) in its short version.

METHODS

This work consists of the creation of a translated version according to a rigorous methodology and the evaluation of its psychometric properties in a statistical study.

RESULTS

The validation study was done on a sample of 130 smokers with a majority of men (95%). It showed a high acceptability and homogeneity with a Cronbach's alpha coefficient of 0.82. The four scale factors showed a high discriminant validity. Finally, the scale showed high reproducibility with an inter-observer stability of 0.95 and 0.94 between tests and retests.

CONCLUSION

The Moroccan version of the TCQ-12 scale shows good validity indices for measuring craving in Moroccan smokers and also shows that it measures independently the four clinical dimensions of the scale.

Chronic ethanol exposure produces long-lasting, subregion-specific physiological adaptations in RMTg-projecting mPFC neurons

Chronic ethanol exposure produces neuroadaptations in the medial prefrontal cortex (mPFC) which facilitate the maladaptive behaviors interfering with recovery from alcohol use disorder. Despite evidence that different cortico-subcortical projections play distinct roles in behavior, few studies have examined the physiological effects of chronic ethanol at the circuit level. The rostromedial tegmental nucleus (RMTg) is a GABAergic midbrain region involved in aversive signaling and is functionally altered by chronic ethanol exposure. Our recent work identified a dense input from the mPFC to the RMTg, yet the effects of chronic ethanol exposure on this circuitry is unknown. In the current study, we examined physiological changes after chronic ethanol exposure in prelimbic (PL) and infralimbic (IL) mPFC neurons projecting to the RMTg. Adult male Long-Evans rats were injected with fluorescent retrobeads into the RMTg and rendered dependent using a 14-day chronic intermittent ethanol (CIE) vapor exposure paradigm. Whole-cell patch-clamp electrophysiological recordings were performed in fluorescently-labeled (RMTg-projecting) and -unlabeled (projection-undefined) layer 5 pyramidal neurons 7-10 days following ethanol exposure. CIE significantly increased intrinsic excitability as well as excitatory and inhibitory synaptic drive in RMTg-projecting IL neurons. In contrast, no lasting changes in excitability were observed in RMTg-projecting PL neurons, although a CIE-induced reduction in excitability was observed in projection-undefined PL neurons. CIE also increased excitatory synaptic drive in RMTg-projecting PL neurons. These data uncover novel subregion- and circuit-specific neuroadaptations in the mPFC following chronic ethanol exposure and reveal that the IL mPFC-RMTg projection is uniquely vulnerable to long-lasting effects of chronic ethanol.

Enhancing Relapse Prevention: Examining the Impact of Experiential Avoidance, Integrative Self-Knowledge, and Basic Psychological Needs in Substance Use Treatment

Background

The harmful effects of drug relapse have always been one of the major challenges in addiction treatment. The present study aimed to predict drug relapse in addicted men under treatment based on experiential avoidance, integrative self-knowledge, and basic psychological needs.

Methods

The present study was a correlational one. The statistical population included all addicted men in Choubindar prison in Qazvin in 2021, among whom 200 individuals were selected randomly. Then, the participants filled out the Relapse Prediction Scale (RPS), Multidimensional Experiential Avoidance Questionnaire (MEAQ), Integrative Self-Knowledge Scale (ISK), and Basic Psychological Needs Scale (BPNS). Data were analyzed using stepwise regression via SPSS software (version 25).

Findings

The results of the study demonstrated that some of the components of experiential avoidance including distraction, distress endurance, behavioral avoidance, and distress aversion could account for 14.0% of the variance of the relapse in the addicts (P<0.05). Moreover, the obtained results considering the reflective self-knowledge component and the overall score of integrative self-knowledge could explain 15.0% of the variance in relapse in the addicts. Among the basic psychological needs, communication could predict 3.8% of the variance in relapse.

Conclusion

Based on the results of the present study, it is suggested that through addiction treatment and prevention of relapse programs, psychologists reduce drug relapse in addicts by decreasing distractions and behavioral avoidance, increasing distress endurance, enhancing self-knowledge, and improving efficient relationships.

Tobacco Images Choice and Its Association with Craving and Dependence in Cigarette Smokers

Introduction

Increased salience of drug-related cues over non-drug reinforcers can drive drug use and contribute to tobacco use disorder (TUD). An important scientific and clinical goal is to effectively measure this elevated drug-seeking behavior in TUD. However, most TUD assessments rely on self-reported cravings and cigarette consumption, not providing an objective measure of the impact of drug-cues on biasing behavior towards drugs. The probabilistic image choice (PIC) task investigates the choice of viewing drug-related pictures as compared to other salient pictures (e.g., pleasant and unpleasant). This study aimed to develop and validate the PIC task for TUD and evaluate the associations between behavioral choice and tobacco craving, daily cigarette consumption, quit attempts and motivation to quit, and nicotine dependence (the Fagerström score).

Methods

We recruited 468 smokers and 121 nonsmokers using the Prolific online platform. Participants performed the PIC task twice (at a one-month interval) and completed other measures relevant to TUD.

Results

compared to nonsmokers, tobacco smokers selected to view significantly more tobacco images and less pleasant (non-drug reinforcer) images, a profile that remained stable at retest. Individual differences in choice of tobacco as compared to pleasant images on the PIC task were associated with craving but not with the other tobacco dependence measures, suggesting that the task may serve as a behavioral proxy measure of drug "wanting" rather than of cumulative nicotine exposure or physical dependence.

Conclusions

these results suggest that the PIC task can be a valuable tool for objectively assessing craving-associated tobacco seeking in TUD.

IUPHAR Review: New strategies for medications to treat substance use disorders

Substance use disorders (SUDs) and drug overdose are a public health emergency and safe and effective treatments are urgently needed. Developing new medications to treat them is expensive, time-consuming, and the probability of a compound progressing to clinical trials and obtaining FDA-approval is low. The small number of FDA-approved medications for SUDs reflects the low interest of pharmaceutical companies to invest in this area due to market forces, characteristics of the population (e.g., stigma, and socio-economic and legal disadvantages), and the high bar regulatory agencies set for new medication approval. In consequence, most research on medications is funded by government agencies, such as the National Institute on Drug Abuse (NIDA). Multiple scientific opportunities are emerging that can accelerate the discovery and development of new medications for SUDs. These include fast and efficient tools to screen new molecules, discover new medication targets, use of big data to explore large clinical data sets and artificial intelligence (AI) applications to make predictions, and precision medicine tools to individualize and optimize treatments. This review provides a general description of these new research strategies for the development of medications to treat SUDs with emphasis on the gaps and scientific opportunities. It includes a brief overview of the rising public health toll of SUDs; the justification, challenges, and opportunities to develop new medications; and a discussion of medications and treatment endpoints that are being evaluated with support from NIDA.

Stress-Induced Sensitization of Insula Activation Predicts Alcohol Craving and Alcohol Use in Alcohol Use Disorder

BACKGROUND

Stress and alcohol cues trigger alcohol consumption and relapse in alcohol use disorder. However, the neurobiological processes underlying their interaction are not well understood. Thus, we conducted a randomized, controlled neuroimaging study to investigate the effects of psychosocial stress on neural cue reactivity and addictive behaviors.

METHODS

Neural alcohol cue reactivity was assessed in 91 individuals with alcohol use disorder using a validated functional magnetic resonance imaging (fMRI) task. Activation patterns were measured twice, at baseline and during a second fMRI session, prior to which participants were assigned to psychosocial stress (experimental condition) or a matched control condition or physical exercise (control conditions). Together with fMRI data, alcohol craving and cortisol levels were assessed, and alcohol use data were collected during a 12-month follow-up. Analyses tested the effects of psychosocial stress on neural cue reactivity and associations with cortisol levels, craving, and alcohol use.

RESULTS

Compared with both control conditions, psychosocial stress elicited higher alcohol cue-induced activation in the left anterior insula (familywise error-corrected p < .05) and a stress- and cue-specific dynamic increase in insula activation over time (F22,968 = 2.143, p = .007), which was predicted by higher cortisol levels during the experimental intervention (r = 0.310, false discovery rate-corrected p = .016). Cue-induced insula activation was positively correlated with alcohol craving during fMRI (r = 0.262, false discovery rate-corrected p = .032) and alcohol use during follow-up (r = 0.218, false discovery rate-corrected p = .046).

CONCLUSIONS

Results indicate a stress-induced sensitization of cue-induced activation in the left insula as a neurobiological correlate of the effects of psychosocial stress on alcohol craving and alcohol use in alcohol use disorder, which likely reflects changes in salience attribution and goal-directed behavior.

Comparative Effects of Cognitive Rehabilitation and Photobiomodulation on Drug Craving in Treatment-Seeking Opioid Addicts

Background: Drug addiction refers to a maladaptive pattern of drug use that frequently leads to substance abuse problems and accompanying cognitive and behavioral symptoms. Among the crucial criteria of drug addiction, craving stands out as a potent factor contributing to ongoing drug abuse and relapse following period of abstinence. To date, there is no definitive method for eradicating opioid cravings. The introduction of novel neurocognitive interventions, such as cognitive rehabilitation and photobiomodulation (PBM), into the realm of psychiatric treatments holds promise due to the parallels between drug addiction and other psychiatric disorders. These innovative techniques offer potential value in addressing drug addiction. Objective: This study aimed to assess and compare the efficacy of cognitive rehabilitation and PBM in alleviating drug cravings among individuals undergoing addiction treatment in clinical settings. Methods: The research used randomized clinical trial as the chosen research method. The statistical population encompassed all clients receiving treatment for addiction at clinics, selected through the convenience sampling method, with α = 0.05 significance level and an effect size of 85%. Gpower software was utilized to determine three equal groups. Sixty-three participants, each having a mean total score higher than 3 out of 5 on the Desire for Drug Questionnaire (DDQ), were randomly assigned to two experimental groups (n = 21 each) and a control group (n = 21). For the assessment of immediate and periodic opioid craving, the DDQ and the Obsessive Compulsive Drug Use Scale were used. In the low-level laser group, an 810 nm wavelength with continuous irradiation was applied twice a week at a distance of 1 cm by 1 cm to the prefrontal part of the brain for duration of 6 weeks (12 sessions). In the brain rehabilitation group, the stop signal and n-back tasks software were used twice a week for period of 6 weeks (comprising 12 sessions, each lasting 30 min). Results: The results demonstrated that each intervention significantly reduced drug craving in both the post-test and follow-up phases compared to the control group. The Bonferroni post hoc test indicated that PBM was more effective than cognitive rehabilitation in terms of working memory (WM) and inhibitory control for reducing drug craving (p < 0.05). Conclusions: While both PBM and cognitive rehabilitation targeting WM and inhibitory control effectively reduced opioid drug craving, low-level laser therapy proved to be more effective than cognitive rehabilitation in this regard.

The ventral hippocampus and nucleus accumbens as neural substrates for cocaine contextual memory reconsolidation

Drug craving triggered by cues that were once associated with drug intoxication is a major contributor to continued drug-seeking behaviors. Addictive drugs engage molecular pathways of associative learning and memory. Reactivated memories are vulnerable to disruption by interference with the process of reconsolidation, hence targeting reconsolidation could be a strategy to reduce cue-induced drug craving and relapse. Here we examined the circuitry of cocaine contextual memory reconsolidation and explored neuroplasticity following memory reactivation. Mice underwent chemogenetic inhibition of either nucleus accumbens (NA) neurons or the glutamatergic projection neurons from the ventral hippocampus (vHPC) to NA using inhibitory designer receptors exclusively activated by designer drugs (iDREADD). Mice underwent cocaine conditioned place preference followed by reactivation of the cocaine contextual memory. Clozapine-N-oxide (CNO) was administered after memory reactivation to inhibit either NA neurons or the accumbens-projecting vHPC neurons during the reconsolidation period. When retested 3 days later, a significant reduction in the previously established preference for the cocaine context was found in both conditions. FosTRAP2-Ai14 mice were used to identify neurons activated by cocaine memory recall and to evaluate plasticity in NA medium spiny neurons (MSNs) and vHPC pyramidal neurons upon recall of cocaine memories. Results indicate a significant increase in dendritic spine density in NA MSNs activated by cocaine memory recall, particularly of the thin spine type. Sholl analysis indicated longer dendritic length and more branching of NA MSNs after cocaine memory recall than without memory reactivation. vHPC neurons showed increased spine density, with the most robust change in stubby spines. These results implicate a circuit involving glutamatergic projections from the vHPC onto NA neurons which is necessary for the reconsolidation of cocaine memories. Interruption of cocaine memory reconsolidation reduced drug-seeking behavior.

Laboratory and Real-World Experimental Approaches to Understanding Alcohol Relapse

Alcohol use disorder is highly prevalent and high risk of relapse remains a significant treatment challenge. Therefore, the utility of human laboratory models of relapse to further the understanding of psychobiological mechanisms that precipitate relapse risk and allow testing of novel interventions could be of benefit in expediting the development of effective treatments to target high relapse risk. Stress is a risk factor for the development of AUD and for relapse, and furthermore, chronic alcohol use leads to adaptations in central and peripheral stress biology. Here, we review our efforts to assess the integrity of these stress pathways in individuals with alcohol use disorder and whether adaptations in these systems play a role in relapse risk. Using validated human laboratory procedures to model two of the most common situations that contribute to relapse risk, namely stress and alcohol cues, we review how such models in the laboratory can predict subsequent relapse, and how we can measure specific identified biobehavioral markers of relapse effectively and ecologically in the real world. Finally, we discuss the significant implications of these findings for the development of novel and effective interventions that target stress dysregulation and craving as risk factors to treatment.

Neuroplasticity of the extended amygdala in opioid withdrawal and prolonged opioid abstinence

Opioid use disorder is characterized by excessive use of opioids, inability to control its use, a withdrawal syndrome upon discontinuation of opioids, and long-term likelihood of relapse. The behavioral stages of opioid addiction correspond with affective experiences that characterize the opponent process view of motivation. In this framework, active involvement is accompanied by positive affective experiences which gives rise to "reward craving," whereas the opponent process, abstinence, is associated with the negative affective experiences that produce "relief craving." Relief craving develops along with a hypersensitization to the negatively reinforcing aspects of withdrawal during abstinence from opioids. These negative affective experiences are hypothesized to stem from neuroadaptations to a network of affective processing called the "extended amygdala." This negative valence network includes the three core structures of the central nucleus of the amygdala (CeA), the bed nucleus of the stria terminalis (BNST), and the nucleus accumbens shell (NAc shell), in addition to major inputs from the basolateral amygdala (BLA). To better understand the major components of this system, we have reviewed their functions, inputs and outputs, along with the associated neural plasticity in animal models of opioid withdrawal. These models demonstrate the somatic, motivational, affective, and learning related models of opioid withdrawal and abstinence. Neuroadaptations in these stress and motivational systems are accompanied by negative affective and aversive experiences that commonly give rise to relapse. CeA neuroplasticity accounts for many of the aversive and fear-related effects of opioid withdrawal via glutamatergic plasticity and changes to corticotrophin-releasing factor (CRF)-containing neurons. Neuroadaptations in BNST pre-and post-synaptic GABA-containing neurons, as well as their noradrenergic modulation, may be responsible for a variety of aversive affective experiences and maladaptive behaviors. Opioid withdrawal yields a hypodopaminergic and amotivational state and results in neuroadaptive increases in excitability of the NAc shell, both of which are associated with increased vulnerability to relapse. Finally, BLA transmission to hippocampal and cortical regions impacts the perception of conditioned aversive effects of opioid withdrawal by higher executive systems. The prevention or reversal of these varied neuroadaptations in the extended amygdala during opioid withdrawal could lead to promising new interventions for this life-threatening condition.

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.

The Moderating Role of Sex in the Relation between Cue-Induced Craving and Resting-State Functional Connectivity in the Salience Network of Non-Clinically Diagnosed Drinkers

INTRODUCTION

Previous research indicates a relation between craving and increased connectivity in the resting-state salience network. However, the link between cue-induced craving and connectivity in the salience network remains unclear. Further investigation is needed to understand the effect of sex on the relationship between cue-induced craving and the salience network. We investigated the role of sex in the association between the resting-state functional connectivity (RSFC) salience network and subjective cue-induced craving.

METHODS

Twenty-six males (mean age = 25.3) and 23 females (mean age = 26.0), with a score of 12 or higher on the alcohol use disorder identification test, were included in the current study. No significant difference in age was observed between males and females. Participants underwent a resting-state MRI scan for 6 min. Following the MRI scan, participants completed an alcohol cue-exposure task for 5.5 min to assess cue-induced craving using the desire to drink alcohol questionnaire. We applied independent component analysis methods to determine functional connectivity within the salience network. Subsequently, we investigated how cue-induced craving is related to the salience network's RSFC and if this relationship is moderated by sex.

RESULTS

The association between the salience network and cue-induced craving was not statistically significant nor did we find a moderating effect for sex.

CONCLUSION

The null findings in the study may be explained by a lack of power. Alternatively, alcohol use sex disparities may be more prevalent in the recreational/impulsive stage, whereas participants in our study were in the later stage of addiction.

The Stage-Based Model of Addiction-Using Drosophila to Investigate Alcohol and Psychostimulant Responses

Addiction is a progressive and complex disease that encompasses a wide range of disorders and symptoms, including substance use disorder (SUD), for which there are few therapeutic treatments. SUD is the uncontrolled and chronic use of substances despite the negative consequences resulting from this use. The progressive nature of addiction is organized into a testable framework, the neurobiological stage-based model, that includes three behavioral stages: (1) binge/intoxication, (2) withdrawal/negative affect, and (3) preoccupation/anticipation. Human studies offer limited opportunities for mechanistic insights into these; therefore, model organisms, like Drosophila melanogaster, are necessary for understanding SUD. Drosophila is a powerful model organism that displays a variety of SUD-like behaviors consistent with human and mammalian substance use, making flies a great candidate to study mechanisms of behavior. Additionally, there are an abundance of genetic tools like the GAL4/UAS and CRISPR/Cas9 systems that can be used to gain insight into the molecular mechanisms underlying the endophenotypes of the three-stage model. This review uses the three-stage framework and discusses how easily testable endophenotypes have been examined with experiments using Drosophila, and it outlines their potential for investigating other endophenotypes.

Effects of 10 add-on HF-rTMS treatment sessions on alcohol use and craving among detoxified inpatients with alcohol use disorder: a randomized sham-controlled clinical trial

BACKGROUND AND AIMS

Alcohol use disorder (AUD) is a chronic disorder with high relapse rates. There are currently few clinical trials of high frequency repetitive transcranial magnetic stimulation (HF-rTMS) to reduce alcohol use among AUD patients, and results are mixed. The current study tested the effect of 10 add-on sessions of HF-rTMS over the right dorsolateral pre-frontal cortex (DLPFC) on alcohol use and craving.

DESIGN

Single-center, single blind sham-controlled parallel-group RCT (n = 80), with 3 and 6 months follow-up.

SETTING

Clinical treatment center in Amsterdam, the Netherlands.

PARTICIPANTS

Eighty detoxified and abstinent AUD inpatients in clinical treatment (20 females, average age = 44.35 years).

INTERVENTION

Ten sessions of active or sham HF-rTMS (60 10 Hz trains of 5 sec at 110% motor threshold) over the right DLPFC on 10 consecutive work-days.

MEASUREMENTS

The primary outcome measure is the number of abstinent days over 6-month follow-up (FU). Secondary outcome measures are craving over 6-month FU (alcohol urge questionnaire and obsessive-compulsive drinking scale), time to first relapse over 6-month FU and grams of alcohol consumed over 6-month FU. Additional outcome measures: full abstinence over 6-month FU and treatment success over 12-month FU.

FINDINGS

HF-rTMS did not affect the number of abstinent days over 6 months FU [sham = 124 ± 65.9 days, active = 115 ± 69.8 days, difference: 9 days, 95% confidence interval (CI) = Poisson model: 0.578-3.547]. Moreover, HF-rTMS did not affect craving (AUQ/OCDS) (sham = 15.38/5.28, active = 17.48/4.75, differences = 2.1/-0.53, 95% CI mixed-effects model = -9.14 to 2.07/-1.44 to 2.40).

CONCLUSIONS

There was no clear evidence that high-frequency repetitive transcranial magnetic stimulation over the right dorsolateral pre-frontal cortex treatment has a long-term positive effect on alcohol use or craving as add-on treatment for alcohol use disorder. High treatment response at 6-month follow-up could have limited the possibility to find an effect.

Comorbidity of Post-Traumatic Stress Disorder and Alcohol Use Disorder: Animal Models and Associated Neurocircuitry

Post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) are prevalent neuropsychiatric disorders and frequently co-occur concomitantly. Individuals suffering from this dual diagnosis often exhibit increased symptom severity and poorer treatment outcomes than those with only one of these diseases. Lacking standard preclinical models limited the exploration of neurobiological mechanisms underlying PTSD and AUD comorbidity. In this review, we summarize well-accepted preclinical model paradigms and criteria for developing successful models of comorbidity. We also outline how PTSD and AUD affect each other bidirectionally in the nervous nuclei have been heatedly discussed recently. We hope to provide potential recommendations for future research.

Neurosteroids (allopregnanolone) and alcohol use disorder: From mechanisms to potential pharmacotherapy

Alcohol Use Disorder (AUD) is a multifaceted relapsing disorder that is commonly comorbid with psychiatric disorders, including anxiety. Alcohol exposure produces a plethora of effects on neurobiology. Currently, therapeutic strategies are limited, and only a few treatments - disulfiram, acamprosate, and naltrexone - are available. Given the complexity of this disorder, there is a great need for the identification of novel targets to develop new pharmacotherapy. The GABAergic system, the primary inhibitory system in the brain, is one of the well-known targets for alcohol and is responsible for the anxiolytic effects of alcohol. Interestingly, GABAergic neurotransmission is fine-tuned by neuroactive steroids that exert a regulatory role on several endocrine systems involved in neuropsychiatric disorders including AUD. Mounting evidence indicates that alcohol alters the biosynthesis of neurosteroids, whereas acute alcohol increases and chronic alcohol decreases allopregnanolone levels. Our recent work highlighted that chronic alcohol-induced changes in neurosteroid levels are mediated by epigenetic modifications, e.g., DNA methylation, affecting key enzymes involved in neurosteroid biosynthesis. These changes were associated with changes in GABAA receptor subunit expression, suggesting an imbalance between excitatory and inhibitory signaling in AUD. This review will recapitulate the role of neurosteroids in the regulation of the neuroendocrine system, highlight their role in the observed allostatic load in AUD, and develop a framework from mechanisms to potential pharmacotherapy.

Pharmacological Treatments for Cocaine Craving: What Is the Way Forward? A Systematic Review

BACKGROUND

cocaine craving is a core feature of cocaine use disorder and remains a critical challenge for abstinence and relapse prevention. This review summarizes the anti-craving efficacy of pharmacotherapies tested for cocaine use disorder, in the context of randomized-controlled clinical trials.

OBJECTIVES

we assessed the databases of the U.S. National Library of Medicine, Google Scholar, and PsycINFO, without date restrictions up to August 2022, to identify relevant studies.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

we included double-blinded randomized-controlled trials investigating pharmacotherapies for cocaine craving and/or cocaine use disorder whose outcomes included cocaine craving.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two authors screened studies' titles and abstracts for inclusion, and both read all the included studies. We systematically gathered information on the following aspects of each study: title; author(s); year of publication; sample size; mean age; sample characteristics; study set-ting; whether participants were treatment-seeking; study design; craving measures; study interventions; drop-out rates; and other relevant outcomes.

RESULTS

Overall, we appraised 130 clinical trials, including 8137 participants. We further considered the drugs from the studies that scored equal to or greater than six points in the quality assessment. There was a correlation between craving and cocaine use outcomes (self-reports, timeline follow-back or urinary benzoylecgonine) in the vast majority of studies. In the short-term treatment, acute phenylalanine-tyrosine depletion, clonidine, fenfluramine, meta-chlorophenylpiperazine (m-CPP) and mecamylamine presented promising effects. In the long term, amphetamine, biperiden, carbamazepine, lisdexamfetamine, lorcaserin, methamphetamine, mirtazapine, pioglitazone, progesterone, guanfacine, levodopa, nefazodone presented promising anti-craving effects. Unfortunately, the highly tested medications were not successful in most of the trials, as follows: propranolol in the short term; amantadine, aripiprazole, bromocriptine, citicoline, ketamine, modafinil, olanzapine, topiramate in the long term. The remaining 52 medications had no positive anti-craving outcomes.

LIMITATIONS

Our review was limited by high heterogeneity of craving assessments across the studies and by a great range of pharmacotherapies. Further, the majority of the studies considered abstinence and retention in treatment as the main outcomes, whereas craving was a secondary outcome and some of the studies evaluated patients with cocaine use disorder with comorbidities such as opioid or alcohol use disorder, schizophrenia, bipolar disorder or attention deficit hyperactivity. Lastly, most of the studies also included non-pharmacological treatments, such as counseling or psychotherapy.

CONCLUSIONS

There is a direct association between craving and cocaine use, underscoring craving as an important treatment target for promoting abstinence among persons with cocaine use disorder. Clonidine, fenfluramine and m-CPP showed to be promising medications for cocaine craving in the short-term treatment, and amphetamine, biperiden, carbamazepine, lisdexamfetamine, lorcaserin, methamphetamine, mirtazapine, pioglitazone, progesterone, guanfacine, levodopa, nefazodone in the long-term treatment.

Alcohol’s Negative Emotional Side: The Role of Stress Neurobiology in Alcohol Use Disorder

This article is part of a Festschrift commemorating the 50th anniversary of the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Established in 1970, first as part of the National Institute of Mental Health and later as an independent institute of the National Institutes of Health, NIAAA today is the world’s largest funding agency for alcohol research. In addition to its own intramural research program, NIAAA supports the entire spectrum of innovative basic, translational, and clinical research to advance the diagnosis, prevention, and treatment of alcohol use disorder and alcohol-related problems. To celebrate the anniversary, NIAAA hosted a 2-day symposium, “Alcohol Across the Lifespan: 50 Years of Evidence-Based Diagnosis, Prevention, and Treatment Research,” devoted to key topics within the field of alcohol research. This article is based on Dr. Sinha’s presentation at the event. NIAAA Director George F. Koob, Ph.D., serves as editor of the Festschrift.

Underlying mechanisms in the relationship between stress and alcohol consumption in regular and risky drinkers (MESA): methods and design of a randomized laboratory study

Background

Excessive alcohol consumption and alcohol use disorders (AUD) are among the leading preventable causes of premature morbidity and mortality and are considered a major public health concern. In order to reduce the individual and societal burden of excessive alcohol use, it is crucial to identify high-risk individuals at earlier stages and to provide effective interventions to prevent further progression. Stressful experiences are important risk factors for excessive alcohol consumption and AUDs. However, the underlying biological and psychological mechanisms are still poorly understood.

Methods

The project “Underlying mechanisms in the relationship between stress and alcohol consumption in regular and risky drinkers (MESA)” is a randomized controlled study that started in December 2018 and is conducted in a laboratory setting, which aims to identify moderators and mediators of the relationship between acute stress and alcohol consumption among regular and risky drinkers. Regular and risky drinkers are randomly assigned to a stress induction or a control condition. Several processes that may mediate (emotional distress, endocrine and autonomic stress reactivity, impulsivity, inhibitory control, motivational sensitization) or moderate (trait impulsivity, childhood maltreatment, basal HPA-axis activity) the relation between stress and alcohol consumption are investigated. As primary dependent variable, the motivation to consume alcohol following psychosocial stress is measured.

Discussion

The results of this study could help to provide valuable targets for future research on tailored interventions to prevent stress-related alcohol consumption.

Daily stress predicts later drinking initiation via craving in heavier social drinkers: A prospective in-field daily diary study

Stress has been linked to increased alcohol use but how stress may increase drinking in social drinkers is not well understood. Negative reinforcement processes may explain this link but the role of specific motivational processes, such as craving, and how these motivational processes are altered by drinking have not been studied. The current study assessed social drinkers (n = 81) for recent quantity and frequency of alcohol intake (quantity and frequency index, QFI) upon study enrollment, who then completed 30 days of electronic daily records of stress, craving, and alcohol intake. Multilevel structural equation models tested if person-averaged (between-person) and daily (within-person) craving mediated the link between stress and later drinking each evening and if recent quantity-frequency of drinking (QFI) moderated these associations. At the between-person level, both greater subjective stress, Est = .38, 95% confidence interval (CI) [.19, .57], and higher QFI predicted higher levels of craving, Est = .34, 95% CI [.20, .49]. Higher craving predicted more frequent drinking throughout the study, Est = .34, 95% CI [.01, .29]. At the within-person level, higher subjective stress predicted higher within-person craving; and the link between craving and later drinking was significant among those who had a higher QFI, Est = .84, 95% CI [.58, 1.12]. The subjective stress-drinking relationship was mediated by a greater alcohol craving response in social drinkers, and higher the QFI, greater the alcohol craving response. These results indicate that both higher levels of stress and greater recent alcohol intake patterns sensitize the craving response that in turn facilitates later alcohol intake. The findings suggest that higher recent alcohol use predict greater stress-potentiated initiation of drinking via higher craving responses. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

How drug cravings affect metacognitive monitoring in methamphetamine abusers

BACKGROUND AND OBJECTIVE

Metacognitive monitoring refers to the process in which an individual analyzes their own mental state, then monitors and adjusts cognitive activities to achieve a predetermined goal. Recent research has suggested a strong link between metacognition and drug cravings. Conversely, few studies on the impact of metacognitive monitoring on methamphetamine (MA) cravings exist. Thus, this study investigated whether drug cravings would impair MA abusers' metacognitive monitoring and explored the prediction effects of drug cravings.

METHOD

Seventy MA abusers from the Zhejiang Compulsory Isolation Drug Rehabilitation Center and 65 non-users from the Wenzhou Medical University were recruited for this experimental study. The judgment of learning (JOL) paradigm was used to examine metacognitive monitoring, and cue-induced pictures were used to induce MA abusers' drug cravings. Analysis of covariance (ANCOVA), partial correlation, and regression analysis were performed.

RESULTS

Compared with non-users, MA abusers had significantly poorer metacognitive monitoring and tended to overestimate their performance. Furthermore, there was a significant correlation between the accuracy of JOLs and drug cravings, which indicated that metacognitive monitoring was weakened by drug cravings with higher cravings imposing more severe impacts. In addition, the regression analysis suggested that drug cravings can predict metacognitive monitoring.

Influence of improved behavioral inhibition on decreased cue-induced craving in heroin use disorder: A preliminary intermittent theta burst stimulation study

BACKGROUND

Impaired behavioral inhibition is a critical factor in drug addiction and relapse. Repetitive transcranial magnetic stimulation (rTMS) reduces the craving of heroin-addicted individuals for drug-related cues. However, it is unclear whether this technique also improves impaired behavioral inhibition and how improved behavioral inhibition affects craving.

OBJECTIVE

The intermittent theta-burst stimulation (iTBS) has been recently shown to be non-inferior relative to rTMS for depression. Here, we aim to investigate the effect of iTBS on heroin-addicted individuals' behavioral inhibition and cue-induced craving and the relationship between the alteration of behavioral inhibition and craving.

METHOD

42 of 56 initially recruited individuals with the heroin-use disorder in the abstinent-course treatment were randomized to undergo active or sham iTBS to the left dorsolateral prefrontal cortex and received three daily iTBS treatments for 10 consecutive days. We measured participants' performance during a two-choice oddball task (80% standard and 20% deviant trials) and heroin-related cue-induced craving before and immediately after treatment.

RESULTS

The group that received active iTBS showed significantly improved two-choice oddball task performance after 10 days of intervention compared to both pre-intervention and the group who received sham iTBS. Similarly, a significant reduction in cue-induced craving was observed after following the intervention in the active iTBS group but not the sham iTBS group. The moderation model indicated that iTBS categories play a significant moderating role in the relationship between accuracy cost changing and altered cue-induced craving.

CONCLUSIONS

The iTBS treatment protocol positively affects behavioral inhibition in patients with heroin addiction. Improvements in behavioral inhibition can substantially reduce craving.

Association of Drug Cues and Craving With Drug Use and Relapse: A Systematic Review and Meta-analysis

Importance

Craving, which is a strong desire for drugs, is a new DSM-5 diagnostic criterion for substance use disorders (SUDs), which are the most prevalent, costly, and deadly forms of psychopathology. Despite decades of research, the roles of drug cues and craving in drug use and relapse remain controversial.

Objective

To assess whether 4 types of drug cue and craving indicators, including cue exposure, physiological cue reactivity, cue-induced craving, and self-reported craving (without cue exposure), are prospectively associated with drug use and relapse.

Data Sources

Google Scholar was searched for published studies from inception through December 31, 2018. In addition, backward and forward searches were performed on included articles to identify additional articles.

Study Selection

Included studies reported a prospective statistic that linked cue and craving indicators at time 1 to drug use or relapse at time 2, in humans.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Study characteristics and statistics were extracted and/or coded by 1 of the 2 authors and then checked by the other. Statistical analyses were performed from May to July 2021.

Main Outcomes and Measures

Random-effects models were used to calculate prospective odds ratios (ORs) representing the association between cue and craving indicators and subsequent drug use/relapse.

Results

A total of 18 205 records were identified, and 237 studies were included. Across 656 statistics, representing 51 788 human participants (21 216 with confirmed SUDs), a significant prospective association of all cue and craving indicators with drug use/relapse was found (OR, 2.05; 95% CI, 1.94-2.15), such that a 1-unit increase in cue and craving indicators was associated with more than double the odds of future drug use or relapse. A Rosenthal fail-safe analysis revealed that 180 092 null studies would need to be published to nullify this finding. Trim-and-fill analysis brought the adjusted effect size to an OR of 1.31 (95% CI, 1.25-1.38). Moderator analyses showed that some of the strongest associations were found for cue-induced craving, real cues or images, drug use outcome, same-day time lag, studies using ecological momentary assessment, and male participants.

Conclusions and Relevance

Findings from this systematic review and meta-analysis suggest that drug cue and craving indicators play significant roles in drug use and relapse outcomes and are an important mechanism underlying SUDs. Clinically, these results support incorporating craving assessment across stages of treatment, as early as primary care.

A Pilot Randomized Control Study on Effect Brief Heart Rate Variability Biofeedback as a Complementary Treatment in Men with Methamphetamine Use Disorder

The aims of this study were to investigate the efficacy of heart rate variability biofeedback (HRVBFB) intervention in terms of reducing craving, severity of dependence, and rate of positive methamphetamine urine testing in men taking part in a methamphetamine use disorder outpatient treatment program. Sixty-one adult men received either HRVBFB treatment plus treatment as usual (TAU) over four weeks or TAU only. Men receiving HRVBFB showed significantly greater reductions in craving, dependence severity, and the rate of positive methamphetamine urine testing at the end of the intervention and four weeks of follow-up. The analyses further showed that the levels of craving and dependence severity at treatment entry were predictive of changes in craving and dependence severity at the end of treatment and follow-up, respectively. The baseline status of a positive methamphetamine urine test only predicted a positive methamphetamine urine test at the end of treatment, not at the end of the follow-up period. Our results showed HRVBFB intervention has merits as an adjunct treatment to ameliorate cravings and reduce the severity of dependence experienced by persons with methamphetamine use disorder. An added value of HRVBFB intervention is the fact that it can be easily and affordably implemented in everyday life.

Acting with awareness moderates the association between lifetime exposure to interpersonal traumatic events and craving via trauma symptoms: a moderated indirect effects model

BACKGROUND

History of exposure to traumatic events (ETE) is common among women in substance use disorder (SUD) treatment and is related to craving. We examined whether ETE (i.e., emotional, physical, sexual abuse) in childhood, adulthood, or both is related to craving via trauma symptoms and how trait mindfulness might attenuate this association.

METHODS

Baseline data from a larger randomized clinical trial of a mindfulness-based intervention for women (N = 245) in SUD treatment were used. Inclusion criteria were: 18-65 years of age, SUD diagnosis, English fluency, no cognitive impairment, and willingness to be audio recorded and provide consent. Demographics and validated measures of ETE, posttraumatic stress symptoms, trait mindfulness, and substance use craving were collected via in-person interviews. Descriptive statistics, correlational analysis, and relative direct, indirect, and conditional indirect effects models were run.

RESULTS

Most participants identified as Hispanic (58.5%), had at least a high school education (52.2%), with a mean age of 32.2. Women reported ETE in childhood only (20.4%), adulthood only (17.5%), both childhood and adulthood (50.0%), and never (11.4%). Compared to women with ETE in both childhood and adulthood, those with exposure in adulthood only (β = -.10, 95% CI = -.20, -.02) or no exposure (β = -.11, 95% CI = -.23, -.03; [∆R2= .347, F(8, 245) = 15.7, p < .001) had lower craving via lower trauma symptomatology but no difference when compared to those with ETE only in childhood. Acting with awareness moderated this indirect effect (∆R2 = .04, F(3, 245) = 4.66, p = .004. At low levels of awareness, women with ETE during both childhood and adulthood reported higher craving via trauma symptomatology than women with no exposure or only adulthood exposure.

CONCLUSIONS

Low levels of acting with awareness may worsen trauma symptoms after ETE, which in turn may lead to more craving for women in substance use treatment. Despite a small moderating effect size, acting with awareness may have clinical significance due to the prevalence of trauma symptoms among women in SUD treatment.

A Cluster-Randomized Trial Comparing Songwriting and Recreational Music Therapy via Craving and Withdrawal in Adults on a Detoxification Unit

BACKGROUND

Craving and withdrawal can contribute to the development and maintenance of substance use disorder (SUD), relapse, and overdose. Although music therapy can positively impact craving and withdrawal in adults with SUD on a detoxification unit, there is a lack of randomized research comparing different music therapy interventions as well as studies measuring within-session changes in these critical constructs.

OBJECTIVE

The purpose of this effectiveness study was to compare motivational-educational songwriting (MESW) and recreational music therapy (RMT) via measures of craving and withdrawal in adults with SUD on a detoxification unit using a two-group pre- and posttest design.

METHOD

Participants (N = 134) were cluster-randomized to a single group MESW or RMT condition. Established craving and withdrawal psychometric instruments were used as pre- and posttests to determine potential within- and between-group differences.

RESULTS

There were significant within-group differences in craving subscales of urges and coping as well as withdrawal, all p < .001. Within-group effect sizes ranged from .244 to .456 with favorable changes from pre- to posttest. There was no between-group difference among the MESW and RMT conditions, all p > .05.

CONCLUSIONS

Although the specific music therapy intervention did not impact craving or withdrawal, a single MESW or RMT session can have an immediate and significant positive impact on craving and withdrawal in adults with SUD on a detoxification unit. As the MESW condition also addressed motivational and educational aspects of recovery, perhaps MESW interventions are ideal in detoxification settings.

Repetitive transcranial magnetic stimulation combined with cognitive behavioral therapy treatment in alcohol-dependent patients: A randomized, double-blind sham-controlled multicenter clinical trial

BACKGROUND

Alcohol dependence (AD) is a complex addictive disorder with a high relapse rate. Previous studies have shown that both repetitive transcranial magnetic stimulation (rTMS) and cognitive behavioral therapy (CBT) may be effective for AD, and we aim to explore more effective treatment options to reduce relapse rates for AD.

MATERIALS AND METHODS

A total of 263 AD patients were recruited. They were divided into six groups according to the location and the type of rTMS: left dorsolateral prefrontal cortex (DLPFC), right DLPFC, sham stimulation, and whether they received CBT treatment: with a fixed schedule (C1) and without a fixed plan (C0). There were included in sham rTMS + C0 group (n = 50), sham rTMS + C1 group (n = 37), right rTMS + C0 group (n = 45), right rTMS + C1 group (n = 42), left rTMS + C0 group (n = 49), left rTMS + C1 group (n = 40). We used obsessive compulsive drinking scale (OCDS), visual analogue scale (VAS), alcohol dependence scale (ADS), montreal cognitive assessment (MoCA), generalized anxiety disorder-7 (GAD-7), patient health questionnaire-9 items (PHQ-9), and Pittsburgh sleep quality index (PSQI) to assess alcohol cravings, alcohol dependence, cognition, anxiety, depression, and sleep quality. They were followed up and evaluated for relapse.

RESULTS

The sham rTMS + C0 group relapse rate was significantly higher than the right rTMS + C1 group (P = 0.006), the left rTMS + C0 group (P = 0.031), the left rTMS + C1 group (P = 0.043). The right rTMS + C0 group showed significantly higher relapse rate compared to the right rTMS + C1 group (P = 0.046). There was no significant difference in relapse rates between other groups. The repeated-measures ANOVA showed an interaction effect between group and time was significant in the rate of patient health questionnaire-9 items (PHQ-9) scale reduction (P = 0.020). Logistic analysis indicated that smoking and alcohol consumption were independent determinants of relapse (P < 0.05). At 24 weeks of follow-up, Kaplan-Meier survival analysis reveal that there is statistically significant relapse rate between six groups (P = 0.025), left rTMS + C1 group has the best treatment effect for alcohol dependent patients. Cox regression analysis confirmed that current smoking, total cholesterol, and total bilirubin (TBIL) level were risk factors of relapse (P < 0.05).

CONCLUSION

This study is the first to suggest that the combination of rTMS and CBT may be a potentially effective treatment for reducing relapse.

Abnormal white matter within brain structural networks is associated with high-impulse behaviour in codeine-containing cough syrup dependent users

Codeine-containing cough syrup (CCS) is considered as one of the most popular drug of dependence among adolescents because of its inexpensiveness and easy availability. However, its relationship with neurobiological effects remains sparsely explored. Herein, we examined how high-impulse behaviours relate to changes in the brain structural networks. Forty codeine-containing cough syrup dependent (CCSD) users and age-, gender-, and number of cigarettes smoked per day -matched forty healthy control (HC) subjects underwent structural brain imaging via MRI. High-impulse behaviour was assessed using the 30-item self-rated Barratt Impulsiveness Scale (BIS-11), and structural networks were constructed using diffusion tensor imaging and AAL-90 template. Between-group topological metrics were compared using nonparametric permutations. Benjamin-Hochberg false discovery rate correction was used to correct for multiple comparisons (P < 0.05). The relationships between abnormal network metrics and clinical characteristics of CCS dependent (BIS-11 total score, CCS- dependent duration and mean dose) were examined by Spearman's correlation. Structural networks of the CCSD group demonstrated lower small-world properties than those of the HC group. Abnormal changes in nodal properties among CCSD users were located mainly in the frontal gyrus, inferior parietal lobe and olfactory cortex. NBS analysis further indicated disrupted structural connections between the frontal gyrus and multiple brain regions. There were significant correlations between abnormal nodal properties of the frontal gyrus and clinical characteristics (BIS-11 total score, CCS dependent duration and mean dose) in the CCSD group. These findings suggest that the high-impulse behavioural expression in CCS addiction is associated with widespread brain regions, particularly within those in the frontal cortex. Aberrant brain regions and disrupted connectivity of structural network may be the bases of neuropathology for underlying symptoms of high-impulse behaviours in CCSD users, which may provide a novel sight to better treat and prevent codeine dependency in adolescents.

Assessing combinatorial effects of HIV infection and former cocaine dependence on cognitive control processes: A high-density electrical mapping study of response inhibition

Stimulant drug use in HIV + patients is associated with poor personal and public health outcomes, including high-risk sexual behavior and faster progression from HIV to AIDS. Inhibitory control--the ability to withhold a thought, feeling, or action--is a central construct involved in the minimization of risk-taking behaviors. Recent neuroimaging and behavioral evidence indicate normalization of inhibitory control processes in former cocaine users as a function of the duration of drug abstinence, but it is unknown whether this recovery trajectory persists in former users with comorbid HIV. Here, we investigate the neural correlates of inhibitory control in 103 human subjects using high-density EEG recording as participants performed a Go/NoGo response inhibition task. Four groups of participants were recruited, varying on HIV and cocaine-dependence status. Electrophysiological responses to successful inhibitions and behavioral task performance were compared among groups. Results indicate persistent behavioral and neurophysiological impairment in HIV+ patients' response inhibition despite current abstinence from cocaine. Analysis of task performance showed that HIV+ abstinent cocaine-dependent participants demonstrate the lowest performance of all groups across all metrics of task accuracy. Planned comparisons of electrophysiological components revealed a main effect of scalp site and an interaction between HIV-status and scalp site on N2 amplitudes during successful inhibitions. Analysis of the P3 time region showed a main effect of scalp site and an interaction between HIV-status and cocaine dependence. These results suggest synergistic alterations in the neurophysiology of response inhibition and indicate that abstinence-related recovery of inhibitory control may be attenuated in patients with HIV.

Incentive motivation: 'wanting' roles of central amygdala circuitry

The central nucleus of amygdala (CeA) mediates positively-valenced reward motivation as well as negatively-valenced fear. Optogenetic or neurochemical stimulation of CeA circuitry can generate intense incentive motivation to pursue and consume a paired natural food, sex, or addictive drug reward, and even create maladaptive 'wanting what hurts' such as attraction to a shock rod. Evidence indicates CeA stimulations selectively amplify incentive motivation ('wanting') but not hedonic impact ('liking') of the same reward. Further, valence flips can occur for CeA contributions to motivational salience. That is, CeA stimulation can promote either incentive motivation or fearful motivation, even in the same individual, depending on situation. These findings may carry implications for understanding CeA roles in neuropsychiatric disorders involving aberrant motivational salience, ranging from addiction to paranoia and anxiety disorders.

Functional evaluation of NK1 antagonism on cue reactivity in opiate dependence; An fMRI study

BACKGROUND

Opiate addiction is a major health challenge with substantial societal cost. Though harm minimisation strategies have been effective, there is a growing need for new treatments for detoxification and relapse prevention. Preclinical research has found neurokinin 1 (NK1) receptors have prominent effects on opiate reward and reinforcement, and human studies have found NK1 antagonism led to reductions in craving and withdrawal. However, its effect on brain mechanisms in opiate addiction has not yet been examined.

METHODS

This study aims to assess the impact of NK1 antagonist aprepitant on heroin cue-elicited changes in blood-oxygenation level dependent (BOLD) signal in opiate dependent individuals undergoing detoxification. Participants will attend two scanning sessions and receive a single dose of aprepitant (320 mg) and a placebo in a randomised, cross-over design. During functional magnetic resonance imaging participants will undergo two runs of a cue reactivity task, which consists of passive viewing of drug cues or neutral cues in a block design fashion. We hypothesise that NK1 antagonism will attenuate the BOLD response to drug cues in the caudate nucleus and amygdala. Regions of interest were selected based on NK1 receptor density and their role in cue reactivity and craving.

Measurement of Motivation States for Physical Activity and Sedentary Behavior: Development and Validation of the CRAVE Scale

Physical activity, and likely the motivation for it, varies throughout the day. The aim of this investigation was to create a short assessment (CRAVE: Cravings for Rest and Volitional Energy Expenditure) to measure motivation states (wants, desires, urges) for physical activity and sedentary behaviors. Five studies were conducted to develop and evaluate the construct validity and reliability of the scale, with 1,035 participants completing the scale a total of 1,697 times. In Study 1, 402 university students completed a questionnaire inquiring about the want or desire to perform behaviors "at the present moment (right now)." Items related to physical activity (e.g., "move my body") and sedentary behaviors (e.g., "do nothing active"). An exploratory structural equation model (ESEM) revealed that 10 items should be retained, loading onto two factors (5 each for Move and Rest). In Study 2, an independent sample (n = 444) confirmed these results and found that Move and Rest desires were associated with stage-of-change for exercise behavior. In Study 3, 127 community-residing participants completed the CRAVE at 6-month intervals over two years- two times each session. Across-session interclass correlations (ICC) for Move (ICC = 0.72-0.95) and Rest (ICC = 0.69-0.88) were higher than when they were measured across 24-months (Move: ICC = 0.53; Rest: ICC = 0.49), indicating wants/desires have state-like qualities. In Study 4, a maximal treadmill test was completed by 21 university students. The CRAVE was completed immediately pre and post. Move desires decreased 26% and Rest increased 74%. Changes in Move and Rest desires were moderately associated with changes in perceived physical fatigue and energy. In Study 5, 41 university students sat quietly during a 50-min lecture. They completed the CRAVE at 3 time points. Move increased 19.6% and Rest decreased 16.7%. Small correlations were detected between move and both perceived energy and tiredness, but not calmness or tension. In conclusion, the CRAVE scale has good psychometric properties. These data also support tenets of the WANT model of motivation states for movement and rest (Stults-Kolehmainen et al., 2020a). Future studies need to explore how desires to move/rest relate to dynamic changes in physical activity and sedentarism.

Altered intrinsic connectivity distribution in internet gaming disorder and its associations with psychotherapy treatment outcomes

Alterations in brain connectivity have been implicated in internet gaming disorder (IGD). However, little is known about alterations in whole-brain connectivity and their associations with long-term treatment outcomes. Here, we used a relatively new analytic approach, intrinsic connectivity distribution (ICD) analysis, to examine brain connectivity in 74 IGD participants and 41 matched healthy controls (HCs) and conducted post hoc seed-based resting-state functional connectivity (rsFC) analyses based on the ICD findings. We also examined how these findings related to outcomes involving a craving behavioral intervention (CBI) for IGD. IGD participants showed less whole-brain connectivity in the left angular gyrus and ventromedial prefrontal cortex (vmPFC) compared with HC participants. Seed-based rsFC analyses revealed that the left angular gyrus in the IGD group showed less connectivity with areas involved in the default-mode network and greater connectivity with areas in the salience and executive control networks. CBI was associated with improved connectivity within regions in the default-mode network and regions across the default-mode and salience networks. ICD-identified connectivity differences in the left angular gyrus and vmPFC were related to changes in craving and severity of addiction 6 months after the intervention. The findings suggest that IGD is associated with alterations in brain connectivity that may be sensitive to interventions. Thus, the findings have implications for understanding mechanisms underlying CBI effects and for further treatment development.

A deeper insight into how GABA-B receptor agonism via baclofen may affect alcohol seeking and consumption: lessons learned from a human laboratory investigation

Previous studies suggest that GABA-B receptor agonism may represent an effective pharmacological approach to treat addictive disorders. Baclofen is a selective GABA-B receptor agonist which has been investigated as a potential treatment for alcohol use disorder. However, research is needed to understand the biobehavioral mechanisms underlying baclofen's effect on alcohol use. In the present randomized, double-blind, placebo-controlled study, thirty-four alcohol-dependent individuals were randomized to receive baclofen (30 mg/d) or placebo for a week, and then participated in a laboratory experiment consisting of three procedures: alcohol cue-reactivity, priming, and self-administration. During the experiment, craving and other subjective responses to alcohol were assessed, and blood samples were collected for pharmacokinetic measurements. The effects of baclofen on the relationships between different alcohol-related laboratory parameters were investigated. Baclofen pharmacokinetic parameters and their correlations with behavioral measures were also examined. Results showed that baclofen disrupted the link between alcohol priming and self-administration, as indicated by significant interaction effects between drug condition (baclofen vs. placebo) and some of the priming variables (alcohol craving: F3,9 = 6.03, p = 0.01; alcohol sedation: F3,6 = 7.16, p = 0.01) on the total amount of alcohol self-administered. Considerable interindividual variability in baclofen pharmacokinetic parameters was observed. Maximum plasma concentrations of baclofen negatively correlated with cue-induced alcohol craving (r = -0.57, p = 0.03) and priming-induced ratings of 'like more' (r = -0.59, p = 0.02). In conclusion, baclofen may work by dissociating the link between an initial drink (priming) and subsequent alcohol consumption (self-administration). Considerable pharmacokinetic variability is an important factor to take into account when employing baclofen as a treatment for alcohol use disorder.

Insights into the Neurobiology of Craving in Opioid Use Disorder

Purpose of review

Opioids remain the most potent form of pain relief currently available, yet have a high abuse liability. Here we discuss underlying neurobiological changes in Opioid Use Disorder (OUD) that likely contribute to drug craving, which in turn drives continued drug use and relapse.

Recent findings

Craving has emerged as a strong indicator in drug-seeking and relapse. Studies have demonstrated a number of allostatic changes in circuitry that facilitate learning of drug-stimuli relationships, thereby augmenting cue-triggered drug use and relapse.

Summary

This review will focus on key neurobiological changes in underlying circuitry observed during the initial and continued exposure to opioids that result in an increase in neural-reactivity to drug-related intrinsic and extrinsic drug cues, and to enhanced learning of drug-context correlations. This sensitized learning state may be an indication of the underlying framework that drives craving and ultimately, motivates increased salience of drug cues and drives drug-seeking.

Polymorphisms in Stress-Related Genes Are Associated with Reduced Cocaine Abuse and Longer Retention in Methadone Maintenance Treatment for Opioid Use Disorder

BACKGROUND

As CRH-binding protein (CRHBP) SNP rs1500 was associated with reduced cocaine abuse after 1 year in methadone maintenance treatment (MMT) for heroin addiction, we evaluated the association of additional 28 selected SNPs, in 17 stress-related genes, with MMT outcome.

METHODS

The distribution of genotypes of each SNP by cocaine abuse after 1 year in MMT was assessed under the dominant and recessive models using χ2. Cumulative retention (up to 26.5 years) was studied using Kaplan-Meier analyses. Logistic regression and Cox model were used for multivariate analyses.

RESULTS

Of a nonselective sample of 404 patients, 25 patients with <50% Europeans/Middle Eastern ancestry were excluded. Of the remaining 379 patients, 330 (87.1%) stayed at least 1 year in treatment. Four SNPs were associated with cocaine abuse after 1 year in MMT. A lower proportion of cocaine abusers was found in the groups of subjects with the following genotypes: arginine vasopressin (AVP) SNP rs2282018 CC, CRHBP rs7728378 TT, galanin rs3136541 TT/TC, and neuropeptide Y receptor Y1 (NPY1R) rs4518200 AA. The following independent variables were associated with lack of cocaine in urine after 1 year (multivariate analyses): CRHBP rs7728378 TT, NPY1R rs4518200 AA, no cocaine in urine on admission, as well as opiate and benzodiazepine use after 1 year in MMT. Cumulative retention (n = 379) was longer in carriers of AVP rs2282018 CC (13.7 years, 95% CI 11.1-16.2) versus TT/TC genotypes (10.5, 95% CI 9.4-11.5) (p = 0.0230) Conclusions: The study suggests that a reduction in cocaine abuse and longer retention among MMT patients is mediated in part by variants in stress-related genes and is a step toward precision medicine.

Opioid-induced structural and functional plasticity of medium-spiny neurons in the nucleus accumbens

Opioid Use Disorder (OUD) is a chronic relapsing clinical condition with tremendous morbidity and mortality that frequently persists, despite treatment, due to an individual's underlying psychological, neurobiological, and genetic vulnerabilities. Evidence suggests that these vulnerabilities may have neurochemical, cellular, and molecular bases. Key neuroplastic events within the mesocorticolimbic system that emerge through chronic exposure to opioids may have a determinative influence on behavioral symptoms associated with OUD. In particular, structural and functional alterations in the dendritic spines of medium spiny neurons (MSNs) within the nucleus accumbens (NAc) and its dopaminergic projections from the ventral tegmental area (VTA) are believed to facilitate these behavioral sequelae. Additionally, glutamatergic neurons from the prefrontal cortex, the basolateral amygdala, the hippocampus, and the thalamus project to these same MSNs, providing an enriched target for synaptic plasticity. Here, we review literature related to neuroadaptations in NAc MSNs from dopaminergic and glutamatergic pathways in OUD. We also describe new findings related to transcriptional, epigenetic, and molecular mechanisms in MSN plasticity in the different stages of OUD.

Investigating the link between serum concentrations of brain-derived neurotrophic factor and behavioral measures in anxious alcohol-dependent individuals

Brain-derived neurotrophic factor (BDNF) plays a role in different neurophysiological processes, including those involved in alcohol- and anxiety-related behaviors. Preclinical and clinical studies indicate that chronic excessive alcohol use leads to a downregulation of BDNF production in the periphery and in the brain. In addition, a decrease in BDNF concentrations in the blood has been reported to be associated with increased anxiety levels. Non-treatment-seeking alcohol-dependent individuals with high trait anxiety were studied to assess whether serum BDNF concentrations may be linked to self-reported levels of alcohol drinking, anxiety, and other behavioral measures. Participants had a current diagnosis of alcohol dependence, high trait anxiety score, and were not seeking treatment for alcohol dependence or anxiety. A fasting blood sample was collected from each participant and serum BDNF was measured using an enzyme-linked immunosorbent assay (ELISA). Behavioral data were collected on the same day, including measures of alcohol drinking, craving, dependence severity, and anxiety. Bivariate correlations were run between BDNF levels and behavioral measures. Serum BDNF concentrations were negatively correlated with average drinks per drinking days (r = -0.41, p = 0.02) and positively correlated with obsessive-compulsive drinking scale (r = 0.48, p = 0.007) and state-trait anxiety inventory (r = 0.52, p = 0.003) scores. These findings shed light on the possible role of the BDNF system in the neurobiology of alcohol- and anxiety-related behaviors.

Atrial natriuretic peptide (ANP): A novel mechanism for reducing ethanol consumption and seeking behaviors in female alcohol preferring (P) rats

Atrial Naturietic Peptide (ANP) is a neuropeptide that regulates function of the hypothalamic-pituitary-adrenal (HPA) axis, immune and neuroimmune system, and epigenetic factors. Research has indicated that ANP may mediate alcohol intake, withdrawal, and craving like behaviors. ANP receptors are present in the mesocorticolimbic (MCL) reward pathway of the brain, which includes the nucleus accumbens (Acb) and the ventral tegmental area (VTA). The objectives of the present study were to examine the effects of ANP microinjected into Acb subregions (Shell (Sh), Core (Co), ventral to AcbSh) on operant ethanol (EtOH) self-administration and into posterior VTA (pVTA) on EtOH-seeking behavior of female alcohol-preferring (P) rats. In the first experiment, ANP (0, 10 μg, or 100 μg) was microinjected into subregions of the Acb to determine its effects on EtOH self-administration. In the second experiment, ANP was microinjected into pVTA to determine its effects on Pavlovian Spontaneous Recovery (PSR) of responding, a measure of context-induced EtOH-seeking behavior. Administration of ANP directly into the AcbSh significantly reduced EtOH self-administration compared to vehicle, whereas ANP into the AcbCo or areas directly ventral to the AcbSh did not alter responding for EtOH. Microinjection of ANP into the pVTA significantly reduced responding on the EtOH-associated lever during the PSR test. The data indicate that activation of ANP systems in the (a) AcbSh can inhibit EtOH intake, and (b) in the pVTA can inhibit EtOH-seeking behavior. The results suggest that manipulations of the ANP system could be a potential target for pharmacotherapeutic intervention to treat alcohol use disorder. Supported in part by AA07462, AA07611, AA10717, AA10721, AA013522, AA019366, AA020908, AA022287, and AA024612.

Test-retest reliability of DSM-5 substance disorder measures as assessed with the PRISM-5, a clinician-administered diagnostic interview

AIM

In DSM-5, the definitions of substance use disorders (SUD) were changed considerably, yet little is known about the reliability of DSM-5 SUD and its new features.

METHODS

The test-retest reliability of DSM-5 SUD and DSM-IV substance dependence (SD) was evaluated in 565 adult substance users, each interviewed twice by different clinician interviewers using the semi-structured Psychiatric Research Interview for Substance and Mental Disorders, DSM-5 version (PRISM-5). DSM-5 SUD and DSM-IV SD criteria were assessed for past year and lifetime, yielding diagnoses and severity levels for alcohol, tobacco, cannabis, cocaine, heroin, opioids, sedatives, hallucinogen, and stimulant use disorders. Cohen's and intraclass correlation coefficients (ICC) assessed reliability for categorical and graded outcomes, respectively. Factors potentially influencing reliability were explored, including inpatient vs. community participant, days between interviews gender, age, race/ethnicity, and SUD severity.

RESULTS

DSM-5 SUD diagnoses had substantial to excellent reliability for most substances (κ = 0.63-0.94), and moderate for others (hallucinogens, stimulants, sedatives; κ = 0.50-0.59). For graded outcomes (DSM-5 SUD mild, moderate, severe; criteria count 0-11), reliability was substantial to excellent (ICC = 0.74-0.99). Comparisons of DSM-5 SUD and DSM-IV SD reliability showed few significant differences. Reliability of the DSM-5 craving criterion was excellent for heroin (κ = 0.84-0.95) and moderate to substantial for other substances (κ = 0.49-0.76). The only factor influencing reliability of SUD was severity, with milder disorders significantly more likely to be discordant between the interviews.

CONCLUSION

Reproducibility is crucial to good measurement. In a large sample using rigorous methodology, diagnoses and dimensional measures from clinician-administered interviews for DSM-5 SUD were generally highly reliable.

Choosing the Optimal Brain Target for Neuromodulation Therapies as Alcohol Addiction Progresses—Insights From Pre-Clinical Studies

Purpose of the Review

Development of addiction involves a transition from reward-driven to habitual behavior, mediated by neuroplastic changes. Based on preclinical findings, this article article reviews the current knowledge on the use of neuromodulation therapies to target alcohol addiction and essentially reduce relapse.

Recent Findings

To date, only a limited number of preclinical studies have investigated the use of neuromodulation in alcohol addiction, with the focus being on targeting the brain reward system. However, as addiction develops, additional circuits are recruited. Therefore, a differential setup may be required when seeking to alter the chronic alcohol-dependent brain, as opposed to treating earlier phases of alcohol addiction.

Summary

To promote enduring relapse prevention, the choice of brain target should match the stage of the disorder. Further studies are needed to investigate which brain areas should be targeted by neuromodulating strategies, in order to sufficiently alter the behavior and pathophysiology as alcohol addiction progresses.