Drug addiction: the neurobiology of disrupted self-control

Evidence for post-decisional conflict monitoring in delay discounting

Choice impulsivity can be measured by offering a sequence of various binary choices between smaller, immediately available rewards and larger, later available rewards. An individual's delay discount (DD) rate reflects the aggregate decision-making tendency. Given the broad spectrum of disorders associated with a high DD rate, this may be an important transdiagnostic factor. This study aimed to establish whether post-decisional neurophysiological processes reflecting the presence of error monitoring are involved in delay discounting. A large sample (N = 97) was investigated, including 46 females and 51 males. The electroencephalogram (EEG) was recorded during the classic monetary choice questionnaire (MCQ-27). Error-related event-related potentials (ERPs) and event-related oscillations (EROs) following responses were analyzed. A modest relationship between error positivity (Pe) and DD rate was seen centro-parietal, with higher amplitude for low DD individuals after choosing immediate rewards. A robust association was found between DD rate and theta oscillation power increases. This was most prominent in low DD individuals after making an immediate reward choice. Theta power was positively associated with decision (reaction) time, suggesting an association between pre- and post-decisional conflict. No evidence was found for an error-related negativity (ERN) and delta oscillations. This study provides clear evidence for conflict monitoring as a post-decision process in delay discounting. Findings suggest that diminished theta band power bursts and lower Pe amplitude, observed after choosing an immediate reward, reflect the neurophysiological consequence and possibly the cause of steep delay discounting. High DD was characterized by prefrontal hypoactivation and appears to result from affective decision-making.

Impulse and reason? Justifications in problem gambling

People often use justifications to make desirable choices, but little is known about these justificatory thoughts in gambling. We conducted an exploratory Study 1 (n = 101) and a confirmatory Study 2 (n = 154) using online surveys, recruiting gamblers with prior and current experience of trying to reduce their gambling. Using justifications recognized in the domains of eating and consumer behavior (e.g., prior use of effort, feelings of achievement), we examined whether justifications were associated with problem gambling severity, and whether they explained additional variance above trait impulsivity and cognitive distortions. In both studies, justifications were positively associated with problem gambling severity, after accounting for trait impulsivity and cognitive distortions. Additionally, justifications were positively correlated with trait urgency and cognitive distortions, indicating that such thinking may not be antithetical to impulsivity. These data provide proof-of-principle evidence that justificatory thinking occurs in the context of gambling, is related to problem gambling severity, and may therefore represent a neglected aspect of gambling-related cognitions.

Abnormal resting-state functional connectivity of the right anterior cingulate cortex in chronic ketamine users and its correlation with cognitive impairments

BACKGROUND

Chronic ketamine use leads to cognitive impairments, however, the neural mechanisms underpinning these impairments are still unclear.

AIMS

Many studies showed Anterior cingulate cortex (ACC)is strongly involved in cognition and drug addiction, as supported by our previous studies. The objective of this study was to assess the variations in resting-state functional connectivity (FC) changes in the right anterior cingulate cortex (ACC) of chronic ketamine users (CKUs) and their relationship with cognitive performance.

METHODS

The study enrolled 28 chronic ketamine users (CKUs) and 30 healthy controls (HCs). Resting-state functional magnetic resonance imaging (fMRI) data were gathered from both groups. Cognitive functions were evaluated using the MATRICS Consensus Cognitive Battery (MCCB).

RESULTS

CKUs demonstrated significantly poorer cognitive performance than HCs in various cognitive domains, including Visual Learning, Speed of Processing, Working Memory, and the composite score of MCCB. Group-level comparisons revealed that CKUs exhibited enhanced functional connectivity between the right ACC and the right postcentral gyrus (PCG) compared to HCs. There was a positive relationship between the connectivity of right ACC-PCG and reasoning and problem-solving score, but there was no significant association with the characteristics of ketamine use.

CONCLUSION

CKUs showed enhanced connectivity between the right ACC and the right PCG. This enhanced functional connectivity may indicate functional compensation for cognitive deficits in CKUs, especially for reasoning and problem-solving impairments in CKUs.

Cross-Sectional Study on the Effect of Bilingualism, Age, Gender, and Family Income on Executive Function Development in a Sample of Lebanese School-Aged Children

This study investigates executive functions (EFs) and selected developmental factors in 120 children aged 6-11 years. By examining inhibition, working memory, and cognitive flexibility, the research evaluates the potential influences of age, gender, bilingualism, and family income on these EF skills. Tests adapted to Lebanese Arabic were used to assess EFs. Results indicate a linear development of inhibition, working memory, and flexibility with age. Gender differences were observed, affecting verbal and visuospatial working memory as well as flexibility. Bilingualism positively impacts EFs, with early bilinguals outperforming late bilinguals. Family income, however, shows no significant effect on EFs.

Decoding Cognitive Control and Cognitive Flexibility as Concomitants for Experiential Avoidance in Social Anxiety

Background and objectives: Avoidance is regarded as a central hallmark of social anxiety. Experiential avoidance is perilous for social anxiety, specifically among university students (young adults). Additionally, cognitive control and cognitive flexibility are crucial components of executive functions for a fulfilling and healthy lifestyle. The current research is a modest attempt to understand how cognitive flexibility and cognitive control affect the emergence of experiential avoidance in social anxiety in young adults. Methods: Using an ex-post facto design, the Social Phobia Inventory was employed to screen university students with social anxiety based on which one hundred and ninety-five were identified. Thereafter, participants completed the standardized measures on experiential avoidance, cognitive control and cognitive flexibility. Results: A stepwise multiple regression analysis was computed wherein the cognitive control predicts an amount of 5% of variance towards experiential avoidance, whereas a 10% of additional variance has been contributed by cognitive flexibility. Interpretation and Conclusions: The statistical outcome indicated that cognitive control is positively associated with experiential avoidance which is a negative correlate to cognitive flexibility among university students. Both also emerged as significant predictors of experiential avoidance and add a cumulative variance of 15% towards the same. This conclusion supports the need for improved and efficient management techniques in counseling and clinical settings.

Opioid Maintenance Therapy: A Review of Methadone, Buprenorphine, and Naltrexone Treatments for Opioid Use Disorder

The rates of opioid use and opioid related deaths are escalating in the United States. Despite this, evidence-based treatments for Opioid Use Disorder are underutilized. There are three medications FDA approved for treatment of Opioid Use Disorder: Methadone, Buprenorphine, and Naltrexone. This article reviews the history, criteria, and mechanisms associated with Opioid Use Disorder. Pertinent pharmacology considerations, treatment strategies, efficacy, safety, and challenges of Methadone, Buprenorphine, and Naltrexone are outlined. Lastly, a practical decision making algorithm is discussed to address pertinent psychiatric and medical comorbidities when prescribing pharmacology for Opioid Use Disorder.

Executive functions and their relationship with age: Insights from a novel neuropsychological Assessment Battery in Children-a pilot study

Executive functions (EFs) are a set of cognitive processes that enable individuals to manage and coordinate their thoughts and actions toward achieving specific goals. EFs include planning, organizing, initiating, and monitoring actions, and have been found to improve with age due to the maturation of the brain, especially during childhood. Therefore, our correlational study sought to determine the relationship between the performance in executive functions and age in 79 children (36 girls, 45.6%) throughout development, between the ages of 6 and 12 (mean = 9.25; SD = 2.05), using a battery designed in Chile: BEFE (Batería de Evaluación de las Funciones Ejecutivas: Executive Function Assessment Battery) based on traditional neuropsychological tests to evaluate Working Memory, Inhibitory Control, Cognitive Flexibility, and Planning skills. Our results showed various correlations between the variables age and performance in various behavioral parameters, demonstrating an increase in the number of correct responses (positive correlation) and/or a decrease in errors (negative correlation) with age (6-12) in the subtests that correspond to dimensions of Cognitive Flexibility (Semantic and Phonological Fluency, Card Sorting Game, and Tracing Tasks), Inhibitory Control (ENA-F and Sentence Completion), Working Memory (Audio-verbal WM Forward and Ordering, and Visuospatial WM Forward and Backward), and Planning (La Portada de Antofagasta and FISA Maps). These results are consistent with previous empirical evidence and support the notion of a developmental relationship between EF performance and age. Additionally, this study contributes to understanding EF development in culturally specific contexts, highlighting the importance of contextually relevant assessment tools in evaluating cognitive development.

Do Substances Used in Adolescence Predict the Persistence of Substance Use Disorders in Adulthood? A 15-Year Study of Youth After Detention

PURPOSE

Investigate if the type of substance use disorder (SUD) in adolescence predicts SUDs in adulthood and examine sex and racial/ethnic differences in the persistence of SUDs.

METHODS

Data are from the Northwestern Juvenile Project, a 15-year longitudinal study of 1829 youth randomly sampled from detention in Chicago, IL (1995-1998). Interviewers assessed SUDs using structured diagnostic interviews.

RESULTS

Compared with females without an SUD at detention, females with cannabis alone, comorbid alcohol and cannabis, or SUDs other than alcohol and cannabis at detention had higher odds of having an SUD 5 years later (25%, 32%, and 36% vs. 15%, adjusted odds ratio [AOR] = 1.94, 95% confidence interval [CI] 1.11-3.40; AOR = 2.76, 95% CI 1.58-4.83; AOR = 3.46, 95% CI 1.56-7.66, respectively). Males and females with SUDs other than alcohol and cannabis at detention had greater odds of having an SUD 15 years later, compared with those without an SUD at detention (males: 36% vs. 14%, AOR = 2.98, 95% CI 1.14-7.83; females: 29% vs. 8%, AOR = 4.77, 95% CI 1.85-12.30). Among youth with an SUD at detention, males were more likely than females to have an SUD 15 years later (AOR = 1.84, 95% CI 1.03-3.29); non-Hispanic White and Hispanic males were more likely to persist than Black males (AOR = 3.32, 95% CI 1.50-7.35; AOR = 2.32, 95% CI 1.04-5.18, respectively).

DISCUSSION

The type of SUD during adolescence matters. Youth with SUDs such as cocaine and opioids fared the worst. Healthcare providers must collaborate with correctional officials to increase service provision.

A systems identification approach using Bayes factors to deconstruct the brain bases of emotion regulation

Cognitive reappraisal is fundamental to cognitive therapies and everyday emotion regulation. Analyses using Bayes factors and an axiomatic systems identification approach identified four reappraisal-related components encompassing distributed neural activity patterns across two independent functional magnetic resonance imaging (fMRI) studies (n = 182 and n = 176): (1) an anterior prefrontal system selectively involved in cognitive reappraisal; (2) a fronto-parietal-insular system engaged by both reappraisal and emotion generation, demonstrating a general role in appraisal; (3) a largely subcortical system activated during negative emotion generation but unaffected by reappraisal, including amygdala, hypothalamus and periaqueductal gray; and (4) a posterior cortical system of negative emotion-related regions downregulated by reappraisal. These systems covaried with individual differences in reappraisal success and were differentially related to neurotransmitter binding maps, implicating cannabinoid and serotonin systems in reappraisal. These findings challenge 'limbic'-centric models of reappraisal and provide new systems-level targets for assessing and enhancing emotion regulation.

Neurofeedback for alcohol addiction: Changes in resting state network activity✰

Alcohol dependence continues to be a major global burden despite significant research progress and treatment development. The aim of this study was to investigate whether neurofeedback training can alter resting state fMRI activity in brain regions that play a crucial role in addiction disorders in patients with alcohol dependence. For this purpose, a total of 52 patients were recruited for the present study, randomized, and divided into an active and a sham group. Patients in the active group received three sessions of neurofeedback training. We compared the resting state data in the active group as part of the NF training on six measurement days. When comparing the results of the active group from neurofeedback day 3 with baseline 1, a significant reduction in activated voxels in the ventral attention network area was seen. This suggests that reduced activity over the course of therapy in subjects may lead to greater independence from external stimuli. Overall, a global decrease in activated voxels within all three analysed networks compared to baseline was observed in the study. The use of resting-state data as potential biomarkers, as activity changes within these networks, may be to help restore cognitive processes and alcohol abuse-related craving and emotions.

Impulsivity and aggression in alcohol withdrawal syndrome is modulated by the interaction of ZNF804A and mTOR polymorphism

Alcohol withdrawal syndrome (AWS) is a poorly studied phenotype of alcohol use disorder. Understanding the relationship between allelic interactions and AWS-related impulsivity and aggression could have significant implications. This study aimed to investigate the main and interacting effects of ZNF804A and mTOR on impulsivity and aggression during alcohol withdrawal. 446 Chinese Han adult males with alcohol dependence were included in the study. Impulsivity and aggression were assessed, and genomic DNA was genotyped. Single gene analysis showed that ZNF804A rs1344706 (A allele/CC homozygote) and mTOR rs1057079 (C allele/TT homozygote) were strongly associated with AWS-related impulsivity and aggression. In the allelic group, MANOVA revealed a significant gene x gene interaction, suggesting that risk varied systematically depending on both ZNF804A and mTOR alleles. Additionally, a significant interactive effect of ZNF804A rs1344706 and mTOR rs7525957 was found on motor impulsivity and physical aggression, and the ZNF804A rs1344706 gene variant had significant effects on motor impulsivity and physical aggression only in mTOR rs7525957 TT homozygous carriers. The study showed that specific allelic combinations of ZNF804A and mTOR may have protective or risk-enhancing effects on AWS-related impulsivity and aggression.

Neurovascular effects of cocaine: relevance to addiction

Cocaine is a highly addictive drug, and its use is associated with adverse medical consequences such as cerebrovascular accidents that result in debilitating neurological complications. Indeed, brain imaging studies have reported severe reductions in cerebral blood flow (CBF) in cocaine misusers when compared to the brains of healthy non-drug using controls. Such CBF deficits are likely to disrupt neuro-vascular interaction and contribute to changes in brain function. This review aims to provide an overview of cocaine-induced CBF changes and its implication to brain function and to cocaine addiction, including its effects on tissue metabolism and neuronal activity. Finally, we discuss implications for future research, including targeted pharmacological interventions and neuromodulation to limit cocaine use and mitigate the negative impacts.

Associations between Gross and Fine Motor Skills, Physical Activity, Executive Function, and Academic Achievement: Longitudinal Findings from the UK Millennium Cohort Study

Accumulating evidence from behavioral studies and neuroscience suggests that motor and cognitive development are intrinsically intertwined. To explore the underlying mechanisms of this motor-cognition link, our study examined the longitudinal relationship of early motor skills and physical activity with later cognitive skills. The sample was 3188 children from the United Kingdom Millennium Cohort Study, followed at 9 months and 5, 7, and 11 years. Early motor skills were examined at 9 months. Children's daily physical activity level was measured using accelerometers at 7 years and a questionnaire was conducted at 11 years. Cognitive skills, including executive function and academic achievement, were measured at age 11. The results suggest that gross motor skills were positively associated with spatial working memory, whereas fine motor skills were predictive of good English and science outcomes. Moderate-to-vigorous activity was found to be negatively associated with English performance, although self-reported activity frequency was positively linked to math. Our results highlight the significant role of both gross and fine motor skills in cognitive development. This study also elucidates the limitations of using activity intensity to assess the impact of motor activity on children's cognitive development, suggesting that attention to the effects of specific types of physical activity would better elucidate the motor/cognition link.

The role of anticipated emotions in self-control: linking self-control and the anticipatory ability to engage emotions associated with upcoming events

Self-control is typically attributed to "cold" cognitive control mechanisms that top-down influence "hot" affective impulses or emotions. In this study we tested an alternative view, assuming that self-control also rests on the ability to anticipate emotions directed toward future consequences. Using a behavioral within-subject design including an emotion regulation task measuring the ability to voluntarily engage anticipated emotions towards an upcoming event and a self-control task in which subjects were confronted with a variety of everyday conflict situations, we examined the relationship between self-control and anticipated emotions. We found that those individuals (n = 33 healthy individuals from the general population) who were better able to engage anticipated emotions to an upcoming event showed stronger levels of self-control in situations where it was necessary to resist short-term temptations or to endure short-term aversions to achieve long-term goals. This finding suggests that anticipated emotions may play a functional role in self-control-relevant deliberations with respect to possible future consequences and are not only inhibited top-down as implied by "dual system" views on self-control.

Multimodal personalised executive function intervention (E-Fit) for school-aged children with complex congenital heart disease: protocol for a randomised controlled feasibility study

INTRODUCTION

Children with congenital heart disease (CHD) are at risk for executive functions (EF) impairments. To date, interventions have limited effects on EF in children and adolescents with complex CHD. Therefore, we developed a new multimodal and personalised EF intervention (E-Fit). This study aims to test the feasibility of this intervention called 'E-Fit' for children with complex CHD and EF impairments.

METHODS AND ANALYSIS

This is a single-centre, single-blinded, randomised controlled feasibility study exploring the E-Fit intervention. We aim to enrol 40 children with CHD aged 10-12 years who underwent infant cardiopulmonary bypass surgery and show clinically relevant EF impairments (T-score ≥60 on any Behaviour Rating Inventory for Executive Function questionnaire summary scale). The multimodal intervention was developed with focus groups and the Delphi method involving children and adolescents with CHD, their parents and teachers, and health professionals. The intervention is composed of three elements: computer-based EF training using CogniFit Inc 2022, performed three times a week at home; weekly EF remote strategy coaching and analogue games. The content of the computer and strategy training is personalised to the child's EF difficulties. The control group follows their daily routines as before and completes a diary about their everyday activities four times a week. Participants will be randomised in a 1:1 ratio. Feasibility is measured by the participants' and providers' ratings of the participants' adherence and exposure to the intervention, recruitment rates and the evaluation of the intended effects of the programme.

ETHICS AND DISSEMINATION

Local ethics committee approval was obtained for the study (BASEC-Nr: 2021-02413). Parents provide written informed consent. Key outputs from the trial will be disseminated through presentations at conferences, peer-reviewed publications and directly to participating families. Furthermore, these results will inform the decision whether to proceed to a randomised controlled trial to investigate effectiveness.

TRIAL REGISTRATION NUMBER

NCT05198583.

Childhood trauma, intraindividual reaction time variability, baseline respiratory sinus arrhythmia, and perceived relapse tendency among males with substance use disorders

Background: People with substance use disorders (SUDs) who have experienced serious childhood trauma may have executive function impairments contributing to relapse. Baseline respiratory sinus arrhythmia (RSA) reflects physiological regulation capacity, which has been found to buffer the negative effects of childhood trauma. Baseline RSA has also been found to be related to intraindividual reaction time variability (IIRTV), which is an index of executive function.Objectives: The present study examined the relationship between childhood trauma and perceived relapse tendency, the mediation role of IIRTV, and the moderation role of baseline RSA.Methods: The study is cross-sectional, a total of 110 males with SUDs participated (Mage = 46.45 years, SD = 11.24). The Childhood Trauma Questionnaire and Intention to Rehabilitate Questionnaire were used to assess childhood trauma and perceived relapse tendency, the two-choice oddball task was used to measure IIRTV, and electrocardiogram (ECG) data were collected to obtain baseline RSA.Results: IIRTV mediated the relationship between childhood trauma and perceived relapse tendency (Coeff = 0.049, Boot CI [0.004, 0.121]); interaction of childhood trauma and Baseline RSA negatively influences IIRTV (β = -0.208, t = -2.022, p = .046).Conclusion: The results suggest that males with SUDs who have experienced serious childhood trauma may have executive function impairments that contribute to relapse, and baseline RSA may buffer the negative effect of childhood trauma on IIRTV. These findings suggest that the prevention of relapse through cognitive enhancement can be complemented by the enhancement of physiological regulation.

The role of the D3 dopamine receptor and its partial agonist cariprazine in patients with schizophrenia and substance use disorder

INTRODUCTION

Comorbidity of substance use disorder (SUD) with schizophrenia, referred to as dual disorder (DD), significantly increases morbidity and mortality compared to schizophrenia alone. A dopaminergic dysregulation seems to be a common pathophysiological basis of the comorbidity.

AREAS COVERED

This article reports the current evidence on the role of dopamine dysregulations in DD, the pharmacological profile of cariprazine, a partial agonist of D3 and D2 dopamine receptors, and first clinical observations that may support its usefulness in the therapy of DD. PubMed/MEDLINE was searched for the keywords 'cariprazine,' 'schizophrenia,' 'dual disorder,' 'dopamine,' and 'dopamine receptor.' Preclinical and clinical studies, and reviews published in English were retrieved.

EXPERT OPINION

Although the management of DD remains challenging, and the evidence for pharmacologic treatments is still unsatisfactory, cariprazine may be a candidate medication in DD due to its unique mechanism of action. Preliminary clinical experiences suggest that cariprazine has both antipsychotic and anticraving properties and should be considered early in patients with DD.

Alpha and Theta Oscillations Are Causally Linked to Interference Inhibition: Evidence from High-Definition Transcranial Alternating Current Stimulation

(1) Background: The Go/NoGo task and color-word Stroop task were used to investigate the effect of applying different frequency bands of neural oscillations to the lDLPFC on inhibitory control modulation. (2) Methods: Participants were randomly categorized into four groups and received HD-tACS at 6, 10, and 20 Hz or sham stimulation at 1.5 mA for 20 min. All participants performed a color-word Stroop task and Go/NoGo task before and immediately after the stimulation; closed-eye resting-state EEG signals were acquired for 3 min before and after the tasks. (3) Results: There were no significant differences in the Go/NoGo behavioral indices task across the four groups. In the color-word Stroop task, the Stroop effect of response time was significantly reduced by 6 and 10 Hz stimulations compared to sham stimulation, and the Stroop effect of accuracy was significantly reduced by 10 Hz stimulation. There were no significant differences in the frequency range-specific (delta, theta, alpha, beta, or gamma) resting EEG power before and after stimulation. (4) Conclusions: HD-tACS at 6 and 10 Hz effectively improved participants' performance on the color-word Stroop task, demonstrating the importance of the lDLPFC in interference inhibition and supporting a causal relationship between theta and alpha oscillations in interference inhibition.

Towards neuromarkers for tailored smoking cessation treatments

Vulnerability to compulsive drug use stems from dysregulated activity within the neural networks that underlie reward and executive functions. Empirical evidence suggests that a) attributing high motivational salience to drug-related stimuli leads to compulsive drug seeking and b) cognitive control deficits lead to compulsive drug taking. Noninvasive neuroimaging techniques enable brain activity monitoring during affective and cognitive processing and are paving the way to precision medicine for substance use disorders. Identifying robust neuromarkers of affective and cognitive dysregulation would allow clinicians to personalize treatments by targeting individual psychophysiological vulnerabilities. However, methodological choices have biased the field toward experimental paradigms that cannot optimally assess individual differences in the motivational salience of drug-related cues and in the ability to control drug-related decisions, choices which have hindered the identification of clinically relevant neuromarkers. Here, we show that once these shortcomings are amended, replicable neuromarkers of the tendency to attribute motivational salience to drug-related cues and the ability to control drug-related decisions emerge. While we use tobacco use disorder as a model, we also show that the methodological issues highlighted here are relevant to other disorders characterized by maladaptive appetitive behaviors.

Examination of college student health behaviors and self-reported executive functions

Objective: Emerging adulthood is characterized by maturation of executive functions (EF) and changes in health behaviors (HB). Interestingly, EF are bi-directionally related to many specific HB; yet how EF performs in relation to overall patterns of HB engagement is unclear. Groupings of HB and the relationship between these HB groupings and EF were examined.

PARTICIPANTS

Full-time college students were recruited from three large Mid- and Southwest universities (N = 1,387).

METHODS

Online self-report questionnaires assessing demographics, HB, and EF were completed.

RESULTS

Latent class analysis of HB revealed three classes: (1) High Substance Use, (2) Moderately Healthy, (3) Healthy. In general, the Healthy class had significantly greater EF compared to no significant differences between the other two classes.

CONCLUSIONS

Collective engagement in HB is associated with EF. Interventions targeting both HB and EF simultaneously may be most efficacious.

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.

Neurobiological Basis of Aversion-Resistant Ethanol Seeking in C. elegans

Persistent alcohol seeking despite the risk of aversive consequences is a crucial characteristic of alcohol use disorders (AUDs). Therefore, an improved understanding of the molecular basis of alcohol seeking despite aversive stimuli or punishment in animal models is an important strategy to understand the mechanism that underpins the pathology of AUDs. Aversion-resistant seeking (ARS) is characterized by disruption in control of alcohol use featured by an imbalance between the urge for alcohol and the mediation of aversive stimuli. We exploited C. elegans, a genetically tractable invertebrate, as a model to elucidate genetic components related to this behavior. We assessed the seb-3 neuropeptide system and its transcriptional regulation to progress aversion-resistant ethanol seeking at the system level. Our functional genomic approach preferentially selected molecular components thought to be involved in cholesterol metabolism, and an orthogonal test defined functional roles in ARS through behavioral elucidation. Our findings suggest that fmo-2 (flavin-containing monooxygenase-2) plays a role in the progression of aversion-resistant ethanol seeking in C. elegans.

From concepts to treatment: a dialog between a preclinical researcher and a clinician in addiction medicine

The debate surrounding the brain disease model and the associated questioning of the relevance of animal models is polarizing the field of addiction, and tends to widen the gap between preclinical research and addiction medicine. Here, we aimed at bridging this gap by establishing a dialog between a preclinical researcher and a clinician in addiction medicine. Our objective was to evaluate animal models and the neuroscientific conceptualization of addiction in light of alcohol or drug dependence and treatment in patients struggling with an addiction. We sought to determine how preclinical research influenced addiction medicine over past decades, and reciprocally, what can preclinical researchers learn from addiction medicine that could lead to more effective approaches. In this dialog, we talk about the co-evolution of addiction concepts and treatments from neuroscientific and medical perspectives. This dialog illustrates the reciprocal influences and mutual enrichment between the two disciplines and reveals that, although preclinical research might not produce new pharmacotherapies, it does shape the theoretical conceptualization of addiction and could thereby contribute to the implementation of therapeutic approaches.

Moral disciplining: The cognitive and evolutionary foundations of puritanical morality

Why do many societies moralize apparently harmless pleasures, such as lust, gluttony, alcohol, drugs, and even music and dance? Why do they erect temperance, asceticism, sobriety, modesty, and piety as cardinal moral virtues? According to existing theories, this puritanical morality cannot be reduced to concerns for harm and fairness: It must emerge from cognitive systems that did not evolve for cooperation (e.g., disgust-based "purity" concerns). Here, we argue that, despite appearances, puritanical morality is no exception to the cooperative function of moral cognition. It emerges in response to a key feature of cooperation, namely that cooperation is (ultimately) a long-term strategy, requiring (proximately) the self-control of appetites for immediate gratification. Puritanical moralizations condemn behaviors which, although inherently harmless, are perceived as indirectly facilitating uncooperative behaviors, by impairing the self-control required to refrain from cheating. Drinking, drugs, immodest clothing, and unruly music and dance are condemned as stimulating short-term impulses, thus facilitating uncooperative behaviors (e.g., violence, adultery, free-riding). Overindulgence in harmless bodily pleasures (e.g., masturbation, gluttony) is perceived as making people slave to their urges, thus altering abilities to resist future antisocial temptations. Daily self-discipline, ascetic temperance, and pious ritual observance are perceived as cultivating the self-control required to honor prosocial obligations. We review psychological, historical, and ethnographic evidence supporting this account. We use this theory to explain the fall of puritanism in western, educated, industrialized, rich, and democratic (WEIRD) societies, and discuss the cultural evolution of puritanical norms. Explaining puritanical norms does not require adding mechanisms unrelated to cooperation in our models of the moral mind.

Neural structural abnormalities behind altered brain activation in obesity: Evidence from meta-analyses of brain activation and morphometric data

Obesity represents a risk factor for disability with a major bearing on life expectancy. Neuroimaging techniques are contributing to clarify its neurobiological underpinnings. Here, we explored whether structural brain abnormalities might accompany altered brain activations in obesity. We combined and compared data from brain activation studies for food stimuli and the data reported in structural voxel-based morphometry studies. We found that obese individuals have reduced grey matter density and functional activations in the thalamus and midbrain. A functional connectivity analysis based on these two clusters and its quantitative decoding showed that these regions are part of the reward system functional brain network. Moreover, we found specific grey matter hypo-densities in prefrontal cortex for the obese subjects, regions involved in controlled behaviour. These results support theories of obesity that point to reduced bottom-up reward processes (i.e., the Reward Deficit Theory), but also top-down theories postulating a deficit in cognitive control (i.e., the Inhibitory Control Deficit Theory). The same results also warrant a more systematic exploration of obesity whereby the reward of food and the intentional control over consummatory behaviour is manipulated.

Prefrontal Cortical Control of Activity in Nucleus Accumbens Core Is Weakened by High-Fat Diet and Prevented by Co-Treatment with N-Acetylcysteine: Implications for the Development of Obesity

A loss of neuroplastic control on nucleus accumbens (NAc) neuronal activity exerted by the medial prefrontal cortex (mPFC) through long-term depression (LTD) is involved in triggering drug-seeking behavior and relapse on several substances of abuse due to impaired glutamate homeostasis in tripartite synapses of the nucleus accumbens (NAc) core. To test whether this maladaptive neuroplastic mechanism underlies the addiction-like behavior induced in young mice by a high-fat diet (HFD), we utilized 28-days-old male mice fed HFD ad-libitum over 2 weeks, followed by 5 days of HFD abstinence. Control groups were fed a regular diet. HFD fed mice showed increased ΔFosB levels in the NAc core region, whereas LTD triggered from the mPFC became suppressed. Interestingly, LTD suppression was prevented by an i.p. injection of 100 mg/kg N-acetylcysteine 2.5 h before inducing LTD from the mPFC. In addition, excessive weight gain due to HFD feeding was diminished by adding 2mg/mL N-acetylcysteine in drinking water. Those results show a loss of neuroplastic mPFC control over NAc core activity induced by HFD consumption in young subjects. In conclusion, ad libitum consumption of HFD can lead to neuroplastic changes an addiction-like behavior that can be prevented by N-acetylcysteine, helping to decrease the rate of excessive weight gain.

Frontostriatal Functional Connectivity Underlies the Association between Punishment Sensitivity and Procrastination

Procrastination is defined as putting off an intended course of action voluntarily despite the harmful consequences. Previous studies have suggested that procrastination is associated with punishment sensitivity in that high punishment sensitivity results in increased negative utility for task performance. We hypothesized the effects of punishment sensitivity on procrastination would be mediated by a network connecting the caudate nucleus and prefrontal cortex, both of which have been previously associated with self-control and emotional control during procrastination. We employed voxel-based morphometry (VBM) and resting-state functional connectivity (rsFC) to examine the neural substrates of punishment sensitivity and its relationship with procrastination (N = 268). The behavioral results indicated a strong positive correlation between measures of punishment sensitivity and procrastination. The VBM analysis revealed that the gray matter (GM) volume of the right caudate was significantly positively correlated with punishment sensitivity. The primary rsFC analysis revealed connectivity between this caudate location and the bilateral middle frontal gyrus (MFG) was significantly negatively correlated with punishment sensitivity. A mediation model indicated punishment sensitivity completely mediated the relation between functional connectivity within a caudate–bilateral MFG network and procrastination. Our results support the theory that those with higher punishment sensitivity have weaker effective emotional self-control supported by the caudate–MFG network, resulting in greater procrastination.

Chronic early-life lead exposure sensitizes adolescent rats to cocaine: Role of the dopaminergic system

Exposure to heavy metals has been associated with psychiatric disorders and recent studies suggest an association between childhood lead (Pb²⁺) intoxication and schizophrenia (SZ). In animal models, Pb²⁺ exposure recapitulates key neuropathological and dopaminergic system alterations present in SZ. Given the high comorbidity of mental disorders such as SZ and substance abuse, coupled with evidence showing that Pb²⁺ exposure affects addiction circuits, we hypothesized that early life Pb²⁺ exposure could sensitize neuronal systems relevant to SZ and substance abuse. To this goal, we examined the effects of chronic developmental Pb²⁺ exposure on the acute locomotor response to cocaine (0, 5, and 15 mg kg^–1) and behavioral sensitization. We also examined the role of the dopaminergic system in the psychostimulant effects of cocaine, and measured D1-dopamine receptor (D1R) levels in the rat brain using [³H]-SCH23390 quantitative receptor autoradiography, as well as the ability of the D1R antagonist SCH23390 to block the cocaine effects on locomotor activation. These studies were performed in male and female rats at different developmental ages consisting of juveniles (postnatal, PN14), early-adolescent (PN28), late adolescent (PN50), and adults (PN120). Our results show that chronic developmental Pb²⁺ exposure increases the acute locomotor response to the higher dose of cocaine in Pb²⁺-exposed male adolescent (PN28 and PN50) rats, and to the lower dose of cocaine in adolescent female rats. No changes in the locomotor activity were detected in adult rats. Behavioral sensitization experiments showed a sustained sensitization in early adolescent Pb²⁺-exposed male but not female rats. The cocaine-induced effects on locomotor activity were abrogated by injection of a D1R antagonist suggesting the involvement of this dopamine receptor subtype. Furthermore, Pb²⁺-induced increases D1R levels in several brain regions were prominent in juveniles and early adolescence but not in late adolescence or in adults. In summary, early chronic developmental Pb²⁺ exposure results in age and sex-dependent effect on the locomotor response to cocaine, suggesting differential susceptibilities to the neurotoxic effects of Pb²⁺ exposure. Our data provides further support to the notion that Pb²⁺ exposure is an environmental risk factor for psychiatric disorders and substance abuse.

The Influence of Acute Aerobic Exercise on Craving Degree for University Students with Mobile Phone Dependency: A Randomized Controlled Trial

These days, mobile phone dependency (MPD) has become one of the most imperative and impressive puzzles in the area of behavioral addictions and public health across the world, especially the individuals with MPD that might frequently crave using mobile phones themselves. The target of the current study was to determine whether moderate-intensity aerobic exercise could reduce the craving degree for mobile phones for university students with MPD by a randomized, controlled trial. Sixty Chinese undergraduates, including 30 male and 30 female students aged from 18 to 22 years (20.08 ± 1.94 years) with MPD were recruited and then randomly assigned to the exercise group (n = 30) or the control group (n = 30) with even numbers by gender and major. Participants in the exercise group were required to perform an acute moderate-intensity treadmill exercise lasting for 30 min at 45−68% heart rate reserve (HRR) with background music, while the control group were only asked to listen to the same music for 40 min without any exercise. Sport watches were employed to monitor their heart rate (HR), and the exercise group was also obliged to report their rating of perceived exertion (RPE). After completing the experimental task, a visual analog scale (VAS) was used to evaluate their craving degree for mobile phones, and an independent samples t-test was computed to reveal the difference in the scores of craving degree for mobile phones between the two groups. The results showed that the VAS score for the exercise group (3.77 ± 1.36) was significantly lower (p < 0.001) than that of the control group (6.11 ± 1.39). The findings suggested that acute moderate-intensity aerobic exercise could be an effective and reliable means to help deal with the issue of mobile phones craving for the undergraduates with MPD, and more longitudinal intervention studies and control trial designs should be conducted in the near future to further test the long-term effects of this exercise.

Machine Learning to Predict Executive Function in Adolescents with Repaired d-Transposition of the Great Arteries, Tetralogy of Fallot, and Fontan Palliation

OBJECTIVE

To identify predictors of impaired executive function in adolescents after surgical repair of critical congenital heart disease (CHD).

STUDY DESIGN

We analyzed patient factors, medical and surgical history, and family social class from 3 single-center studies of adolescents with d-transposition of the great arteries (d-TGA), tetralogy of Fallot (TOF), and Fontan repair. Machine learning models were developed using recursive partitioning to predict an executive function composite score based on five subtests (population mean 10, SD 3) of the Delis-Kaplan Executive Function System.

RESULTS

The sample included 386 patients (139 d-TGA, 91 TOF, 156 Fontan) of age 15.1 ± 2.1 (mean ± SD) years and an executive function composite score of 8.6 ± 2.4. Family social class emerged as the most important predictive factor. The lowest (worst) mean executive function score (5.3) occurred in patients with low to medium social class (Hollingshead index <56) with one or more neurologic events and a diagnosis of TOF. The highest (best) mean score (9.7) occurred in subjects with high social class (Hollingshead index ≥56) and shorter duration of deep hypothermic circulatory arrest. Other factors predicting lower executive function scores included low birth weight and a greater number of catheterizations.

CONCLUSIONS

In regression tree modeling, family social class was the strongest predictor of executive function in adolescents with critical CHD, even in the presence of medical risk factors. Additional predictors included CHD diagnosis, birth weight, neurologic events, and number of procedures. These data highlight the importance of social class in mitigating risks of executive dysfunction in CHD.

Catechol-O-methyltransferase activity in individuals with substance use disorders: a case control study

BACKGROUND

Impulsivity and substance use disorders (SUD) have been both associated with changes in dopaminergic processes. In this study, we intended to evaluate the dopaminergic function in imprisoned SUD offenders through the determination of s-COMT activity.

METHODS

The study included 46 male individuals from a Portuguese penal institution. The participants were assessed through a battery of standardised instruments: Psychopathy Checklist-Revised (PCL-R), Barratt Impulsivity Scale Version 11 (BIS-11), and the European version of the Addiction Severity Index (EuropASI). In addition, s-COMT erythrocyte activity was evaluated.

RESULTS

Overall, 73.9% (n = 34) of the individuals had Antisocial personality disorder (ASPD) and 58.7% (n = 27) presented SUD. We evidenced, for the first time, that, in individuals with SUD, s-COMT activity was correlated with the severity of drug dependence (EuropASI) (p = 0.009), and with BIS-11 factors self-control (p < 0.0001) and non-planning (p = 0.002).

CONCLUSIONS

This study opens new perspectives regarding the pharmacological intervention on substance dependence through the interference on dopamine pathways.

Digital Addiction and Sleep

In 2020, the World Health Organization formally recognized addiction to digital technology (connected devices) as a worldwide problem, where excessive online activity and internet use lead to inability to manage time, energy, and attention during daytime and produce disturbed sleep patterns or insomnia during nighttime. Recent studies have shown that the problem has increased in magnitude worldwide during the COVID-19 pandemic. The extent to which dysfunctional sleep is a consequence of altered motivation, memory function, mood, diet, and other lifestyle variables or results from excess of blue-light exposure when looking at digital device screens for long hours at day and night is one of many still unresolved questions. This article offers a narrative overview of some of the most recent literature on this topic. The analysis provided offers a conceptual basis for understanding digital addiction as one of the major reasons why people, and adolescents in particular, sleep less and less well in the digital age. It discusses definitions as well as mechanistic model accounts in context. Digital addiction is identified as functionally equivalent to all addictions, characterized by the compulsive, habitual, and uncontrolled use of digital devices and an excessively repeated engagement in a particular online behavior. Once the urge to be online has become uncontrollable, it is always accompanied by severe sleep loss, emotional distress, depression, and memory dysfunction. In extreme cases, it may lead to suicide. The syndrome has been linked to the known chronic effects of all drugs, producing disturbances in cellular and molecular mechanisms of the GABAergic and glutamatergic neurotransmitter systems. Dopamine and serotonin synaptic plasticity, essential for impulse control, memory, and sleep function, are measurably altered. The full spectrum of behavioral symptoms in digital addicts include eating disorders and withdrawal from outdoor and social life. Evidence pointing towards dysfunctional melatonin and vitamin D metabolism in digital addicts should be taken into account for carving out perspectives for treatment. The conclusions offer a holistic account for digital addiction, where sleep deficit is one of the key factors.

BDNF as a therapeutic candidate for cocaine use disorders

Cocaine self-administration disturbs intracellular signaling in multiple reward circuitry neurons that underlie relapse to drug seeking. Cocaine-induced deficits in prelimbic (PL) prefrontal cortex change during abstinence, resulting in different neuroadaptations during early withdrawal from cocaine self-administration than after one or more weeks of abstinence. Infusion of brain-derived neurotrophic factor (BDNF) into the PL cortex immediately following a final session of cocaine self-administration attenuates relapse to cocaine seeking for an extended period. BDNF affects local (PL) and distal subcortical target areas that mediate cocaine-induced neuroadaptations that lead to cocaine seeking. Blocking synaptic activity selectively in the PL projection to the nucleus accumbens during early withdrawal prevents BDNF from decreasing subsequent relapse. In contrast, blocking synaptic activity selectively in the PL projection to the paraventricular thalamic nucleus by itself decreases subsequent relapse and prior intra-PL BDNF infusion prevents the decrease. Infusion of BDNF into other brain structures at different timepoints after cocaine self administration differentially alters cocaine seeking. Thus, the effects of BDNF on drug seeking are different depending on the brain region, the timepoint of intervention, and the specific pathway that is affected.

Adolescent Self-Control and Individual Physical and Mental Health in Adulthood: A Chinese Study

Despite its association with individual health, few studies have focused on the relationship between adolescent self-control and individual physical and mental health in adulthood. We aimed, therefore, to explore the impact of adolescent self-control on individual physical and mental health in adulthood. We employed the dataset of China Labor-Force Dynamics Surveys [CLDS] (2016). 13,389 respondents with an average age of 45.621 years are consisted in this study. The respondents were asked to report their adolescent self-control through recall. The ordered probit and the ordinary least squares (OLS) models were employed to estimate the effects of adolescent self-control on physical and mental health in adulthood, respectively. We adopted the propensity score matching (PSM) method to address the self-selection bias of samples. The results indicated that adolescent self-control significantly affected individual physical health (coefficient = 0.0126, p < 0.01) and mental health (coefficient = −0.1067, p < 0.01) in adulthood. The mechanism analysis suggested that adolescent self-control partially promoted physical and mental health in adulthood by education and income instead of self-control in adulthood. In conclusion, paying attention to the cultivation of self-control before adulthood may be an effective way to improve individual physical and mental health in adulthood.

The Path to Hedonic Information System Use Addiction: A Process Model in the Context of Social Networking Sites

Addiction to hedonic information systems yields significant negative consequences for users. Although we know about the causes of addictions, particularly those related to individual differences, recent evidence suggests that addiction evolves gradually over time and is rooted in shared characteristics of users and technology. This paper provides a longitudinal perspective over how and why hedonic information systems (IS) use addiction develops. Based on our analysis, we break down this process into three phases characterized by different types of use, whether nominal, compulsive, or addicted. Each phase highlights salient psychological needs that motivate, technology features that enable, and affordances that are actualized into each type of use. We also provide a detailed account of individuals’ self-control mechanisms, explaining how deficiencies in sensing, comparing, or regulating behavior facilitate one’s transition toward addiction. These insights are applicable to other hedonic IS that are similar in terms of ubiquity and constant access through mobile apps. They point to heterogeneous (preventive or intervening) strategies that can be used to help people regain their control over use, depending on where they are in their trajectory toward addicted use. Our findings carry implications for the design of systems and features that can help reduce the likelihood of addiction development.

Gene knockdown of HCN2 ion channels in the ventral tegmental area reduces ethanol consumption in alcohol preferring rats

Background: Hyperpolarization-Activated Cyclic Nucleotide-Gated (HCN) ionic channels are known to play a key role in the control of neuron excitability and have been proposed as a molecular target of ethanol. Previous studies in rats have shown that gene-induced overexpression of the HCN2 channel in the ventral tegmental area (VTA) increases the rewarding effects of ethanol and its intake by the animals.Objective: The aim of this work was to study the effects of VTA HCN2 gene knockdown in the voluntary ethanol consumption of alcohol-preferring UChB rats.Methods: Two lentiviral vectors were generated; LV-siRNA-HCN2, coding for a siRNA that elicited >95% reduction of HCN2 protein levels in vitro, and a control vector coding for a scrambled siRNA sequence. Female UChB naïve rats (n = 14) were microinjected into the VTA with LV-siRNA-HCN2 or the scrambled control vector (n = 11). Four days after, animals were given a daily free access to 10% ethanol and water for 10 days.Results: Rats treated with the LV-siRNA-HCN2 vector showed a ~ 70% reduction (p < .001) in their ethanol preference and ethanol intake compared to control animals. No changes were observed in the total fluid intake of both groups. HCN2 levels in the VTA were measured by Western blot showing a reduction of 40% (p < .05) in the rats injected with LV-siRNA-HCN2, compared to control animals.Conclusion: These results show that knockdown of HCN2 ionic channels in the VTA of UChB rats markedly reduces their voluntary ethanol intake, supporting the idea that HCN2 channels may constitute a therapeutic target for alcohol use disorders.

Repetitive transcranial magnetic stimulation modulates coupling among large-scale brain networks in heroin-dependent individuals: A randomized resting-state functional magnetic resonance imaging study

The abnormal interactions of three key large-scale brain networks (default mode [DMN], salience and executive control [ECN]) were showed underlie dysfunctions in heroin addiction. Repetitive transcranial magnetic stimulation (rTMS) targeting the left dorsolateral prefrontal cortex (DLPFC) is a potential treatment for heroin addiction. It is unclear whether impaired coupling among the large-scale brain networks would be improved by rTMS in treated heroin-dependent individuals. Thirty-five heroin-dependent individuals were included in this sham-controlled, randomized study. The patients received either active or sham rTMS for 1 week. The craving for heroin and resting-state functional magnetic resonance imaging data were collected before and after 1-week rTMS. Twenty-two healthy subjects were included as controls not receiving rTMS. After 1-week rTMS, only the active rTMS group showed a significant decrease in spontaneous and heroin cue-induced craving. The coupling between left DLPFC (a key node of left ECN) and left parahippocampal gyrus (PHG, included in DMN) significantly increased for the active group with a tendency towards that of controls. The coupling between the right precentral gyrus and three key regions included in DMN (posterior cingulate cortex/precuneus and bilateral inferior parietal cortex) significantly decreased for the active group with a tendency towards that of healthy controls. For the active rTMS individuals, the left DLPFC-PHG coupling negatively correlated with the spontaneous craving and the drug cue-induced craving. It suggested that the rTMS could reduce heroin craving, which might be related to the modulation of ECN-DMN coupling. This finding might shed light on the mechanism of rTMS for heroin addiction treatment.

A Scoping Review of Drug Epidemic Models

The phenomenon of drug epidemics has been a global issue in the past decades, causing enormous damages to the physical and mental health of drug users and social well-being. Despite great efforts to curb drug epidemics at the governmental or social level, the total number of drug users has still been on the rise in recent years, along with illicit production and trafficking around the world. Inspired by dynamical epidemic models of infectious disease, a flourishment of promising results has been observed in the exploration of drug epidemic models. In this review, we aim to provide a scoping review of all existing drug epidemic modeling studies, and it has been shown that most studies focused on analyses of theoretical behaviors of the model systems, lacking emphasis on practical applications in real settings. We found that the drug epidemic models were characterized by a longer time scale, no incubation period, no significant prevention vaccines interfered, and population specificity. This review could assist policymakers and public health workers in gaining deeper insights into modeling tools, and help modelers improve their works, thus narrowing gaps between mathematical epidemiology and public health studies.

Neuropeptidergic regulation of compulsive ethanol seeking in C. elegans

Despite the catastrophic consequences of alcohol abuse, alcohol use disorders (AUD) and comorbidities continue to strain the healthcare system, largely due to the effects of alcohol-seeking behavior. An improved understanding of the molecular basis of alcohol seeking will lead to enriched treatments for these disorders. Compulsive alcohol seeking is characterized by an imbalance between the superior drive to consume alcohol and the disruption or erosion in control of alcohol use. To model the development of compulsive engagement in alcohol seeking, we simultaneously exploited two distinct and conflicting Caenorhabditis elegans behavioral programs, ethanol preference and avoidance of aversive stimulus. We demonstrate that the C. elegans model recapitulated the pivotal features of compulsive alcohol seeking in mammals, specifically repeated attempts, endurance, and finally aversion-resistant alcohol seeking. We found that neuropeptide signaling via SEB-3, a CRF receptor-like GPCR, facilitates the development of ethanol preference and compels animals to seek ethanol compulsively. Furthermore, our functional genomic approach and behavioral elucidation suggest that the SEB-3 regulates another neuropeptidergic signaling, the neurokinin receptor orthologue TKR-1, to facilitate compulsive ethanol-seeking behavior.

Parental education is associated with differential engagement of neural pathways during inhibitory control

Response inhibition and socioeconomic status (SES) are critical predictors of many important outcomes, including educational attainment and health. The current study extends our understanding of SES and cognition by examining brain activity associated with response inhibition, during the key developmental period of adolescence. Adolescent males (N = 81), aged 16–17, completed a response inhibition task while undergoing fMRI brain imaging and reported on their parents’ education, one component of socioeconomic status. A region of interest analysis showed that parental education was associated with brain activation differences in the classic response inhibition network (right inferior frontal gyrus + subthalamic nucleus + globus pallidus) despite the absence of consistent parental education-performance effects. Further, although activity in our main regions of interest was not associated with performance differences, several regions that were associated with better inhibitory performance (ventromedial prefrontal cortex, middle frontal gyrus, middle temporal gyrus, amygdala/hippocampus) also differed in their levels of activation according to parental education. Taken together, these results suggest that individuals from households with higher versus lower parental education engage key brain regions involved in response inhibition to differing degrees, though these differences may not translate into performance differences.

Resting Heart Rate Variability, Perceived Emotion Regulation, and Low-Risk Drug Use in College-Aged Adults: Gender as a Moderator

Identification of individual differences in drug use is warranted, as a history of use is associated with future drug problems. Such drug use is thought to disrupt inhibitory and motivation networks involved in emotion regulation (ER). Higher resting heart rate variability (HRV), a biomarker of effective inhibitory abilities, is associated with less substance (e.g., alcohol, opioid) use. Higher HRV is associated with lower perceived ER difficulties, and this link is stronger in women relative to men. Evidence suggests women might engage in drug use primarily to reduce stress, and men primarily to induce feelings of elation. Research has yet to examine associations among individuals' difficulties in ER, resting HRV, and a recent history of drug use; the current study explored this, in addition to how these associations might differ as a function of gender. Young and healthy college students (N = 190; 88 women) completed a 5-min baseline to assess resting HRV, followed by the 36-item difficulties in ER Scale and 10-item Drug Abuse Screening Test. Higher difficulties in ER, but not resting HRV, were associated with a greater history of "low-risk" drug use in the full sample and moderation tests confirm this link was stronger in women. Moderated-mediation results confirmed an indirect association between resting HRV and drug use, mediated by self-reported difficulties among women only. A significant association between resting HRV and Difficulties in Emotion Regulation Scale (DERS) emerged only among women without a history of drug use. These results indicate that difficulties in ER are both associated with a low-risk history of drug use and underlie an indirect link between resting HRV and drug use history in women only. Among these women with a history of drug use relative to women without, there was no link between resting HRV and self-reported difficulties in ER, suggesting a disrupted inhibitory-motivational pathway. Additional work is needed to understand the psychophysiological correlates of a history of low-risk drug use in young men. These data are in line with research suggesting gender differences in the motivation to engage in recreational drug use and ER interventions might be important in women who engage in low-risk recreational drug use.

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.

Mitochondrial function influences expression of methamphetamine-induced behavioral sensitization

Repeated methamphetamine use leads to long lasting brain and behavioral changes in humans and laboratory rats. These changes have high energy requirements, implicating a role for mitochondria. We explored whether mitochondrial function underpins behaviors that occur in rats months after stopping methamphetamine self-administration. Accordingly, rats self-administered intravenous methamphetamine for 3 h/day for 14 days. The mitochondrial toxin rotenone was administered as (1 mg/kg/day for 6 days) via an osmotic minipump starting at 0, 14 or 28 days of abstinence abstinence. On abstinence day 61, expression of methamphetamine-induced behavioral sensitization was obtained with an acute methamphetamine challenge in rotenone-free rats. Rotenone impeded the expression of sensitization, with the most robust effects obtained with later abstinence exposure. These findings verified that self-titration of moderate methamphetamine doses results in behavioral (and thus brain) changes that can be revealed months after exposure termination, and that the meth-initiated processes progressed during abstinence so that longer abstinence periods were more susceptible to the consequences of exposure to a mitochondrial toxin.

An exploration of associations between smoking motives and behavior as a function of body mass index

Objective

Cigarette smoking and obesity are the leading causes of premature morbidity and mortality and increase the risk of all-cause mortality four-fold when comorbid. Although research suggests that smoking motives may differ based on body mass index (BMI), it is unclear how these differences translate to smoking behavior.

Method

Three groups of adults who smoke cigarettes (N = 79; obese n = 25, overweight n = 30, and lean n = 24) completed measures of smoking and the Smoking Motivations Questionnaire. Groups did not differ on age, education, cigarettes per day (CPD), pack-years, or nicotine dependence, as measured by the Fagerström Test for Cigarette Dependence (FTCD).

Results

Analyses revealed different associations between reasons for smoking and smoking behavior depending on lean, overweight, or obesity status. Participants (N = 37 female, average age 39.8 years) self-reported smoking was positively associated with Addictive, and Automatic subscale scores among lean participants, with only the Addictive subscale score among those with overweight, and only the Automatic subscale score among those with obesity. Post hoc MANCOVA analysis revealed a significant interaction effect of Group x Automatic Smoking on Pack-years (F(2, 79)=3.34, p = 0.04).

Conclusion

Findings suggest smoking motives are differentially associated with smoking behavior in adults who smoke depending on weight status. The daily smoking rate of participants with obesity may be less related to the addictive quality of smoking, and automaticity may be less associated with smoking history in those with overweight. Additional research on the influence of BMI on cigarette smoking is necessary to fully elucidate how obesity may impact treatment outcomes to optimize smoking cessation treatment among those with excess body weight.

A Virtual Reality Meditative Intervention Modulates Pain and the Pain Neuromatrix in Patients with Opioid Use Disorder

OBJECTIVE

Standard of care for opioid use disorder (OUD) includes medication and counseling. However, there is an unmet need for complementary approaches to treat OUD patients coping with pain; furthermore, few studies have probed neurobiological features of pain or its management during OUD treatment. This preliminary study examines neurobiological and behavioral effects of a virtual reality-based meditative intervention in patients undergoing methadone maintenance treatment (MMT).

DESIGN

Prospective, non-blinded, single-arm, 12-week intervention with standardized assessments.

SETTING

Academic research laboratory affiliated with an on-site MMT clinic.

METHODS

Fifteen (11 female) MMT patients completed a virtual reality, therapist-guided meditative intervention that included breathing and relaxation exercisessessions were scheduled twice weekly. Assessments included functional magnetic resonance imaging (fMRI) of pain neuromatrix activation and connectivity (pre- and post-intervention), saliva cortisol and C-reactive protein (CRP) at baseline and weeks 4, 8 and 12; and self-reported pain and affective symptoms before and after each intervention session.

RESULTS

After each intervention session (relative to pre-session), ratings of pain, opioid craving, anxiety and depression (but not anger) decreased. Saliva cortisol (but not CRP) levels decreased from pre- to post-session. From pre- to post-intervention fMRI assessments, pain task-related left postcentral gyrus (PCG) activation decreased. At baseline, PCG showed positive connectivity with other regions of the pain neuromatrix, but this pattern changed post-intervention.

CONCLUSIONS

These preliminary findings demonstrate feasibility, therapeutic promise, and brain basis of a meditative intervention for OUD patients undergoing MMT.

Prefrontal fNIRS-based clinical data analysis of brain functions in individuals abusing different types of drugs

Background

The activation degree of the orbitofrontal cortex (OFC) functional area in drug abusers is directly related to the craving for drugs and the tolerance to punishment. Currently, among the clinical research on drug rehabilitation, there has been little analysis of the OFC activation in individuals abusing different types of drugs, including heroin, methamphetamine, and mixed drugs. Therefore, it becomes urgently necessary to clinically investigate the abuse of different drugs, so as to explore the effects of different types of drugs on the human brain.

Methods

Based on prefrontal high-density functional near-infrared spectroscopy (fNIRS), this research designs an experiment that includes resting and drug addiction induction. Hemoglobin concentrations of 30 drug users (10 on methamphetamine, 10 on heroin, and 10 on mixed drugs) were collected using fNIRS and analyzed by combining algorithm and statistics.

Results

Linear discriminant analysis (LDA), Support vector machine (SVM) and Machine-learning algorithm was implemented to classify different drug abusers. Oxygenated hemoglobin (HbO2) activations in the OFC of different drug abusers were statistically analyzed, and the differences were confirmed. Innovative findings: in both the Right-OFC and Left-OFC areas, methamphetamine abusers had the highest degree of OFC activation, followed by those abusing mixed drugs, and heroin abusers had the lowest. The same result was obtained when OFC activation was investigated without distinguishing the left and right hemispheres.

Conclusions

The findings confirmed the significant differences among different drug abusers and the patterns of OFC activations, providing a theoretical basis for personalized clinical treatment of drug rehabilitation in the future.