Computational modelling of reinforcement learning and functional neuroimaging of probabilistic reversal for dissociating compulsive behaviours in gambling and cocaine use disorders

BACKGROUND

Individuals with cocaine use disorder or gambling disorder demonstrate impairments in cognitive flexibility: the ability to adapt to changes in the environment. Flexibility is commonly assessed in a laboratory setting using probabilistic reversal learning, which involves reinforcement learning, the process by which feedback from the environment is used to adjust behavior.

AIMS

It is poorly understood whether impairments in flexibility differ between individuals with cocaine use and gambling disorders, and how this is instantiated by the brain. We applied computational modelling methods to gain a deeper mechanistic explanation of the latent processes underlying cognitive flexibility across two disorders of compulsivity.

METHOD

We present a re-analysis of probabilistic reversal data from individuals with either gambling disorder (n = 18) or cocaine use disorder (n = 20) and control participants (n = 18), using a hierarchical Bayesian approach. Furthermore, we relate behavioural findings to their underlying neural substrates through an analysis of task-based functional magnetic resonanceimaging (fMRI) data.

RESULTS

We observed lower 'stimulus stickiness' in gambling disorder, and report differences in tracking expected values in individuals with gambling disorder compared to controls, with greater activity during reward expected value tracking in the cingulate gyrus and amygdala. In cocaine use disorder, we observed lower responses to positive punishment prediction errors and greater activity following negative punishment prediction errors in the superior frontal gyrus compared to controls.

CONCLUSIONS

Using a computational approach, we show that individuals with gambling disorder and cocaine use disorder differed in their perseverative tendencies and in how they tracked value neurally, which has implications for psychiatric classification.

Fenneman et al.'s (2022) review of formal impulsivity models: Implications for theory and measures of impulsivity

In Fenneman et al.'s (2022) review of theories and integrated impulsivity model, the authors distinguish between information impulsivity (i.e., acting without considering consequences) and temporal impulsivity (i.e., the tendency to pick sooner outcomes over later ones). The authors find that both types of impulsivity can be adaptive in different contexts. For example, when individuals experience scarcity of resources or when they are close to a minimum level of reserves (critical threshold). In this commentary, we extend their findings to a discussion about the measurement of impulsivity. We argue that a common method for measuring temporal impulsivity in which people make decisions between outcomes that are spaced out in time (intertemporal choice tasks), puts individuals in a specific context that is unlikely to generalize well to other situations. Furthermore, trait measures of impulsivity may only be modestly informative about future impulsive behavior because they largely abstract away from important context. To address these issues, we advocate for the development of dynamic measures of the two types of impulsivity. We argue that measuring temporal impulsivity in naturalistic contexts with varying environmental and state parameters could provide insights into whether individuals (i.e., humans and nonhuman animals) react to environmental changes adaptively, while trait measures of impulsivity more generally should collect and provide more contextual information. Dynamic measurement of different types of impulsivity will also allow for more discussion about adaptive impulsive responses in different contexts, which could help combat the stigmatization of various disorders associated with impulsivity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The influence of stress on the neural underpinnings of disinhibited eating: a systematic review and future directions for research

Disinhibited eating involves overconsumption and loss of control over food intake, and underpins many health conditions, including obesity and binge-eating related disorders. Stress has been implicated in the development and maintenance of disinhibited eating behaviours, but the mechanisms underlying this relationship are unclear. In this systematic review, we examined how the impact of stress on the neurobiological substrates of food-related reward sensitivity, interoception and cognitive control explains its role in disinhibited eating behaviours. We synthesised the findings of functional magnetic resonance imaging studies including acute and/or chronic stress exposures in participants with disinhibited eating. A systematic search of existing literature conducted in alignment with the PRISMA guidelines identified seven studies investigating neural impacts of stress in people with disinhibited eating. Five studies used food-cue reactivity tasks, one study used a social evaluation task, and one used an instrumental learning task to probe reward, interoception and control circuitry. Acute stress was associated with deactivation of regions in the prefrontal cortex implicated in cognitive control and the hippocampus. However, there were mixed findings regarding differences in reward-related circuitry. In the study using a social task, acute stress associated with deactivation of prefrontal cognitive control regions in response to negative social evaluation. In contrast, chronic stress was associated with both deactivation of reward and prefrontal regions when viewing palatable food-cues. Given the small number of identified publications and notable heterogeneity in study designs, we propose several recommendations to strengthen future research in this emerging field.

Examining the efficacy of a telehealth intervention targeting addictive eating in Australian adults (the TRACE Programme): a randomised controlled trial protocol

INTRODUCTION

Approximately 15%-20% of the adult population self-report symptoms of addictive eating. There are currently limited options for management. Motivational interviewing-based interventions, containing personalised coping skills training, have been found to be effective for behaviour change in addictive disorders (eg, alcohol). This project builds upon foundations of an addictive eating feasibility study previously conducted and co-design process involving consumers. The primary aim of this study is to examine the efficacy of a telehealth intervention targeting addictive eating symptoms in Australian adults compared with passive intervention and control groups.

METHODS AND ANALYSIS

This three-arm randomised controlled trial will recruit participants 18-85 years, endorsing ≥3 symptoms on the Yale Food Addiction Scale (YFAS) 2.0, with body mass index >18.5 kg/m². Addictive eating symptoms are assessed at baseline (pre-intervention), 3 months (post-intervention) and 6 months. Other outcomes include dietary intake and quality, depression, anxiety, stress, quality of life, physical activity and sleep hygiene. Using a multicomponent clinician-led approach, the active intervention consists of five telehealth sessions (15-45 min each) delivered by a dietitian over 3 months. The intervention uses personalised feedback, skill-building exercises, reflective activities and goal setting. Participants are provided with a workbook and website access. The passive intervention group receives the intervention via a self-guided approach with access to the workbook and website (no telehealth). The control group receives personalised written dietary feedback at baseline and participants advised to follow their usual dietary pattern for 6 months. The control group will be offered the passive intervention after 6 months. The primary endpoint is YFAS symptom scores at 3 months. A cost-consequence analysis will determine intervention costs alongside mean change outcomes.

ETHICS AND DISSEMINATION

Human Research Ethics Committee of University of Newcastle, Australia provided approval (H-2021-0100). Findings will be disseminated via publication in peer-reviewed journals, conference presentations, community presentations and student theses.

TRIAL REGISTRATION NUMBER

Australia New Zealand Clinical Trials Registry (ACTRN12621001079831).

Episodic future thinking and compassion reduce non-compliance urges regarding public health guidelines: a randomised controlled trial

BACKGROUND

People often feel urges to engage in activities that violate pandemic public health guidelines. Research on these urges has been reliant on measures of typical behaviour, which fail to capture these urges as they unfold. Guideline adherence could be improved through interventions, but few methods allow for ecologically valid observation of the range of behaviours that pandemic guidelines prescribe.

METHODS

In this preregistered parallel randomised trial, 95 participants aged 18-65 from the UK were assigned to three groups using blinded block randomisation, and engaged in episodic future thinking (n = 33), compassion exercises (n = 31), or a control procedure (n = 31). Following an ecological momentary assessment procedure, participants report on the intensity of their occurrent urges (min. 1, max. 10) and their ability to control them. The study further investigates whether, and through which mechanism, state impulsivity and vaccine attitudes affect guideline adherence.

RESULTS

Episodic future thinking (b = -1.80) and compassion exercises (b = -1.45) reduced the intensity of urges. State impulsivity is associated with stronger urges, but we found no evidence that vaccine hesitancy predicts lesser self-control.

CONCLUSIONS

We conclude that episodic future thinking exercises and compassion training may be used to decrease non-compliance urges of individuals who are an acute public health risk for the community, such as those in voluntary isolation.

The relationship between sleep and appetitive conditioning: A systematic review and meta-analysis

This systematic review and meta-analysis (PROSPERO registration animal/human studies: CRD42021234793/CRD42021234790) examined the relationship between sleep and appetitive conditioning. Inclusion criteria included: a) appetitive conditioning paradigm; b) measure of conditioning; c) sleep measurement and/or sleep loss; d) human and/etor non-human animal samples; and e) written in English. Searches of seven databases returned 3777 publications. The final sample consisted of 42 studies using primarily animal samples and involving food- and drug-related conditioning tasks. We found sleep loss disrupted appetitive conditioning of food rewards (p < 0.001) but potentiated appetitive conditioning of drug rewards (p < 0.001). Furthermore, sleep loss negatively impacted extinction learning irrespective of the reward type. Post-learning sleep was associated with increases in REM sleep (p = 0.02). Findings suggest sleep loss potentiates the impact of psychoactive substances in a manner likely to produce an increased risk of problematic substance use. In obese/overweight populations, sleep loss may be associated with deficits in the conditioning and extinction of reward-related behaviours. Further research should assess the relationship between sleep and appetitive conditioning in humans.

Designing an online intervention for adults with addictive eating: a qualitative integrated knowledge translation approach

INTRODUCTION

Codesign is a meaningful end-user engagement in research design. The integrated knowledge translation (IKT) framework involves adopting a collaborative research approach to produce and apply knowledge to address real-world needs, resulting in useful and useable recommendations that will more likely be applied in policy and practice. In the field of food addiction (FA), there are limited treatment options that have been reported to show improvements in FA symptoms.

OBJECTIVES

The primary aim of this paper is to describe the step-by-step codesign and refinement of a complex intervention delivered via telehealth for adults with FA using an IKT approach. The secondary aim is to describe our intervention in detail according to the TIDieR checklist.

DESIGN

This study applies the IKT process and describes the codesign and refinement of an intervention through a series of online meetings, workshops and interviews.

PARTICIPANTS

This study included researchers, clinicians, consumers and health professionals.

PRIMARY OUTCOME MEASURE

The primary outcome was a refined intervention for use in adults with symptoms of FA for a research trial.

RESULTS

A total of six female health professionals and five consumers (n=4 female) with lived overeating experience participated in two interviews lasting 60 min each. This process resulted in the identification of eight barriers and three facilitators to providing and receiving treatment for FA, eight components needed or missing from current treatments, telehealth as a feasible delivery platform, and refinement of key elements to ensure the intervention met the needs of both health professionals and possible patients.

CONCLUSION

Using an IKT approach allowed for a range of viewpoints and enabled multiple professions and disciplines to engage in a semiformalised way to bring expertise to formulate a possible intervention for FA. Mapping the intervention plan to the TIDieR checklist for complex interventions, allowed for detailed description of the intervention and the identification of a number of areas that needed to be refined before development of the finalised intervention protocol.

State impulsivity amplifies urges without diminishing self-control

A disproportionate amount of research on impulsivity has focused on trait-related aspects rather than state fluctuations. As a result, the relationship between state impulsivity and moment-to-moment behaviour is unclear. Impulsivity is assumed to negatively affect self-control, but an alternative explanation, yet to be tested, could be that changes in state impulsivity and its homeostatic drivers influence the intensity of urges. We tested whether state impulsivity and hunger affected behaviour through a dual-process model, affecting both the experience of various urges, and self-control, using a smartphone-based experience sampling approach. We found that state impulsivity is associated with stronger urges, but we found no evidence of an association with diminished self-control. Being hungry amplifies urges across different types of urges, and both hunger and late hours are negatively related to the likelihood of controlling urges. These findings imply that the influence of hunger is not limited to the food domain, and provide new insight into the role of state impulsivity in daily life.

How do cannabis users mentally travel in time? Evidence from an fMRI study of episodic future thinking

RATIONALE

Episodic future thinking (EFT) is a cognitive function that allows individuals to imagine novel experiences that may happen in the future. Prior studies show that EFT is impaired in different groups of substance users. However, there is no evidence regarding the neurobiological mechanisms of EFT in cannabis users.

OBJECTIVES

We aimed to compare brain activations of regular cannabis users and non-using controls during an EFT fMRI task. Exploratory analyses were also conducted to investigate the association between EFT and cannabis use variables (e.g., duration of use, age onset, frequency of use).

METHODS

Twenty current cannabis users and 22 drug-naïve controls underwent an fMRI scanning session while completing a task involving envisioning future-related events and retrieval of past memories as a control condition. The EFT fMRI task was adapted from the autobiographical interview and composed of 20 auditory cue sentences (10 cues for past and 10 cues for future events). Participants were asked to recall a past or generate a future event, in response to the cues, and then rate their vividness after each response.

RESULTS

We found that cannabis users compared to non-user controls had lower activation within the cerebellum, medial and superior temporal gyrus, lateral occipital cortex, and occipital fusiform gyrus while envisioning future events. Cannabis users rated the vividness of past events significantly lower than non-users (P < 0.005). There were marginal group differences for rating the vividness of future events (P = 0.052). Significant correlations were also found between the medial and superior temporal gyrus activities and behavioral measures of EFT and episodic memory.

CONCLUSIONS

Cannabis users, compared to drug-naïve controls, have lower brain activation in EFT relevant regions. Thus, any attempts to improve aberrant EFT performance in cannabis users may benefit from EFT training.

Development of Goal Management Training+ for Methamphetamine Use Disorder Through Collaborative Design

BACKGROUND

Methamphetamine use disorder (MUD) is associated with executive dysfunctions, which are linked with poorer treatment outcomes including earlier drop out and relapse. However, current treatments for MUD do not address executive functions. Goal Management Training (GMT) is an evidence-based cognitive remediation program for executive dysfunction, although required modifications to enhance its relevance and application within addiction treatment settings. This study aimed to (1) tailor GMT to the key cognitive deficits and typical treatment duration of MUD; (2) explore consumers' (people with MUD) engagement with the revised program; (3) implement a prototype of the program with consumers; and (4) present the manualized standard administration to clinical service providers.

METHODS

We followed the Medical Research Council Complex Interventions Framework and employed an evidence- and person-based intervention development process. We used a four-phased approach and collaborated with neuropsychology experts, design researchers in healthcare, consumers with MUD, and clinical service providers. Each aim was addressed in a separate study phase; including content refinement and review with neuropsychology experts (phase 1), intervention design and collaboration with consumers (phase 2), prototype development and review with consumers (phase 3), and final program modifications and review with clinical stakeholders (phase 4).

RESULTS

Findings from phase 1 indicated support for targeting four cognitive processes (attention, impulse control, goal setting, and decision-making). Key feedback included the need to help habitualize cognitive strategies and to guide consumers in applying these strategies in emotionally salient situations. Findings from phases 2 and 3 indicated consumer support for the program strategies and materials but highlighted the need to further enhance the personal relevance of specific content and journal activities. Findings from phase 4 provided clinicians support for the revised program but indicated an opportunity to minimize unintended effects. We present the intervention materials for the final revised program, Goal Management Training⁺ (GMT⁺), in line with TIDieR guidelines.

CONCLUSIONS

GMT⁺ targets key cognitive processes and is sensitive to the clinical needs of people with MUD. Our intervention development process was important for informing the active ingredients and materials for GMT⁺, and indicated initial consumer and provider acceptability prior to conducting a clinical trial.

White matter microstructure differences in individuals with dependence on cocaine, methamphetamine, and nicotine: Findings from the ENIGMA-Addiction working group

BACKGROUND

Nicotine and illicit stimulants are very addictive substances. Although associations between grey matter and dependence on stimulants have been frequently reported, white matter correlates have received less attention.

METHODS

Eleven international sites ascribed to the ENIGMA-Addiction consortium contributed data from individuals with dependence on cocaine (n = 147), methamphetamine (n = 132) and nicotine (n = 189), as well as non-dependent controls (n = 333). We compared the fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) of 20 bilateral tracts. Also, we compared the performance of various machine learning algorithms in deriving brain-based classifications on stimulant dependence.

RESULTS

The cocaine and methamphetamine groups had lower regional FA and higher RD in several association, commissural, and projection white matter tracts. The methamphetamine dependent group additionally showed lower regional AD. The nicotine group had lower FA and higher RD limited to the anterior limb of the internal capsule. The best performing machine learning algorithm was the support vector machine (SVM). The SVM successfully classified individuals with dependence on cocaine (AUC = 0.70, p < 0.001) and methamphetamine (AUC = 0.71, p < 0.001) relative to non-dependent controls. Classifications related to nicotine dependence proved modest (AUC = 0.62, p = 0.014).

CONCLUSIONS

Stimulant dependence was related to FA disturbances within tracts consistent with a role in addiction. The multivariate pattern of white matter differences proved sufficient to identify individuals with stimulant dependence, particularly for cocaine and methamphetamine.

The evidential value of research on cognitive training to change food-related biases and unhealthy eating behavior: A systematic review and p-curve analysis

Cognitive bias modification (CBM), which retrains implicit biases towards unhealthy foods, has been proposed as a promising adjunct to improve the efficacy of weight loss interventions. We conducted a systematic review of research on three CBM approaches (i.e., cue-specific inhibitory control, approach bias modification, and attentional bias modification) for reducing unhealthy eating biases and behavior. We performed a p-curve analysis to determine the evidential value of this research; this method is optimally suited to clarify whether published results reflect true effects or false positives due to publication and reporting biases. When considering all CBM approaches, our results suggested that the findings of CBM trials targeting unhealthy eating are unlikely to be false positives. However, only research on attentional bias modification reached acceptable levels of power. These results suggest that CBM interventions may be an effective strategy to enhance the efficacy of weight loss interventions. However, there is room for improvement in the methodological standards of this area of research, especially increasing the statistical power can help to fully clarify the clinical potential of CBM, and determine the role of potential moderators.

Factors associated with the absence of cocaine craving in treatment-seeking individuals during inpatient cocaine detoxification

BACKGROUND

Anecdotal evidence suggests a substantial proportion of individuals with cocaine use disorder do not report craving during inpatient detoxification.

OBJECTIVE

To examine prevalence and clinical correlates of consistent absence of cocaine craving among inpatients during detoxification. We hypothesized that craving absence would be associated with less severity of cocaine use, depression, and anxiety. Alternative explanations were also explored.

METHODS

Craving absence (i.e., non-cravers) was defined as a daily score of zero across two separate craving visual analogue scales in each of the inpatient days. Participants scoring ≥1 on ≥1 day were considered cravers. Severity of cocaine use disorder as well as in-treatment depression and anxiety were assessed. Alternative contributors included presence of cocaine and other substances in urine at admission, in-treatment prescription of psychotropic medications, treatment motivation, executive function, interoception, and social desirability.

RESULTS

Eighty-seven participants (78.2% males) met criteria as either non-cravers (n = 29; 33.3%) or cravers (n = 58; 66.7%). Mean length of admission in non-cravers and cravers was, respectively, 10.83 and 13.16 days. Binary logistic regression model showed that non-cravers scored significantly lower than cravers on cocaine use during last month before treatment (OR, 95% CI; 0.902, 0.839-0.970), in-treatment depression (OR, 95% CI; 0.794, 0.659-0.956), and in-treatment prescribing of antipsychotics (OR, 95% CI; 0.109, 0.014-0.823). Model prediction accuracy was 88.9%.

CONCLUSIONS

One in three patients undergoing inpatient detoxification experienced absence of craving, linked to less pretreatment cocaine use, better mood, and decreased administration of antipsychotics. Findings may inform pretreatment strategies and improve treatment cost-effectiveness.

Binge Eating and Binge Drinking: A Two-Way Road? An Integrative Review

Unhealthy diet and alcohol are serious health problems, especially in adolescents and young adults. "Binge" is defined as the excessive and uncontrolled consumption of food (binge eating) and alcohol (binge drinking). Both behaviors are frequent among young people and have a highly negative impact on health and quality of life. Several studies have explored the causes and risk factors of both behaviors, and the evidence concludes that there is a relationship between the two behaviors. In addition, some research postulates that binge eating is a precipitating factor in the onset and escalation of excessive alcohol consumption, while other studies suggest that alcohol consumption leads to excessive and uncontrollable food consumption. Given that no review has yet been published regarding the directionality between the two behaviors, we have set out to provide an upto- date overview of binge eating and binge drinking problems, analyzing their commonalities and differences, and their uni- and bidirectional associations. In addition, we explore the reasons why young people tend to engage in both behaviors and consider directions for future research and clinical implications.

Cardiac defense reactivity and cognitive flexibility in high- and low-resilience women

Resilience is a protective health variable that contributes to successful adaptation to stressful experiences. However, in spite of its relevance, few studies have examined the psychophysiological and neuropsychological mechanisms involved in resilience. The present study analyzes, in a sample of 54 young women, the relationships between high- and low-resilience, measured with the Spanish versions of Connor-Davidson Resilience Scale questionnaire and the Resilience Scale, and two indices of psychophysiological and neuropsychological adaptability, the cardiac defense response (CDR) and cognitive flexibility. The CDR is a specific reaction to an unexpected intense noise characterized by two acceleration-deceleration heart rate components. Cognitive flexibility, defined as the ability to adapt our behavior to changing environmental demands, is measured in this study with the CAMBIOS neuropsychological test. The results showed that the more resilient people, in addition to having better scores on mental health questionnaires, had a larger initial acceleration-deceleration of the CDR-indicative of greater vagal control, obtained better scores in cognitive flexibility, and evaluated the intense noise as less unpleasant than the less resilient people. No group differences were found in the second acceleration-deceleration of the CDR-indicative of sympathetic cardiac control, in the skin conductance response, or in subjective intensity of the noise. The present findings broaden the understanding of how resilient people change their adaptable responses to address environmental demands.

Stressing diets? Amygdala networks, cumulative cortisol, and weight loss in adolescents with excess weight

OBJECTIVE

The amygdala is importantly involved in stress and obesity, but its role on weight change and diet-related stress remains unexplored among adolescents with excess weight. We aimed to examine the functional connectivity of the Central and Basolateral amygdala nuclei (CeA and BLA) among adolescents, and to explore the longitudinal association between brain connectivity measures and diet-related cortisol and weight loss in adolescents with excess weight.

METHODS

We compared resting-state functional connectivity between adolescents with excess (EW, N = 34; Age = 16.44 ± 1.66) and normal weight (NW, N = 36; Age = 16.50 ± 1.40) using a seed-based (CeA and BLA) whole-brain approach. Then, in a subset of 30 adolescents with EW, followed-up after 3-months of dietary/lifestyle intervention, we explored for interactions between connectivity in the CeA/BLA networks and weight loss. Regression analyses were performed to explore the relationship between accumulated cortisol and weight loss, and to test the potential effect of the amygdala networks on such association.

RESULTS

In EW compared with NW, the CeA regions showed higher functional connectivity with anterior portions, and lower connectivity with posterior portions of the cingulate cortex, while the left BLA regions showed lower connectivity with the dorsal caudate and angular gyrus. In addition, higher connectivity between the left CeA-midbrain network was negatively associated with weight loss. Hair cortisol significantly predicted weight change (p = 0.012). However, this association was no longer significant (p = 0.164) when considering the CeA-midbrain network in the model as an additional predictor.

CONCLUSIONS

Adolescents with EW showed functional connectivity alterations within the BLA/CeA networks. The CeA-midbrain network might constitute an important brain pathway regulating weight change.

Evaluation of Motivation for the Treatment of Drug Addicts with Personality Disorders

Lack of motivation for the treatment of drug addiction is associated with dropout and relapses. Further, personality disorders (PD) have traditionally been linked to low motivation and therapeutic failure. Thus, the present study aims to analyze the structure of the Motivation for Treatment Questionnaire (MTQ-8), as well as to determine differences in motivation due to the presence of PD and the impact of psychological adjustment on motivation. The sample included 125 patients (84% male) who started a treatment for their addiction to cocaine and alcohol. Rasch analysis was applied for the first objective, and means contrast and regression analysis for the others. The two subscales of the MTQ-8 fit the Rasch model, with appropriate psychometric characteristics when merging Items 5 and 7. The presence of PD was not associated with reduced motivation. Motivation for treatment was greater when abstinence was less than three weeks, and psychological distress predicted motivation for treatment. The present study confirms that MTQ-8 subscales are suitable for measuring motivation for treatment and readiness for change in drug-dependent patients. It is noted that the presence of PD should not be associated with a lower level of motivation, and that psychological distress influences motivation.

Neural-based valuation of functional foods among lean and obese individuals

Functional foods may contribute to establish healthy eating habits and reduce obesity and related comorbidities. Differences in the brain mechanisms underpinning the valuation of functional foods in individuals with excess weight may inform the development of attractive functional foods. We aimed to compare brain function during the Willingness to Pay task for functional vs standard foods between individuals with healthy weight (HW), overweight (OW), and obesity (OB). We hypothesized that, in participants with OB, willingness to pay for functional foods would evoke greater activation/connectivity in brain regions previously associated with subjective value. Thirty-six HW, 19 OW, and 20 OB adults performed a functional magnetic resonance imaging-Willingness to Pay task that requires them to decide how much they would pay for presented standard and functional food images tasted in a previous buffet. Whole-brain analyses compared task-related activation and connectivity between participants with OB, OW, and HW. Individuals with OB, relative to HW, showed more similar willingness to pay for functional and standard food. At the brain level, they also showed hyperactivation in the ventral posterior cingulate cortex and the right angular gyrus, as well as an increased functional connectivity between the ventral posterior cingulate cortex and the intraparietal cortices to the valuation of the functional vs the standard foods. Increased willingness to pay for functional foods in people with excessive weight may be driven by recruitment of brain regions that direct attention to internal goals.

The neural interface between negative emotion regulation and motivation for change in cocaine dependent individuals under treatment

BACKGROUND

Emotion regulation is important for cocaine addiction treatment success, particularly during early abstinence. In addition, the neural underpinnings of emotion processing overlap with those of motivation and goal-directed behavior. We examined if the neural underpinnings of emotion maintenance and its regulation correlate with cocaine treatment motivation.

METHODS

Forty-five cocaine dependent individuals (CDIs) starting outpatient treatment in a public specialized addiction treatment clinic in Granada (Spain) underwent fMRI scans while performing a Reappraisal task, and completed the University of Rhode Island Change Assessment Scale (URICA), to measure treatment motivation. We conducted correlation analyses to examine the association between emotion maintenance and regulation related brain activation and URICA's Readiness to Change scores. We also explored links between Emotional reports during the fMRI reappraisal task, duration of abstinence, and anxiety and depression symptoms.

RESULTS

Readiness to Change scores were positively correlated with activations in the right dorsolateral prefrontal and right parietal cortices, the midbrain (p ≤ 0.001, cluster extents ≥109 voxels), and basolateral amygdala (P_FWE-SVC<0.05), while negatively with emotion maintenance related activation in the same cortical areas and activations in the dorsomedial frontal cortex, the nucleus accumbens and the left fusiform gyrus. Emotional reactivity negatively correlated with right dorsolateral prefrontal cortex reappraisal related activation (r= -0.40, p = 0.007), and the Regulate score positively correlated with the left fusiform gyrus emotion maintenance related activation (r = 0.31, p = 0.04).

CONCLUSIONS

Emotional related activation in frontoparietal, accumbens, fusiform, amygdala and midbrain regions engaged during emotion regulation and its maintenance correlate with early treatment motivation in CDIs.

Combined effects of age and BMI are related to altered cortical thickness in adolescence and adulthood

Overweight and obesity are associated with functional and structural alterations in the brain, but how these associations change across critical developmental periods remains unknown. Here, we examined the relationship between age, body mass index (BMI) and cortical thickness (CT) in healthy adolescents (n = 70; 14-19 y) and adults (n = 75; 25-45 y). We also examined the relationship between adiposity, impulsivity, measured by delay discounting (DD), and CT of the inferior frontal gyrus (IFG), a region key to impulse control. A significant age-by-BMI interaction was observed in both adolescents and adults; however, the direction of this relationship differed between age groups. In adolescents, increased age-adjusted BMI Z-score attenuated age-related CT reductions globally and in frontal, temporal and occipital regions. In adults, increased BMI augmented age-related CT reductions, both globally and in bilateral parietal cortex. Although DD was unrelated to adiposity in both groups, increased DD and adiposity were both associated with reduced IFG thickness in adolescents and adults. Our findings suggest that the known age effects on CT in adolescence and adulthood are moderated by adiposity. The association between weight, cortical development and its functional implications would suggest that future studies of adolescent and adult brain development take adiposity into account.

Transcranial electrical and magnetic stimulation (tES and TMS) for addiction medicine: A consensus paper on the present state of the science and the road ahead

There is growing interest in non-invasive brain stimulation (NIBS) as a novel treatment option for substance-use disorders (SUDs). Recent momentum stems from a foundation of preclinical neuroscience demonstrating links between neural circuits and drug consuming behavior, as well as recent FDA-approval of NIBS treatments for mental health disorders that share overlapping pathology with SUDs. As with any emerging field, enthusiasm must be tempered by reason; lessons learned from the past should be prudently applied to future therapies. Here, an international ensemble of experts provides an overview of the state of transcranial-electrical (tES) and transcranial-magnetic (TMS) stimulation applied in SUDs. This consensus paper provides a systematic literature review on published data - emphasizing the heterogeneity of methods and outcome measures while suggesting strategies to help bridge knowledge gaps. The goal of this effort is to provide the community with guidelines for best practices in tES/TMS SUD research. We hope this will accelerate the speed at which the community translates basic neuroscience into advanced neuromodulation tools for clinical practice in addiction medicine.

Impulsivity and cognitive distortions in different clinical phenotypes of gambling disorder: Profiles and longitudinal prediction of treatment outcomes

BACKGROUND

Impulsivity and cognitive distortions are hallmarks of gambling disorder (GD) but it remains unclear how they contribute to clinical phenotypes. This study aimed to (1) compare impulsive traits and gambling-related distortions in strategic versus non-strategic gamblers and online versus offline gamblers; (2) examine the longitudinal association between impulsivity/cognitive distortions and treatment retention and relapse.

METHODS

Participants seeking treatment for GD (n = 245) were assessed for gambling modality (clinical interview), impulsive traits (Urgency, Premeditation, Perseverance and Sensation Seeking [UPPS] scale) and cognitive distortions (Gambling Related Cognitions Scale) at treatment onset, and for retention and relapse (as indicated by the clinical team) at the end of treatment. Treatment consisted of 12-week standardized cognitive behavioral therapy, conducted in a public specialized clinic within a general public hospital.

RESULTS

Strategic gamblers had higher lack of perseverance and gambling-related expectancies and illusion of control than non-strategic gamblers, and online gamblers had generally higher distortions but similar impulsivity to offline gamblers. Lack of perseverance predicted treatment dropout, whereas negative urgency and distortions of inability to stop gambling and interpretative bias predicted number of relapses during treatment.

CONCLUSIONS

Individuals with online and strategic GD phenotypes have heightened gambling related biases associated with premature treatment cessation and relapse. Findings suggest that these GD phenotypes may need tailored treatment approaches to reduce specific distortions and impulsive facets.

Sex differences in the association between impulsivity and driving under the influence of alcohol in young adults: The specific role of sensation seeking

INTRODUCTION

There is an outstanding need to identify predictors of driving under the influence of alcohol (DUI) among young adults, particularly women. Impulsivity, or the tendency to act without thinking, is a predictor of DUI, but the specific facets of impulsivity that predict DUI and their interaction with sex differences remain unclear. We aimed to investigate sex differences in the link between impulsivity facets and DUI. Moreover, we sought to replicate previous findings regarding sex differences on impulsivity, and associations between impulsivity facets and DUI.

METHOD

A total of 506 university students participated in the study (males, n = 128; females, n = 378). Participants completed measures of impulsivity (UPPS-P short version), alcohol use (AUDIT-C), frequency of DUI episodes and related perception of risk. The UPPS-P assesses five facets of impulsivity: sensation seeking, (lack of) premeditation and perseverance and positive and negative urgency.

RESULTS

Men showed higher sensation seeking and lack of perseverance, alcohol use and DUI frequency and lower risk perception than women. DUI frequency was negatively associated with perception of risk and positively associated with alcohol use and the five impulsivity facets. After controlling for alcohol use and risk perception, only lack of premeditation was associated with DUI frequency in the whole sample. Sensation seeking was positively associated with DUI frequency only in women.

DISCUSSION

The link between lack of premeditation and DUI suggest that pre-drinking planning strategies can contribute to prevent risky driving. In women, specific links between sensation seeking and DUI suggest the need for personality-tailored prevention strategies.

Impulsivity and body fat accumulation are linked to cortical and subcortical brain volumes among adolescents and adults

Obesity is associated not only with metabolic and physical health conditions, but with individual variations in cognition and brain health. This study examined the association between body fat (an index of excess weight severity), impulsivity (a vulnerability factor for obesity), and brain structure among adolescents and adults across the body mass index (BMI) spectrum. We used 3D T1 weighted anatomic magnetic resonance imaging scans to map the association between body fat and volumes in regions associated with obesity and impulsivity. Participants were 127 individuals (BMI: 18–40 kg/m²; M = 25.69 ± 5.15), aged 14 to 45 years (M = 24.79 ± 9.60; female = 64). Body fat was measured with bioelectric impendence technology, while impulsivity was measured with the UPPS-P Impulsive Behaviour Scale. Results showed that higher body fat was associated with larger cerebellar white matter, medial orbitofrontal cortex (OFC), and nucleus accumbens volume, although the latter finding was specific to adolescents. The relationship between body fat and medial OFC volume was moderated by impulsivity. Elevated impulsivity was also associated with smaller amygdala and larger frontal pole volumes. Our findings link vulnerability and severity markers of obesity with neuroanatomical measures of frontal, limbic and cerebellar structures, and unravel specific links between body fat and striatal volume in adolescence.

Hypothalamic Networks in Adolescents With Excess Weight: Stress-Related Connectivity and Associations With Emotional Eating

OBJECTIVE

Adolescents with excess weight are particularly sensitive to stress, which may contribute to the presence of emotional eating behaviors. It is proposed that this may be due to alterations in the connectivity between hypothalamic networks and regions of the "emotional nervous system," involved in the regulation of energy balance and stress processing. However, this remains to be clarified in adolescents with excess weight.

METHOD

We investigated whole-brain differences in the functional connectivity of the medial and lateral hypothalamus (MH and LH) between adolescents with excess weight (EW, n = 53; mean age = 14.64 years, SD = 1.78) and normal weight (NW, n = 51; mean age = 15.29 years, SD = 1.75) using seed-based resting-state analyses. Then, in a subset of 22 adolescents with EW (mean age = 15.75 years, SD = 1.70) and 32 with NW (mean age = 15.27, SD = 2.03), we explored for group interactions between the MH/LH networks and stress response in the Trier Social Stress Task (TSST) and emotional eating, assessed with the Dutch Eating Behavior Questionnaire (DEB-Q).

RESULTS

Compared to NW, EW showed higher functional connectivity in the LH-orbitofrontal cortex, ventral striatum, anterior insula, and in the MH-middle temporal cortex networks. EW also showed lower connectivity in the LH-cerebellum, and in the MH-middle prefrontal, pre-, and postcentral gyri networks. In EW, higher connectivity of the LH-nucleus accumbens and LH-midbrain networks were associated with stress response. Higher connectivity in the LH-midbrain was also associated with a greater presence of emotional eating behaviors in EW.

CONCLUSION

Adolescents with EW showed functional connectivity alterations within both MH/LH networks. Alterations in the LH network were linked with higher levels of stress response and emotional-driven eating patterns.

The Cognitive Drivers of Compulsive Eating Behavior

Compulsivity is a central feature of obsessive-compulsive and addictive disorders, which share considerable overlap with excessive eating in terms of repetitive behavior despite negative consequences. Excessive eating behavior is characteristic of several eating-related conditions, including eating disorders [bulimia nervosa (BN), binge eating disorder (BED)], obesity, and food addiction (FA). Compulsivity is proposed to be driven by four distinct cognitive components, namely, contingency-related cognitive flexibility, task/attentional set-shifting, attentional bias/disengagement and habit learning. However, it is unclear whether repetitive behavior in eating-related conditions is underpinned by deficits in these cognitive components. The current mini-review synthesizes the available evidence for performance on compulsivity-related cognitive tasks for each cognitive domain among populations with excessive eating behavior. In three of the four cognitive domains, i.e., set-shifting, attentional bias and habit learning, findings were mixed. Evidence more strongly pointed towards impaired contingency-related cognitive flexibility only in obesity and attentional bias/disengagement deficits only in obesity and BED. Overall, the findings of the reviewed studies support the idea that compulsivity-related cognitive deficits are common across a spectrum of eating-related conditions, although evidence was inconsistent or lacking for some disorders. We discuss the theoretical and practical importance of these results, and their implications for our understanding of compulsivity in eating-related conditions.

Specific aspects of cognitive impulsivity are longitudinally associated with lower treatment retention and greater relapse in therapeutic community treatment

INTRODUCTION

Impulsivity has been consistently associated with poorer addiction treatment outcomes. However, impulsivity is a multifaceted construct and current evidence have failed to unravel which specific aspects explain this relationship. There is also limited research examining long-term outcomes. We aimed to examine the longitudinal association between baseline performance on a comprehensive battery of impulsivity measures and retention and relapse at the end of treatment.

METHODS

The sample comprised 68 participants with miscellaneous diagnoses of substance use disorders and polysubstance use patterns, enrolled in public residential therapeutic communities in Andalusia (Spain). At baseline, we applied measures of selective attention (Stroop), response inhibition (Affective Go/No Go), delay discounting (Monetary Choice Questionnaire; MCQ), and decision-making (Iowa Gambling Task; IGT). At the end of treatment (mean = 148.36 days, range = 22-289 days), we collected outcome measures of retention (coded by the clinical team as completion or dropout based on statewide practice guidelines) and relapse (defined as at least two separate alcohol/drug use episodes based on urine analyses).

RESULTS

Cox regression models showed that poorer decision-making in the IGT was associated with premature treatment dropout, whereas elevated commission errors in the Affective Go/No Go were associated with higher relapse rates. Selective attention and delay discounting were unrelated to outcomes.

CONCLUSION

Long-term based decision-making skills are important to commit to the complex and intensive treatment programs of therapeutic communities. The ability to withhold behavioural responses under positive affect is relevant to prevent relapse. Both skills should be assessed and potentially trained during therapeutic community treatment.

Questionnaire of core beliefs related to drug use and craving for assessment of relapse risk

This study was aimed at designing a questionnaire for the assessment of addiction-related core beliefs and craving. The sample comprised 215 patients (85.8% males and 14.2% females) in treatment for dependence to alcohol (40%), cocaine (36.3%) and cannabis (23.7%). Descriptive statistics were used to characterize the sample. Variance, regression and factorial analyses were conducted to study the questionnaire structure and its relation with variables such as abstinence and craving. Items about drug-related beliefs yielded a four-factor structure: what patient think that they could not do without drug use, lack of withdrawal, conditions required to use drugs again, and use of drugs as the only way to feel good. Items related to craving yielded three factors: negative emotions as precipitants of drug use, positive emotions, and difficulties attributed to coping with craving. Furthermore, beliefs were more important to predict craving than abstinence time. The present questionnaire allows to assess a set of significant factors to design prevention relapse programs.

Self-deception as a mechanism for the maintenance of drug addiction

BACKGROUND

This study was aimed at: (i) examining levels of self-deception in substance dependent individuals following addiction treatment, and (ii) examining the association between participants&rsquo; levels of self-deception and (a) personality disorders, (b) addiction-related beliefs, (c) duration of abstinence, and (d) estimates of craving.

METHOD

We administered self-report questionnaires of self-deception and mixtification, and core beliefs related to addiction and craving. The sample comprised 79 outpatients who were consecutively recruited at the Centro Provincial de Drogodependencias in Granada: 87.3% were males and the mean age was 37.68 years old. Thirty-four percent of participants were diagnosed with comorbid personality disorders.

RESULTS

Results showed that individuals with substance dependence exhibit elevated scores of self-deception, particularly in the domains of active denial, selective amnesia, projection, and confabulation. Individuals with comorbid personality disorders display greater levels of self-deception compared to individuals without dual diagnosis.

CONCLUSIONS

Moreover, there is a significant association between levels of self-deception and addiction-related beliefs and craving. In addition, there is a negative association between levels of self-deception and duration of abstinence.

Neural correlates of impaired self-awareness of apathy, disinhibition and dysexecutive deficits in cocaine-dependent individuals

Cocaine addiction is characterized by impaired self-awareness about cognitive and motivational deficits, leading to poor treatment outcomes. However, there is still limited understanding of the neurophysiological underpinnings of this impairment. We aimed to establish if impaired self-awareness is underpinned by brain structural phenotypes among cocaine-dependent individuals (CDI). Sixty-five CDI and 65 designated informants completed the Frontal Systems Behavior Scale, and a subsample of 40 CDI were scanned via magnetic resonance imaging. We applied multiple regression models to establish the association between levels of self-awareness indexed by Frontal Systems Behavior Scale's discrepancy scores (i.e. informant ratings minus self-reports of apathy, disinhibition and dysexecutive deficits) and gray matter volumes indexed by magnetic resonance imaging voxel-based measures within five brain regions of interest: anterior cingulate cortex, orbitofrontal cortex (OFC), striatum, insula and dorsolateral prefrontal cortex (DLPFC). We also examined the neural underpinnings of underestimation versus overestimation of deficits, by splitting the CDI group according to the positive or negative value of their discrepancy scores. We found that poorer self-awareness of apathy deficits was associated with greater gray matter volume in the dorsal striatum, and poorer self-awareness of disinhibition deficits was associated with greater gray matter volume in the OFC in the whole sample. More underestimation and more overestimation of executive deficits were linked to lower DLPFC volume. We show that impaired self-awareness of cognitive and motivational deficits in cocaine addiction has a neural underpinning, implicating striatum, OFC and DLPFC structural phenotypes.

Altered cross-talk between the hypothalamus and non-homeostatic regions linked to obesity and difficulty to lose weight

Interactions between the hypothalamus and non-homeostatic regions may contribute to explain the difficulty to lose weight in obesity, an assumption never tested in human longitudinal studies. We investigated whether the functional connectivity between the medial and lateral hypothalamus (MH and LH) and corticostriatal regions differs between individuals with excess weight (n = 42) and normal weight (n = 39) using a seed-based resting-state approach. In addition, we examined the longitudinal association between functional connectivity and weight loss in a 3-month follow-up diet. Results showed that participants with excess weight had increased connectivity between the MH and the striatum and subgenual anterior cingulate cortex, and decreased connectivity with the middle frontal gyrus, and the bed nucleus of the stria terminalis (BNST), as well as a decreased connectivity between the LH and the cerebellum. Decreased connectivity between the MH and the posterior part of the BNST, and between the LH and the cerebellar cortex, predicted a greater percentage of weight loss. Functional connectivity measures explained 36% of the 3-month weight change among individuals with excess weight. We conclude that altered functional connectivity between homeostatic-hypothalamic regions and non-homeostatic corticostriatal and cerebellar regions is linked to obesity and difficulty to lose weight.

Trait and neurobiological underpinnings of negative emotion regulation in gambling disorder

BACKGROUND AND AIMS

Gambling disorder is characterized by poor regulation of negative emotions and impulsive behaviours. This study aimed to (1) compare gambling disorder patients (GDPs) and healthy controls (HCs) in self-report and brain activation measures of emotion regulation; and (2) establish its relationship with negative emotion-driven impulsivity.

DESIGN

Two cross-sectional case-control studies including GDPs and HCs.

SETTING AND PARTICIPANTS

GDPs and HCs were recruited from specialized gambling clinics in Andalusia (Spain), where they were following out-patient treatment, and from the community, respectively. Study 1 included 41 GDPs and 45 HCs [All males; M_age  = 35.22, 33.22; standard deviation (SD) = 11.16, 8.18; respectively]. Study 2 included 17 GDPs and 21 HCs (16/20 males; M_age  = 32.94, 31.00; SD = 7.77, 4.60; respectively).

MEASUREMENTS

In study 1, we compared both groups on suppression and re-appraisal emotion regulation strategies [Emotion Regulation Questionnaire (ERQ)]. In study 2, we compared GDPs with HCs on brain activation associated with down-regulation of negative emotions in a cognitive re-appraisal task, measured with functional magnetic resonance imaging (fMRI). In both studies, we correlated the measures of emotion regulation with mood-related impulsivity indicated by negative urgency (UPPS-P impulsive behaviour scale).

FINDINGS

GDPs relative to HCs showed higher levels of emotional suppression [F = 4.525; P = 0.036; means difference M_HCs -M_GDPs  = -2.433, 95% confidence interval (CI) = -4.706, -0.159] and higher activation of the premotor cortex and middle frontal gyrus during negative emotion regulation in the fMRI task [P ≤ 0.005, cluster size (CS) > 50 voxels]. Negative urgency correlated positively with emotional suppression (r = 0.399, 95% CI = 0.104, 0.629, one-tailed P = 0.005) and middle frontal gyrus activation during negative emotion regulation (P ≤ 0.005, CS > 50) in GDPs.

CONCLUSIONS

Gambling disorder is associated with greater use of emotional suppression and stronger pre-motor cortex and middle frontal gyrus activation for regulating negative emotions, compared with healthy controls. Emotional suppression use and middle frontal gyrus activation during negative emotion regulation are linked with negative emotion-driven impulsivity in this disorder.

Personality patterns predict the risk of antisocial behavior in Spanish-speaking adolescents

INTRODUCTION

There is a renewed interest in incorporating personality variables in criminology theories in order to build models able to integrate personality variables and biological factors with psychosocial and sociocultural factors. The aim of this article is the assessment of personality dimensions that contribute to the prediction of antisocial behavior in adolescents.

METHODS

For this purpose, a sample of adolescents from El Salvador, Mexico, and Spain was obtained. The sample consisted of 1035 participants with a mean age of 16.2. There were 450 adolescents from a forensic population (those who committed a crime) and 585 adolescents from the normal population (no crime committed). All of participants answered personality tests about neuroticism, extraversion, psychoticism, sensation seeking, impulsivity, and violence risk.

RESULTS

Principal component analysis of the data identified two independent factors: (i) the disinhibited behavior pattern (PDC), formed by the dimensions of neuroticism, psychoticism, impulsivity and risk of violence; and (ii) the extrovert behavior pattern (PEC), formed by the dimensions of sensation risk and extraversion. Both patterns significantly contributed to the prediction of adolescent antisocial behavior in a logistic regression model which properly classifies a global percentage of 81.9%, 86.8% for non-offense and 72.5% for offense behavior.

CONCLUSIONS

The classification power of regression equations allows making very satisfactory predictions about adolescent offense commission. Educational level has been classified as a protective factor, while age and gender (male) have been classified as risk factors.

Is gambling disorder associated with impulsivity traits measured by the UPPS-P and is this association moderated by sex and age?

OBJECTIVES

Impulsivity is a construct that is strongly associated with Gambling Disorder (GD). The main objectives in the present study are: 1) to explore the role of sex and age on impulsivity levels in GD patients; 2) to identify the relationship of the different impulsivity facets with comorbid psychopathology and other personality traits in GD patients; and (3) to assess whether impulsivity is a predictor for the severity of GD.

METHOD

The final sample consisted of 406 consecutive participants. All of them were seeking treatment for GD (88.4% male and 11.6% female) and completed the South Oaks Gambling Screen (SOGS), the UPPS-P Impulsive Behavior Scale, the Symptom Checklist (SCL-90-R), the Temperament and Character Inventory-R (TCI-R) as well as other clinical and psychopathological measures.

RESULTS

Results show a negative linear trend between age and lower sensation seeking levels as well as lack of premeditation (the higher the age the lower the UPPS-P scores), and a positive linear trend between age and positive urgency (UR) (the higher the age the higher the UPPS-P score). However, no sex differences were found for the assessed impulsivity dimensions. Lack of perseverance was positively associated with obsessive-compulsive symptoms and harm avoidance trait, and negatively related to persistence and self-directedness traits. Positive UR and negative UR were positively correlated with general psychopathology and the total number of DSM-IV criteria, and negatively associated to the following personality traits: self-directedness and cooperativeness. Finally, only the sensation seeking and negative UR of the UPPS-P showed predictive capacity on the severity of the disorder (the higher the impulsivity scores the higher the illness severity).

CONCLUSIONS

These findings highlight the association between impulsivity traits (measured by the UPPS-P) and GD in a large and consecutively recruited clinical sample with GD, taking into account the variables sex and age.

Impact of general cognition and executive function deficits on addiction treatment outcomes: Systematic review and discussion of neurocognitive pathways

This systematic review aims to examine growing evidence linking cognitive-executive functions with addiction treatment outcomes, and to discuss significant cognitive predictors drawing upon addiction neuroscience theory. We conducted a systematic search to identify studies using measures of general cognition and executive functions in patients with substance use disorders for the purpose of predicting two treatment outcomes: therapeutic adherence and relapse. Forty-six studies were selected, and sample characteristics, timing of assessments, and cognitive measures were analyzed. We observed significant methodological differences across studies, resulting in substantial variability in the relationships between cognitive-executive domains and treatment outcomes. Notwithstanding this variability, we found evidence of associations, of medium effect size, between general cognition and treatment adherence, and between reward-based decision-making and relapse. The link between general cognition and treatment adherence is consistent with emerging evidence linking limited cognitive-executive resources with less ability to benefit from talk therapies. The link between reward-based decision-making and relapse accords with decision neuroscience models of addiction. Findings may inform preclinical and clinical research concerning addiction treatment mechanisms.

Independent functional connectivity networks underpin food and monetary reward sensitivity in excess weight

Overvaluation of palatable food is a primary driver of obesity, and is associated with brain regions of the reward system. However, it remains unclear if this network is specialized in food reward, or generally involved in reward processing. We used functional magnetic resonance imaging (fMRI) to characterize functional connectivity during processing of food and monetary rewards. Thirty-nine adults with excess weight and 37 adults with normal weight performed the Willingness to Pay for Food task and the Monetary Incentive Delay task in the fMRI scanner. A data-driven graph approach was applied to compare whole-brain, task-related functional connectivity between groups. Excess weight was associated with decreased functional connectivity during the processing of food rewards in a network involving primarily frontal and striatal areas, and increased functional connectivity during the processing of monetary rewards in a network involving principally frontal and parietal areas. These two networks were topologically and anatomically distinct, and were independently associated with BMI. The processing of food and monetary rewards involve segregated neural networks, and both are altered in individuals with excess weight.

White matter disruptions in male cocaine polysubstance users: Associations with severity of drug use and duration of abstinence

BACKGROUND

Cocaine dependence has been associated with alterations in the brain's white matter integrity, yet relevant questions remain about what alterations are linked to cocaine use and/or polysubstance use, and whether they are amenable to abstinence.

METHODS

This study applied a single measurement session of diffusion tensor imaging (DTI) to examine white matter structure in male cocaine polysubstance users (n=37) versus male healthy controls (n=38), along with correlations between DTI measures and patterns of polysubstance use and duration of abstinence. Specifically, we conducted voxel-wise analyses of fractional anisotropy (FA) in the corpus callosum, frontolimbic, striatal and cingulate tracts relevant to drug sequelae.

RESULTS

Cocaine polysubstance users, compared to controls, showed lower FA in the body of the corpus callosum, anterior cingulate, uncinate fasciculus and retrolenticular part of the internal capsule. Duration of cocaine use had a marginal negative association with FA in the corpus callosum, and duration of alcohol use was negatively associated with FA in the internal capsule and the uncinate fasciculus. Duration of cocaine abstinence was positively correlated with FA in the uncinate fasciculus, posterior cingulate and fornix-striatum. In the context of cocaine polysubstance use, chronicity of cocaine use is therefore likely to be associated with lower FA in the corpus callosum, and chronicity of alcohol use with lower FA in the frontal-striatal and frontal-limbic tracts. Longer abstinence was correlated to greater FA in frontal-striatal and frontal-limbic tracts, though the direction of causality remains unclear.

CONCLUSION

Since the results did not survive multiple comparison-corrected thresholds, more studies are needed to confirm these indications.

Brain reward system's alterations in response to food and monetary stimuli in overweight and obese individuals

The brain's reward system is crucial to understand obesity in modern society, as increased neural responsivity to reward can fuel the unhealthy food choices that are driving the growing obesity epidemic. Brain's reward system responsivity to food and monetary rewards in individuals with excessive weight (overweight and obese) versus normal weight controls, along with the relationship between this responsivity and body mass index (BMI) were tested. The sample comprised 21 adults with obesity (BMI > 30), 21 with overweight (BMI between 25 and 30), and 39 with normal weight (BMI < 25). Participants underwent a functional magnetic resonance imaging (fMRI) session while performing two tasks that involve the processing of food (Willing to Pay) and monetary rewards (Monetary Incentive Delay). Neural activations within the brain reward system were compared across the three groups. Curve fit analyses were conducted to establish the association between BMI and brain reward system's response. Individuals with obesity had greater food-evoked responsivity in the dorsal and ventral striatum compared with overweight and normal weight groups. There was an inverted U-shape association between BMI and monetary-evoked responsivity in the ventral striatum, medial frontal cortex, and amygdala; that is, individuals with BMIs between 27 and 32 had greater responsivity to monetary stimuli. Obesity is associated with greater food-evoked responsivity in the ventral and dorsal striatum, and overweight is associated with greater monetary-evoked responsivity in the ventral striatum, the amygdala, and the medial frontal cortex. Findings suggest differential reactivity of the brain's reward system to food versus monetary rewards in obesity and overweight. Hum Brain Mapp 38:666-677, 2017. © 2016 Wiley Periodicals, Inc.

Impulsivity in men with prescription of benzodiazepines and methadone in prison

Benzodiazepines and methadone use has been associated with various neuropsychological impairments. However, to the best of our knowledge, no studies have been carried out on the effect of these substances (either separately or combined) on impulsive personality, including studies in prisoners. The aim of this study is to examine the impulsive personality of a sample of 134 male prisoners using the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (Torrubia, Avila, Molto, &amp; Caseras, 2001) and the UPPS-P Scale (Cyders et al., 2007). Some of these were methadone users, methadone and benzodiazepines users, polydrug users in abstinence and non-dependent drug users. The results showed that drug users have greater sensitivity to reward, positive urgency, negative urgency and sensation seeking than non-dependent users. Methadone users showed more sensitivity to punishment and lack of perseverance with respect to other users. No differences were found between methadone+benzodiazepines users and other groups. The secondary aim is to examine which impulsive personality dimensions are related to the two motivational systems proposed by Gray (BIS-BAS) using exploratory factor analysis. Results showed two different components. One component was defined by the subscales sensitivity to reinforcement, positive urgency, negative urgency and sensation seeking. The second component was defined by the subscales sensitivity to punishment, lack of perseverance and lack of premeditation.

Altered Decision-Making under Risk in Obesity

Background

The negative consequences of energy dense foods are well known, yet people increasingly make unhealthy food choices leading to obesity (i.e., risky decisions). The aims of this study were: [1] to compare performance in decision-making tasks under risk and under ambiguity between individuals with obesity, overweight and normal weight; [2] to examine the associations between body mass index (BMI) and decision-making, and the degree to which these associations are modulated by reward sensitivity.

Methods

Seventy-nine adults were recruited and classified in three groups according to their BMI: obesity, overweight and normal-weight. Groups were similar in terms of age, education and socio-economic status, and were screened for comorbid medical and mental health conditions. Decision-making under risk was measured via the Wheel of Fortune Task (WoFT) and decision-making under ambiguity via the Iowa Gambling Task (IGT). Reward sensitivity was indicated by the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ).

Results

Individuals with obesity made riskier choices in the WoFT, specifically in choices with an expected value close to zero and in the propensity to risk index. No differences were found in IGT performance or SPSRQ scores. BMI was associated with risk-taking (WoFT performance), independently of reward sensitivity.

Conclusions

Obesity is linked to a propensity to make risky decisions in experimental conditions analogous to everyday food choices.

Gambling with Rose-Tinted Glasses on: Use of Emotion-Regulation Strategies Correlates with Dysfunctional Cognitions in Gambling Disorder Patients

Background and aims Existing research shows that gambling disorder patients (GDPs) process gambling outcomes abnormally when compared against healthy controls (HCs). These anomalies present the form of exaggerated or distorted beliefs regarding the expected utility of outcomes and one's ability to predict or control gains and losses, as well as retrospective reinterpretations of what caused them. This study explores the possibility that the emotional regulation strategies GDPs use to cope with aversive events are linked to these cognitions. Methods 41 GDPs and 45 HCs, matched in sociodemographic variables, were assessed in gambling severity, emotion-regulation strategies (cognitive emotion-regulation questionnaire, CERQ), and gambling-related cognitions (gambling-related cognitions scale, GRCS). Results GDPs showed higher scores in all gambling-related cognition dimensions. Regarding emotion regulation, GDPs were observed to use self-blame and catastrophizing, but also positive refocusing, more often than controls. Additionally, in GDPs, putatively adaptive CERQ strategies shared a significant portion of variance with South Oaks gambling screen severity and GRCS beliefs. Shared variability was mostly attributable to the roles of refocusing on planning and putting into perspective at positively predicting severity and the interpretative bias (GDPs propensity to reframe losses in a more benign way), respectively. Discussion and conclusions Results show links between emotion-regulation strategies and problematic gambling-related behaviors and cognitions. The pattern of those links supports the idea that GDPs use emotion-regulation strategies, customarily regarded as adaptive, to cope with negative emotions, so that the motivational and cognitive processing of gambling outcomes becomes less effective in shaping gambling-related behavior.

Increased corticolimbic connectivity in cocaine dependence versus pathological gambling is associated with drug severity and emotion-related impulsivity

Neural biomarkers for the active detrimental effects of cocaine dependence (CD) are lacking. Direct comparisons of brain connectivity in cocaine-targeted networks between CD and behavioural addictions (i.e. pathological gambling, PG) may be informative. This study therefore contrasted the resting-state functional connectivity networks of 20 individuals with CD, 19 individuals with PG and 21 healthy individuals (controls). Study groups were assessed to rule out psychiatric co-morbidities (except alcohol abuse and nicotine dependence) and current substance use or gambling (except PG). We first examined global connectivity differences in the corticolimbic reward network and then utilized seed-based analyses to characterize the connectivity of regions displaying between-group differences. We examined the relationships between seed-based connectivity and trait impulsivity and cocaine severity. CD compared with PG displayed increased global functional connectivity in a large-scale ventral corticostriatal network involving the orbitofrontal cortex, caudate, thalamus and amygdala. Seed-based analyses showed that CD compared with PG exhibited enhanced connectivity between the orbitofrontal and subgenual cingulate cortices and between caudate and lateral prefrontal cortex, which are involved in representing the value of decision-making feedback. CD and PG compared with controls showed overlapping connectivity changes between the orbitofrontal and dorsomedial prefrontal cortices and between amygdala and insula, which are involved in stimulus-outcome learning. Orbitofrontal-subgenual cingulate cortical connectivity correlated with impulsivity and caudate/amygdala connectivity correlated with cocaine severity. We conclude that CD is linked to enhanced connectivity in a large-scale ventral corticostriatal-amygdala network that is relevant to decision making and likely to reflect an active cocaine detrimental effect.

Planning deficits in polysubstance dependent users: Differential associations with severity of drug use and intelligence

BACKGROUND

Polysubstance use is associated with alterations in different components of executive functioning such as working memory and response inhibition. Nevertheless, less attention has been given to executive planning skills, which are required to benefit of low structured interventions. This study examines the association between severity of use of cocaine, heroin, alcohol, fluid and crystallized intelligence and planning tasks varying on degree of structure.

METHODS

Data were collected from 60 polysubstance users and 30 healthy controls. Cognitive assessment consisted of three planning tasks with different structure levels: Stockings of Cambridge, Zoo Map test, and Multiple Errands Test.

RESULTS

Polysubstance users had significant planning deficits across the three tasks compared to healthy controls. Hierarchical regression models showed that severity of drug use and fluid and crystallized intelligence significantly explained performance in all the planning tasks. However, these associations were higher for low-structured real world tasks. These low-structured tasks also showed a unique association with crystallized but not fluid intelligence.

CONCLUSION

Drug abuse is negatively associated with planning abilities, and intelligence is positively associated with planning performance in real-world tasks.