Impulsive Decision Making in Young Adult Social Drinkers and Detoxified Alcohol-Dependent Patients: A Cross-Sectional and Longitudinal Study

Clustering of behavioral economic biases in decision-making and risk for cigarette smoking and other substance use in women and men

BACKGROUND

Low loss aversion (LA) and high delay discounting (DD) are behavioral-economic decision-making biases that independently predict cigarette smoking and other risky substance use. Here we examine (1) whether low-LA and high-DD co-occur, (2) does co-occurrence increase the odds of current smoking and other substance use compared to only low-LA, high-DD, or neither; and (3) potential gender differences in these associations.

METHOD

Data are from five studies with U.S. adults who currently smoked or never-smoked cigarettes recruited using online convenience sampling matching on gender and education. Participants completed identical sociodemographic, substance use (cigarette, other drugs, alcohol), and LA (hypothetical 50-50 gambles) and DD (monetary-choice questionnaire) measures. LA and DD scores were dichotomized as low and high using Receiver-Operating-Characteristic Curve logistic regression.

RESULTS

LA and DD each independently predicted substance use and with few exceptions were not influenced by gender. Low-LA compared to high-LA predicted two-fold greater odds of co-occurring high-DD (AOR = 2.120, 95%CI:1.749-2.571, p < .0001). Similarly, high-DD compared to low DD predicted two-fold greater odds of low-LA (AOR = 2.118, 95%CI:1.747-2.568, p < .0001). Among those with co-occurring low-LA and high-DD, odds of substance use were 5-10 times greater than those exhibiting neither, and 2-3 times greater than those exhibiting only low-LA or high-DD.

CONCLUSIONS

Low-LA and high-DD cluster in women and men such that exhibiting one of these decision-making biases doubles the odds of exhibiting the other. These results demonstrate reliable clustering of low-LA and high-DD and a striking increase in risk for substance use relative to having only one or neither decision-making bias.

Loss, gain and choice difficulty in gambling patients: Neural and behavioural processes

Impaired decision-making is often displayed by individuals suffering from gambling disorder (GD). Since there are a variety of different phenomena influencing decision-making, we focused in this study on the effects of GD on neural and behavioural processes related to loss aversion and choice difficulty. Behavioural responses as well as brain images of 23 patients with GD and 20 controls were recorded while they completed a mixed gambles task, where they had to decide to either accept or reject gambles with different amounts of potential gain and loss. We found no behavioural loss aversion in either group and no group differences regarding loss and gain-related choice behaviour, but there was a weaker relation between choice difficulty and decision time in patients with GD. Similarly, we observed no group differences in processing of losses or gains, but choice difficulty was weaker associated with brain activity in the right anterior insula and anterior cingulate cortex in patients with GD. Our results showed for the first time the effects of GD on neural processes related to choice difficulty. In addition, our findings on choice difficulty give new insights on the psychopathology of GD and on neural processes related to impaired decision-making in GD.

Value-based decision-making predicts alcohol use and related problems in young men

BACKGROUND

Alcohol consumption is a leading cause of morbidity and mortality worldwide, disproportionately affecting young men. Heavy episodic drinking is particularly prevalent among men, with this behavior peaking between the ages of 20 and 24.

AIMS

We sought to identify dimensions of decision-making in men that would predict the development of hazardous alcohol use through emerging adulthood.

METHODS

This prospective observational study profiled value-based decision-making in 198 healthy men at age 18 and assessed their alcohol involvement annually until age 24. Latent growth curve modeling estimated individual variability in trajectories of alcohol involvement and regressed this variability on five choice dimensions.

RESULTS

Low loss aversion predicted sustained heavy episodic drinking from age 18 to 24. Both high delay discounting and risk-seeking for gains independently predicted a considerably higher cumulative alcohol use during these 6 years, with high delay discounting indicating escalating consumption from age 21. Risk-seeking for gains additionally predicted meeting more criteria for Alcohol Use Disorder in these 6 years. Risk-seeking for losses was not significantly related to alcohol outcomes. Choice preferences were largely independent of each other but were correlated with choice consistency, with low consistency predicting heavy episodic drinking from age 18 to 24 beyond these associations.

CONCLUSIONS

The predictive effects collectively suggest that overvaluing immediate and probabilistic incentives, rather than underestimating harm, drives hazardous drinking in young men. The differential relations of choice preferences and consistency to alcohol involvement through emerging adulthood provide distinct cognitive-behavioral patterns that warrant consideration in the development of harm reduction interventions.

Neurocognitive predictors of addiction-related outcomes: A systematic review of longitudinal studies

It is well-established that addiction is typically associated with a distinct pattern of neurocognitive functioning with a consensus that it is typified by impaired top-down executive control and aberrant risk-reward processing. Despite a consensus that neurocognition plays an important role in characterizing and maintaining addictive disorders, there is a lack of systematic, bottom-up synthesis of quantitative evidence showing that neurocognition predicts addictive behaviors, and which neurocognitive constructs have the best predictive validity. This systematic review aimed to assess whether cognitive control and risk-reward processes as defined by the Research Domain Criteria (RDoC) predict the development and maintenance of addictive behaviors specifically, consumption, severity, and relapse. The findings from this review expose the substantial lack of evidence for neurocognition predicting addiction outcomes. However, there is evidence that suggests reward-related neurocognitive processes may be important for the detection of early risk for addiction, as well as a potentially viable target for designing novel, more effective interventions.

Adolescent Neurodevelopment Within the Context of Impulsivity and Substance Use

Purpose of Review

The aim of the present review is to provide an update on recent studies examining adolescent neurodevelopment in the context of impulsivity and substance use. We provide a review of the neurodevelopmental changes in brain structure and function related to impulsivity, substance use, and their intersection.

Recent Findings

When examining brain structure, smaller gray matter volume coupled with lower white matter integrity is associated with greater impulsivity across three components: trait impulsivity, choice impulsivity, and response inhibition. Altered functional connectivity in networks including the inhibitory control network and reward processing network confers risk for greater impulsivity and substance use.

Summary

Across brain structure and function, there is evidence to suggest that overlapping areas involved in the rise in impulsivity during adolescence contribute to early substance use initiation and escalation. These overlapping neurodevelopmental correlates have promising implications for prevention and early intervention efforts for adolescent substance use.

Risky Decision-Making in Adults with Alcohol Use Disorder-A Systematic and Meta-Analytic Review

Alcohol use disorder (AUD) forms a major health concern and is the most common substance use disorder worldwide. The behavioural and cognitive deficits associated with AUD have often been related to impairments in risky decision-making. The aim of this study was to examine the magnitude and type of risky decision-making deficits of adults with AUD, as well as to explore the potential mechanisms behind these deficits. To this end, existing literature comparing risky decision-making task performance of an AUD group to a control group (CG) was systematically searched and analysed. A meta-analysis was performed to address overall effects. In total, 56 studies were included. In the majority of studies (i.e., 68%), the performance of the AUD group(s) deviated from the CG(s) on one or more of the adopted tasks, which was confirmed by a small to medium pooled effect size (Hedges' g = 0.45). This review therefore provides evidence of increased risk taking in adults with AUD as compared to CGs. The increased risk taking may be due to deficits in affective and deliberative decision-making. Making use of ecologically valid tasks, future research should investigate whether risky decision-making deficits predate and/or are consequential to the addiction of adults with AUD.

Constitutive depletion of brain serotonin differentially affects rats' social and cognitive abilities

Central serotonin appears a promising transdiagnostic marker of psychiatric disorders and a modulator of some of their key behavioral symptoms. In adult male Tph2 ^-/- rats, constitutively lacking central serotonin, we tested individual's cognitive, social and non-social abilities and characterized group's social organization under classical and ethological testing conditions. Using unsupervised machine learning, we identified the functions most dependent on serotonin. Although serotonin depletion did not affect cognitive performances in classical testing, in the home-cage it induced compulsive aggression and sexual behavior, hyperactive and hypervigilant stereotyped behavior, reduced self-care and exacerbated corticosterone levels. This profile recalled symptoms of impulse control and anxiety disorders. Serotonin appeared essential for behavioral adaptation to dynamic social environments. Our animal model challenges the essential role of serotonin in decision-making, flexibility, impulsivity, and risk-taking. These findings highlight the importance of studying everyday life functions within the dynamic social living environment to model complexity in animal models.

The Effects of Citalopram and Thalamic Dopamine D2/3 Receptor Availability on Decision-Making and Loss Aversion in Alcohol Dependence

Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for patients who misuse alcohol, especially in the context of comorbid depressive symptoms. Deficits in impulse control and decision-making are linked to routine alcohol consumption and alcohol dependence. The goal of this study was to determine the effects of a single dose of citalopram on measures of impulsivity, decision-making, and/or brain dopamine receptor availability in alcohol-dependent individuals. A double-blind, placebo-controlled, within-subject, outpatient study was conducted with active alcohol-dependent (DSM-IV-TR criteria) participants (n = 12) and matched healthy controls (n = 13). Serial doses of both citalopram (40 mg) and saline were administered intravenously before laboratory tests of decision-making (Balloon Analogue Risk Task, delay discounting task, and Loss Aversion Gambling Task) and positron emission tomography with [¹⁸F]-fallypride to measure dopamine D_2/3 receptor availability, separated by at least one week. Alcohol-dependent participants demonstrated greater loss aversion than healthy controls, but there were no group differences in risk taking on the Balloon Analogue Risk Task. Citalopram increased delay discounting across groups, with no group difference in the effect. There were no effects of citalopram on risk taking on the Balloon Analogue Risk Task. PET showed a negative correlation between thalamic dopamine D_2/3 receptor availability and loss aversion across groups. The effect of citalopram to decrease the valuation of monetary reward as a function of delay raises the possibility that SSRIs can influence risky decision-making in clinical populations. In addition, these results suggest that altered thalamic dopamine signaling may play an important role in disproportionately valuing losses in patients with Alcohol Use Disorder. This trial is registered under ClinicalTrials.gov registration NCT01657760.

Decision Making in Addictive Behaviors Based on Prospect Theory: A Systematic Review

Traditionally, research on addictive behaviors has been based on the study of their risk factors, with impulsivity being the main risk factor. However, this study aims to approach this topic from the analysis of decision making. According to the prospect theory, low levels of loss and risk aversion will increase the probability of showing addictive behaviors. A systematic review of the possible relationships between these behaviors and prospect theory was carried out. To this end, the works that have studied loss and risk aversion in populations with addictive behaviors to date (N = 15) were compiled. Apart from other eligibility criteria, the selection process was only performed with studies that included the prospect theory or cumulative prospect theory, in English or Spanish, since 1979. WoS, Scopus, Dialnet and PsycInfo were the information sources selected. For this purpose, PRISMA guidelines have been followed. It was found that users of addictive substances show less loss aversion than nonusers. These results cannot be transferred to pathological gamblers. The significance of this work for future research and the implementation of prevention and intervention programs is highlighted. The results show an approach to addictions from a novel perspective.

A Model Guided Approach to Evoke Homogeneous Behavior During Temporal Reward and Loss Discounting

Background

The tendency to devaluate future options as a function of time, known as delay discounting, is associated with various factors such as psychiatric illness and personality. Under identical experimental conditions, individuals may therefore strongly differ in the degree to which they discount future options. In delay discounting tasks, this inter-individual variability inevitably results in an unequal number of discounted trials per subject, generating difficulties in linking delay discounting to psychophysiological and neural correlates. Many studies have therefore focused on assessing delay discounting adaptively. Here, we extend these approaches by developing an adaptive paradigm which aims at inducing more comparable and homogeneous discounting frequencies across participants on a dimensional scale.

Method

The proposed approach probabilistically links a (common) discounting function to behavior to obtain a probabilistic model, and then exploits the model to obtain a formal condition which defines how to construe experimental trials so as to induce any desired discounting probability. We first infer subject-level models on behavior on a non-adaptive delay discounting task and then use these models to generate adaptive trials designed to evoke graded relative discounting frequencies of 0.3, 0.5, and 0.7 in each participant. We further compare and evaluate common models in the field through out-of-sample prediction error estimates, to iteratively improve the trial-generating model and paradigm.

Results

The developed paradigm successfully increases discounting behavior during both reward and loss discounting. Moreover, it evokes graded relative choice frequencies in line with model-based expectations (i.e., 0.3, 0.5, and 0.7) suggesting that we can successfully homogenize behavior. Our model comparison analyses indicate that hyperboloid models are superior in predicting unseen discounting behavior to more conventional hyperbolic and exponential models. We report out-of-sample error estimates as well as commonalities and differences between reward and loss discounting, demonstrating for instance lower discounting rates, as well as differences in delay perception in loss discounting.

Conclusion

The present work proposes a model-based framework to evoke graded responses linked to cognitive function at a single subject level. Such a framework may be used in the future to measure cognitive functions on a dimensional rather than dichotomous scale.

Altered striatal-opercular intrinsic connectivity reflects decreased aversion to losses in alcohol use disorder

The persistence of addictive behaviours despite their adverse consequences highlights decreased punishment sensitivity as a facet of decision-making impairments in Alcohol Use Disorder (AUD). This attitude departs from the typical loss aversion (LA) pattern, i.e. the stronger sensitivity to negative than positive outcomes, previously associated with striatal and limbic-somatosensory responsiveness in healthy individuals. Consistent evidence highlights decreased LA as a marker of disease severity in AUD, but its neural bases remain largely unexplored. AUD-specific modulations of frontolateral activity by LA were previously related to the higher executive demands of anticipating losses than gains, but the relationship between LA and executive/working-memory performance in AUD is debated. Building on previous evidence of overlapping neural bases of LA during decision-making and at rest, we investigated a possible neural signature of altered LA in AUDs, and its connections with executive skills, in terms of complementary facets of resting-state functioning. In patients, smaller LA than controls, unrelated to executive performance, reflected reduced connectivity within striatal and medial temporal networks, and altered connectivity from these regions to the insular-opercular cortex. AUD-specific loss-related modulations of intrinsic connectivity thus involved structures previously associated both with drug-seeking and with coding the trade-off between appetitive and aversive motivational drives. These findings fit the hypothesis that altered striatal coding of choice-related incentive value, and interoceptive responsiveness to prospective outcomes, enhance neural sensitivity to drug-related stimuli in addictions. LA and its neural bases might prove useful markers of AUD severity and effectiveness of rehabilitation strategies targeting the salience of negative choice outcomes.

Associations of delay discounting and drinking trajectories from ages 14 to 22

BACKGROUND

While drinking alcohol, one must choose between the immediate rewarding effects and the delayed reward of a healthier lifestyle. Individuals differ in their devaluation of a delayed reward based on the time required to receive it, i.e., delay discounting (DD). Previous studies have shown that adolescents discount more steeply than adults and that steeper DD is associated with heavier alcohol use in both groups.

METHODS

In a large-scale longitudinal study, we investigated whether higher rates of DD are an antecedent or a consequence of alcohol use during adolescent development. As part of the IMAGEN project, 2220 adolescents completed the Monetary Choice Questionnaire as a DD measure, the Alcohol Use Disorders Identification Test, and the Timeline Follow Back interview at ages 14, 16, 18, and 22. Bivariate latent growth curve models were applied to investigate the relationship between DD and drinking. To explore the consequences of drinking, we computed the cumulative alcohol consumption and correlated it with the development of discounting. A subsample of 221 participants completed an intertemporal choice task (iTeCh) during functional magnetic resonance imaging at ages 14, 16, and 18. Repeated-measures ANOVA was used to differentiate between high-risk and low-risk drinkers on the development of neural processing during intertemporal choices.

RESULTS

Overall, high rates of DD at age 14 predicted a greater increase in drinking over 8 years. In contrast, on average, moderate alcohol use did not affect DD from ages 14 to 22. Of note, we found indicators for less brain activity in top-down control areas during intertemporal choices in the participants who drank more.

CONCLUSIONS

Steep DD was shown to be a predictor rather than a consequence of alcohol use in low-level drinking adolescents. Important considerations for future longitudinal studies are the sampling strategies to be used and the reliability of the assessments.

Racial/Ethnic Differences in Alcohol and Drug Misuse Among IPV-Victimized Women: Exploring the Role of Difficulties Regulating Positive Emotions

Alcohol and drug misuse is prevalent and problematic among women who experience intimate partner violence (IPV). Emotional dysfunction has been identified as a key mechanism in the etiology, maintenance, and treatment of alcohol and drug misuse. However, existing research has not considered the role of race/ethnicity in the relations between emotional dysfunction and alcohol and drug misuse. Furthermore, past research in this area has focused almost exclusively on emotional dysfunction stemming from negative (vs. positive) emotions. The goals of the current study were as follows: (a) to explore whether levels of difficulties regulating positive emotions differ among Latina, African American, and White IPV-victimized women, and (b) to examine the moderating role of race/ethnicity in the relations between difficulties regulating positive emotions and alcohol and drug misuse. Participants were 197 IPV-victimized women recruited through the criminal justice system (M_age = 36.14; 51.8% African American, 31.5% White, and 16.8% Latina). Difficulties regulating positive emotions did not differ as a function of race/ethnicity. However, relations among difficulties regulating positive emotions and alcohol and drug misuse were significant for Latina and White but not African American IPV-victimized women. Moreover, race/ethnicity moderated an association between difficulties regulating positive emotions and drug misuse; this relation was significant and positive for White (compared with African American) IPV-victimized women. While preliminary, these results may inform culturally sensitive interventions for alcohol and drug misuse that are tailored to the unique needs of Latina, African American, and White IPV-victimized women.

Energy drink consumption and its relationship to alcohol use disorders and impulsiveness in health sciences students in Turkey

PURPOSE

We aimed to examine energy drink (ED) consumption and its relationship to alcohol use disorders and impulsiveness in health sciences students.

DESIGN AND METHODS

This cross-sectional research was conducted with 1202 health sciences students. Data collection tools were "Energy Drink Consumption Form," "Alcohol Use Disorders Identification Test (AUDIT)," and "Barratt Impulsiveness Scale-11 (BIS-11)."

FINDINGS

Of the students, 30.6% who used EDs reported doing so in the past year. AUDIT and BIS-11 scores of students with high ED consumption were higher than those with less ED consumption and who do not consume at all (p < 0.05).

PRACTICE IMPLICATIONS

Education of students in departments of health should include EDs and their drawbacks as part of nutrition or health coursework.

Posterior fronto-medial atrophy reflects decreased loss aversion, but not executive impairment, in alcohol use disorder

Decreased punishment sensitivity in alcohol use disorder (AUD) might reflect a reduction in the typical human tendency to overweigh negative choice outcomes compared with equivalent positive ones, that is, 'loss aversion.' While this hypothesis is supported by previous reports of reduced loss aversion in AUD, it is still unknown whether such decreased sensitivity to prospective losses represents a specific facet of altered decision-making or a secondary effect of executive/working-memory impairments. We addressed this issue by assessing whether lower loss aversion in 22 AUD patients compared with 19 healthy controls is explained by their differential executive or working-memory performance and by investigating its neural basis in terms of grey matter density and cortical thickness via voxel- and surface-based morphometry, respectively. A significant decrease of loss aversion in patients, unrelated to their impaired executive/working-memory performance, reflected the reduction of posterior fronto-medial grey matter density and right frontopolar cortical thickness. Rather than their executive deficits, patients' reduced loss aversion reflects the structural damage of the posterior fronto-medial cortex previously associated with solving conflicts at the response level, where earlier functional magnetic resonance imaging (fMRI) studies have shown a 'neural loss aversion' pattern of steeper deactivation for losses than activation for gains, and of the frontopolar cortex in charge of managing competing goals. These findings highlight possible directions for addressing AUD patients' high relapse rate, for example, cognitive-behavioural rehabilitative interventions enhancing the awareness of the adverse outcomes of addiction or neurostimulation protocols targeting the regions processing their salience.

The Association Between Impulsivity and Relapse in Patients With Alcohol Use Disorder: A Literature Review

AIM

Impulsivity has been identified as a key relapse risk factor in patients with alcohol use disorder (AUD); however, the inherent characteristics of this relationship have been largely understudied. The heterogeneity of AUD and variation in impulsivity constructs require careful consideration to inform future work examining the relationship. This study sought to review empirical findings examining facets of impulsivity and AUD relapse.

METHODS

A systematic search strategy was employed to capture studies on impulsivity measures related to AUD relapse. Impulsivity measures were qualitatively organized in terms of 'trait impulsivity'-typically measured by self-report questionnaires-and 'behavioural impulsivity', i.e. 'motor impulsivity', 'impulsive choice' and 'reflection impulsivity, assessed with cognitive-behavioural tasks.

RESULTS

Seventeen peer-reviewed papers were identified. Relapse outcomes varied substantially in relation to impulsivity measures. Twelve papers included aspects of 'trait impulsivity', and nine studies included 'behavioural impulsivity' measures, from which five studies dealt with the 'impulsive choice' subcategory. The Barratt Impulsivity Scale was the self-report questionnaire that was most frequently used.

CONCLUSIONS

All three included facets of impulsivity ('trait-, motor- and impulsive choice impulsivity') were associated with AUD relapse, but none seemed to be superior to another. This study confirmed that research on the relation between impulsivity and AUD relapse is relatively scarce. Future research and treatment options are proposed.

Exploring the Role of Alcohol Metabolizing Genotypes in a 12-Week Clinical Trial of Naltrexone for Alcohol Use Disorder

Background: The efficacy of naltrexone in the treatment of alcohol use disorder (AUD) has been associated with a set of variables not directly related with the expression of opioid receptors. All the variables have been found to be highly associated with AUD itself or more severe clinical levels of AUD. Objectives: Given the high association between alcohol metabolizing enzymes (AME) and the outcome of AUD, the present study aims to investigate the role of AME genotype variants in the treatment of AUD with naltrexone. Methods: We carried out a 12-week longitudinal clinical trial based on the treatment of AUD patients with naltrexone (N = 101), stratified by different alcohol metabolization genotypes. Genotyping was performed after the inclusion of the patients in the study, based on the individual presence of single nucleotide polymorphisms (SNPs) in the ADH (alcohol dehydrogenase)1B (ADH1B*2 and ADH1B*3), ADH1C (ADHC*1) and ALDH (aldehyde dehydrogenase) 2 (ALDH2*2) genes. The outcome of alcohol use has been monitored employing the timeline follow-back during the treatment. Results: The ADH1C*1 (Ile350Val, rs698) and ALDH2*2 (Glu504Lys, rs671) polymorphisms were associated with a better response to naltrexone treatment, whereas the ADH1B*3 (Arg370Cys, rs2066702) allelic variant showed a negative outcome. Conclusions: The present study explores a genomic setting for the treatment of AUD with naltrexone. According to our findings, the association between ADH1C*1 and ALDH2*2 variants and better outcomes suggests a successful treatment, whereas the ADH1B*3 mutated allele might lead to an unsuccessful treatment. Further studies should be performed to investigate the relationship between alcohol metabolizing genotypes, the family history of alcohol use disorders and the effect of naltrexone on the outcomes. Genotyping may be a valuable tool for precision-medicine and individualized approach, especially in the context of alcohol use disorders. The small number of subjects was the main limitation of the present study.

Influence of dopamine-related genes on craving, impulsivity, and aggressiveness in Korean males with alcohol use disorder

Dopamine is a major neuromodulator that is acutely involved in various cognitive processes, reward-motivated behaviors, and impulsivity. Abnormality in dopaminergic neurotransmission is implicated in the pathophysiology of alcohol use disorder (AUD). The present study examined the genetic influence of dopamine system on problematic drinking, impulsivity, and aggressiveness in a Korean male population with AUD. Five single nucleotide polymorphisms (SNPs) (rs4532 in DRD1, rs2283265 in DRD2, rs6280 in DRD3, rs1800497 in ANKK1, and rs4680 in COMT) and a variable number of tandem repeats (VNTRs) in DAT1 in 295 male patients with AUD were genotyped. For AUD-related clinical characteristics, the Alcohol Use Disorders Identification Test and the Obsessive-Compulsive Drinking Scale (OCDS) were used to assess the severity of hazardous drinking and craving symptoms, respectively. Participants also completed the UPPS-P Impulsive Behavior Scale (UPPS-P) and Buss-Perry Aggression Questionnaire (BPAQ). Analyses were performed using R package SNPassoc; statistical significance was set as p < 0.0083 after Bonferroni correction. A significant association was detected between DRD3 SNP rs6280 and OCDS scores. In regard to impulsivity and aggressiveness, rs4532 of DRD1 was significantly associated with UPPS-P score. Also, rs4532 demonstrated a nominally significant association with BPAQ score, although it did not reach statistical significance after correction for multiple comparisons. Results of this study support the idea that genetic variations in the dopamine system may contribute to alcohol cravings and impulsivity in patients with AUD.

Possible mechanisms of HIV neuro-infection in alcohol use: Interplay of oxidative stress, inflammation, and energy interruption

Alcohol use and HIV-1 infection have a pervasive impact on brain function, which extends to the requirement, distribution, and utilization of energy within the central nervous system. This effect on neuroenergetics may explain, in part, the exacerbation of HIV-1 disease under the influence of alcohol, particularly the persistence of HIV-associated neurological complications. The objective of this review article is to highlight the possible mechanisms of HIV/AIDS progression in alcohol users from the perspective of oxidative stress, neuroinflammation, and interruption of energy metabolism. These include the hallmark of sustained immune cell activation and high metabolic energy demand by HIV-1-infected cells in the central nervous system, with at-risk alcohol use. Here, we discussed the point that the increase in energy supply requirement by HIV-1-infected neuroimmune cells as well as the deterrence of nutrient uptake across the blood-brain barrier significantly depletes the energy source and neuro-environment homeostasis in the CNS. We also described the mechanistic idea that comorbidity of HIV-1 infection and alcohol use can cause a metabolic shift and redistribution of energy usage toward HIV-1-infected neuroimmune cells, as shown in neuropathological evidence. Under such an imbalanced neuro-environment, meaningless energy waste is expected in infected cells, along with unnecessary malnutrition in non-infected neuronal cells, which is likely to accelerate HIV neuro-infection progression in alcohol use. Thus, it will be important to consider the factor of nutrients/energy imbalance in formulating treatment strategies to help impede the progression of HIV-1 disease and associated neurological disorders in alcohol use.

Empathy and the ability to experience one's own emotions modify the expression of blatant and subtle prejudice among young male adults

Prejudices can lead to discrimination, social exclusion, and violence particularly among young male adults. Previous findings suggest that the degree of holding prejudices is linked to low levels of empathy, while low levels of empathy have been associated with alexithymia, the inability to experience one's own feelings. We tested the hypothesis that the impact of a lack of empathy on reporting blatant and subtle prejudices is moderated by the inability to identify one's own feelings. In a sample of n = 136 young male adults aged 21 years (mean = 21.5 years; sd = 0.3), we conducted correlation and moderator analyses to determine possible relationships between prejudices, empathy, and alexithymia as assessed by self-report questionnaires. Prejudices were assessed by the Blatant and Subtle Prejudice Scale (BSPS), empathy was assessed by the German modified version of the Interpersonal Reactivity Index (IRI), and alexithymia by the 20-item Toronto Alexithymia Scale (TAS-20). Self-reported empathy levels were correlated with the strength of subtle and blatant prejudices. The moderation analyses revealed that the negative association between empathy and subtle prejudice increased with decreasing alexithymia. The negative association between empathy and blatant prejudice, on the other hand, was significant only for participants with low levels of alexithymia. These results suggest that empathy can limit the expression of blatant and to some degree also subtle prejudice when subjects are capable to identify their own feelings in a group of young males.

Impulsivity traits and neurocognitive mechanisms conferring vulnerability to substance use disorders

Impulsivity - the tendency to act without sufficient consideration of potential consequences in pursuit of short-term rewards - is a vulnerability marker for substance use disorders (SUD). Since impulsivity is a multifaceted construct, which encompasses trait-related characteristics and neurocognitive mechanisms, it is important to ascertain which of these aspects are significant contributors to SUD susceptibility. In this review, we discuss how different trait facets, cognitive processes and neuroimaging indices underpinning impulsivity contribute to the vulnerability to SUD. We reviewed studies that applied three different approaches that can shed light on the role of impulsivity as a precursor of substance use related problems (versus a consequence of drug effects): (1) longitudinal studies, (2) endophenotype studies including non-affected relatives of people with SUD, and (3) clinical reference groups-based comparisons, i.e., between substance use and behavioural addictive disorders. We found that, across different methodologies, the traits of non-planning impulsivity and affect-based impulsivity and the cognitive processes involved in reward-related valuation are consistent predictors of SUD vulnerability. These aspects are associated with the structure and function of the medial orbitofrontal-striatal system and hyperexcitability of dopamine receptors in this network. The field still needs more theory-driven, comprehensive studies that simultaneously assess the different aspects of impulsivity in relation to harmonised SUD-related outcomes. Furthermore, future studies should investigate the impact of impulsivity-related vulnerabilities on novel patterns of substance use such as new tobacco and cannabinoid products, and the moderating impact of changes in social norms and lifestyles on the link between impulsivity and SUD. This article is part of the special issue on 'Vulnerabilities to Substance Abuse'.

Metabolic state and value-based decision-making in acute and recovered female patients with anorexia nervosa

BACKGROUND

Patients with anorexia nervosa forgo eating despite emaciation and severe health consequences. Such dysfunctional decision-making might be explained by an excessive level of self-control, alterations in homeostatic and hedonic regulation, or an interplay between these processes. We aimed to understand value-based decision-making in anorexia nervosa and its association with the gut hormone ghrelin. Besides its homeostatic function, ghrelin has been implicated in the hedonic regulation of appetite and reward via the modulation of phasic dopamine signalling.

METHODS

In a cross-sectional design, we studied acutely underweight (n = 94) and recovered (n = 37) patients with anorexia nervosa of the restrictive subtype, as well as healthy control participants (n = 119). We assessed plasma concentrations of desacyl ghrelin and parameters of delay discounting, probability discounting for gains and losses, and loss aversion.

RESULTS

Recovered patients displayed higher risk aversion for gains, but we observed no group differences for the remaining decision-making parameters. Desacyl ghrelin was higher in acutely underweight and recovered participants with anorexia nervosa relative to healthy controls. Moreover, we found a significant group × desacyl ghrelin interaction in delay discounting, indicating that in contrast to healthy controls, acutely underweight patients with anorexia nervosa who had high desacyl ghrelin concentrations preferably chose the delayed reward option.

LIMITATIONS

We probed decision-making using monetary rewards, but patients with anorexia nervosa may react differently to disorder-relevant stimuli. Furthermore, in contrast to acyl ghrelin, the functions of desacyl ghrelin are unclear. Therefore, the interpretation of the results is preliminary.

CONCLUSION

The propensity for risk aversion as found in recovered patients with anorexia nervosa could help them successfully complete therapy, or it could reflect sequelae of the disorder. Conversely, ghrelin findings might be related to a mechanism contributing to disease maintenance; that is, in acutely underweight anorexia nervosa, a hungry state may facilitate the ability to forgo an immediate reward to achieve a (dysfunctional) long-term goal.

Are hazardous drinkers more impulsive than light drinkers? A comprehensive assessment in young adults

Those with alcohol dependence are characteristically impulsive. It is unclear whether the same is true of hazardous drinkers (i.e., women routinely drinking more than 14 units in a typical week but fewer than 35, and men drinking more than 14 units but fewer than 50). Yet, it is important to understand the mechanisms involved in such drinking, since it places the drinker at risk for future harm. The present study thus comprehensively assessed whether impulsivity was elevated in hazardous drinkers, compared to lighter drinkers. An opportunity sample of 57 light and 49 hazardous drinkers was assessed on the following impulsivity subdomains (via the measures in parentheses): (i) trait impulsivity (the Barratt Impulsiveness Scale, Version 11); (ii) temporal impulsivity (the Monetary Choice Questionnaire); (iii) stopping impulsivity (the Stop-Signal Task); (iv) waiting impulsivity (the Continuous Performance Task or CPT); (v) reward-sensitivity (the Behavioural Activation Scales); and (vi) risk-taking (the Balloon Analogue Risk Task). Alcohol- and other drug-dependent individuals were excluded from the study, while socio-demographics (age, gender, and socio-economic status), mood, binge drinking, and nicotine intake were all controlled for. The groups were compared via a series of Bonferroni-corrected, independent-measures t tests. The results revealed that hazardous drinkers were more impulsive than light drinkers on the CPT; there were no other statistically significant group differences. Consistent with the above, a logistic regression, with drinking group as the dependent variable and the impulsivity indices as independent variables, revealed that only CPT performance was a significant predictor of drinking status. Other than gender, none of the control variables significantly correlated with CPT performance. A sequential linear regression revealed that drinking status continued to predict CPT performance, after first accounting for gender. Thus, from a battery of impulsivity measures, only waiting impulsivity (i.e., CPT score) was elevated in hazardous drinkers, relative to lighter drinkers. Waiting impulsivity may thus be important in the maintenance of hazardous drinking.

Inter-individual and inter-strain differences in cognitive and social abilities of Dark Agouti and Wistar Han rats

Healthy animals displaying extreme behaviours that resemble human psychiatric symptoms are relevant models to study the natural psychobiological processes of maladapted behaviours. Using a Rat Gambling Task, healthy individuals spontaneously making poor decisions (PDMs) were found to co-express a combination of other cognitive and reward-based characteristics similar to symptoms observed in human patients with impulse-control disorders. The main goals of this study were to 1) confirm the existence of PDMs and their unique behavioural phenotypes in Dark Agouti (DA) and Wistar Han (WH) rats, 2) to extend the behavioural profile of the PDMs to probability-based decision-making and social behaviours and 3) to extract key discriminative traits between DA and WH strains, relevant for biomedical research. We have compared cognitive abilities, natural behaviours and physiological responses in DA and WH rats at the strain and at the individual level. Here we found that the naturally occurring PDM's profile was consistent between both rat lines. Then, although the PDM individuals did not take more risks in probability discounting task, they seemed to be of higher social ranks. Finally and despite their similarities in performance, WH and DA lines differed in degree of reward sensitivity, impulsivity, locomotor activity and open space-occupation. The reproducibility and conservation of the complex phenotypes of PDMs and GDMs (good decision makers) in these two genetically different strains support their translational potential. Both strains, present large phenotypic variation in behaviours pertinent for the study of the underlying mechanisms of poor decision making and associated disorders.

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

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

Impulsive decision-making predicts the course of substance-related and addictive disorders

BACKGROUND

This study investigated whether patterns of impulsive decision-making (i) differ between individuals with DSM-5 substance use disorders (SUD) or non-substance-related addictive disorders (ND) and healthy controls, and (ii) predict the increase of SUD and ND severity after one year.

METHODS

In a prospective-longitudinal community study, 338 individuals (19-27 years, 59% female) were included in one of three groups: SUD (n = 100), ND (n = 118), or healthy controls (n = 120). Group differences in four impulsive decision-making facets were analyzed with the Bayesian priors: delay discounting (mean = 0.37, variance = 0.02), probability discounting for gains and for losses (each - 0.16, 0.02), and loss aversion (- 0.44, 0.02). SUD and ND severity were assessed at baseline and after 1 year (n = 312, 92%). Predictive associations between decision-making and SUD/ND severity changes were analyzed with the Bayesian prior: mean = 0.25, variance = 0.016.

RESULTS

Compared with controls, the SUD group displayed steeper delay discounting and lower probability discounting for losses; the ND group displayed lower probability discounting for losses (posterior probabilities > 98%). SUD symptom increase after 1 year was predicted by steeper delay discounting and lower loss aversion; ND symptom increase by lower probability discounting for losses and lower loss aversion (posterior probabilities > 98%). There was low evidence for predictive relations between decision-making and the quantity-frequency of addictive behaviours.

DISCUSSION

Impulsive decision-making characterizes SUD and ND and predicts the course of SUD and ND symptoms but not the engagement in addictive behaviours. Strength of evidence differed between different facets of impulsive decision-making and was mostly weaker than a priori expected.

Neurocognitive Dysfunctions and Their Therapeutic Modulation in Patients With Methamphetamine Dependence: A Pilot Study

AIM

Methamphetamine (MA) abuse and dependence are increasing worldwide and are commonly associated with cognitive deficits. Some studies indicate that such impairments can improve if users become abstinent, but overall results remain inconclusive. Hence, we have performed a longitudinal case-control study investigating key surrogates for attention and impulsive decision-making before and after treatment.

METHODS

Thirty patients with MA dependence and 24 non-substance-abusing control participants were recruited. Groups were matched on age, sex and education. All subjects performed a baseline assessment to obtain neurocognitive measures of sustained attention and delay discounting. Patients subsequently participated in an MA-specific relapse prevention program including repeated monitoring of relapse status. After 3 months, participants of both groups were reevaluated for neurocognitive performance.

RESULTS

At baseline, MA patients showed a significantly higher number of omissions compared to controls, indicative of lower sustained attention. Interestingly, we observed a steep decrease of omissions in MA patients to control-group level post treatment. On the other hand, MA patients discounted delayed rewards significantly stronger than controls, indicating a more impulsive choice behavior both before and after treatment.

LIMITATION

The results should be interpreted with care because of the small sample and short follow-up period.

CONCLUSION

Our data support earlier findings on partial recovery of cognitive deficits in MA patients. They also strengthen the indication for recently recommended psychotherapeutic interventions and may provide a behavioral monitoring tool to inform treatment progress.

Alcohol use disorder relapse factors: A systematic review

A relapsing-remitting course is very common in patients with an Alcohol Use Disorder (AUD). Understanding the determinants associated with alcohol resumption remains a formidable task. This paper examines relapse determinants based on a systematic review of recent alcohol literature (2000-2019). Relevant databases were consulted for articles that contained information about specific relapse determinants and reported statistical significance of each relapse determinant in predicting relapse. Relapse was broadly defined based on the characterization in the included articles. From the initial identified 4613 papers, a total of 321 articles were included. Results encompass multiple relapse determinants, which were ordered according to biopsychosocial and spiritual categories, and presented, using a descriptive methodology. Psychiatric co-morbidity, AUD severity, craving, use of other substances, health and social factors were consistently significantly associated with AUD relapse. Conversely, supportive social network factors, self efficacy, and factors related to purpose and meaning in life, were protective against AUD relapse. Despite heterogeneity in different methods, measures, and sample characteristics, these findings may contribute to a better therapeutic understanding in which specific factors are associated with relapse and those that prevent relapse. Such factors may have a role in a personalized medicine framework to improve patient outcomes.

On the Complexity of Discounting, Choice Situations, and People

Although steep delay discounting is associated with various behavioral problems, perhaps most prominently substance abuse, we argue that it is best not conceived of as a character flaw such as impulsivity. Such a view, although part of a centuries-old tradition, does not distinguish between actions whose outcomes involve gains and losses, or between delayed outcomes and probabilistic outcomes, nor does it acknowledge that how steeply an individual discounts one of these kinds of outcome appears to be independent of how steeply they discount other kinds. Therefore, we advocate an approach that does not require making judgments about the character of the individuals involved. We show that when drug-dependent individuals are compared with controls, a substantial number of the drug-dependent individuals discount delayed monetary rewards less steeply than the average (median) member of the control group. Moreover, a substantial number of the controls discount more steeply than the average drug-dependent individual. Finally, we point out that many everyday choice situations differ from those studied in most discounting experiments in that they involve both gains and losses as well as qualitatively different outcomes that may be both delayed and probabilistic. Past research on discounting that focused on simple choice situations has provided a solid foundation, but research on more complicated situations is now needed. We believe that the principles revealed by such research will both inform the choices of treatment providers and improve our understanding of the complicated decisions that people face every day.

Baseline impulsivity may moderate L-DOPA effects on value-based decision-making

Research has indicated a major role of dopamine in decision-making processes, but the underlying mechanisms remain largely unknown due to inconsistency in effects of dopaminergic drugs. To clarify the impact of dopamine on impulsive choice, we administered 150 mg L-DOPA to 87 healthy adults in a randomized, placebo-controlled, double-blind, crossover study, evaluating performance in four value-based decision-making tasks. We predicted that baseline impulsivity would moderate L-DOPA effects. In support of our hypothesis, L-DOPA had no main effect on impulsive choice, but reduced risk-seeking for gains in more-impulsive subjects. Because L-DOPA effects may be influenced by body weight, we repeated our analyses on data from half of the sample (n = 44) with lower weight, anticipating a stronger effect. In addition to the effect on risk-seeking for gains, low-weight participants also exhibited baseline-dependent effects of L-DOPA on loss aversion and delay discounting. Our results are consistent with the hypothesis of an inverted U-shaped dopamine function in which both low and high extremes of dopamine signaling are associated with high-impulsive choice. Consideration of differential baseline impulsivity and body weight may resolve previous seemingly paradoxical pharmacological results and might deepen our understanding of dopaminergic mechanisms underlying impulsivity.

Acute alcohol effects on impulsive choice in adolescents

BACKGROUND

Neurodevelopmental and alcohol-induced changes in decision-making have been proposed to critically influence impulsive behaviour in adolescents.

OBJECTIVE

This study tested the influence of acute alcohol administration on impulsive choice in adolescents.

METHODS

Fifty-four males aged 18-19 years were tested in a single-blind placebo-controlled cross-over design. During alcohol administration (infusion resulting in an arterial blood alcohol concentration of 80 mg%) and placebo condition (saline infusion), participants performed a task battery providing estimates of delay discounting, probability discounting for gains, for losses and loss aversion, and also rated subjectively experienced alcohol effects. Additionally, baseline alcohol consumption (Alcohol Use Disorders Identification Test, blood phosphatidylethanol levels), motives (Drinking Motive Questionnaire, Alcohol Expectancy Questionnaire and Obsessive Compulsive Drinking Scale), family history and self-report measures of impulsivity (Barratt Impulsiveness Scale, Substance Use Risk Profile Scale) were provided.

RESULTS

No overall effects of treatment on choice behaviour were found. However, individual differences were observed. In the alcohol condition, more impulsive choice tendencies for delay discounting were associated with higher subjectively experienced alcohol effects. Further, higher risk aversion for probabilistic gains and higher loss aversion during alcohol condition were related to higher levels of real-life alcohol consumption and a family history of alcohol problems, respectively. Finally, the time to make a decision was substantially shortened for choices involving negative prospects.

CONCLUSIONS

Contrary to common beliefs, acute alcohol intoxication did not generally incite impulsive decision-making. It rather appears that alcohol-induced behavioural changes in adolescents vary considerably depending on prior experiences and subjective effects of alcohol.

Risk-seeking for losses is associated with 5-HTTLPR, but not with transient changes in 5-HT levels

RATIONALE

Serotonin (5-HT) plays a key role in different aspects of value-based decision-making. A recent framework proposed that tonic 5-HT (together with dopamine, DA) codes future average reward expectations, providing a baseline against which possible choice outcomes are compared to guide decision-making.

OBJECTIVES

To test whether high 5-HT levels decrease loss aversion, risk-seeking for gains, and risk-seeking for losses.

METHODS

In a first session, 611 participants were genotyped for 5-HTTLPR and performed a mixed gambles (MGA) task and two probability discounting tasks for gains and losses, respectively (PDG/PDL). Afterwards, a subsample of 105 participants (44 with S/S, 6 with S/L, 55 with L/L genotype) completed the pharmacological study using a crossover design with tryptophan depletion (ATD), loading (ATL), and balanced (BAL) conditions. The same decision constructs were assessed.

RESULTS

We found increased risk-seeking for losses in S/S compared to L/L individuals at the first visit (p = 0.002). Neither tryptophan depletion nor loading affected decision-making, nor did we observe an interaction between intervention and 5-HTTLPR genotype.

CONCLUSION

Our data do not support the idea that transient changes of tonic 5-HT affect value-based decision-making. We provide evidence for an association of 5-HTTLPR with risk-seeking for losses, independent of acute 5-HT levels. This indicates that the association of 5-HTTLPR and risk-seeking for losses is mediated via other mechanisms, possibly by differences in the structural development of neural circuits of the 5-HT system during early life phases.