Impulsivity traits and neurocognitive mechanisms conferring vulnerability to substance use disorders

Modeling social cognition in alcohol use disorder: lessons from schizophrenia

A better understanding of social deficits in alcohol use disorder (AUD) has the potential to improve our understanding of the disorder. Clinical research shows that AUD is associated with interpersonal problems and the loss of a social network which impedes response to treatment. Translational research between animal models and clinical research may benefit from a discussion of the models and methods that currently guide research into social cognition in AUD. We propose that research in AUD should harness recent technological developments to improve ecological validity while maintaining experimental control. Novel methods allow us to parse naturalistic social cognition into tangible components, and to investigate previously neglected aspects of social cognition. Furthermore, to incorporate social cognition as a defining element of AUD, it is critical to clarify the timing of these social disturbances. Currently, there is limited evidence to distinguish factors that influence social cognition as a consequence of AUD, and those that precede the onset of the disorder. Both increasing the focus on operationalization of social cognition into objective components and adopting a perspective that spans the clinical spectrum will improve our understanding in humans, but also possibly increase methodological consistency and translational dialogue across species. This commentary underscores current challenges and perspectives in this area of research.

Sleep and Substance Use: Exploring Reciprocal Impacts and Therapeutic Approaches

PURPOSE OF REVIEW

Sleep disturbances are prevalent among those with comorbid substance use disorders (SUD), significantly impacting the initiation, maintenance and relapse of these conditions.

RECENT FINDINGS

This review explores the latest research on the reciprocal relationship between sleep and substance misuse, the effects of treating sleep on substance use outcomes, and the potential therapeutic uses of cannabis for sleep disorders in people with and without SUDs. Understanding these interactions may be critical for augmenting current treatment strategies aimed at improving sleep disturbances and recovery outcomes in individuals with SUDs.

Neural correlates of choosing alcohol over a palatable food reward in humans

BACKGROUND

In a population of light and heavy, nontreatment seeking drinkers, we recently showed that choice for alcohol versus a concurrently available snack reward was sensitive to the relative cost of alcohol. Here, we examined the neural substrates of alcohol choice using functional magnetic resonance imaging (MRI) in a new sample of light and heavy drinkers.

METHODS

Participants were scanned during the Concurrent Alcohol Food Choice task, and collected points associated with the images of alcohol or snack rewards that they could redeem at the end of the experiment. As cost manipulation, point values were equal or varied so that they favored alcohol or the snack reward. Linear mixed-effects models were used for the analyses of behavioral and brain data.

RESULTS

In a replication of prior findings, alcohol choice was sensitive to the relative value of alcohol in both groups. Neural activations in, among others, orbitofrontal cortex and insula were associated to relative value during choice. In addition, we observed that choosing alcohol as opposed to snack engaged two separate sets of brain regions. We did not replicate our prior finding of increased choice preference for alcohol in heavy compared to light drinkers and found no between-group differences in brain activity.

CONCLUSIONS

Overall, we replicated intact sensitivity to relative costs of alcohol in heavy drinkers and found its associated brain activity regions involved in value and salience attribution. Alcohol choice engaged regions involved in value-based behavior while snack preference elicited activity in areas linked to externally oriented attention. The failure to replicate the between-group differences may be due to the artificial MRI environment or observed differences in personality traits.

Animal models of cocaine use: importance of social context and co-use

Cocaine-use disorders (CUDs) continue to be a major public health problem that requires effective treatments. Despite decades of preclinical research, there are no FDA-approved pharmacotherapies for cocaine use. While there are numerous potential reasons why no efficacious treatments have been identified or approved for cocaine use, we discuss two possible reasons in this review: the low number of studies incorporating social variables and the overlooking of the clinical reality of polysubstance use. These variables impact drug use across the substance-use cycle, including vulnerability, maintenance, and treatment. Recent preclinical and clinical data suggest that cocaine users who engage in polysubstance use should be viewed as a distinct and more prevalent population who require unique behavioral and pharmacological approaches to reduce cocaine use. Therefore, to understand the neurobiology and eventual treatments for CUDs, both variables should be included in animal models.

Impulsivity facets and substance use involvement: insights from genomic structural equation modeling

BACKGROUND

Impulsivity is a multidimensional trait associated with substance use disorders (SUDs), but the relationship between distinct impulsivity facets and stages of substance use involvement remains unclear.

METHODS

We used genomic structural equation modeling and genome-wide association studies (N = 79,729-903,147) to examine the latent genetic architecture of nine impulsivity traits and seven substance use (SU) and SUD traits.

RESULTS

We found that the SU and SUD factors were strongly genetically inter-correlated (rG=0.77) but their associations with impulsivity facets differed. Lack of premeditation, negative and positive urgency were equally positively genetically correlated with both the SU (rG=.0.30-0.50) and SUD (rG=0.38-0.46) factors; sensation seeking was more strongly genetically correlated with the SU factor (rG=0.27 versus rG=0.10); delay discounting was more strongly genetically correlated with the SUD factor (rG=0.31 versus rG=0.21); and lack of perseverance was only weakly genetically correlated with the SU factor (rG=0.10). After controlling for the genetic correlation between SU/SUD, we found that lack of premeditation was independently genetically associated with both the SU (β=0.42) and SUD factors (β=0.21); sensation seeking and positive urgency were independently genetically associated with the SU factor (β=0.48, β=0.33, respectively); and negative urgency and delay discounting were independently genetically associated with the SUD factor (β=0.33, β=0.36, respectively).

CONCLUSIONS

Our findings show that specific impulsivity facets confer risk for distinct stages of substance use involvement, with potential implications for SUDs prevention and treatment.

Impulsivity and Cognitive Functioning in Inpatients with Concurrent Disorders: A Comparative Study with Healthy Controls and Evaluation of Treatment-Related Changes: Impulsivité et fonctionnement cognitif chez les patients hospitalisés présentant des troubles concomitants : étude comparative avec des témoins sains et évaluation des changements liés au traitement

OBJECTIVE

This study investigated impulsivity and working memory among CD inpatients across treatment and compared to controls.

METHODS

Patients (N = 56, Mage = 38.2, SD = 11.7, 17F) and healthy controls (N = 50, Mage = 31.9, SD = 10.0, 25F) completed a battery of self-report questionnaires and behavioural tasks assessing working memory and impulsivity (response inhibition, delay discounting, reflection, decision-making). Patients were assessed within 2 weeks of admission (baseline) and at 6 months (follow-up). Controls completed a single session at baseline. Patient demographics, diagnostic status, and treatment outcome (discharge with or without medical advice) were retrieved from medical records.

RESULTS

Group differences in demographics were probed for inclusion as covariates. At baseline, patients had greater self-reported impulsivity on the UPPS-P (negative and positive urgency) and BIS (motor and non-planning), and greater delay discounting than controls. Among patients, there was no association between treatment adherence and working memory, self-report, or behavioural impulsivity, and no change in behavioural impulsivity was observed from baseline to follow-up.

CONCLUSIONS

This is the first study to assess impulsivity and working memory in the context of CD treatment. Patients exhibited greater impulsivity on choice-based and various self-report measures. The absence of treatment-related changes in impulsivity and working memory outcomes suggests that conventional treatments may be neglecting to target potentially key areas of functioning. Further research is needed to examine how treatment affects impulsivity and related functions in individuals with CD, and their impact on clinical outcomes.

The effectiveness of mindfulness-based intervention for psychological distress and emotion regulation in college students with non-suicidal self-injury

This study explored the effectiveness of a short-term mindfulness-based intervention (MBI) on psychological distress, mindfulness levels, emotion regulation, and impulsivity among college students with non-suicidal self-injury (NSSI). Participants completed four questionnaires, including the Five Facet Mindfulness Questionnaire, the Depression Anxiety Stress Scale, the Emotion Regulation Questionnaire, and the Brief Barratt Impulsivity Scale, and two behavioral tasks, including an emotion regulation task and a stop signal task (SST), at three time points. Compared with the healthy group, the NSSI group had a significantly greater level of psychological distress and a lower level of mindfulness. Compared with the NSSI control group and the healthy group, the NSSI MBI group had significantly increased mindfulness levels and decreased psychological distress after the intervention. In the NSSI MBI group, regardless of which emotion regulation strategy was adopted when viewing negative pictures, the intensity of negative emotions during the emotion regulation task was significantly reduced. Moreover, in the NSSI MBI group, the effectiveness of the MBI on the mindfulness level, stress level, and emotion regulation process was maintained at the follow-up. The present study provided empirical support that short-term MBI has the potential to help individuals with NSSI by enhancing their emotion regulation.

Computational Mechanisms of Learning and Forgetting Differentiate Affective and Substance Use Disorders

Depression and anxiety are common, highly co-morbid conditions associated with a range of learning and decision-making deficits. While the computational mechanisms underlying these deficits have received growing attention, the transdiagnostic vs. diagnosis-specific nature of these mechanisms remains insufficiently characterized. Individuals with affective disorders (iADs; i.e., depression with or without co-morbid anxiety; N=168 and 74, respectively) completed a widely-used decision-making task. To establish diagnostic specificity, we also incorporated data from a sample of individuals with substance use disorders (iSUDs; N=147) and healthy comparisons (HCs; N=54). Computational modeling afforded separate measures of learning and forgetting rates, among other parameters. Compared to HCs, forgetting rates (reflecting recency bias) were elevated in both iADs and iSUDs (p = 0.007, η 2 = 0.022). In contrast, iADs showed faster learning rates for negative outcomes than iSUDs (p = 0.027, η 2 = 0.017), but they did not differ from HCs. Other model parameters associated with learning and information-seeking also showed suggestive relationships with early adversity and impulsivity. Our findings demonstrate distinct differences in learning and forgetting rates between iSUDs, iADs, and HCs, suggesting that different cognitive processes are affected in these conditions. These differences in decision-making processes and their correlations with symptom dimensions suggest that one could specifically develop interventions that target changing forgetting rates and/or learning from negative outcomes. These results pave the way for replication studies to confirm these relationships and establish their clinical implications.

Characterizing impulsivity in individuals with methamphetamine and methcathinone use disorders

Background

Individuals with substance use disorder (SUD) are characterized by loss of control in drug use, such as increased impulsivity. Methamphetamine and methcathinone are psychostimulants, the use of which is accompanied by a high level of impulsivity. Whether individuals with methamphetamine use disorder (MUD) and methcathinone use disorder (MCUD) differ in different aspects of impulsivity is unclear.

Methods

We investigated impulsivity traits and behaviors in individuals with MUD and MCUD. The Barratt Impulsiveness Scale (BIS), Sensation Seeking Scale (SSS), and delay discounting task (DDT) were assessed in individuals with MUD and MCUD and in healthy controls (HCs); then, we performed network-based analysis and computational modeling to understand the potential differences among the three groups.

Results

MUD subjects scored higher than MCUD subjects in terms of motor impulsivity, nonplanning impulsivity, and total BIS scores. The network analysis revealed that there were no significant differences between MUD and MCUD subjects in any centrality indices. The discount rate of MUD and MCUD subjects was significantly greater than that of HCs, whereas there was no difference in the discount rate between the two addiction groups.

Conclusions

These findings suggest that MUD and MCUD participants differ in impulsivity traits but not in impulsive behaviors, implying that impulsive traits and behaviors represent different aspects of impulsivity.

Working Memory Performance Predicts, but Does Not Reduce, Cocaine and Cannabinoid Seeking in Adult Male Rats

BACKGROUND

Cognitive deficits reflecting impaired executive function are commonly associated with psychiatric disorders, including substance use. Cognitive training is proposed to improve treatment outcomes for these disorders by promoting neuroplasticity within the prefrontal cortex, enhancing executive control, and mitigating cognitive decline due to drug use. Additionally, brain derived neurotrophic factor (BDNF) can facilitate plasticity in the prefrontal cortex and reduce drug-seeking behaviors. We investigated whether working memory training could elevate BDNF levels in the prefrontal cortex and if this training would predict or protect against cocaine or cannabinoid seeking.

METHODS

Adult male rats were trained to perform a "simple" or "complex" version of a delayed-match-to-sample working memory task. Rats then self-administered cocaine or the synthetic cannabinoid WIN55,212-2 and were tested for cued drug seeking during abstinence. Tissue from the prefrontal cortex and dorsal hippocampus was analyzed for BDNF protein expression.

RESULTS

Training on the working memory task enhanced endogenous BDNF protein levels in the prelimbic prefrontal cortex but not the dorsal hippocampus. Working memory training did not impact self-administration of either drug but predicted the extent of WIN self-administration and cocaine seeking during abstinence.

CONCLUSIONS

These results suggest that working memory training promotes endogenous BDNF but does not alter drug-seeking or drug-taking behavior. However, individual differences in cognitive performance before drug exposure may predict vulnerability to future drug use.

Associations of Reversal Learning Performance With Personality Disorder Profile and Drug Abuse History in a Sample of Prison Inmates

Prison inmate samples present a high prevalence of impulsivity- and compulsivity-related behavioral problems. The Probabilistic Reversal Learning Task (PRLT) is a useful tool to assess decision-making, and we explore its associations with inmates' personality disorder (antisocial personality disorder, APD; obsessive-compulsive personality disorder, OCPD; or both) and history of drug abuse. Mixed-effects methods were used to model acquisition and reacquisition curves across PRLT, in a sample of 275 prison inmates diagnosed with OCPD, APD, or both. Two aspects were assessed: general discrimination learning and decision-making inflexibility. Participants with a mixed personality disorder profile showed a clear pattern of decisional inflexibility. A history of drug abuse was associated with a general poorer performance but not with decision-making inflexibility. Inability to adapt to changing contingencies, and thus to adverse consequences of previously rewarded choices, was not linked to compulsivity, as hypothesized to be present in OCPD and substance use disorders, but to the mixed APD/OCPD profile.

Working memory performance predicts, but does not reduce, cocaine- and cannabinoid-seeking in adult male rats

Background

Cognitive deficits reflecting impaired executive function are commonly associated with psychiatric disorders, including substance use. Cognitive training is proposed to improve treatment outcomes for these disorders by promoting neuroplasticity within the prefrontal cortex, enhancing executive control, and mitigating cognitive decline due to drug use. Additionally, brain derived neurotrophic factor (BDNF) can facilitate plasticity in the prefrontal cortex and reduce drug-seeking behaviors. We investigated whether working memory training could elevate BDNF levels in the prefrontal cortex and if this training would predict or protect against cocaine or cannabinoid seeking.

Methods

Adult male rats were trained to perform a 'simple' or 'complex' version of a delayed- match-to-sample working memory task. Rats then self-administered cocaine or the synthetic cannabinoid WIN55,212-2 and were tested for cued drug-seeking during abstinence. Tissue from the prefrontal cortex and dorsal hippocampus was analyzed for BDNF protein expression.

Results

Training on the working memory task enhanced endogenous BDNF protein levels in the prelimbic prefrontal cortex but not the dorsal hippocampus. Working memory training did not impact self-administration of either drug but predicted the extent of WIN self-administration and cocaine seeking during abstinence.

Conclusions

These results suggest that working memory training promotes endogenous BDNF but does not alter drug-seeking or drug-taking behavior. However, individual differences in cognitive performance prior to drug exposure may predict vulnerability to future drug use.

Analysis of writing in personality disorders in prison population

Abstract

Writing involves the activation of different processing modes than reading comprehension, and therefore the level of activation varies depending on the moment and the task.

Objectives

to analyze the profiles in terms of the proposed coding from the PROESC in terms of personality disorders [Antisocial Personality Disorder (ASPD) with drugs possession and consumption crimes (DPCC) and Obsessive-Compulsive Personality Disorder (OCPD)] with gender violence crimes (GVC) in the prisoners.

Design

The sample was composed of 194 men. The participants were divided into two groups. Group 1 (ASPD; DPCC) consisted of 81 men, and Group 2 (OCPD; GVC) consisted of 113 men.

Main outcome measures

They completed the Demographic, Offense, and Behavioral Interview in Institutions, the International Personality Disorders Examination (IPDE), and Writing Processes Evaluation Battery (PROESC).

Results

Group 2 made more mistake than Group 1 in narratives tasks.

Conclusion

Participants know phoneme-grapheme correspondence rules, language disturbances of a reiterative and persistent nature may appear in those who show compulsive behavior.

Making decisions one drink at a time and the "just one drink" effect: A fuzzy-trace theory model of harmful drinking

BACKGROUND

Understanding the decision factors that drive harmful alcohol use among young adults is of practical and theoretical importance. We apply fuzzy-trace theory (FTT) to investigate a potential danger that may arise from the arguably correct notion that a single drink carries no meaningful risk. Decisions that are mentally represented as one drink at a time could contribute to excessive drinking.

METHODS

College students (N = 351) made a series of decisions to take or decline eight hypothetical drinks presented one at a time. Outcome measures included each decision, recent alcohol consumption (weekly drinks, peak blood alcohol content, and binges), and alcohol-related harms (scores on the Brief Young Adult Alcohol Consequences Questionnaire and Alcohol Use Disorders Identification Test). Linear regression models predicted each outcome from sex, perceived risk of a single drink, perceived risk of heavy drinking, perceived consequences of drinking, and general health-related risk sensitivity.

RESULTS

Consistent with FTT, decisions to have a first drink and up to four additional drinks in short succession were each associated with lower perceived risk of one drink-a "just-one drink" effect-independent of perceived risks of heavy drinking, perceived consequences of drinking, and general risk sensitivity. Similarly, all measures of recent alcohol consumption and consequent harms were associated with perceived risk of one drink. Participants reporting "zero risk" of a single drink had worse outcomes on all measures than those reporting at least "low risk."

CONCLUSIONS

Results are consistent with the theoretically informed premise that consumption decisions are typically made one drink at a time rather than by deciding the total number of drinks to be consumed in a sitting. When decisions about alcohol use proceed one drink at a time, a perception of zero risk in a single drink may contribute to heavy drinking.

What does metaphoric language say about aggression? The relationships between metaphoric language, impulsivity, and aggression

Aggressive behavior among adolescents has been identified as a serious worldwide problem, especially when combined with trait impulsivity. This study investigates the impact of an overlooked aspect of language, namely, metaphor comprehension, on impulsivity and aggression in adolescents. A total of 204 adolescents completed self-reported questionnaires assessing impulsivity and aggression and underwent tests assessing familiar and less familiar metaphor comprehension. The findings reveal inverse relationships between metaphor comprehension and both impulsivity and aggression. Regarding aggression, notable distinctions were observed in the correlations between familiar and less familiar metaphors with specific aggression types. Additionally, impulsivity was found to mediate the relationship between the comprehension of familiar metaphors and aggression. These results are elucidated in the context of cognitive and executive functions, emphasizing the significance of considering metaphor comprehension as a cognitive process capable of modulating aggressive behavior.

Pramipexole restores behavioral inhibition in highly impulsive rats through a paradoxical modulation of frontostriatal networks

Impulse control disorders (ICDs), a wide spectrum of maladaptive behaviors which includes pathological gambling, hypersexuality and compulsive buying, have been recently suggested to be triggered or aggravated by treatments with dopamine D2/3 receptor agonists, such as pramipexole (PPX). Despite evidence showing that impulsivity is associated with functional alterations in corticostriatal networks, the neural basis of the exacerbation of impulsivity by PPX has not been elucidated. Here we used a hotspot analysis to assess the functional recruitment of several corticostriatal structures by PPX in male rats identified as highly (HI), moderately impulsive (MI) or with low levels of impulsivity (LI) in the 5-choice serial reaction time task (5-CSRTT). PPX dramatically reduced impulsivity in HI rats. Assessment of the expression pattern of the two immediate early genes C-fos and Zif268 by in situ hybridization subsequently revealed that PPX resulted in a decrease in Zif268 mRNA levels in different striatal regions of both LI and HI rats accompanied by a high impulsivity specific reduction of Zif268 mRNA levels in prelimbic and cingulate cortices. PPX also decreased C-fos mRNA levels in all striatal regions of LI rats, but only in the dorsolateral striatum and nucleus accumbens core (NAc Core) of HI rats. Structural equation modeling further suggested that the anti-impulsive effect of PPX was mainly attributable to the specific downregulation of Zif268 mRNA in the NAc Core. Altogether, our results show that PPX restores impulse control in highly impulsive rats by modulation of limbic frontostriatal circuits.

Addiction: A treatise from 1561

BACKGROUND AND AIMS

In 1561, physician and philosopher Pascasius Justus Turq published a monograph on the description and treatment of pathological gambling. When the monograph came to the attention of the authors in 2006, there existed no known translation of it in any modern language. In 2014, it was translated and published in French. This paper analyses the monograph's key content elements and its place in the history of the concept of addiction.

METHODS

A contextual analysis of the late Italian Renaissance, followed by key excerpts from the text and commentaries on the meaning and significance of the monograph.

FINDINGS AND CONCLUSIONS

Pascasius Justus Turq's 1561 monograph on pathological gambling outlines a disease view of gambling, identifies cognitive processes and biological vulnerabilities as aetiological factors, avoids religious or moral judgements and recommends cognitive treatment to change the beliefs and expectancies of gamblers. This study shows that a 'disease formulation' of addiction was enunciated as early as the 16th century, and its contemporary resonance suggests that current clinical features of addictive disorders have existed for centuries.

Insula Connectivity Abnormalities Predict Impulsivity in Chronic Heroin Use Disorder: A Cross-Sectional Resting-State fMRI Study

Patients with heroin use disorder (HUD) often exhibit trait impulsivity, which may be an important factor in and a good predictor of addiction. However, the factor structure of HUD trait impulsivity (motor, attentional, and nonplanning) and its neural correlates are not yet known. A total of 24 male volunteers with HUD and 16 healthy control volunteers were recruited for this cross-sectional study. The Barratt Impulsiveness Scale (BIS-11) and resting-state functional magnetic resonance imaging (rs-fMRI) were employed using the insula as a seed point in an effort to understand the association between trait impulsivity and its intrinsic factors and functional connectivity (FC) between the insula and the whole brain. The HUD group in this study exhibited higher total trait impulsivity scores, motor impulsivity, and nonplanning impulsivity than the control group. Changes in FC between the right insula and the lateral occipital cortex and the right angular gyrus were significantly positively correlated with total trait impulsivity scores, motor impulsivity, and nonplanning impulsivity, whereas changes in the FC between the left insula and the left superior frontal gyrus and left frontopolar brain region were significantly negatively correlated with trait impulsivity. Thus, the insula may serve as an important biomarker for identifying trait impulsivity and its intrinsic factor structure in patients with HUDs.

Validation of the UPPS-P Impulsive Behavior Scale and Clinical Correlates of its Scores in French-Speaking Patients Starting a Residential Detoxification Program

Background

Impulsivity is a multifaceted construct that plays a prominent role in substance use disorder (SUD). The UPPS-P model distinguishes five impulsivity components (positive urgency, negative urgency, lack of perseverance, lack of premeditation, and sensation seeking). This study aimed to explore the structure of the UPPS-P in patients hospitalized for SUDs and to investigate the relationship between the dimensions of impulsivity and clinical variables.

Method

Inpatients of a residential detoxification service (n = 125) were recruited. A confirmatory factor analysis was performed, and associations were assessed between the components of impulsivity and clinical indexes.

Results

The factor analysis supported a model of impulsivity with five interrelated latent variables. Good internal consistency was found. External validity was supported by relationships with psychological difficulties. Multiple correlations (Kendall) suggested that, except for its sensation-seeking component, impulsivity is a significant risk factor for both the severity of addictive problems and their comorbidities.

Conclusion

This study provides further evidence in favor of the 5-dimensional model of impulsivity. It highlights impulsivity as a transdiagnostic risk factor that should be considered in the management of SUD.

Global prevalence of smoking among individuals with obsessive-compulsive disorder and symptoms: a systematic review and meta-analysis

Disease from nicotine dependency continues to be a leading cause of preventable death worldwide, and therefore research that elucidates potential correlates of tobacco use may facilitate the advancement of research, clinical practice, and policy in this area to target this public health challenge. One potential tobacco use correlate is obsessive-compulsive disorder (OCD) phenomena. The growing research evidence on the association between tobacco use and OCD phenomena is mixed, making it difficult to synthesize extant findings into meaningful conclusions. Indeed, there has never been a systematic review or meta-analysis of this area of research. To this end, a systematic review was carried out with studies between 1988 and 2021, and from this review, 71 independent estimations (n = 10,475; Females = 51.95%; mean age = 37.29, SD = 13.78) were extracted for meta-analysis. We found that about three in ten participants with OCD are likely to use tobacco, which is higher than the general population. The prevalence was the same among OCD participants at all levels (those with symptomology but no confirmed diagnosis, those surpassing a clinical cutoff for OCD but no confirmed diagnosis, and those with a confirmed OCD diagnosis). The results also indicated considerable variability across study results and a wide confidence interval associated with the tobacco use prevalence rate among those with OCD phenomena. The findings provide support for continued study of this comorbidity, perhaps with longitudinal and experimental designs to test for reciprocal associations between tobacco use and OCD phenomena in the service of targeting nicotine dependence as a substantial global public health concern.

Repeated Cocaine Intake Differentially Impacts Striatal D2/3 Receptor Availability, Psychostimulant-Induced Dopamine Release, and Trait Behavioral Markers of Drug Abuse

Current research indicates that altered dopamine (DA) transmission in the striatum contributes to impulsivity and novelty-seeking, and it may mediate a link concerning a higher susceptibility to drug abuse. Whether increased susceptibility to drug abuse results from a hyperdopaminergic or hypodopaminergic state is still debated. Here, we simultaneously tracked changes in DA D2/3 receptor (D2/3R) availability and amphetamine-(AMPH)-induced DA release in relation to impulsivity and novelty-seeking prior to, and following, cocaine self-administration (SA) in Roman high- (RHA) and low- (RLA) avoidance rats. We found that high-impulsive/high novelty-seeking RHA rats exhibited lower D2/3R availabilities and higher AMPH-induced DA release in the striatum that predicted higher levels of cocaine intake compared with RLAs. Cocaine SA did not alter striatal D2/3R availability or impulsivity in RHA or RLA rats. Critically, cocaine exposure led to a baseline-dependent blunting of stimulated DA release in high-impulsive/high novelty-seeking RHA rats only, and to a baseline-dependent increase in novelty-seeking in low-impulsive/low novelty-seeking RLA rats only. Altogether, we propose that susceptibility to drug abuse results from an innate hyper-responsive DA system, promoting impulsive action and novelty-seeking, and producing stronger initial drug-reinforcing effects that contribute to the initiation and perpetuation of drug use. However, with repeated cocaine use, a tolerance to drug-induced striatal DA elevations develops, leading to a compensatory increase in drug consumption to overcome the reduced reward effects.

Profiles of HIV-Related Knowledge and Self-Regulation Factors in At-Risk Pre-Adolescents

Disrupted self-regulation can increase youths' risk for substance use and HIV acquisition. Latent profile analysis (LPA) was used to explore profiles among 124 youth ages 11-13 who had impulse control disorders. LPA was based on self-regulation factors and three HIV/AIDS-specific domains: AIDS-related knowledge; perceived severity of AIDS; and worry about HIV. LPA identified four profiles: 1) low knowledge/low regulation; 2) low perceived severity/high regulation; 3) high knowledge/low regulation; and 4) moderate knowledge/moderate regulation. Youth with the highest HIV/AIDS knowledge showed the highest impulsivity, emotion dysregulation, and violence exposure. Youth may benefit from tailored prevention based on HIV-related knowledge/beliefs and self-regulation.

Candidate biomarkers in psychiatric disorders: state of the field

The field of psychiatry is hampered by a lack of robust, reliable and valid biomarkers that can aid in objectively diagnosing patients and providing individualized treatment recommendations. Here we review and critically evaluate the evidence for the most promising biomarkers in the psychiatric neuroscience literature for autism spectrum disorder, schizophrenia, anxiety disorders and post-traumatic stress disorder, major depression and bipolar disorder, and substance use disorders. Candidate biomarkers reviewed include various neuroimaging, genetic, molecular and peripheral assays, for the purposes of determining susceptibility or presence of illness, and predicting treatment response or safety. This review highlights a critical gap in the biomarker validation process. An enormous societal investment over the past 50 years has identified numerous candidate biomarkers. However, to date, the overwhelming majority of these measures have not been proven sufficiently reliable, valid and useful to be adopted clinically. It is time to consider whether strategic investments might break this impasse, focusing on a limited number of promising candidates to advance through a process of definitive testing for a specific indication. Some promising candidates for definitive testing include the N170 signal, an event-related brain potential measured using electroencephalography, for subgroup identification within autism spectrum disorder; striatal resting-state functional magnetic resonance imaging (fMRI) measures, such as the striatal connectivity index (SCI) and the functional striatal abnormalities (FSA) index, for prediction of treatment response in schizophrenia; error-related negativity (ERN), an electrophysiological index, for prediction of first onset of generalized anxiety disorder, and resting-state and structural brain connectomic measures for prediction of treatment response in social anxiety disorder. Alternate forms of classification may be useful for conceptualizing and testing potential biomarkers. Collaborative efforts allowing the inclusion of biosystems beyond genetics and neuroimaging are needed, and online remote acquisition of selected measures in a naturalistic setting using mobile health tools may significantly advance the field. Setting specific benchmarks for well-defined target application, along with development of appropriate funding and partnership mechanisms, would also be crucial. Finally, it should never be forgotten that, for a biomarker to be actionable, it will need to be clinically predictive at the individual level and viable in clinical settings.

Multi-Level Protective Factors of Adolescent Smoking and Drinking

Adolescence is the most critical life stage for experimentation with substance use; however, this is also the most suitable period for strengthening protective factors and thus promoting adult physical and mental health. Since smoking and drinking still appear among the most frequent types of substance abuse in Europe, this study aims to examine the role of potential protective factors at multiple levels for adolescent smoking and drinking: psychological factors at the individual level, aspects of school attachment at the school level, social support variables at the social level, and measures of quality of life at the level of mental health. This cross-sectional survey involved a sample of adolescents (aged 11-18 years, N = 276) in Budapest and villages in its metropolitan area (Hungary). In addition to descriptive statistics, logistic regression analyses were used to detect odds for potential protective factors. There were no sex differences in adolescents' substance use. Self-control seems to be a universal and most determining protective factor against substance use, while other potential protective factors (self-esteem, resilience, social support from family or significant others, school attachment, and mental well-being) may also contribute to prevention. However, age and friend support acted as risk factors. Findings suggest that a complex approach to prevention should receive consideration.

Exploring the nature and prevalence of targeted violence perpetrated by persons found not criminally responsible on account of mental disorder

Although mental illness has a demonstrated link with violence, the prevalence of targeted (planned and goal-directed) violence perpetrated by individuals with mental illness and its association with psychiatric symptoms is relatively unexplored. File information was compared for all 293 individuals found not criminally responsible due to mental illness in British Columbia between 2001 and 2005, of whom 19% had committed targeted violence. Most individuals with targeted offenses displayed at least one warning behavior before their offense (93%); all displayed delusions and approximately one third exhibited hallucinations. Compared to individuals who perpetrated non-targeted offenses, the individuals with targeted offenses displayed greater proportions of threats/criminal harassment, had female victims, displayed a psychotic disorder and/or personality disorder, and displayed delusions during the offense. This implies that severe psychiatric disorders do not preclude the perpetration of planned violence and suggests that exploring symptoms of mental illness that may be proximally indicative of targeted violence is important in preventing future acts.

Value-based decision-making network functional connectivity correlates with substance use and delay discounting behaviour among young adults

Substance use disorders are characterized by reduced control over the quantity and frequency of psychoactive substance use and impairments in social and occupational functioning. They are associated with poor treatment compliance and high rates of relapse. Identification of neural susceptibility biomarkers that index risk for developing a substance use disorder can facilitate earlier identification and treatment. Here, we aimed to identify the neurobiological correlates of substance use frequency and severity amongst a sample of 1,200 (652 females) participants aged 22-37 years from the Human Connectome Project. Substance use behaviour across eight classes (alcohol, tobacco, marijuana, sedatives, hallucinogens, cocaine, stimulants, opiates) was measured using the Semi-Structured Assessment for the Genetics of Alcoholism. We explored the latent organization of substance use behaviour using a combination of exploratory structural equation modelling, latent class analysis, and factor mixture modelling to reveal a unidimensional continuum of substance use behaviour. Participants could be rank ordered along a unitary severity spectrum encompassing frequency of use of all eight substance classes, with factor score estimates generated to represent each participant's substance use severity. Factor score estimates and delay discounting scores were compared with functional connectivity in 650 participants with imaging data using the Network-based Statistic. This neuroimaging cohort excludes participants aged 31 and over. We identified brain regions and connections correlated with impulsive decision-making and poly-substance use, with the medial orbitofrontal, lateral prefrontal and posterior parietal cortices emerging as key hubs. Functional connectivity of these networks could serve as susceptibility biomarkers for substance use disorders, informing earlier identification and treatment.

Type of medication therapy for ADHD and stimulant misuse during adolescence: a cross-sectional multi-cohort national study

Background

Attention-deficit/hyperactivity disorder (ADHD) is associated with higher substance use rates. Stimulant and non-stimulant pharmacotherapy improve adolescent ADHD, but their associations with prescription stimulant misuse (PSM), cocaine, and methamphetamine use are unclear. Using 2005-2020 US Monitoring the Future data, we investigated relationships between ADHD pharmacotherapy history and PSM, cocaine, or methamphetamine use.

Methods

Secondary students (13-19 years) provided data on pharmacotherapy history (N = 199,560; 86.3% of total sample) between January 1, 2005 and May 31, 2020 in a cross-sectional multi-cohort study; weights assured a nationally representative sample. Participants were grouped by ADHD pharmacotherapy history: none (88.7%; principally non-ADHD controls); stimulant-only (5.8%); non-stimulant-only (3.3%); both stimulant and non-stimulant (2.1%). Outcomes were past-year PSM, cocaine, and methamphetamine use. Logistic regressions examined relationships between pharmacotherapy history and outcomes, controlling for sociodemographics, recent substance use, and stimulant treatment cessation.

Findings

Past-year outcome rates were lowest in adolescents with no pharmacotherapy history: 4.7% for PSM [8310/174,561], 1.6% for cocaine [2858/174,688], and 0.7% for methamphetamine [1036/148,378]. A history of both stimulant and non-stimulant treatment was associated with the highest rates: 22.3% for PSM [940/4098], 10.4% for cocaine [450/4110], and 7.8% for methamphetamine [275/3427]. Adolescents who received monotherapy (stimulant- or non-stimulant-only) had intermediate rates, with no differences between monotherapy groups.

Interpretation

While elevated PSM and illicit stimulant use rates are likely influenced by ADHD, our findings suggested adolescents with a history of both stimulant and non-stimulant pharmacotherapy are at highest risk for these stimulant outcomes. Adolescents receiving ADHD pharmacotherapy should be monitored for PSM and illicit stimulant use.

Funding

National Institute on Drug Abuse/National Institutes of Health (USA) and Food and Drug Administration (USA).

Dual-systems models of the genetic architecture of impulsive personality traits: Neurogenetic evidence of distinct but related factors

Background

Dual-systems models provide a parsimonious framework for understanding the interplay between cortical and subcortical brain regions relevant to impulsive personality traits (IPTs) and their associations with psychiatric disorders. Despite recent developments in multivariate analysis of genome-wide association studies (GWAS), molecular genetic investigations of these models have not been conducted.

Methods

Using extant IPT GWAS, we conducted confirmatory genomic structural equation models (GenomicSEM) to empirically evaluate dual-systems models of the genetic architecture of IPTs. Genetic correlations between results of multivariate GWAS of dual-systems factors and GWAS of relevant cortical and subcortical neuroimaging phenotypes (regional/structural volume, cortical surface area, cortical thickness) were calculated and compared.

Results

Evaluation of GenomicSEM model fit indices for dual-systems models suggested that these models highlight important sources of shared and unique genetic variance between top-down and bottom-up constructs. Specifically, a dual-systems genomic model consisting of sensation seeking and lack of self-control factors demonstrated distinct but related sources of genetic influences ( r g =.60). Genetic correlation analyses provided evidence of differential associations between dual-systems factors and cortical neuroimaging phenotypes (e.g., lack of self-control negatively associated with cortical thickness, sensation seeking positively associated with cortical surface area). However, no significant associations were observed for subcortical phenotypes inconsistent with hypothesized functional localization of dual-systems constructs.

Conclusions

Dual-systems models of the genetic architecture of IPTs tested here demonstrate evidence of shared and unique genetic influences and associations with relevant neuroimaging phenotypes. These findings emphasize potential advantages in utilizing dual-systems models to study genetic influences for IPTs and transdiagnostic associations with psychiatric disorders.

Role of Orbitofrontal Cortex and Differential Effects of Acute and Chronic Stress on Motor Impulsivity Measured With 1-Choice Serial Reaction Time Test in Male Rats

BACKGROUND

Deficits in motor impulsivity, that is, the inability to inhibit a prepotent response, are frequently observed in psychiatric conditions. Several studies suggest that stress often correlates with higher impulsivity. Among the brain areas affected by stress, the orbitofrontal cortex (OFC) is notable because of its role in impulse control. OFC subregions with unique afferent and efferent circuitry play distinct roles in impulse control, yet it is not clear what OFC subregions are engaged during motor impulsivity tasks.

METHODS

In this study we used a rodent test of motor impulsivity, the 1-choice serial reaction time test, to explore activation of OFC subregions either during a well-learned motor impulsivity task or in a challenge task with a longer wait time that increases premature responding. We also examined the effects of acute inescapable stress, chronic intermittent cold stress and chronic unpredictable stress on motor impulsivity.

RESULTS

Fos expression increased in the lateral OFC and agranular insular cortex during performance in both the mastered and challenge conditions. In the ventral OFC, Fos expression increased only during challenge, and within the medial OFC, Fos was not induced in either condition. Inescapable stress produced a transient effect on premature responses in the mastered task, whereas chronic intermittent cold stress and chronic unpredictable stress altered premature responses in both conditions in ways specific to each stressor.

CONCLUSIONS

These results suggest that different OFC subregions have different roles in motor impulse control, and the effects of stress vary depending on the nature and duration of the stressor.

Child executive function and future externalizing and internalizing problems: A meta-analysis of prospective longitudinal studies

To determine the association between executive function and later externalizing and internalizing problems, we conducted a meta-analysis of 167 studies (1098 effect sizes, total N = 66,119) that explored the longitudinal associations between executive functions in children and subsequent externalizing and internalizing problems. The results indicated that greater child executive function was prospectively associated with fewer attention-deficit/hyperactivity disorder (ADHD) symptoms, fewer conduct problems, fewer oppositional defiant disorder symptoms, less substance use, fewer broad externalizing problems, fewer depression symptoms, and fewer broad internalizing problems, but not with subsequent anxiety symptoms. Moderator analyses revealed that the sample type moderated the associations of executive function with both ADHD symptoms and conduct problems. Age of assessment moderated the association with broad externalizing problems, and executive function context moderated associations with both substance use and broad internalizing problems. These findings suggest that executive function in children prospectively predicts numerous externalizing and internalizing behaviors, suggesting that executive function may be an important target for psychopathology prevention programs and interventions.

Neural substrates of substance use disorders

PURPOSE OF REVIEW

Substance use disorders account for a tremendous burden to society, yet despite substantial progress in basic studies, our understanding of the brain-basis of these disorders is still emerging. This review summarizes the recent findings of neuroimaging studies with substance use disorder individuals.

RECENT FINDINGS

Resting-state functional connectivity studies support for some but not all substances of abuse and disruption in executive control. Structural neuroimaging findings point towards reduced subcortical volumes, which may emerge as an interaction between preexisting factors and recent substance use. Longitudinal studies implicate some of the same core brain structures and their functional role that have also been identified via case-control studies. Finally, meta-analyses support the idea of dysregulation of cortical control over subcortical salience processing.

SUMMARY

Although progress has been made and there is both structural and functional imaging evidence of an imbalance between brain structures involved in executive control and salience processing, there is emerging evidence that brain-behaviour relationships, which are core to discovering the neural processes that lead to and maintain substance use, are small and require larger consortia that prospectively examine individuals with substance use disorder.

Poor Response Inhibition and Symptoms of Inattentiveness Are Core Characteristics of Lifetime Illicit Substance Use among Young Adults in the General Norwegian Population: The HUNT Study

BACKGROUND

Impairments in neurocognitive functioning are associated with substance use behavior. Previous studies in neurocognitive predictors of substance use typically use self-report measures rather than neuropsychological performance measures and suffer from low sample sizes and use of clinical diagnostic cut offs.

METHODS

Crossectional data from the HUNT4 Study (Helseundersøkelsen i Trøndelag) was used to study executive neuropsychological performance and self-reported measures of neurocognitive function associated with a history of illicit substance use in a general population sample of young adults in Norway. We performed both between group comparisons and logistic regression modeling and controlled for mental health symptomatology.

RESULTS

Subjects in our cohort with a self-reported use of illicit substances had significantly higher self-reported mental health and neurocognitive symptom load. A logistic regression model with substance use as response included sex, commission errors and self-reported inattentiveness and anxiety as significant predictors. After 10-fold cross-validation this model achieved a moderate area under the receiver-operator curve of 0.63. To handle the class imbalance typically found in such population data, we also calculated balanced accuracy with a optimal model cut off of 0.234 with a sensitivity of 0.50 and specificity of 0.76 as well as precision recall-area under the curve of 0.28.

CONCLUSIONS

Subtle cognitive dysfunction differentiates subjects with and without a history of illicit substance use. Neurocognitive factors outperformed the effects of depressive symptoms on substance use behavior in this cohort. We highlight the need for using adequate statistical tools for evaluating the performance of models in unbalanced datasets.

Patients admitted to treatment for substance use disorder in Norway: a population-based case-control study of socio-demographic correlates and comparative analyses across substance use disorders

Background

Improved knowledge regarding socio-demographic correlates of people with substance use disorders (SUDs) is essential to better plan and provide adequate services for SUD patients and their families, and to improve our understanding of the complex mechanisms underlying progression into and development of various SUDs. This study aimed to: i) describe demographic, economic, and social correlates of people with SUDs in comparison with those of the general population and ii) compare these correlates across SUDs from licit versus illicit substances, as well as across specific SUDs.

Methods

A national population-based case–control study included all SUD patients enrolled in specialized drug treatment in Norway in 2009–2010 (N = 31 245) and a population control sample, frequency-matched on age and gender (N = 31 275). Data on education level, labour market participation, income level and sources, and family/living arrangement were obtained by linkages to national registers.

Results

Demographic, economic, and social correlates of SUD patients differed substantially from those of the general population, and across specific SUDs. Among SUD patients, those with illicit – as compared to licit – SUDs were younger (mean quotient = 0.72 [0.71–0.72]), more often had low education level (RR = 1.68 [1.63–1.73]), were less often in paid work (RR = 0.74 [0.72–0.76]) and had lower income (mean quotient = 0.61 [0.60–0.62]). Comparison of patients with different SUD diagnoses revealed substantial demographic differences, including the relatively low mean age among cannabis patients and the high share of females among sedatives/hypnotics patients. Opioid patients stood out by being older, and more often out of work, receiving social security benefits, and living alone. Cocaine and alcohol patients were more often better educated, included in the work force, and had a better financial situation.

Conclusion

Findings revealed substantial and important differences in socio-demographic correlates between SUD patients and the general population, between SUD patients with illicit and with licit substance use, and across specific SUD patient groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13199-5.

A Comparison Study of Impulsiveness, Cognitive Function, and P300 Components Between Gamma-Hydroxybutyrate and Heroin-Addicted Patients: Preliminary Findings

Purpose

The aim of this study was to investigate and compare impulsiveness, negative emotion, cognitive function, and P300 components among gamma-hydroxybutyrate (GHB)-addicted patients, heroin-dependent patients, and methadone maintenance treatment (MMT) subjects.

Methods

A total of 48 men including 17 GHB addicts, 16 heroin addicts, 15 MMT subjects, and 15 male mentally healthy controls (HC) were recruited. All subjects were evaluated for symptoms of depression, anxiety, impulsiveness, and cognitive function through the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder 7-item (GAD-7), the Barratt Impulsiveness Scale version II (BIS-II), the Beijing version of the Montreal Cognitive Assessment (BJ-MoCA), the behavioral test (response time), and event-related potential P300 detection.

Results

(1) The mean scores of BIS-II in the GHB addiction group, heroin dependence group, and MMT group were significantly higher than those of the HC group (F = 30.339, P = 0.000). (2) The total scores of BJ-MOCA in GHB addiction group was the worst among the four groups, followed by heroin addiction, MMT group and HC group (F = 27.880, P = 0.000). (3) The response time in the GHB addiction group was the longest among the four groups, followed by the heroin addiction, MMT, and HC groups (F = 150.499, P = 0.000). (4) The amplitude and latency of P300 in GHB addiction subjects were significantly lower and longer than those of the MMT group and the HC group. (5) For the three types of addiction, the P300 amplitudes at Fz, Cz, Pz, T5, and T6 were negatively correlated with the scores of GAD-7, PHQ-9, and BIS-II; the P300 latencies were positively correlated with the response time and negatively correlated with the scores of the BJ-MoCA.

Conclusion

People with an addiction were likely to have increased impulsiveness. The cognitive function of the GHB and heroin-addicted subjects, including the heroin detoxification and the MMT groups, was severely impaired, especially for the GHB-addicted patients. The impairment manifested as abnormalities of BJ-MoCA, response time, and P300 components.

Impulsivity and Reflective Thinking in Veterans Seeking Care for Substance Use Disorder

Objective: Substance use disorder (SUD) is a major public health crisis, with increased overdose deaths in the past decade. This has coincided with a tremendous amount of research on those who misuse substances. However, extensive research on SUD vulnerability characteristics such as impulsivity may be complemented by research on theoretically relevant aspects of cognition. The Cognitive Reflection Test (CRT) was designed to measure a person's ability to subdue quick, intuitive decisions to reflect or deliberate. To some decision making theorists, this measure may help explain why some people are better able to inhibit "gut reactions" than others. Methods: We recruited 140 veterans from a Veterans Affairs medical center; 91 of whom were receiving SUD treatment. Participants completed the CRT and a measure of trait impulsivity (the UPPS-P). We ran planned ANCOVAs assessing differences in the number of correct answers on the CRT and the proportion of errors that were intuitive. Results: Participants who were receiving treatment gave significantly fewer correct, reflective answers on the CRT compared to controls. However, there were no significant differences in the proportion of errors that were due to intuitive responses. These findings did not change when controlling for age and/or trait impulsivity. Conclusion: Those suffering from SUD may exhibit cognitive deficits that do not stem from intuitive thinking. These deficits may, in turn, exacerbate issues arising from elevated impulsivity. Additional research which better incorporates decision making theory may be invaluable in providing clinically-relevant results and positive public health outcomes.

Associations between Impulsivity and Exercise Addiction, Disordered Eating, and Alcohol Use Behaviors: A Latent Profile Analysis

BackgroundDespite the known negative consequences of exercise addiction and preliminary evidence suggesting that it may co-occur with other health risk behaviors, no studies to date have examined exercise addiction among college students in conjunction with disordered eating behaviors and alcohol use. The aim of this study was to describe which college students are most at-risk for co-occurring health risk behaviors to enhance the efficiency of health risk prevention efforts. Method: Guided by multidimensional theories of impulsivity and substance use models of comorbidity, this study used latent profile analysis to examine whether separate, conceptually meaningful profiles of risk for exercise addiction, disordered eating behaviors, and alcohol use would emerge among 503 college students from a large public university. Results: The best-fitting model supported three profiles. MANOVA results revealed significant profile differences based on exercise addiction, binge eating, purging, laxative/pill/diuretic use, exercising longer than 60 minutes, negative urgency, and problematic alcohol use. Profile 3 students (n = 29), labeled the Affect Driven Health Risk-Takers, demonstrated the highest levels of impulsivity (i.e., negative urgency, lack of premeditation, lack of perseverance, and sensation seeking) and the most risk behaviors compared to the other two profiles. Profile membership was associated with distinct levels of negative urgency, exercise addiction, disordered eating behaviors, and problematic alcohol use. A small proportion of undergraduates demonstrated co-occurring exercise addiction, disordered eating behaviors, and problematic alcohol use. Profile membership also predicted the health outcomes of clinically significant exercise addiction and hazardous alcohol use. Conclusions: Findings illuminated how patterns of risk behavior engagement were associated with clinically significant exercise addiction and hazardous alcohol use and will inform prevention efforts and clinical interventions with at-risk college students.

Preconception paternal morphine exposure leads to an impulsive phenotype in male rat progeny

RATIONALE

Identifying the long-term neurocognitive implications of opioid addiction may further our understanding of the compulsive nature of this brain disorder. The aim of this study was to examine the effects of paternal adolescent opiate exposure on cognitive performance (visual attention, impulsivity, and compulsivity) in the next generation.

METHODS

Male Wistar rats received escalating doses of morphine (2.5-25 mg/kg, s.c.) or saline for 10 days during adolescence (P30-39). In adulthood (P70-80), these rats were allowed to mate with drug-naive females. Male offspring from morphine- and saline-exposed sires, once in adulthood, were trained and tested in the 5-choice serial reaction time test (5-CSRTT) to evaluate their cognitive abilities under baseline, drug-free conditions as well as following acute (1, 3, 5 mg/kg morphine) and subchronic morphine (5 mg/kg morphine for 5 days) treatment. Behavioral effects of the opioid receptor antagonist naloxone were also assessed.

RESULTS

Morphine-sired offspring exhibited delayed learning when the shortest stimulus duration (1 s) was introduced, i.e., when cognitive load was highest. These subjects also exhibited a reduced ability to exert inhibitory control, as reflected by increased premature and perseverative responding under drug-free baseline conditions in comparison to saline-sired rats. These impairments could not be reversed by administration of naloxone. Moreover, impulsive behavior was further enhanced in morphine-sired rats following acute and subchronic morphine treatment.

CONCLUSION

Paternal opiate exposure during adolescence was found to primarily impair inhibitory control in male progeny. These results further our understanding of the long-term costs and risk of opioid abuse, extending across generations.

Neurochemical substrates linked to impulsive and compulsive phenotypes in addiction: A preclinical perspective

Drug compulsion manifests in some but not all individuals and implicates multifaceted processes including failures in top-down cognitive control as drivers for the hazardous pursuit of drug use in some individuals. As a closely related construct, impulsivity encompasses rash or risky behaviour without foresight and underlies most forms of drug taking behaviour, including drug use during adverse emotional states (i.e., negative urgency). While impulsive behavioural dimensions emerge from drug-induced brain plasticity, burgeoning evidence suggests that impulsivity also predates the emergence of compulsive drug use. Although the neural substrates underlying the apparently causal relationship between trait impulsivity and drug compulsion are poorly understood, significant advances have come from the interrogation of defined limbic cortico-striatal circuits involved in motivated behaviour and response inhibition, together with chemical neuromodulatory influences from the ascending neurotransmitter systems. We review what is presently known about the neurochemical mediation of impulsivity, in its various forms, and ask whether commonalities exist in the neurochemistry of compulsive drug-motivated behaviours that might explain individual risk for addiction.

A unified online test battery for cognitive impulsivity reveals relationships with real-world impulsive behaviours

Impulsive behaviours are a major contributor to the global burden of disease, but existing measures of cognitive impulsivity have suboptimal reliability and validity. Here, we introduce the Cognitive Impulsivity Suite, comprising three computerized/online tasks using a gamified interface. We conceptualize rapid-response impulsive behaviours (disinhibition) as arising from the failure of three distinct cognitive mechanisms: attentional control, information gathering and monitoring/shifting. We demonstrate the construct and criterion validity of the Cognitive Impulsivity Suite in an online community sample (N = 1,056), show test-retest reliability and between-subjects variability in a face-to-face community sample (N = 63), and replicate the results in a community and clinical sample (N = 578). The results support the theoretical architecture of the attentional control, information gathering and monitoring/shifting constructs. The Cognitive Impulsivity Suite demonstrated incremental criterion validity for prediction of real-world, addiction-related problems and is a promising tool for large-scale research on cognitive impulsivity.

Resting State Functional Connectivity Associated With Sahaja Yoga Meditation

Neuroscience research has shown that meditation practices have effects on brain structure and function. However, few studies have combined information on the effects on structure and function in the same sample. Long-term daily meditation practice produces repeated activity of specific brain networks over years of practice, which may induce lasting structural and functional connectivity (FC) changes within relevant circuits. The aim of our study was therefore to identify differences in FC during the resting state between 23 Sahaja Yoga Meditation experts and 23 healthy participants without meditation experience. Seed-based FC analysis was performed departing from voxels that had shown structural differences between these same participants. The contrast of connectivity maps yielded that meditators showed increased FC between the left ventrolateral prefrontal cortex and the right dorsolateral prefrontal cortex but reduced FC between the left insula and the bilateral mid-cingulate as well as between the right angular gyrus and the bilateral precuneus/cuneus cortices. It thus appears that long-term meditation practice increases direct FC between ventral and dorsal frontal regions within brain networks related to attention and cognitive control and decreases FC between regions of these networks and areas of the default mode network.

Factors mediating pain-related risk for opioid use disorder

Pain is a complex experience with far-reaching organismal influences ranging from biological factors to those that are psychological and social. Such influences can serve as pain-related risk factors that represent susceptibilities to opioid use disorder. This review evaluates various pain-related risk factors to form a consensus on those that facilitate opioid abuse. Epidemiological findings represent a high degree of co-occurrence between chronic pain and opioid use disorder that is, in part, driven by an increase in the availability of opioid analgesics and the diversion of their use in a non-medical context. Brain imaging studies in individuals with chronic pain that use/abuse opioids suggest abuse-related mechanisms that are rooted within mesocorticolimbic processing. Preclinical studies suggest that pain states have a limited impact on increasing the rewarding effects of opioids. Indeed, many findings indicate a reduction in the rewarding and reinforcing effects of opioids during pain states. An increase in opioid use may be facilitated by an increase in the availability of opioids and a decrease in access to non-opioid reinforcers that require mobility or social interaction. Moreover, chronic pain and substance abuse conditions are known to impair cognitive function, resulting in deficits in attention and decision making that may promote opioid abuse. A better understanding of pain-related risk factors can improve our knowledge in the development of OUD in persons with pain conditions and can help identify appropriate treatment strategies. This article is part of the special issue on 'Vulnerabilities to Substance Abuse.'.