Inhibitory Control Deficits in Childhood and Risk for Substance Use Disorders: A Review

Alcohol sipping patterns, personality, and psychopathology in Children: Moderating effects of dorsal anterior cingulate cortex (dACC) activation

BACKGROUND

Alcohol, the most consumed drug in the United States, is associated with various psychological disorders and abnormal personality traits. Despite extensive research on adolescent alcohol consumption, the impact of early alcohol sipping patterns on changes in personality and mental health over time remains unclear. There is also limited information on the latent trajectory of early alcohol sipping, beginning as young as 9-10 years old. The dorsal anterior cingulate cortex (dACC) is crucial for cognitive control and response inhibition. However, the role of the dACC remains unclear in the relationship between early alcohol sipping and mental health outcomes and personality traits over time.

METHODS

Utilizing the large data from the Adolescent Brain Cognitive Development study (N = 11,686, 52% males, 52% white, mean [SD] age 119 [7.5] months, 9807 unique families, 22 sites), we aim to comprehensively examine the longitudinal impact of early alcohol sipping patterns on psychopathological measures and personality traits in adolescents, filling crucial gaps in the literature.

RESULTS

We identified three latent alcohol sipping groups, each demonstrating distinct personality traits and depression score trajectories. Bilateral dACC activation during the stop-signal task moderated the effect of early alcohol sipping on personality and depression over time. Additionally, bidirectional effects were observed between alcohol sipping and personality traits.

CONCLUSIONS

This study provides insights into the impact of early alcohol consumption on adolescent development. The key finding of our analysis is that poor response inhibition at baseline, along with increased alcohol sipping behaviors may accelerate the changes in personality traits and depression scores over time as individuals transition from childhood into adolescence.

Corticostriatal responses to social reward are linked to trait reward sensitivity and subclinical substance use in young adults

Aberrant levels of reward sensitivity have been linked to substance use disorder and are characterized by alterations in reward processing in the ventral striatum (VS). Less is known about how reward sensitivity and subclinical substance use relate to striatal function during social rewards (e.g. positive peer feedback). Testing this relation is critical for predicting risk for development of substance use disorder. In this pre-registered study, participants (N = 44) underwent fMRI while completing well-matched tasks that assess neural response to reward in social and monetary domains. Contrary to our hypotheses, aberrant reward sensitivity blunted the relationship between substance use and striatal activation during receipt of rewards, regardless of domain. Moreover, exploratory whole-brain analyses showed unique relations between substance use and social rewards in temporoparietal junction. Psychophysiological interactions demonstrated that aberrant reward sensitivity is associated with increased connectivity between the VS and ventromedial prefrontal cortex during social rewards. Finally, we found that substance use was associated with decreased connectivity between the VS and dorsomedial prefrontal cortex for social rewards, independent of reward sensitivity. These findings demonstrate nuanced relations between reward sensitivity and substance use, even among those without substance use disorder, and suggest altered reward-related engagement of cortico-VS responses as potential predictors of developing disordered behavior.

The influence of adverse childhood experiences and depression on addiction severity among methamphetamine users: exploring the role of perseveration

Aims

This investigation aimed to clarify the intricate relationship among depression, cognitive function, adverse childhood experiences (ACEs), and their combined influence on methamphetamine use disorder (MUD).

Methods

Utilizing a battery of psychological tests, this study ascertained the impact of ACEs on the condition of 76 people with MUD who meet the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, aged 42.17 on average. The Iowa Gambling Task (IGT), Conners' Continuous Performance-II (CPT-II), the self-report Severity of Dependence Scale (SDS), and the Beck Depression Inventory-II (BDI-II) were used for these evaluations. Individuals involved in the study were categorized into two discrete cohorts, mild (ME) and severe (SE), based on the extent of their ACEs exposure. This study employed the PROCESS regression, the independent t-test andχ2 tests for the analysis.

Results

The findings revealed notable discrepancies in the psychological consequences between the two groups with different degrees of ACEs; however, no substantial differences were observed in the demographic parameters. The SE group exhibited elevated BDI-II scores, more evident indications of MUD, and a higher degree of CPT-II cognitive perseveration. The PROCESS model revealed that cognitive perseveration moderated the impact of depression on ACEs and subjective MUD severity, explaining 20.2% of the variance. The ACEs and depression predicted 28.6% of the variance in MUD symptoms. However, no statistically significant differences were detected between the two groups regarding the parameters in the IGT-2 assessment.

Conclusions

These results indicate that the interaction between cognitive and depressive factors mediates the effect of ACEs on subjective MUD severity but not on MUD symptoms. The ACEs significant impact on mental health severity perception is explained by cognitive and depressive factors. This implies that MUD treatment and rehabilitation should address cognitive dysfunction and developmental trauma.

Distinct Constellations of Common Risk Factors Differentially Relate to Executive-Function Ability in Children

Executive functioning (EF) has been shown to relate to academic achievement and well-being. Independent bodies of work have aimed to understand what environmental or personal attributes influence EF ability. However, most research has not considered how constellations of risk factors create distinct patterns of influence on EF ability. The current study tested a sample of children aged 9 to 10 years from the United States (N = 10,323, 48.06% female, Mage = 9.9 years, age range = 8.9-11.08 years) using a latent profile analysis (LPA) to detect subgroups that varied in their combinations of various risk factors. Six distinct groups of risk factors for children emerged, which in turn related to different average EF abilities. We found that family socioeconomic measures related to a subgroup having above- or below-average EF ability, but we also found an effect on EF across different risk factors. These results inform our understanding of individual variations in EF ability and highlight the idea that EF interventions should consider risk holistically.

Corticostriatal Responses to Social Reward are Linked to Trait Reward Sensitivity and Subclinical Substance Use in Young Adults

Aberrant levels of reward sensitivity have been linked to substance use disorder and are characterized by alterations in reward processing in the ventral striatum (VS). Less is known about how reward sensitivity and subclinical substance use relate to striatal function during social rewards (e.g., positive peer feedback). Testing this relation is critical for predicting risk for development of substance use disorder. In this pre-registered study, participants (N=44) underwent fMRI while completing well-matched tasks that assess neural response to reward in social and monetary domains. Contrary to our hypotheses, aberrant reward sensitivity blunted the relationship between substance use and striatal activation during receipt of rewards, regardless of domain. Moreover, exploratory whole-brain analyses showed unique relations between substance use and social rewards in temporoparietal junction. Psychophysiological interactions demonstrated that aberrant reward sensitivity is associated with increased connectivity between the VS and ventromedial prefrontal cortex during social rewards. Finally, we found that substance use was associated with decreased connectivity between the VS and dorsomedial prefrontal cortex for social rewards, independent of reward sensitivity. These findings demonstrate nuanced relations between reward sensitivity and substance use, even among those without substance use disorder, and suggest altered reward-related engagement of cortico-VS responses as potential predictors of developing disordered behavior.

Effects of Stimulant Treatment on Changes in Brain Activation During Reward Notifications in Drug Naïve Youth With ADHD

BACKGROUND

Research examining the potential effects of stimulant exposure in childhood on subsequent development of substance use disorder (SUD) have focused on differences in the brain reward system as a function of risk.

METHODS

18 drug naïve children ages 7 to 12 years (11 High Risk [ADHD + ODD/CD]; 7 Low Risk [ADHD only]), underwent fMRI scans before and after treatment with mixed amphetamine salts, extended release (MAS-XR). We examined correlations between clinical ratings and fMRI activation at baseline and following treatment as a function of risk status.

RESULTS

High Risk children had higher activation than Low Risk children at baseline during both the Reward and Surprising Non-Reward conditions. Treatment produced strong differential effects on brain activation pertinent to group and reward outcome.

CONCLUSIONS

Findings support the hypothesized role of reward mechanisms in SUD risk, and suggest that stimulant treatment may have differential effects on reward processing in relation to SUD risk.

Aberrant functional connectivity between reward and inhibitory control networks in pre-adolescent binge eating disorder

BACKGROUND

Behavioral features of binge eating disorder (BED) suggest abnormalities in reward and inhibitory control. Studies of adult populations suggest functional abnormalities in reward and inhibitory control networks. Despite behavioral markers often developing in children, the neurobiology of pediatric BED remains unstudied.

METHODS

58 pre-adolescent children (aged 9-10-years) with BED (mBMI = 25.05; s.d. = 5.40) and 66 age, BMI and developmentally matched control children (mBMI = 25.78; s.d. = 0.33) were extracted from the 3.0 baseline (Year 0) release of the Adolescent Brain Cognitive Development (ABCD) Study. We investigated group differences in resting-state functional MRI functional connectivity (FC) within and between reward and inhibitory control networks. A seed-based approach was employed to assess nodes in the reward [orbitofrontal cortex (OFC), nucleus accumbens, amygdala] and inhibitory control [dorsolateral prefrontal cortex, anterior cingulate cortex (ACC)] networks via hypothesis-driven seed-to-seed analyses, and secondary seed-to-voxel analyses.

RESULTS

Findings revealed reduced FC between the dlPFC and amygdala, and between the ACC and OFC in pre-adolescent children with BED, relative to controls. These findings indicating aberrant connectivity between nodes of inhibitory control and reward networks were corroborated by the whole-brain FC analyses.

CONCLUSIONS

Early-onset BED may be characterized by diffuse abnormalities in the functional synergy between reward and cognitive control networks, without perturbations within reward and inhibitory control networks, respectively. The decreased capacity to regulate a reward-driven pursuit of hedonic foods, which is characteristic of BED, may in part, rest on this dysconnectivity between reward and inhibitory control networks.

Role of preexisting inhibitory control deficits vs. drug use history in mediating insensitivity to aversive consequences in a rat model of polysubstance use

RATIONALE

The nature and predictors of insensitivity to aversive consequences of heroin + cocaine polysubstance use are not well characterized.

OBJECTIVES

Translational methods incorporating a tightly controlled animal model of drug self-administration and measures of inhibitory control and avoidance behavior might be helpful for clarifying this issue.

METHODS

The key approach for distinguishing potential contributions of pre-existing inhibitory control deficits vs. drug use history in meditating insensitivity to aversive consequences was comparison of two rat strains: Wistar (WIS/Crl), an outbred strain, and the spontaneously hypertensive rat (SHR/NCrl), an inbred strain shown previously to exhibit heightened cocaine and heroin self-administration and poor inhibitory control relative to WIS/Crl.

RESULTS

In separate tasks, SHR/NCrl displayed greater impulsive action and compulsive-like behavior than WIS/Crl prior to drug exposure. Under two different schedules of drug delivery, SHR/NCrl self-administered more cocaine than WIS/Crl, but self-administered a similar amount of heroin + cocaine as WIS/Crl. When half the session cycles were punished by random foot shock, SHR/NCrl initially were less sensitive to punishment than WIS/Crl when self-administering cocaine, but were similarly insensitive to punishment when self-administering heroin + cocaine. Based on correlation analyses, only trait impulsivity predicted avoidance capacity in rats self-administering cocaine and receiving yoked-saline. In contrast, only amount of drug use predicted avoidance capacity in rats self-administering heroin + cocaine. Additionally, baseline drug seeking and taking predicted punishment insensitivity in rats self-administering cocaine or heroin + cocaine.

CONCLUSIONS

Based on the findings revealed in this animal model, human laboratory research concerning the nature and predictors of insensitivity to aversive consequences in heroin and cocaine polysubstance vs. monosubstance users is warranted.

Sensitization-based risk for substance abuse in vulnerable individuals with ADHD: Review and re-examination of evidence

Evidence of sensitization following stimulants administration in humans is just emerging, which prevents reaching more definitive conclusions in favor or against a purported protective role of stimulant treatments for ADHD for the development of substance use disorders. Existing evidence from both animal and human research suggest that stimulants produce neurophysiological changes in the brain reward system, some of which could be persistent. This could be relevant in choosing optimal treatments for young patients with ADHD who have additional clinical risk factors for substance abuse (e.g. conduct disorder (CD) and/or familial addictions). Here we stipulate that, while the majority of youth with ADHD greatly benefit from treatments with stimulants, there might be a subpopulation of individuals whose neurobiological profiles may confer risk for heightened vulnerability to the effects of stimulants on the responsiveness of the brain reward system. We propose that focused human research is needed to elucidate the unknown effects of prolonged stimulant exposure on the neurophysiology of the brain reward system in young patients with ADHD.

Persistent Deficits in Self-Regulation as a Mediator between Childhood Attention-Deficit/Hyperactivity Disorder Symptoms and Substance Use Disorders

The link between attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUDs) has been largely demonstrated. Some scholars have hypothesized that self-regulation mechanisms might play a key role in explaining this association. Objective(s): The current study tested the hypothesis that retrospective childhood ADHD symptoms might lead to more severe SUDs and this association should be mediated by current self-ratings of behavioral disinhibition, inattention, and emotional dysregulation among 204 treatment-seeking adults (male: 67.3%; female: 32.7%) with a primary diagnosis of alcohol use disorder and other SUDs. Methods: The mediational model was estimated through self-report measures of childhood ADHD symptoms (independent variable; WURS), current self-regulation mechanisms (mediators)-behavioral disinhibition (BIS-11 motor subscale), difficulties with attention regulation (MAAS) and emotion regulation (DERS)-and severity of SUDs (dependent variable; SPQ alcohol, illicit and prescribed drugs). Results: The analysis showed that alterations in the self-regulation system fully mediated the association between the severity of childhood ADHD symptoms and SUDs in adulthood. Behavioral disinhibition and difficulties in attention regulation were the most representative alterations in self-regulation processes that explained this association. Conclusions: These findings suggest it is useful to implement several therapeutic approaches (e.g. behavioral, mindfulness-based, and pharmacological) to increase the self-regulation abilities of children and adolescents with ADHD in order to reduce the probability of SUD onset in adulthood. However, future longitudinal neuroimaging and neuropsychological studies are needed to further support the role of self-regulation mechanisms in explaining the prospective association between childhood ADHD symptoms and SUDs in adulthood.

Does being overweight play a role in the reduced inhibitory control of patients receiving treatment for substance use disorder?

BACKGROUND

Impaired inhibitory control is present in individuals with substance use disorder (SUD) and in those with obesity. However, the question as to whether patients with SUD who are either overweight or obese have impaired inhibitory control, relative to patients with SUD and normal weight, remains unanswered.

METHODS

Sixty-two adult men (mean age: 31.17±8.79) under treatment for SUD performed a general and drug-specific inhibitory control test (GoNogo). Participants were divided in two groups based on their BMI. Patients with a BMI higher or equal than ≥25 kg/m² were in the overweight and obese group (OB), and patients with a BMI lower than 25 kg/m² were in the normal weight group (NW). Analyses of covariance (ANCOVA) were performed to explore differences in drug-specific and general commission errors, as well as reaction time for go trials during both drug-specific and general inhibition tasks. Models were adjusted for anxiety, depression, age, and duration of drug use.

RESULTS

No differences were found for commission errors in both tasks. With regards to reaction time, no differences were found for the general inhibitory control paradigm, whereas the OB group demonstrated slower reaction time during the drug specific paradigm, relative to the NW group (p=0.03, f² = 0.09; OB: 520.65±71.39 ms vs. NW: 486.07±51.75 ms).

CONCLUSION

Our findings suggest that those undergoing treatment for SUD and are either overweight or obese present impaired inhibitory control when facing drug cues. Future research should explore the effects of physical activity, nutritional counseling, and food monitoring on inhibitory control outcomes in SUD rehabilitation.

Genetic underpinnings of risky behaviour relate to altered neuroanatomy

Previous research points to the heritability of risk-taking behaviour. However, evidence on how genetic dispositions are translated into risky behaviour is scarce. Here, we report a genetically informed neuroimaging study of real-world risky behaviour across the domains of drinking, smoking, driving and sexual behaviour in a European sample from the UK Biobank (N = 12,675). We find negative associations between risky behaviour and grey-matter volume in distinct brain regions, including amygdala, ventral striatum, hypothalamus and dorsolateral prefrontal cortex (dlPFC). These effects are replicated in an independent sample recruited from the same population (N = 13,004). Polygenic risk scores for risky behaviour, derived from a genome-wide association study in an independent sample (N = 297,025), are inversely associated with grey-matter volume in dlPFC, putamen and hypothalamus. This relation mediates roughly 2.2% of the association between genes and behaviour. Our results highlight distinct heritable neuroanatomical features as manifestations of the genetic propensity for risk taking.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): II. Externalizing superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical effort to address limitations of traditional mental disorder diagnoses. These include arbitrary boundaries between disorder and normality, disorder co-occurrence in the modal case, heterogeneity of presentation within dis-orders, and instability of diagnosis within patients. This paper reviews the evidence on the validity and utility of the disinhibited externalizing and antagonistic externalizing spectra of HiTOP, which together constitute a broad externalizing superspectrum. These spectra are composed of elements subsumed within a variety of mental disorders described in recent DSM nosologies, including most notably substance use disorders and "Cluster B" personality disorders. The externalizing superspectrum ranges from normative levels of impulse control and self-assertion, to maladaptive disinhibition and antagonism, to extensive polysubstance involvement and personality psychopathology. A rich literature supports the validity of the externalizing superspectrum, and the disinhibited and antagonistic spectra. This evidence encompasses common genetic influences, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, and treatment response. The structure of these validators mirrors the structure of the phenotypic externalizing superspectrum, with some correlates more specific to disinhibited or antagonistic spectra, and others relevant to the entire externalizing superspectrum, underlining the hierarchical structure of the domain. Compared with traditional diagnostic categories, the externalizing superspectrum conceptualization shows improved utility, reliability, explanatory capacity, and clinical applicability. The externalizing superspectrum is one aspect of the general approach to psychopathology offered by HiTOP and can make diagnostic classification more useful in both research and the clinic.

Delay discounting and neurocognitive correlates among inner city adolescents with and without family history of substance use disorder

Adolescents with a family history (FH+) of substance use disorder (SUD) are at a greater risk for SUD, suggested to be partly due to the transmission of behavioral impulsivity. We used a delay discounting task to compare impulsivity in decision-making and its associated brain functioning among FH+ and FH - minority adolescents. Participants chose between Smaller Sooner (SS) and Larger Later (LL) rewards. The SS was available immediately (Now trials) or in the future (Not-Now trials), allowing for greater differentiation between impulsive decisions. The FH+ group showed greater impatience by responding SS more frequently than the FH - group, only on the Now trials, and even when the relative reward differences (RRD) increased. Surprisingly, there were no differences in brain activity between the groups. Combined, the groups showed greater reward activity during the Now vs. Not-Now trials in medial prefrontal/anterior cingulate, posterior cingulate, precuneus, and inferior frontal gyrus (i.e., an immediacy effect). As the RRD increased activation in the reward network decreased, including the striatum, possibly reflecting easy decision-making. These results indicate that risk for SUD, seen behaviorally among FH+ adolescents, may not yet be associated with discernable brain changes, suggesting that early intervention has the potential to reduce this risk.

BOLD responses to inhibition in cannabis-using adolescents and emerging adults after 2 weeks of monitored cannabis abstinence

RATIONALE

Previous studies have suggested that chronic cannabis use has been associated with increased blood oxygen level-dependent (BOLD) response during a response inhibition task; however, these studies primarily included males.

OBJECTIVES

We investigated whether gender moderated the effects of cannabis use on BOLD response and behavioral performance during a Go-NoGo task in adolescents and young adults following 2 weeks of monitored abstinence.

METHODS

Participants included 77 16-26-year olds (MJ = 36, controls = 41). An emotion-based Go-NoGo task required participants to inhibit their response during a calm face. A whole-brain analysis looked at differences between cannabis group, gender, and their interaction.

RESULTS

Significant greater BOLD responses were observed in cannabis users compared with that in controls in the left frontal cortex, left cingulate cortex, and the left thalamus during correct response inhibitions; gender did not moderate these effects.

CONCLUSION

Supporting previous research, cannabis users showed greater BOLD responses in core areas associated with response inhibition during a Go-NoGo task, even after a minimum of 2 weeks of abstinence.

Neurocognitive predictors of treatment completion and daytime activities at follow-up in multiproblem young adults

Previous research has shown an association between cognitive control deficits and problematic behavior such as antisocial behavior and substance use, but little is known about the predictive value of cognitive control for treatment outcome. The current study tests whether selected markers of baseline cognitive control predict (1) treatment completion of a day treatment program involving a combination of approaches for multiproblem young adults and (2) daytime activities a year after the start of treatment, over and above psychological, social, and criminal characteristics. We assessed individual, neurobiological, and neurobehavioral measures, including functional brain activity during an inhibition task and two electroencephalographic measures of error processing in 127 male multiproblem young adults (age 18-27 years). We performed two hierarchical regression models to test the predictive power of cognitive control for treatment completion and daytime activities at follow-up. The overall models did not significantly predict treatment completion or daytime activities at follow-up. However, activity in the anterior cingulate cortex (ACC) during response inhibition, years of regular alcohol use, internalizing problems, and ethnicity were all significant individual predictors of daytime activity at follow-up. In conclusion, cognitive control could not predict treatment completion or daytime activities a year after the start of treatment over and above individual characteristics. However, results indicate a direct association between brain activity during response inhibition and participation in daytime activities, such as work or school, after treatment. As adequate baseline inhibitory control is associated with a positive outcome at follow-up, this suggests interventions targeting cognitive control might result in better outcomes at follow-up.

Higher Risk Taking and Impaired Probability Judgment in Behavioral Addiction

BACKGROUND

Accumulating evidence suggests that deficits in decision-making and judgment may be involved in several psychiatric disorders, including addiction. Behavioral addiction is a conceptually new psychiatric condition, raising a debate of what criteria define behavioral addiction, and several impulse control disorders are equivalently considered as types of behavioral addiction. In this preliminary study with a relatively small sample size, we investigated how decision-making and judgment were compromised in behavioral addiction to further characterize this psychiatric condition.

METHOD

Healthy control subjects (n = 31) and patients with kleptomania and paraphilia as behavioral addictions (n = 16) were recruited. A battery of questionnaires for assessments of cognitive biases and economic decision-making were conducted, as was a psychological test for the assessment of the jumping-to-conclusions bias, using functional near-infrared spectroscopy recordings of prefrontal cortical (PFC) activity.

RESULTS

Although behavioral addicts exhibited stronger cognitive biases than controls in the questionnaire, the difference was primarily due to lower intelligence in the patients. Behavioral addicts also exhibited higher risk taking and worse performance in economic decision-making, indicating compromised probability judgment, along with diminished PFC activity in the right hemisphere.

CONCLUSION

Our study suggests that behavioral addiction may involve impairments of probability judgment associated with attenuated PFC activity, which consequently leads to higher risk taking in decision-making.

Effects of short-term mindfulness-based training on executive function: Divergent but promising

Mindfulness-based training (MBT) has repeatedly been proven effective in improving mental health, as well as in eliciting advantages in executive functions (EFs), as demonstrated by objective measures. However, few studies have discussed the role MBT plays in increasing EFs over short periods of time. This current review, to our knowledge, is the first study to investigate the effect of short-term MBT on EFs. In this case, 14 studies were eventually included after literature screening using PubMed, MEDLINE, Elsevier, Embase, EBSCO and references from retrieved articles. We found that the relationship between short-term MBT and three main components of EFs were found controversial. Some reported that individuals' inhibition, working memory and attention shifting were significantly improved by short-term MBT, whereas others reported no such strong connections between MBT and EFs. These controversial findings result from the use of varied assessment instruments, cognitive tasks and experimental materials. Nonetheless, the findings from this review suggest short-term MBT could be of great value in improving mental health, which might especially enable the enhancement of individuals' inhibition and updating subfunctions of EFs. These practical evidences could have a strong impact on clinical psychology. However, the lack of consistency across the studies in this review indicated that more standardized and profound studies exploring the effects of short-term MBT on EFs are needed in the future.

Can transcranial direct current stimulation (tDCS) improve impulsivity in healthy and psychiatric adult populations? A systematic review

Impulsivity is a multidimensional phenomenon that remains hard to define. It compounds the core pathological construct of many neuropsychiatric illnesses, and despite its close relation to suicide risk, it currently has no specific treatment. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique whose application results in cognitive function improvement, both in healthy and psychiatric populations. Following PRISMA recommendations, a systematic review of the literature concerning tDCS's effects on impulsive behaviour was performed using the PubMed database. The research was based on the combination of the keyword 'tDCS' with 'impulsivity', 'response inhibition', 'risk-taking', 'planning', 'delay discounting' or 'craving'. The initial search yielded 309 articles, 92 of which were included. Seventy-four papers demonstrated improvement in task performance related to impulsivity in both healthy and clinical adult populations. However, results were often inconsistent. The conditions associated with improvement, such as tDCS parameters and other aspects that may influence tDCS's outcomes, are discussed. The overall effects of tDCS on impulsivity are promising. Yet further research is required to develop a more comprehensive understanding of impulsivity, allowing for a more accurate assessment of its behavioural outcomes as well as a definition of tDCS therapeutic protocols for impulsive disorders.

Reward Processing in Drug-Naive Youth with Various Levels of Risk for Substance Use Disorders: A Pilot Study

Background: It has been hypothesized that attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUDs) share common neurobiological features. When abnormalities in the mesolimbic reward system are characteristic of children with ADHD, it is unclear whether youth at particularly elevated risk for SUD may exhibit any further disturbances. The objective of this pilot study is to examine possible neurobiological differences among youth with different levels of SUD risk before exposure to any abusable substances. Methods: We recruited 47 drug-naive children aged 8-13 divided into (1) Low Risk (LR)-ADHD only (n = 16); (2) High Risk (HR)-ADHD+familial SUD (n = 17); and (3) healthy controls (HC, n = 14) who underwent one functional magnetic resonance imaging scan while performing a hybrid task. We used the omnibus analysis of covariance model to assess for group differences in brain activation in regions linked to the brain reward and behavioral control systems. Results: Behavioral analysis showed significant Cue and Flanker main effects, but no significant main effect for Group. Whole-brain analysis showed significant differences in widely distributed networks related to both reward processing and behavioral control. Region of interest (ROI) activations showed that the HR group had the highest activation in the right putamen during both expected rewards and unexpected nonreward outcomes and in the anterior cingulate cortex (ACC) during unexpected nonreward outcomes, while LR and HC youth showed similarly low activation during these contrasts. Furthermore, the LR and HR groups showed lower activation than HC in the right ACC and the right caudate during flanker contrasts. Conclusions: These are the first preliminary results to demonstrate that the magnitude of activation during reward notification differs as a function of reward outcome in youth at high versus LR for SUD, such that youth at LR for SUD exhibit the highest activation for positive rewards, whereas those at HR for SUD exhibit the highest activation during negative rewards.

A developmental cascade model for early adolescent-onset substance use: the role of early childhood stress

BACKGROUNDS AND AIMS

Despite the link between stress and addictive behavior in adulthood, little is known about how early life stress in families predicts the early emergence of substance use in adolescence. This study tested a developmental cascade model, proposing that early stressful life events and negative parent-child interaction covary, and both disrupt the refinement of inhibitory control, which evolves into problem behavior in middle/late childhood and subsequent substance use exploration in early adolescence.

METHODS

Data came from the Early Steps Multisite study, a community sample of at-risk families in the metropolitan US areas of Pittsburgh (Pennsylvania), Eugene (Oregon) and Charlottesville (Virginia) with children aged 2 years at the start of the study and 14 years at the last measurement (n = 364). Structural equation modeling was used to test the proposed model.

RESULTS

Early stressful life events and negative parent-child interaction assessed at ages 2-5 were negatively related to inhibitory control at ages 7 and 8. Low levels of inhibitory control were prognostic of childhood problem behavior at ages 9 and 10. Finally, late childhood problem behavior was associated with substance use at age 14. Parental drug use was directly related to substance use at age 14.

CONCLUSIONS

Early life stress may disrupt child inhibitory control, which can cascade into behavioral and peer problem behavior in childhood and, in turn, heighten the risk for early adolescent substance use.

The neurobiology of impulsivity and substance use disorders: implications for treatment

Impulsivity is strongly associated with substance use disorders (SUDs). Our review discusses impulsivity as an underlying vulnerability marker for SUDs, and treatment of co-occurring impulsivity in SUDs. Three factors should be considered for the complex relationship between impulsivity and a SUD: (1) the trait effect of impulsivity, centering on decreased cognitive and response inhibition, (2) the state effect resulting from either acute or chronic substance use on brain structure and function, and (3) the genetic and environmental factors (e.g., age and sex) may influence impulsive behavior associated with SUDs. Both subjective and objective measures are used to assess impulsivity. Together, treatment developments (pharmacological, behavioral, and neurophysiological) should consider these clinically relevant dimensions assessed by a variety of measures, which have implications for treatment matching in individuals with SUD. Despite its heterogeneity, impulsivity is a marker associated with SUDs and may be understood as an imbalance of bottom-up and top-down neural systems. Further investigation of these relationships may lead to more effective SUD treatments.

Tobacco and cannabis use in college students are predicted by sex-dimorphic interactions between MAOA genotype and child abuse

BACKGROUND

Postsecondary students in Western countries exhibit a high prevalence of cannabis and tobacco use disorders. The etiology of these problems is contributed by several psychosocial factors, including childhood adversity and trauma; however, the mechanisms whereby these environmental determinants predispose to the use of these substances remain elusive, due to our poor knowledge of genetic and biological moderators. Converging evidence points to the monoamine oxidase A (MAOA) gene as a moderator of the effects of lifetime stress on the initiation of substance use.

AIMS

Building on these premises, in this study, we analyzed whether MAOA upstream variable number tandem repeat (uVNTR) alleles interact with child maltreatment history to predict for lifetime cannabis and tobacco consumption.

MATERIALS AND METHODS

Five hundred college students (age: 18-25 years) from a large Midwestern University were surveyed for their child maltreatment history (encompassing emotional, physical, and sexual abuse, as well as emotional and physical neglect) and lifetime consumption of cannabis and tobacco. Saliva samples were obtained to determine the MAOA uVNTR genotype of each participant.

RESULTS

In female students, lifetime tobacco and cannabis use was predicted by the interaction of physical and emotional abuse with high-activity MAOA allelic variants; conversely, in males, the interaction of low-activity MAOA alleles and physical abuse was associated with lifetime use of tobacco, but not cannabis.

DISCUSSION

These findings collectively suggest that the vulnerability to smoke tobacco and cannabis is predicted by sex-dimorphic interactions of MAOA gene with childhood abuse.

CONCLUSION

These biosocial underpinnings of tobacco and cannabis use may prove important in the development of novel personalized preventive strategies for substance use disorders in adolescents.

Cognitive control in young adults with cannabis use disorder: An event-related brain potential study

Contemporary models of substance use disorders emphasize the role of cognitive control, which has been linked to difficulties in resisting the use of substances. In the present study, we measured two aspects of cognitive control, response inhibition (operationalized by a Go/NoGo Task) and performance monitoring (operationalized by an Eriksen Flanker Task), in a group of young cannabis-use disorder (CUD) patients and compared these functions with two control groups (i.e. a group of cigarette smokers and a group of non-smokers). We employed both behavioural and electrophysiological measures. The results indicate that CUD patients displayed reduced NoGo-P3 event-related potentials compared with non-smoking controls, but not compared with smoking controls. In addition, CUD patients were slower on Go trials than both control groups. No other between-group electrophysiological or behavioural differences were observed. These results seem to suggest that CUD patients have problems related to response inhibition, but performance monitoring seems relatively unaffected.

Increased self-reported impulsivity in methamphetamine users maintaining drug abstinence

BACKGROUND

Impulsivity has been proposed as an important factor in the initiation and maintenance of addiction. Indirect evidence suggests that some methamphetamine users report less impulsivity when they are using methamphetamine compared to when abstaining from drug use, but this hypothesis has not been directly tested.

OBJECTIVES/METHODS

In this study, self-reports of impulsivity were obtained from 32 methamphetamine-dependent (DSM-IV) research participants and 41 healthy control subjects, using the Barratt Impulsiveness Scale-11. The methamphetamine users were assessed during an active period of methamphetamine use, as determined through urinalysis, and again after approximately 1 week of confirmed abstinence. Control subjects likewise completed two assessments. A subset of participants also completed serial assessments of the Beck Depression Inventory (Methamphetamine Group, N = 17, Control Group, N = 38) and the Methamphetamine Withdrawal Questionnaire (Methamphetamine Group, N = 12).

RESULTS

There was a significant interaction of group with time on impulsivity (p = 0.044), reflecting a significant increase from the first to the second assessment in the methamphetamine users (p = 0.013), but no change among healthy control subjects. In contrast, depressive and withdrawal symptoms significantly decreased between the first and second assessments in the methamphetamine users (ps ≤0.01). Change in impulsivity in methamphetamine users was not significantly correlated with change in withdrawal or depression (ps >0.05).

CONCLUSIONS

These findings suggest that methamphetamine users report more impulsivity when abstaining from drug use, an effect that is not significantly related to methamphetamine withdrawal. Attenuation of impulsivity may reinforce continued methamphetamine use in these individuals.

Social Self-Control Is a Statistically Nonredundant Correlate of Adolescent Substance Use

The social self-control scale (SSCS), which taps provocative behavior in social situations, was compared with five potentially overlapping measures (i.e., temperament-related impulsivity, psychomotor agitation-related self-control, perceived social competence, and rash action in response to negative and positive affectively charged states) as correlates of tobacco use and other drug use among a sample of 3,356 ninth-grade youth in Southern California high schools. While there was a lot of shared variance among the measures, the SSCS was incrementally associated with both categories of drug use over and above alternate constructs previously implicated in adolescent drug use. Hence, SSC may relate to adolescent drug use through an etiological pathway unique from other risk constructs. Given that youth who tend to alienate others through provocative social behavior are at risk for multiple drug use, prevention programming to modify low SSC may be warranted.

Impulsivity, Stimulant Abuse, and Dopamine Receptor Signaling

The nonmedical use of amphetamine-type stimulants is a worldwide problem, with substantial medical and social consequences. Nonetheless, the identification of a pharmacological treatment for amphetamine use disorder remains elusive. Stimulant users exhibit neurochemical evidence of dopamine-system dysfunction as well as impulsive behaviors that may interfere with the success of treatments for their addiction. This review focuses on the potential role of dopaminergic neurotransmission in impulsivity, both in healthy individuals and chronic stimulant users who meet criteria for methamphetamine dependence. Presented are findings related to the potential contributions of signaling through dopamine D1- and D2-type receptors to self-control impulsivity in methamphetamine- dependent users. The information available points to signaling through striatal D2-type dopamine receptors as a potential therapeutic target for stimulant use disorders, but medications that target D2-type dopamine receptors have not been successful in treating stimulant-use disorders, possibly because D2-type receptors are downregulated. Other means to augment D2-type receptor signaling are therefore under consideration, and one promising approach is the addition of exercise training as an adjunct to behavioral treatment for addiction.

Separating the Association Between Inhibitory Control and Substance Use Prevalence Versus Quantity During Adolescence: A Hurdle Mixed-Effects Model Approach

BACKGROUND

Inhibitory control is a critical component to the self-regulation of affect and behavior. Research consistently demonstrates negative associations between inhibitory control and several problem behaviors including substance misuse during early adolescence. However, analytic approaches previously used have often applied ordinary least squares (OLS) regression to non-normal count data with an excessive number of zeros (i.e., never users), violating several model assumptions. Further, OLS regression fails to model effects of the independent variable, separately, for both prevalence and quantity of use.

OBJECTIVE

The study objective was to simultaneously model associations between inhibitory control and both past 30-day prevalence and amount of cigarette and marijuana use. It was hypothesized that when doing so, inhibitory control would be significantly associated with prevalence, but not quantity of use.

METHOD

Hurdle Mixed-effects Models (HMM) were used for hypothesis testing on data collected from 3,383, 9th grade adolescents (M(age) = 14.08 years).

RESULTS

Results confirmed hypotheses, demonstrating that although significant bivariate associations between inhibitory control and quantity of cigarette and marijuana use existed, HMM analyses established that the associations were more precisely specific to past 30-day prevalence, and not quantity of use.

CONCLUSION

Results from a HMM approach contribute to a more comprehensive and nuanced understanding of which characteristics of cigarette and marijuana use are associated with inhibitory control during early adolescence.

Fronto-striatal circuits in response-inhibition: Relevance to addiction

Disruptions to inhibitory control are believed to contribute to multiple aspects of drug abuse, from preexisting vulnerability in at-risk individuals, through escalation to dependence, to promotion of relapse in chronic users. Paradigms investigating the suppression of actions have been investigated in animal and human research on drug addiction. Rodent research has focused largely on impulsive behaviors, often gauged by premature responding, as a viable model highlighting the relevant role of dopamine and other neurotransmitters primarily in the striatum. Human research on action inhibition in stimulant dependence has highlighted impaired performance and largely prefrontal cortical abnormalities as part of a broader pattern of cognitive abnormalities. Animal and human research implicate inhibitory difficulties mediated by fronto-striatal circuitry both preceding and as a result of excessive stimulus use. In this regard, response-inhibition has proven a useful cognitive function to gauge the integrity of fronto-striatal systems and their role in contributing to impulsive and compulsive features of drug dependence.

Disruptive behavior disorders and indicators of disinhibition in adolescents: The BRIEF-SR, anti-saccade task, and D-KEFS color-word interference test

Disinhibition contributes to the development of disruptive behavior disorders (DBD) in adolescents. Self-reports and behavioral tasks are commonly used to assess disinhibition, each with their unique strengths and limitations. Accordingly, it is important to identify which measure, or combination thereof, is the most effective in predicting DBD symptoms. This study assessed the relationship between DBD (symptoms of ADHD/ODD/CD) and two behavioral disinhibition tasks: the anti-saccade task and the D-KEFS color-word interference test, as well as a self-report measure (the BRIEF-SR). The results indicated that the BRIEF-Inhibit scale accounted for the majority of the variance in the DBD sum score. The anti-saccade task and color-word interference test were also significantly associated with an increase in the number of DBD symptoms endorsed. These behavioral tasks accounted for 9% additional variance than the self-report alone. Therefore, combining self-report measures with behavioral disinhibition tasks may provide the most thorough assessment of adolescent DBD.

Early developmental, temperamental and educational problems in 'substance use disorder' patients with and without ADHD. Does ADHD make a difference?

Introduction

The prevalence of ADHD among patients with substance use disorder (SUD) is substantial. This study addressed the following research questions: Are early developmental, temperamental and educational problems overrepresented among SUD patients with ADHD compared to SUD patients without ADHD? Do this comorbid group receive early help for their ADHD, and are there signs of self-medicating with illicit central stimulants?

Method

An international, multi-centre cross-sectional study was carried out involving seven European countries, with 1205 patients in treatment for SUD. The mean age was 40 years and 27% of the sample was female. All participants were interviewed with the Mini International Neuropsychiatric Interview Plus and the Conners' Adult ADHD Diagnostic Interview for DSM-IV.

Results

SUD patients with ADHD (n = 196; 16.3% of the total sample) had a significantly slower infant development than SUD patients without ADHD (n = 1,009; 83.4%), had greater problems controlling their temperament, and had lower educational attainment. Only 24 (12%) of the current ADHD positive patients had been diagnosed and treated during childhood and/or adolescence. Finally, SUD patients with ADHD were more likely to have central stimulants or cannabis as their primary substance of abuse, whereas alcohol use was more likely to be the primary substance of abuse in SUD patients without ADHD.

Conclusion

The results emphasize the importance of early identification of ADHD and targeted interventions in the health and school system, as well as in the addiction field.

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SUD patients with ADHD had a significantly slower infant development than SUD patients without ADHD.

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Furthermore, the former group had greater problems controlling their temperament, and had lower educational attainment.

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Only 12% of the current SUD and ADHD patients had been diagnosed and treated during childhood and/or adolescence.

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They were more likely to have stimulants or cannabis as their main substance, suggesting some form of self-medication.

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Early identification of ADHD is important, as well as adequate treatment of this comorbid patient group.

Topiramate impairs cognitive function in methadone-maintained individuals with concurrent cocaine dependence

Topiramate is being investigated as a potential pharmacotherapy for the treatment of addictive disorders. However, its cognitive side effects raise concerns about its use, especially in populations with cognitive impairment, such as persons with chronic substance use disorders. This study investigated topiramate's cognitive effects in individuals dually dependent on cocaine and opioids as part of a double-blind, randomized, controlled trial of topiramate for cocaine dependence treatment. After 5 weeks of stabilization on daily oral methadone (M = 96 mg), participants were randomized to topiramate (n = 18) or placebo (n = 22). Cognitive testing took place at 2 time points: study weeks 4 through 5 to assess baseline performance and 10 to 13 weeks later to assess performance during stable dosing (300 mg topiramate or placebo). All participants were maintained on methadone at both testing times, and testing occurred 2 hours after the daily methadone plus topiramate/placebo administration. The topiramate and placebo groups did not differ on sex, level of education, premorbid intelligence, methadone dose, or illicit drug use. Topiramate slowed psychomotor and information processing speed, worsened divided attention, reduced n-back working memory accuracy, and increased the false alarm rate in recognition memory. Topiramate had no effects on visual processing, other measures of psychomotor function, risk-taking, self-control, Sternberg working memory, free recall, and metamemory. These findings indicate that topiramate may cause cognitive impairment in this population. This effect may limit its acceptability and use as a treatment in individuals with chronic opioid and cocaine use disorders, among whom preexisting cognitive impairments are common. (PsycINFO Database Record

The role of language ability and self-regulation in the development of inattentive-hyperactive behavior problems

Previous research has found associations but not established mechanisms of developmental linkage between language ability and inattentive-hyperactive (I-H) behavior problems. The present study examined whether self-regulation mediates the effect of language ability on later I-H behavior problems among young children (N = 120) assessed at 30, 36, and 42 months of age. Cross-lagged panel models tested the direction of effect between language ability and self-regulation and longitudinal effects of language ability on later I-H problems mediated by self-regulation. Language ability was measured by children's scores on the receptive and expressive language subtests of the Differential Ability Scales. Self-regulation was measured by three behavioral tasks requiring inhibitory control. I-H problems were reported by parents and secondary caregivers. Language ability predicted later self-regulation as measured by all three tasks. There was no association, however, between self-regulation and later language ability, suggesting that the direction of effect was stronger from language ability to later self-regulation. Moreover, the effect of language ability on later I-H behavior problems was mediated by children's self-regulation in one of the tasks (for secondary caregivers' but not parents' ratings). Findings suggest that language deficits may explain later I-H behavior problems via their prediction of poorer self-regulatory skills.

Are boys more sensitive to sensitivity? Parenting and executive function in preschoolers

During early childhood, girls outperform boys on key dimensions of cognitive functions, including inhibitory control, sustained attention, and working memory. The role of parenting in these sex differences is unknown despite evidence that boys are more sensitive to the effects of the early environment. In this study, we measured parental sensitivity at 14 and 36 months of age, and children's cognitive and executive functions (sustained attention, inhibitory control, and forward/backward memory) at 52 months of age, in a longitudinal cohort (N=752). Boys scored significantly lower than girls on inhibitory control (more Go/NoGo "commission errors") and short-term memory (forward color recall task), but boys did not differ from girls on attention (Go/NoGo "omission errors") or working memory (backward color recall task). In stratified analyses, parental sensitivity at 36 months of age was negatively associated with number of errors of commission (p=.05) and omission (p=.02) in boys, whereas child's age was the only significant predictor of commission and omission errors in girls. A combined analysis of both sexes confirmed an interaction between sex and parenting for omission errors (p=.03). The results indicate that sex differences in cognitive functions are evident in preschoolers, although not across all dimensions we assessed. Boys appear to be more vulnerable to early parenting effects, but only in association with omission errors (attention) and not with the other cognitive function dimensions.

The neuroscience of free will: implications for psychiatry

Belief in free will has been a mainstay in philosophy throughout history, grounded in large part in our intuitive sense that we consciously control our actions and could have done otherwise. However, psychology and psychiatry have long sought to uncover mechanistic explanations for human behavior that challenge the notion of free will. In recent years, neuroscientific discoveries have produced a model of volitional behavior that is at odds with the notion of contra-causal free will and our sense of conscious agency. Volitional behavior instead appears to have antecedents in unconscious brain activity that is localizable to specific neuroanatomical structures. Updating notions of free will in favor of a continuous model of volitional self-control provides a useful paradigm to conceptualize and study some forms of psychopathology such as addiction and impulse control disorders. Similarly, thinking of specific symptoms of schizophrenia as disorders of agency may help to elucidate mechanisms of psychosis. Beyond clinical understanding and etiological research, a neuroscientific model of volitional behavior has the potential to modernize forensic notions of responsibility and criminal punishment in order to inform public policy. Ultimately, moving away from the language of free will towards the language of volitional control may result in an enhanced understanding of the very nature of ourselves.

Experimentation versus progression in adolescent drug use: A test of an emerging neurobehavioral imbalance model

Based on an emerging neuroscience model of addiction, this study examines how an imbalance between two neurobehavioral systems (reward motivation and executive control) can distinguish between early adolescent progressive drug use and mere experimentation with drugs. Data from four annual assessments of a community cohort (N = 382) of 11- to 13-year-olds were analyzed to model heterogeneity in patterns of early drug use. Baseline assessments of working memory (an indicator of the functional integrity of the executive control system) and three dimensions of impulsivity (characterizing the balance between reward seeking and executive control systems) were used to predict heterogeneous latent classes of drug use trajectories from early to midadolescence. Findings revealed that an imbalance resulting from weak executive control and heightened reward seeking was predictive of early progression in drug use, while heightened reward seeking balanced by a strong control system was predictive of occasional experimentation only. Implications of these results are discussed in terms of preventive interventions that can target underlying weaknesses in executive control during younger years, and potentially enable at-risk adolescents to exercise greater self-restraint in the context of rewarding drug-related cues.

Adult attention-deficit/hyperactivity disorder and nicotine use: a qualitative study of patient perceptions

BACKGROUND

Adult Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with high rates of comorbid substance use disorders, and cigarette smoking has a particularly high prevalence in this population. However, there is an ongoing debate as to whether this tobacco use is an attempt at "self-medication" or due to behavioral disinhibition. There is a surprising lack of qualitative studies that investigate the subjective perceptions of adults with ADHD regarding cigarette smoking. The present study was designed to fill this gap in the literature.

METHODS

We recruited twelve adult patients with ADHD and comorbid tobacco use from our ADHD consultation service, an outpatient facility of the Zurich University Psychiatric Hospital. Subjects were interviewed using qualitative methodology, and Mayring's qualitative content analysis was used to evaluate findings.

RESULTS

We identified two explanatory models linking ADHD and tobacco use: smoking as an attempt at self-medication and "smoking as a social behavior". On one hand, subjects considered tobacco a therapeutic aid, reporting positive effects on "inner tension" and cognitive function, and noted possible antidepressant properties as well. On the other hand, subjects considered smoking to enhance social functioning and to have a positive impact on interpersonal relationships. The majority believed that stimulant medications offered only a transient decrease in patterns of tobacco use because their ability to reduce nicotine cravings wore off quickly. Others believed that stimulants had no effect or even reinforced cigarette use.

CONCLUSIONS

Participants had different views about the link between cigarette smoking and ADHD. While the majority thought of nicotine as a sort of therapy, viewing smoking as a way to self-medicate symptoms of ADHD, motivations for nicotine use were also related to self-image, desire to belong to a peer-group, and a drive to undermine perceived social norms. Ultimately, these findings can be used by clinicians to improve treatment alliance and collaboration.

Altered social and non-social decision-making in recreational and dependent cocaine users

BACKGROUND

Maladaptive decision-making is assumed to be a core feature of cocaine addiction. Indeed, numerous studies have reported deficits in non-social decision-making tasks and reward-related impulsivity in dependent cocaine users. However, social decision-making has not been examined in cocaine users yet. Moreover, it is unknown if even recreational and non-dependent cocaine use is linked to decision-making deficits. Therefore, we investigated whether recreational and dependent cocaine users exhibit alterations in social and non-social decision-making.

METHOD

The performance of healthy controls (n = 68), recreational cocaine users (n = 68) and dependent cocaine users (n = 30) in classical decision-making paradigms (Iowa Gambling Task, Delay Discounting) and in social interaction paradigms (Distribution Game, Dictator Game) was assessed.

RESULTS

Decisions in the social interaction tasks of both cocaine user groups were more self-serving compared with controls as cocaine users preferred higher monetary payoffs for themselves. In the Iowa Gambling Task, only dependent cocaine users were more likely to choose disadvantageous card decks, reflecting worse decision-making. They were also more likely to choose immediate smaller rewards over larger delayed rewards in the Delay Discounting task.

CONCLUSIONS

Our results imply that both recreational and dependent cocaine users are more concerned with their own monetary gain when interacting with another person. Furthermore, primarily dependent cocaine users are less foresighted and more impulsive regarding immediate reward. Overall, social interaction deficits are already present in recreational users, while non-social decision-making deficits occur predominantly in dependent cocaine users. Thus, social interaction training and cognitive remediation strategies may improve treatment success and quality of life in cocaine dependence.

Attention deficit hyperactivity disorder in offenders and the need for early intervention

Attention deficit hyperactivity disorder (ADHD) can be, for some people, a pathway to prison. Intervening at an early age may prevent delinquency. Generally, these interventions consist of a combination of medication, cognitive-behavioral therapy, family intervention, and educational support. Despite these interventions, some people with ADHD still develop antisocial and criminal behavior. This article examines the link between ADHD and delinquency, and reviews relevant treatments.

White matter correlates of cognitive inhibition during development: a diffusion tensor imaging study

Inhibitory control and cognitive flexibility are two key executive functions that develop in childhood and adolescence, increasing one's capacity to respond dynamically to changing external demands and refrain from impulsive behaviors. These gains evolve in concert with significant brain development. Magnetic resonance imaging studies have identified numerous frontal and cingulate cortical areas associated with performance on inhibition tasks, but less is known about the involvement of the underlying anatomical connectivity, namely white matter. Here we used diffusion tensor imaging (DTI) to examine correlations between a DTI-derived parameter, fractional anisotropy (FA) of white matter, and performance on the NEPSY-II Inhibition test (Naming, Inhibition and Switching conditions) in 49 healthy children aged 5-16years (20 females; 29 males). First, whole brain voxel-based analysis revealed several clusters in the frontal projections of the corpus callosum, where higher FA was associated with worse inhibitory performance, as well as several clusters in posterior brain regions and one in the brainstem where higher FA was associated with better cognitive flexibility (in the Switching task), suggesting a dichotomous relationship between FA and these two aspects of cognitive control. Tractography through these clusters identified several white matter tracts, which were then manual traced in native space. Pearson's correlations confirmed associations between higher FA of frontal projections of the corpus callosum with poorer inhibitory performance (independent of age), though associations with Switching were not significant. Post-hoc evaluation suggested that FA of orbital and anterior frontal projections of the corpus callosum also mediated performance differences across conditions, which may reflect differences in self-monitoring or strategy use. These findings suggest a link between the development of inhibition and cognitive control with that of the underlying white matter, and may help to identify deviations of neurobiology in adolescent psychopathology.

Multifactorial determinants of target and novelty-evoked P300 amplitudes in children of addicted parents

Background

Although P300 amplitude reductions constitute a persistent finding in children of addicted parents, relatively little is known about the specificity of this finding. The major aim of this study was to investigate the association between parental rearing, adverse life events, stress-reactivity, substance use and psychopathology on the one hand, and P300 amplitude in response to both target and novel distracter stimuli on the other hand. Moreover, we assessed whether risk group status (i.e., having a parental history of Substance Use Disorders [SUD]) uniquely contributed to P300 amplitude variation above and beyond these other variables.

Methods

Event-related potentials were recorded in high-risk adolescents with a parental history of SUD (HR;n=80) and normal-risk controls (NR;n=100) while performing a visual Novelty Oddball paradigm. Stress-evoked cortisol levels were assessed and parenting, life adversities, substance use and psychopathology were examined by using self-reports.

Results

HR adolescents displayed smaller P300 amplitudes in response to novel- and to target stimuli than NR controls, while the latter only approached significance. Interestingly, the effect of having a parental history of SUD on target-P300 disappeared when all other variables were taken into account. Externalizing problem behavior was a powerful predictor of target-P300. In contrast, risk group status uniquely predicted novelty-P300 amplitude reductions above and beyond all other factors.

Conclusion

Overall, the present findings suggest that the P300 amplitude reduction to novel stimuli might be a more specific endophenotype for SUD than the target-P300 amplitude. This pattern of results underscores the importance of conducting multifactorial assessments when examining important cognitive processes in at-risk adolescents.

Impact of fathers' alcohol problems on the development of effortful control in early adolescence

OBJECTIVE

This article examines the association between fathers' alcohol problems and children's effortful control during the transition from middle childhood to early adolescence (fourth to sixth grade). Additionally, we examined the role of two potential moderators of this association, fathers' antisocial behavior and child gender.

METHOD

The sample consisted of 197 families (102 nonalcoholic [NA]; 95 father alcoholic [FA], in which only the father met diagnostic criteria for alcohol abuse or dependence). The sample was recruited from New York State birth records when the children were 12 months old. This analysis focused on 12-month alcohol problem data and child effortful control data measured in the fourth and sixth grades.

RESULTS

Structural equation modeling revealed that FA status was associated with lower effortful control on the Stroop Color and Word and Tower of London tasks in the sixth grade, but antisocial behavior did not moderate this association. Multiple group analysis revealed that FA status was associated with higher Stroop interference scores in fourth and sixth grade and lower move scores on the Tower of London task for boys but not girls.

CONCLUSIONS

The association between FA status and effortful control may be attenuated in middle childhood (fourth grade) but emerge again in early adolescence (sixth grade). The results indicate that sons of alcoholics may be particularly vulnerable to poor self-regulatory strategies and that early adolescence may be an important time for intervening with these families to facilitate higher self-regulation before the transition to high school.

Effects of the Youth Empowerment Seminar on impulsive behavior in adolescents

PURPOSE

Because impulsivity during adolescence predicts health-risk behaviors and associated harm, interventions that attenuate impulsivity may offer protection. We evaluated effects of the Youth Empowerment Seminar (YES!), a biopsychosocial workshop for adolescents that teaches skills of stress management, emotion regulation, conflict resolution, and attentional focus, on impulsive behavior.

METHODS

High school students (14-18 years of age) in the United States participated in YES! during their physical education classes. Students in a control group attended their usual curriculum and were tested in parallel. We used items from the Barratt Impulsiveness Scale (framed to reflect recent behavior) to assess students' behavior before and after they underwent the program.

RESULTS

Compared with the control group, YES! participants reported less impulsive behavior after the program.

CONCLUSIONS

The results suggest that YES! can promote mental health in adolescents, potentially protecting them from harmful coping behaviors.

Developmental exposure to polychlorinated biphenyls reduces amphetamine behavioral sensitization in Long-Evans rats

PCBs have long been known to affect dopamine (DA) function in the brain. The current study used an amphetamine behavioral sensitization paradigm in rats developmentally exposed to PCBs. Long-Evans rats were given perinatal exposure to 0, 3, or 6mg/kg/day PCBs and behavioral sensitization to d-amphetamine (AMPH) was assessed in one adult male and female/litter. Non-exposed (control) males showed increasing locomotor activity to repeated injections of 0.5mg/kg AMPH, typical of behavioral sensitization. PCB-exposed males showed greater activation to the initial acute AMPH injection, but sensitization occurred later and was blunted relative to controls. Sensitization in control females took longer to develop than in the males, but no exposure-related differences were observed. Analysis of whole brain and serum AMPH content following a final IP injection of 0.5mg/kg revealed no differences among the exposure groups. Overall, these results indicated developmental PCB exposure can alter the motor-stimulating effects of repeated AMPH injections. Males developmentally exposed to PCBs appeared to be pre-sensitized to AMPH, but quickly showed behavioral tolerance to the same drug dose. Results also revealed the behavioral effect was not due to exposure-induced alterations in AMPH metabolism following PCB exposure.

Affective decision-making is predictive of three-month relapse in polysubstance-dependent alcoholics

BACKGROUND/AIMS

Common and long-lasting deficits in decision-making in polysubstance-dependent alcoholics (PSA) reflect neurobiological alterations that define the chronic nature of addiction. These deficits affect goal-directed behavior and might be critical risk factors predicting relapse in PSA.

METHODS

The Delay Discounting Task (DDT) and the Iowa Gambling Task (IGT) assessed the delay-discounting and decision-making skills among 37 abstinent PSA.

RESULTS

The findings indicated that IGT but not DDT performances were associated with 3-month abstinence, irrespective of the influence of personality traits and coexistent medications.

CONCLUSION

The results show that the IGT, which assesses processes that are important in the latter stages of addiction, is ecologically more valid compared to the DDT, which assesses processes important in the early stages. They underline the importance of using neurocognitive measures to identify high relapse risk patients and emphasize the relevance of promoting new treatments.

Adolescent impulsivity phenotypes characterized by distinct brain networks

The impulsive behavior that is often characteristic of adolescence may reflect underlying neurodevelopmental processes. Moreover, impulsivity is a multi-dimensional construct, and it is plausible that distinct brain networks contribute to its different cognitive, clinical and behavioral aspects. As these networks have not yet been described, we identified distinct cortical and subcortical networks underlying successful inhibitions and inhibition failures in a large sample (n = 1,896) of 14-year-old adolescents. Different networks were associated with drug use (n = 1,593) and attention-deficit hyperactivity disorder symptoms (n = 342). Hypofunctioning of a specific orbitofrontal cortical network was associated with likelihood of initiating drug use in early adolescence. Right inferior frontal activity was related to the speed of the inhibition process (n = 826) and use of illegal substances and associated with genetic variation in a norepinephrine transporter gene (n = 819). Our results indicate that both neural endophenotypes and genetic variation give rise to the various manifestations of impulsive behavior.