Neurodevelopment, impulsivity, and adolescent gambling

The relationships between behavioral addictions and the five-factor model of personality

Aims Although relationships between addiction and personality have previously been explored, no study has ever simultaneously investigated the interrelationships between several behavioral addictions, and related these to the main dimensions of the five-factor model of personality. Methods In this study, 218 university students completed questionnaires assessing seven different behavioral addictions (i.e., Facebook addiction, video game addiction, Internet addiction, exercise addiction, mobile phone addiction, compulsive buying, and study addiction) as well as an instrument assessing the main dimensions of the five-factor model of personality. Results Of the 21 bivariate intercorrelations between the seven behavioral addictions, all were positive (and nine significantly). The results also showed that (i) Neuroticism was positively associated with Internet addiction, exercise addiction, compulsive buying, and study addiction, (ii) Extroversion was positively associated with Facebook addiction, exercise addiction, mobile phone addiction, and compulsive buying, (iii) Openness to experience was negatively associated with Facebook addiction and mobile phone addiction, (iv) Agreeableness was negatively associated with Internet addiction, exercise addiction, mobile phone addiction, and compulsive buying, and (v) Conscientiousness was negatively associated with Facebook addiction, video game addiction, Internet addiction, and compulsive buying and positively associated with exercise addiction and study addiction. Conclusions The positive associations between the seven behavioral addictions suggest one or several underlying pathological factors. Hierarchical multiple regressions showed that personality traits explained between 6% and 17% of the variance in the seven behavioral addictions, suggesting that personality to a varying degree explains scores on measures of addictive behaviors.

Risk-taking and decision-making in youth: relationships to addiction vulnerability

BACKGROUND

Decision-making and risk-taking behavior undergo developmental changes during adolescence. Disadvantageous decision-making and increased risk-taking may lead to problematic behaviors such as substance use and abuse, pathological gambling and excessive internet use.

METHODS

Based on MEDLINE searches, this article reviews the literature on decision-making and risk-taking and their relationship to addiction vulnerability in youth.

RESULTS

Decision-making and risk-taking behaviors involve brain areas that undergoing developmental changes during puberty and young adulthood. Individual differences and peer pressure also relate importantly to decision-making and risk-taking.

CONCLUSIONS

Brain-based changes in emotional, motivational and cognitive processing may underlie risk-taking and decision-making propensities in adolescence, making this period a time of heightened vulnerability for engagement in additive behaviors.

CID: a valid incentive delay paradigm for children

Despite several modifications and the wide use of the monetary incentive delay paradigm (MID; Knutson et al. in J Neurosci 21(16):RC159, 2001a) for assessing reward processing, evidence concerning its application in children is scarce. A first child-friendly MID modification has been introduced by Gotlib et al. (Arch Gen Psychiatry 67(4): 380-387, 2010); however, comparability in the results of different tasks and validity across different age groups remains unclear. We investigated the validity of a newly modified MID task for children (CID) using functional magnetic resonance imaging. The CID comprises the integration of a more age appropriate feedback phase. We focused on reward anticipation and their neural correlates. Twenty healthy young adults completed the MID and the CID. Additionally, 10 healthy children completed the CID. As expected, both paradigms elicited significant ventral and dorsal striatal activity in young adults during reward anticipation. No differential effects of the tasks on reaction times, accuracy rates or on the total amount of gain were observed. Furthermore, the CID elicited significant ventral striatal activity in healthy children. In conclusion, these findings demonstrate evidence for the validity of the CID paradigm. The CID can be recommended for the application in future studies on reward processing in children, adolescents, and in adults.

CB1 receptor autoradiographic characterization of the individual differences in approach and avoidance motivation

Typically, approach behaviour is displayed in the context of moving towards a desired goal, while avoidance behaviour is displayed in the context of moving away from threatening or novel stimuli. In the current research, we detected three sub-populations of C57BL/6J mice that spontaneously responded with avoiding, balancing or approaching behaviours in the presence of the same conflicting stimuli. While the balancing animals reacted with balanced responses between approach and avoidance, the avoiding or approaching animals exhibited inhibitory or advance responses towards one of the conflicting inputs, respectively. Individual differences in approach and avoidance motivation might be modulated by the normal variance in the level of functioning of different systems, such as endocannabinoid system (ECS). The present research was aimed at analysing the ECS involvement on approach and avoidance behavioural processes. To this aim, in the three selected sub-populations of mice that exhibited avoiding or balancing or approaching responses in an approach/avoidance Y-maze we analysed density and functionality of CB₁ receptors as well as enzyme fatty acid amide hydrolase activity in different brain regions, including the networks functionally responsible for emotional and motivational control. The main finding of the present study demonstrates that in both approaching and avoiding animals higher CB₁ receptor density in the amygdaloidal centro-medial nuclei and in the hypothalamic ventro-medial nucleus was found when compared with the CB₁ receptor density exhibited by the balancing animals. The characterization of the individual differences to respond in a motivationally based manner is relevant to clarify how the individual differences in ECS activity are associated with differences in motivational and affective functioning.

Family-based association analysis of serotonin genes in pathological gambling disorder: evidence of vulnerability risk in the 5HT-2A receptor gene

Pathological gambling (PG) has become a growing public health problem in many countries around the world. PG is an impulse control disorder and its behavior and psychopathology present similarities with substance abuse disorders. Evidence from twin studies supports a significant genetic predisposition to PG, but the precise genetic loci still remain unclear. The present study investigates the allele and genotype distribution of polymorphisms of the serotonin transporter, serotonin receptor 1B and 2A genes in 140 sib-pairs discordant for the diagnosis of PG. A significant association of the C/C genotype of the serotonin receptor 2A T102C (rs 6313) polymorphism and the PG phenotype was observed [OR = 1.7 (1.1-3.4)]. This preliminary result is consistent with the hypothesis that the serotonin system is associated with addiction behavior and similar results have been reported for nicotine and alcohol dependence.

[Similarities and differences between pathological gambling and substance dependance: A clarification]

Similarities and differences between pathological gambling and substance dependence: a clarification. A critical analysis of a French review of the international literature on gambling.

INTRODUCTION

The integration of pathological gambling in the spectrum of addictive disorders modeled by substance dependence is currently discussed.

OBJECTIVE

To perform a systematic review of the similarities and differences between pathological gambling and substance dependence, and to classify and analyze them, based on the data collected by a previously published French systematic analysis of the international literature on pathological gambling.

METHOD

We established a checklist of each comparison of pathological gambling with substance dependence within the report. Then, every entry was classified as similarity or difference, analyzed and discussed.

RESULTS

Similarities retrieved were epidemiological characteristics (gender, age, socio-demographic characteristics of subjects), diagnostic criteria from DSM-IV (five criteria in common), frequent co-occurrence of pathological gambling and substance dependence, neurobiological and genetic characteristics, cases of spontaneous recovery, and similarities of therapeutic care. Differences retrieved were a more elevated prevalence of mood disorders and suicide among pathological gamblers, intrinsic risk factors related to gambling activity (delay between bid and result, gambling device, big win), cognitive distortion of pathological gamblers (notably chasing), specificities of cognitive behavioral therapies focused on these cognitive distortions, and specificities of social care of pathological gamblers.

DISCUSSION

Pathological gambling shared many similarities with substance dependence, but also some differences. However, our critical analysis of these elements, reported to be specific to pathological gambling, showed significant commonalities with substance dependence. Also, the existence of key symptoms of substance dependence such as craving and loss of control in pathological gambling was not discussed in the review, although other data suggest a common ground. These could be key elements to group together pathological gambling and substance dependence within the addictive disorders.

Differences in spontaneously avoiding or approaching mice reflect differences in CB1-mediated signaling of dorsal striatal transmission

Approach or avoidance behaviors are accompanied by perceptual vigilance for, affective reactivity to and behavioral predisposition towards rewarding or punitive stimuli, respectively. We detected three subpopulations of C57BL/6J mice that responded with avoiding, balancing or approaching behaviors not induced by any experimental manipulation but spontaneously displayed in an approach/avoidance conflict task. Although the detailed neuronal mechanisms underlying the balancing between approach and avoidance are not fully clarified, there is growing evidence that endocannabinoid system (ECS) plays a critical role in the control of these balancing actions. The sensitivity of dorsal striatal synapses to the activation of cannabinoid CB1 receptors was investigated in the subpopulations of spontaneously avoiding, balancing or approaching mice. Avoiding animals displayed decreased control of CB1 receptors on GABAergic striatal transmission and in parallel increase of behavioral inhibition. Conversely, approaching animals exhibited increased control of CB1 receptors and in parallel increase of explorative behavior. Balancing animals reacted with balanced responses between approach and avoidance patterns. Treating avoiding animals with URB597 (fatty acid amide hydrolase inhibitor) or approaching animals with AM251 (CB1 receptor inverse agonist) reverted their respective behavioral and electrophysiological patterns. Therefore, enhanced or reduced CB1-mediated control on dorsal striatal transmission represents the synaptic hallmark of the approach or avoidance behavior, respectively. Thus, the opposite spontaneous responses to conflicting stimuli are modulated by a different involvement of endocannabinoid signaling of dorsal striatal neurons in the range of temperamental traits related to individual differences.

Male batterers' alcohol use and gambling behavior

Little work has examined the interrelations among intimate partner violence (IPV), alcohol use, and gambling behavior, and no studies have examined these relationships among males court-ordered to batterer intervention programs (BIPs). The aim of the current investigation was to explore the associations between IPV, alcohol use, and gambling behavior among 341 males court-mandated to attend BIPs utilizing self-report measures. Voluntary, anonymous questionnaires were administered and completed during regularly scheduled BIP sessions. Compared to the general population, a higher percentage of the sample met criteria for pathological gambling (9%), and problem gambling (17%). Further, males exhibiting pathological gambling were more likely to be hazardous drinkers, and hazardous drinkers were more likely to exhibit pathological gambling. Additionally, pathological gamblers were at an increased risk for the perpetration of both physical and sexual aggression. Finally, gambling behavior uniquely predicted the perpetration of sexual aggression above and beyond alcohol use, impulsivity, and relationship satisfaction. The implications of these results for future research and intervention are discussed.

Increased sensitivity to alcohol induced changes in ERK Map kinase phosphorylation and memory disruption in adolescent as compared to adult C57BL/6J mice

Adolescence is a critical period of brain development that is accompanied by increased probability of risky behavior, such as alcohol use. Emerging research indicates that adolescents are differentially sensitive to the behavioral effects of acute ethanol as compared to adults but the neurobiological mechanisms of this effect remain to be fully elucidated. This study was designed to evaluate effects of acute ethanol on extracellular signal-regulated kinase phosphorylation (p-ERK1/2) in mesocorticolimbic brain regions. We also sought to determine if age-specific effects of ethanol on p-ERK1/2 are associated with ethanol-induced behavioral deficits on acquisition of the hippocampal-dependent novel object recognition (NOR) test. Adolescent and adult C57BL/6J mice were administered acute ethanol (0 0.5, 1, or 3g/kg, i.p.). Brains were removed 30-min post injection and processed for analysis of p-ERK1/2 immunoreactivity (IR). Additional groups of mice were administered ethanol (0 or 1g/kg) prior to the NOR test. Analysis of p-ERK1/2 IR showed that untreated adolescent mice had significantly higher levels of p-ERK1/2 IR in the nucleus accumbens shell, basolateral amygdala (BLA), central amygdala (CeA), and medial prefrontal cortex (mPFC) as compared to adults. Ethanol (1g/kg) selectively reduced p-ERK1/2 IR in the dentate gyrus and increased p-ERK1/2 IR in the BLA only in adolescent mice. Ethanol (3g/kg) produced the same effects on p-ERK1/2 IR in both age groups with increases in CeA and mPFC, but a decrease in the dentate gyrus, as compared to age-matched saline controls. Pretreatment with ethanol (1g/kg) disrupted performance on the NOR test specifically in adolescents, which corresponds with the ethanol-induced inhibition of p-ERK1/2 IR in the hippocampus. These data show that adolescent mice have differential expression of basal p-ERK1/2 IR in mesocorticolimbic brain regions. Acute ethanol produces a unique set of changes in ERK1/2 phosphorylation in the adolescent brain that are associated with disruption of hippocampal-dependent memory acquisition.

Interaction of COMT val158met and externalizing behavior: relation to prefrontal brain activity and behavioral performance

A promising approach in neuroimaging studies aimed at understanding effects of single genetic variants on behavior is the study of gene-trait interactions. Variation in the catechol-O-methyl-transferase gene (COMT) is associated with the regulation of dopamine levels in the prefrontal cortex and with cognitive functioning. Given the involvement of dopaminergic neurotransmission in externalizing behavior, a trait characterized by impulsivity and aggression, especially in men, externalizing (as a trait) may index a set of genetic, environmental, and neural characteristics pertinent to understanding phenotypic effects of genetic variation in the COMT gene. In the current study, we used a gene-trait approach to investigate effects of the COMT val(158)met polymorphism and externalizing on brain activity during moments involving low or high demands on cognitive control. In 104 male participants, interference-related activation depended conjointly on externalizing and val(158)met: stronger activation in the dorsal anterior cingulate and lateral prefrontal cortex was found for val/val individuals with high trait externalizing while stronger activation in cingulate motor areas and sensorimotor precuneus was found for met/met individuals with low externalizing. Our results suggest that the val/val genotype, coupled with high levels of trait externalizing, lowers the efficiency of stimulus conflict resolution, whereas the met/met genotype, coupled with low levels of externalizing, lowers the efficiency of response selection.

Brain processes in discounting: consequences of adolescent methylphenidate exposure

Traits of inattention, impulsivity, and motor hyperactivity characterize children diagnosed with attention-deficit/hyperactivity disorder (ADHD), whose inhibitory control is reduced. In animal models, crucial developmental phases or experimental transgenic conditions account for peculiarities, such as sensation-seeking and risk-taking behaviors, and reproduce the beneficial effects of psychostimulants. An "impulsive" behavioral profile appears to emerge more extremely in rats when forebrain dopamine (DA) systems undergo remodeling, as in adolescence, or with experimental manipulation tapping onto the dopamine transporter (DAT). Ritalin(®) (methylphenidate, MPH), a DAT-blocking drug, is prescribed for ADHD therapy but is also widely abused by human adolescents. Administration of MPH during rats' adolescence causes a long-term modulation of their self-control, in terms of reduced intolerance to delay and diminished proneness for risk when reward is uncertain. Exactly the opposite profile emerges when exogenous alteration of DAT levels is achieved via lentiviral transfection. Both adolescent MPH exposure and DAT-targeting transfection lead to enduring hyperfunction of dorsal striatum and hypofunction of ventral striatum. Together with upregulation of prefronto-cortical phospho-creatine, striatal upregulation of selected genes (like serotonin 7 receptor gene) suggests that enhanced inhibitory control is generated by adolescent MPH exposure. Operant tasks, which assess the balance between motivational drives and inhibitory self-control, are thus useful for investigating reward-discounting processes and their modulation by DAT-targeting tools. In summary, due to the complexity of human studies, preclinical investigations of rodent models are necessary to understand better both the neurobiology of ADHD-like symptoms' etiology and the long-term therapeutic safety of adolescent MPH exposure.

Pathological gambling: a review of phenomenological models and treatment modalities for an underrecognized psychiatric disorder

Pathological gambling (PG) is a prevalent and highly disabling impulse-control disorder. Two dominant phenomenological models for PG have been presented in the literature. According to one model, PG is included as an obsessive-compulsive spectrum disorder, while according to the second model, PG represents a form of nonpharmacologic addiction. In this article, we present an expanded conceptualization of the phenomenology of PG. On the basis of our clinical research experience and a review of data in the field, we propose 3 subtypes of pathological gamblers: the "impulsive" subtype, the "obsessive-compulsive" subtype, and the "addictive" subtype. We also review the current pharmacologic and nonpharmacologic treatment strategies for PG. A further aim of this article is to encourage awareness of the importance of improved screening procedures for the early detection of PG.

Probability and predictors of transition from first use to dependence on nicotine, alcohol, cannabis, and cocaine: results of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

BACKGROUND

This study aims to estimate general and racial-ethnic specific cumulative probability of developing dependence among nicotine, alcohol, cannabis or cocaine users, and to identify predictors of transition to substance dependence.

METHODS

Analyses were done for the subsample of lifetime nicotine (n=15,918), alcohol (n=28,907), cannabis (n=7389) or cocaine (n=2259) users who participated in the first and second wave of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC). Discrete-time survival analyses were implemented to estimate the cumulative probability of transitioning from use to dependence and to identify predictors of transition to dependence.

RESULTS

The cumulative probability estimate of transition to dependence was 67.5% for nicotine users, 22.7% for alcohol users, 20.9% for cocaine users, and 8.9% for cannabis users. Half of the cases of dependence on nicotine, alcohol, cannabis and cocaine were observed approximately 27, 13, 5 and 4 years after use onset, respectively. Significant racial-ethnic differences were observed in the probability of transition to dependence across the four substances. Several predictors of dependence were common across the four substances assessed.

CONCLUSIONS

Transition from use to dependence was highest for nicotine users, followed by cocaine, alcohol and cannabis users. Transition to cannabis or cocaine dependence occurred faster than transition to nicotine or alcohol dependence. The existence of common predictors of transition dependence across substances suggests that shared mechanisms are involved. The increased risk of transition to dependence among individuals from minorities or those with psychiatric or dependence comorbidity highlights the importance of promoting outreach and treatment of these populations.

Topography, power, and current source density of θ oscillations during reward processing as markers for alcohol dependence

Recent studies have linked alcoholism with a dysfunctional neural reward system. Although several electrophysiological studies have explored reward processing in healthy individuals, such studies in alcohol-dependent individuals are quite rare. The present study examines theta oscillations during reward processing in abstinent alcoholics. The electroencephalogram (EEG) was recorded in 38 abstinent alcoholics and 38 healthy controls as they performed a single outcome gambling task, which involved outcomes of either loss or gain of an amount (10 or 50¢) that was bet. Event-related theta band (3.0-7.0 Hz) power following each outcome stimulus was computed using the S-transform method. Theta power at the time window of the outcome-related negativity (ORN) and positivity (ORP) (200-500 ms) was compared across groups and outcome conditions. Additionally, behavioral data of impulsivity and task performance were analyzed. The alcoholic group showed significantly decreased theta power during reward processing compared to controls. Current source density (CSD) maps of alcoholics revealed weaker and diffuse source activity for all conditions and weaker bilateral prefrontal sources during the Loss 50 condition when compared with controls who manifested stronger and focused midline sources. Furthermore, alcoholics exhibited increased impulsivity and risk-taking on the behavioral measures. A strong association between reduced anterior theta power and impulsive task-performance was observed. It is suggested that decreased power and weaker and diffuse CSD in alcoholics may be due to dysfunctional neural reward circuitry. The relationship among alcoholism, theta oscillations, reward processing, and impulsivity could offer clues to understand brain circuitries that mediate reward processing and inhibitory control.

Longitudinal links between impulsivity, gambling problems and depressive symptoms: a transactional model from adolescence to early adulthood

BACKGROUND

Research shows high co-morbidity between gambling problems and depressive symptoms, but the directionality of this link is unclear. Moreover, the co-occurrence of gambling problems and depressive symptoms could be spurious and explained by common underlying risk factors such as impulsivity and socio-family risk. The goals of the present study were to examine 1) whether common antecedent factors explain the concurrent links between depressive symptoms and gambling problems, and 2) whether possible transactional links between depressive symptoms and gambling problems exist from late adolescence to early adulthood.

METHODS

A total of 1004 males from low SES areas participated in the study.

RESULTS

Analyses revealed a positive predictive link between impulsivity at age 14 and depressive symptoms and gambling problems at age 17. In turn, gambling problems at age 17 predicted an increase in depressive symptoms from age 17 to age 23, and depressive symptoms at age 17 predicted an increase in gambling problems from age 17 to age 23.

CONCLUSIONS

Common antecedent factors may explain the initial emergence of an association between depressive symptoms and gambling problems in adolescence. However, once emerged, their escalation seems to be better explained by a mutual direct influence between the two sets of disorders.

Personality, gender, and family history in the prediction of college gambling

The present study examined the degree to which gambling behaviors and gambling-relevant cognitive distortions could be predicted by personality factors, gender, and familial history of substance use and gambling problems in a large sample of college students (N = 581). Results indicate that parental gambling problems and, especially for males, a propensity to experience negative emotions predicted time spent gambling and gambling problems. Negative emotionality, along with parental substance use problems, impulsivity, and being male predicted gambling-related cognitive distortions. The differing pattern for impulsivity with respect to behaviors and beliefs might be explained by the low accessibility of gambling venues for the student population. We compare the present findings with past studies examining gambling behaviors in adult populations.

Neurobiology of decision-making in adolescents

The study examined the relationship between risk-taking behavior during selection of monetary rewards and activations in the anterior cingulate cortex (ACC), orbitofrontal cortex (OFC) and medial prefrontal cortex (mPFC), brain regions that are associated with decision-making. Thirty-three adolescents with no personal or family history of any psychiatric illness were administered the Wheel of Fortune (WOF) task using a functional magnetic resonance imaging protocol. The WOF is a computerized two-choice, probabilistic monetary reward task. Selection of a reward, particularly a low-probability/high-magnitude reward choice, induced greater activations in dorsal ACC, ventrolateral OFC and mPFC than the control condition. Although similar findings have been reported by earlier studies, the results from this study were not impacted by reaction times and expected values and persisted even after controlling for sociodemographic factors. Post hoc analysis revealed greater activation of ACC and mPFC in response to selection of rewards of larger magnitude than those of smaller magnitude when the probability of reward was maintained constant. Adolescents with greater frequency of high-risk behavior (defined as low-probability/high-magnitude reward choice) had lower activation of ACC, OFC and mPFC than those who engaged in this behavior less frequently. These findings suggest individual differences in prefrontal cortical function with regards to decision-making process in adolescents.

Adolescent development and risk of injury: using developmental science to improve interventions

In adolescence, there is a complex interaction among physical, cognitive, and psychosocial developmental processes, culminating in greater risk-taking and novelty-seeking. Concurrently, adolescents face an increasingly demanding environment, which results in heightened vulnerability to injury. In this paper, we provide an overview of developmental considerations for adolescent injury interventions based on developmental science, including findings from behavioural neuroscience and psychology. We examine the role that typical developmental processes play in the way adolescents perceive and respond to risk and how this integrated body of developmental research adds to our understanding of how to do injury prevention with adolescents. We then highlight strategies to improve the translation of developmental research into adolescent injury prevention practice, calling on examples of existing interventions including graduated driver licensing.

Adolescent gambling: a review of an emerging field of research

PURPOSE

The purpose of this review was to summarize the research on adolescent gambling with implications for research and prevention or intervention.

METHOD

The methodology involved a comprehensive and systematic search of "adolescent or youth gambling" in three diverse electronic databases (MedlineAdvanced, PsycINFO, and Sociological Abstracts) and three peer-reviewed journals (International Journal of Gambling Studies, International Journal of Mental Health and Addiction, and Journal of Gambling Issues).

RESULTS

The search resulted in 137 articles (1985-2010) focusing on gambling among youth aged between 9 and 21 years: 103 quantitative, 8 qualitative, and 26 non-empirical. The study of adolescent gambling can be summarized as follows: (a) it is conducted by a relatively small group of researchers in Britain, Canada, and the United States; (b) it is primarily prevalence-focused, quantitative, descriptive, school-based, and atheoretical; (c) it has most often been published in the Journal of Gambling Studies; (d) it is most often examined in relation to alcohol use; (e) it has relatively few valid and reliable screening instruments that are developmentally appropriate for adolescents, and (f) it lacks racially diverse samples.

CONCLUSION

Four recommendations are presented for both research and prevention or intervention which are as follows: (1) to provide greater attention to the development and validation of survey instruments or diagnostic criteria to assess adolescent problem gambling; (2) to begin to develop and test more gambling prevention or intervention strategies; (3) to not only examine the co-morbidity of gambling and alcohol abuse, but also include other behaviors such as sexual activity; and (4) to pay greater attention to racial and ethnic differences in the study of adolescent gambling.

Introduction to behavioral addictions

BACKGROUND

Several behaviors, besides psychoactive substance ingestion, produce short-term reward that may engender persistent behavior, despite knowledge of adverse consequences, i.e., diminished control over the behavior. These disorders have historically been conceptualized in several ways. One view posits these disorders as lying along an impulsive-compulsive spectrum, with some classified as impulse control disorders. An alternate, but not mutually exclusive, conceptualization considers the disorders as non-substance or "behavioral" addictions.

OBJECTIVES

Inform the discussion on the relationship between psychoactive substance and behavioral addictions.

METHODS

We review data illustrating similarities and differences between impulse control disorders or behavioral addictions and substance addictions. This topic is particularly relevant to the optimal classification of these disorders in the forthcoming fifth edition of the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders (DSM-V).

RESULTS

Growing evidence suggests that behavioral addictions resemble substance addictions in many domains, including natural history, phenomenology, tolerance, comorbidity, overlapping genetic contribution, neurobiological mechanisms, and response to treatment, supporting the DSM-V Task Force proposed new category of Addiction and Related Disorders encompassing both substance use disorders and non-substance addictions. Current data suggest that this combined category may be appropriate for pathological gambling and a few other better studied behavioral addictions, e.g., Internet addiction. There is currently insufficient data to justify any classification of other proposed behavioral addictions.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Proper categorization of behavioral addictions or impulse control disorders has substantial implications for the development of improved prevention and treatment strategies.

Interactive effects of cumulative stress and impulsivity on alcohol consumption

BACKGROUND

Alcohol addiction may reflect adaptations to stress, reward, and regulatory brain systems. While extensive research has identified both stress and impulsivity as independent risk factors for drinking, few studies have assessed the interactive relationship between stress and impulsivity in terms of hazardous drinking within a community sample of regular drinkers.

METHODS

One hundred and thirty regular drinkers (56M/74F) from the local community were assessed for hazardous and harmful patterns of alcohol consumption using the Alcohol Use Disorders Identification Test (AUDIT). All participants were also administered the Barratt Impulsiveness Scale (BIS-11) as a measure of trait impulsivity and the Cumulative Stress/Adversity Checklist (CSC) as a comprehensive measure of cumulative adverse life events. Standard multiple regression models were used to ascertain the independent and interactive nature of both overall stress and impulsivity as well as specific types of stress and impulsivity on hazardous and harmful drinking.

RESULTS

Recent life stress, cumulative traumatic stress, overall impulsivity, and nonplanning-related impulsivity as well as cognitive and motor-related impulsivity were all independently predictive of AUDIT scores. However, the interaction between cumulative stress and total impulsivity scores accounted for a significant amount of the variance, indicating that a high to moderate number of adverse events and a high trait impulsivity rating interacted to affect greater AUDIT scores. The subscale of cumulative life trauma accounted for the most variance in AUDIT scores among the stress and impulsivity subscales.

CONCLUSIONS

Findings highlight the interactive relationship between stress and impulsivity with regard to hazardous drinking. The specific importance of cumulative traumatic stress as a marker for problem drinking is also discussed.

Non-substance-addictive behaviors in youth: pathological gambling and problematic Internet use

Adolescence is characterized by participation in multiple novel and potentially risky behaviors. Amongst these behaviors are gambling and use of the Internet, and excessive engagement in these activities (as seen in pathological gambling and problematic Internet use) may be accompanied by serious impairments in school, mental health, and social functioning. This article reviews the potential impact of pathological gambling and problematic Internet use in youth, the relevance of subsyndromal levels of participation, and how prevention and treatment strategies may be considered and tested within a developmental framework.

The relationship between impulse-control disorders and obsessive-compulsive disorder: a current understanding and future research directions

Impulse-control disorders (ICDs) constitute a heterogeneous group of conditions linked diagnostically by difficulties in resisting "the impulse, drive, or temptation to perform an act that is harmful to the person or to others." Specific ICDs share clinical, phenomenological and biological features with obsessive-compulsive disorder (OCD) that have suggested that these disorders might be categorized together. However, other data suggest significant differences between OCD and ICDs. In this article, clinical, phenomenological and biological features of the formal ICDs are reviewed and compared and contrasted with those of OCD. Available data indicate substantial differences between ICDs and OCD that suggest independent categorizations. Existing research gaps are identified and avenues for future research suggested.

Verbal but not performance IQ is highly correlated to externalizing behavior in boys with ADHD carrying both DRD4 and DAT1 risk genotypes

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is often associated with reduced IQ and high levels of externalizing behavior (EB). This study tested if DRD4 7-repeat allele and DAT1 10-repeat allele homozygosity interact in modulating correlations between IQ and EB in affected boys.

METHODS

Boys (n=130) between 6 and 12 years of age diagnosed with ADHD were included in the study. IQ and EB were assessed by WISC-III and Child Behavioral Checklist, respectively. The 40 bp variable number tandem repeat (VNTR) of the DAT1 gene and the 48 bp VNTR of the DRD4 gene polymorphisms were genotyped and 4 subgroups were defined by the presence/absence of the DRD4 7-repeat allele and by the presence/absence of the DAT1 10/10 genotype. Correlation coefficients were compared using the Fisher's Z transformation and regression lines by a Potthoff analysis.

RESULTS

In the total sample, all correlation coefficients between EB score and IQ were non significant. Also, no differences in IQ were observed between the 4 genotype groups. However, different pattern of correlations between IQ and EB score appeared. In boys carrying no or only one genetic risk, IQ and EB score were uncorrelated while in children carrying both risk factors, negative and significant correlations emerged. Notably, correlation of EB to verbal IQ was strong (r=-0.71) and highly significant (P<0.01) in boys carrying both risk alleles. All pair-wise comparisons of correlation coefficients were significant for EB-verbal IQ correlation. Test of coincidence of regression lines did not show significant differences.

CONCLUSIONS

A specific domain of IQ, namely the verbal quotient is highly correlated to the level of EB in boys with ADHD carrying both dopaminergic risk genotypes. Further investigations are required to replicate these results and determine specificity to ADHD.

Executive cognitive functions and impulsivity as correlates of risk taking and problem behavior in preadolescents

Initiation of drug use and other risky behavior in preadolescence is associated with poor developmental outcomes. In this research, we examine models that ascribe the trajectory to (a) weak executive cognitive function (ECF), (b) early manifestation of externalizing problems, or (c) heightened levels of trait impulsivity. We test the explanatory power of these factors in a structural equation model with a community sample of 387 preadolescents ages 10-12 years. Participants were tested with a computerized battery of tasks to assess three facets of ECF (working memory, cognitive control, and reward processing) as well as with an audio assisted computerized self-interview to obtain reports of impulsivity and risk behaviors (use of cigarettes and alcohol as well as engaging in fighting and gambling for money) and a self-administered questionnaire to assess externalizing and internalizing problems. The best fitting model explained both early risk taking and externalizing symptoms as the result of individual differences in impulsivity. Although no ECF was directly related to risk taking, working memory and one measure of reward processing performance (reversal learning) were inversely related to impulsivity. The results are discussed in regard to theories of early risk taking with particular focus on the potential relation between ECF and impulsive behavior tendencies and the implications for early intervention to prevent the dysfunctional trajectory associated with early risk behavior.

Maternal responses to adolescent positive affect are associated with adolescents' reward neuroanatomy

The development of reward-based learning and decision-making, and the neural circuitry underlying these processes, appears to be influenced negatively by adverse child-rearing environments characterized by abuse and other forms of maltreatment. No research to-date has investigated whether normative variations in the child-rearing environment have effects on adolescent brain structure. We examined whether normative variations in maternal responses to adolescents' positive affective behavior were associated with morphometric measures of the adolescents' affective neural circuitry, namely the amygdala, orbitofrontal cortex (OFC), and anterior cingulate cortex (ACC). Healthy adolescents (N = 113) participated in laboratory-based interaction tasks with their mothers, and underwent high-resolution (3T) structural magnetic resonance imaging (MRI). The mother-adolescent interactions included a pleasant event-planning interaction (EPI) and a conflictual problem-solving interaction (PSI). Adolescents, whose mothers displayed more punishing responses to their positive affective behavior during both tasks, and only during the PSI, had larger left dorsal ACC and bilateral OFC volumes, respectively. In addition, boys whose mothers evidenced this pattern of behavior during the EPI had larger right amygdala volumes. These results suggest that normative variations in maternal responses to affective behavior are associated with the structural characteristics of adolescents' affective neural circuitry, which may have implications for the development of their social, cognitive and affective functioning.

Functional consequences of marijuana use in adolescents

Nearly half of 12th graders have tried marijuana, and 6% use daily. This paper reviews studies on neuropsychological functioning, brain structure, brain function, and subjective and objective measures of sleep in relation to adolescent marijuana use. Adolescents who use marijuana heavily tend to show disadvantaged attention, learning, and processing speed; subtle abnormalities in brain structure; increased activation during cognitive tasks despite intact performance; and compromised objective indicators of sleep quality. Some abnormalities appear to persist beyond a month of abstinence, but may resolve within three months if cessation is maintained. Recommendations for future studies include characterizing these indices in youth prior to the onset of marijuana use then examining change after chronic use has started, and using large samples of youth with varying degrees of involvement with marijuana as well as alcohol, nicotine, and other drugs to characterize the interactive influences on neurocognition and neural health.

Affective status in relation to impulsive, motor and motivational symptoms: personality, development and physical exercise

The contributions of impulsive and risk-taking behaviour in depressive and bipolar disorders, motivational and motor behaviours in anhedonic and substance addictive states, and the factors, particularly distress and trauma, underlying the development of neuropathology in affective status are described from clinical, epidemiological and laboratory perspectives. In order to distinguish one case factor for biopsychological substrates of health, an array of self-reported characteristics, e.g., positive or negative affect, stress or energy, optimism, etc., that may be predictive or counterpredictive for the propensity for physical exercise and activity were analysed using a linear regression in twelve different studies. Several individual characteristics were found to be markedly and significantly predictive of the exercise propensity, i.e., positive affect, energy, health-seeking behaviour and character, while optimism was of lesser, though significant, importance. Several individual characteristics were found to be significantly counterpredictive: expression of BDI- and HAD-depression, major sleep problems and lack/negligence of health-seeking behaviour. The consequences of physical activity and exercise for both affective well-being, cognitive mobility and neurogenesis is noted, particularly with regard to developmental assets for younger individuals. Affective disorder states may be studied through analyses of personal characteristics that unfold predispositions for symptoms-profiles and biomarkers derived from properties of dysfunction, such as impulsiveness, temperament dimensions, anhedonia and 'over-sensitivity', whether interpersonal or to reward.

Correlates of gambling among youth in an inner-city emergency department

Correlates of past year gambling were examined in a diverse sample of 1128 youth ages 14 to 18 (54.1% female, 58.0% African American) presenting to an inner-city emergency department (ED). Overall, 22.5% of the sample reported past-year gambling. Male youth were more likely to gamble than female youth, and African American youth reported higher rates of past-year gambling than non-African American youth. Significant bivariate correlates of gambling included lower academic achievement, being out of school, working more than 20 hours per week, alcohol, cigarette, and marijuana use, alcohol problems, severe dating violence, moderate and severe general violence, and carrying a weapon. When examined simultaneously, being male, African American, out of school, working for pay, alcohol and marijuana use, severe general violence, and carrying a weapon all emerged as significant correlates of past-year gambling, largest amount of money gambled, and gambling frequency. In addition, involvement in severe dating violence was associated with frequency and largest amount gambled. The results suggest that gambling is common among youth in the inner city and is associated with several risk behaviors. The inner-city ED may provide a context for screening and intervention to address multiple risk behaviors. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

The relationship between recreational gambling and substance abuse/dependence: data from a nationally representative sample

BACKGROUND

Although recreational gambling is prevalent and co-occurs with substance abuse/dependence, few studies have investigated the relationship between the two.

METHODS

Logistic regression analyses were performed on data from a nationally representative sample from the Gambling Impact and Behavior Study.

RESULTS

Substance-abusing recreational gamblers, as compared to non-substance-abusing ones, differed in gambling motivations, began gambling at earlier ages, reported heavier gambling, and preferred and performed strategic forms of gambling.

CONCLUSIONS

As compared with non-substance-abusing gamblers, substance-abusing gamblers demonstrated different gambling profiles including heavier gambling. These findings suggest the need for additional research on whether and how substance use might promote gambling and vice versa.

The influence of substance use on adolescent brain development

Adolescence is a unique period in neurodevelopment. Alcohol and marijuana use are common. Recent research has indicated that adolescent substance users show abnormalities on measures of brain functioning, which is linked to changes in neurocognition over time. Abnormalities have been seen in brain structure volume, white matter quality, and activation to cognitive tasks, even in youth with as little as 1-2 years of heavy drinking and consumption levels of 20 drinks per month, especially if > 4-5 drinks are consumed on a single occasion. Heavy marijuana users show some subtle anomalies too, but generally not the same degree of divergence from demographically similar non-using adolescents. This article reviews the extant literature on neurocognition, brain structure, and brain function in adolescent substance users with an emphasis on the most commonly used substances, and in the context of ongoing neuromaturational processes. Methodological and treatment implications are provided.

Increased impulsive behavior and risk proneness following lentivirus-mediated dopamine transporter over-expression in rats' nucleus accumbens

Multiple theories have been proposed for sensation seeking and vulnerability to impulse-control disorders [Zuckerman M, Kuhlman DM (2000) Personality and risk-taking: Common biosocial factors. J Pers 68:999-1029], and many of these rely on a dopamine system deficit. Available animal models reproduce only some behavioral symptoms and seem devoid of construct validity. We used lentivirus tools for over-expressing or silencing the dopamine transporter (DAT) and we evaluated the resulting behavioral profiles in terms of motivation and self-control. Wistar adult rats received stereotaxic inoculation of a lentivirus that allowed localized intra-accumbens delivery of a DAT gene enhancer/silencer, or the green fluorescent protein, GFP. These animals were studied for intolerance to delay, risk proneness and novelty seeking. As expected, controls shifted their demanding from a large reward toward a small one when the delivery of the former was increasingly delayed (or uncertain). Interestingly, in the absence of general locomotor effects, DAT over-expressing rats showed increased impulsivity (i.e. a more marked shift of demanding from the large/delayed toward the small/soon reward), and increased risk proneness (i.e. a less marked shift from the large/uncertain toward the small/sure reward), compared with controls. Rats with enhanced or silenced DAT expression did not show any significant preference for a novel environment. In summary, consistent with literature on comorbidity between attention-deficit/hyperactivity disorder and pathological gambling, we demonstrate that DAT over-expression in rats' nucleus accumbens leads to impulsive and risk prone phenotype. Thus, a reduced dopaminergic tone following altered accumbal DAT function may subserve a sensation-seeker phenotype and the vulnerability to impulse-control disorders.

Dopamine and impulse control disorders in Parkinson's disease

There is an increasing awareness that impulse control disorders (ICDs), including compulsive gambling, buying, sexual behavior, and eating, can occur as a complication of Parkinson's disease (PD). In addition, other impulsive or compulsive disorders have been reported to occur, including dopamine dysregulation syndrome (DDS) and punding. Case reporting and prospective studies have reported an association between ICDs and the use of dopamine agonists (DAs), particularly at greater dosages, whereas dopamine dysregulation syndrome has been associated with greater dosages of levodopa or short-acting DAs. Data suggest that risk factors for an ICD may include male sex, younger age or younger age at PD onset, a pre-PD history of ICD symptoms, personal or family history of substance abuse or bipolar disorder, and a personality style characterized by impulsiveness. Although psychiatric medications are used clinically in the treatment of ICDs, there is no empiric evidence supporting their use in PD. Therefore, management for clinically significant ICD symptoms should consist of modifications to dopamine replacement therapy, particularly DAs, and there is emerging evidence that such management is associated with an overall improvement in ICD symptomatology. It is important that PD patients be aware that DA use may lead to the development of an ICD, and that clinicians monitor patients as part of routine clinical care. As empirically validated treatments for ICDs are emerging, it will be important to examine their efficacy and tolerability in individuals with cooccurring PD and ICDs.

Relation of individual differences in impulsivity to nonclinical emotional decision making

Impulsivity has been identified as a behavioral precursor to addiction, and may be the manifestation of a neurological vulnerability. The present study investigated whether individual differences in impulsivity were associated with performance on the Iowa Gambling Task (IGT, a test of emotional decision making thought to be associated in part with ventromedial prefrontal cortex function) and the Wisconsin Card Sorting Task (WCST, a set-shifting thought to be associated in part with dorsolateral prefrontal cortex function). Subjects were screened for impulsivity using the BIS-11 (self-report) and a delay discounting questionnaire (a behavioral measure of impulsivity). High impulsivity was associated with poorer performance on the final block of trials of the IGT but was not significantly related to WCST performance. Both measures were significantly correlated with scores on the BIS. These results provide support for hypothesis that, in a nonclinical sample, impulsivity may vary systematically with performance on neuropsychological indicators of prefrontal function.

Impulsivity, dual diagnosis, and the structure of motivated behavior in addiction

Defining brain mechanisms that control and adapt motivated behavior will not only advance addiction treatment. It will help society see that addiction is a disease that erodes free will, rather than representing a free will that asks for or deserves consequences of drug-use choices. This science has important implications for understanding addiction's comorbidity in mental illness and reducing associated public health and criminal justice burdens.

Pathological gambling: an update on neuropathophysiology and pharmacotherapy

Neurobiological research has shown the potential involvement of serotonergic, dopaminergic and opioid dysfunction in the pathophysiology of pathological gambling. In this review, we present current theories of the neuropathology of pathological gambling, paying particular attention to the role of the neural circuitry underlying motivation, reward, decision-making and impulsivity. This review also presents a literature review of current pharmacological treatment strategies for pathological gambling, such as selective serotonin reuptake inhibitors (SSRIs), opioid receptor antagonists, anti-addiction drugs and mood stabilizers, and also discusses the role of nonpharmacological interventions.A hypothetical model of the clinical subtypes of pathological gambling is presented, e.g. the impulsive subtype, the obsessive-compulsive subtype and the addictive subtype. This model attempts to integrate current knowledge in the field of pathological gambling regarding neuropathology, psychiatric co-morbidity, family history, genetics, course of illness, gender and response to pharmacological treatment. Finally, it is proposed that the existence of possible clinical subtypes of pathological gambling may provide a potential framework for matching the various subtypes with specific pharmacotherapies.

Gender-related differences in individuals seeking treatment for kleptomania

OBJECTIVE

Understanding variations in disease presentation in men and women is clinically important as differences may reflect biological and sociocultural factors and have implications for prevention and treatment strategies. Few empirical investigations have been performed in kleptomania, particularly with respect to gender-related influences.

METHODS

From 2001--2007, 95 adult subjects (n=27 [28.4%] males) with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-defined kleptomania were assessed on sociodemographics and clinical characteristics, including symptom severity, comorbidity, and functional impairment, to identify gender-related differences.

RESULTS

Men and women showed substantial symptom severity and functional impairment. Compared with affected men, women with kleptomania were more likely to be married (47.1% vs 25.9%; P=.039), have a later age at shoplifting onset (20.9 vs 14 years of age; P=.001), steal household items (P<.001), hoard stolen items (P=.020), and have an eating disorder (P=.017) and less likely to steal electronic goods (P<.001) and have another impulse-control disorder (P=.018).

CONCLUSION

Kleptomania is similarly associated with significant impairment in women and men. Gender-related differences in clinical features and co-occurring disorders suggest that prevention and treatment strategies incorporate gender considerations.