Gambling, disordered gambling and their association with major depression and substance use: a web-based cohort and twin-sibling study

Suicidal Behaviour Among Nigerian Undergraduates: Associations with Gambling Disorder and Emotional Dysregulation

Background: There is a high prevalence of suicidal behavior among Nigerian youths. However, the connections between suicidal behavior and precipitating factors, such as gambling disorder and emotional dysregulation (ED) in this population, are not well researched. Objectives: The present study examined the associations between gambling disorder, ED, and suicidal behavior in Nigerian university undergraduate students. Methods: This study was carried out during October 2020 - April 2021 on 1338 undergraduates with a mean ± SD age of 19.84 ± 3.22 years selected using random and purposive sampling for the universities and participants respectively. Participants responded to the Attitudes Towards Gambling Scale, Difficulties in Emotion Regulation Scale, and Redeemer's University Suicidality Scale. Descriptive statistics (simple percentages) and inferential statistics (Pearson’s correlation and regression analysis) were used for data analysis. Results: The Pearson's correlation revealed that suicidal behaviour had significant positive correlations with the nonacceptance of emotional responses or distress (r = 0.22, P = 0), difficulties engaging in goal-directed behaviours (r = 0.21, P = 0), difficulties in impulse control (r = 0.27, P = 0), the lack of emotional awareness (r = 0.14, P = 0), limited access to emotional regulation strategies (r = 0.33, P = 0), the lack of emotional clarity (r = 0.32, P = 0), and difficulties in emotional regulation (r = 0.4, P = 0). Problematic gambling (PG) independently predicted suicidal behavior, while PG and ED dimensions jointly predicted suicidal behavior. The ED dimensions contributed 15% incrementally to the prediction of suicidal behavior and beyond the 2% variance accounted for PG in undergraduates. Conclusions: Our results showed positive links between PG, ED, and suicidal behavior among Nigerian undergraduates. It suggests that the combination of PG and ED increases the severity of suicidal behavior among students.

The structure and subtypes of gambling activities: Genetic, psychiatric and behavioral etiologies of gambling frequency

The multitude of gambling activities has given rise to heterogeneous ways of analyzing these behaviors and may partially underlie the lack of replication in gambling research. The current study used complementary analyses to investigate the structure, typology and etiology of gambling behaviors in a discovery sample of 2,116 twins (54.86% female; M_age = 24.90) and a replication sample of 619 siblings (30.37% female; M_age = 28.00). Our approach was twofold. First, we used confirmatory factor analyses to investigate the structure across the frequency of eight gambling activities. Second, we used factor mixture models to identify gambling frequency subtypes. We assessed associations with gambling frequency as well as conducted genetically informed analyses to estimate the role of genetic and environmental influences. Across samples, a two-factor model fit the data best, with a Common Gambling factor influencing all activities and a separate factor for Skill Gambling. Our study identified four gambling frequency subtypes, which resembled the typology from the Pathways Model. We found distinct demographic, psychiatric, behavioral and genetic risk profiles for the different gambling factors and subtypes with robust associations observed for male sex, risk-taking, sensation seeking, alcohol dependence and problem gambling. Controlling for shared genetic and environmental influences (via co-twin control modeling), we found that sensation seeking directly increased Common Gambling frequency. In sum, we illustrated the utility of multi-dimensional statistical techniques for disentangling the structure and typology from complex multivariate gambling data.

The neural basis of gambling disorder: An activation likelihood estimation meta-analysis

Previous imaging studies suggested that impairments of prefrontal-striatal and limbic circuits are correlated to excessive gambling. However, the neural underpinnings of gambling disorder (GD) continue to be the topic of debate. The present study aimed to identify structural changes in GD and differentiate the specific brain activity patterns associated with decision-making and reward-processing. We performed a systematic review complemented by Activation likelihood estimation (ALE) meta-analyses on morphometric and functional studies on neural correlates of GD. The ALE meta-analysis on structural studies revealed that patients with GD showed significant cortical grey-matter thinning in the right ventrolateral and ventromedial prefrontal cortex compared to healthy subjects. The ALE meta-analyses on functional studies revealed that patients with GD showed a significant hyperactivation in the medial prefrontal cortex and in the right ventral striatum during decision-making and gain processing compared to healthy subjects. These findings suggest that GD is related to an alteration of brain mechanisms underlying top-down control and appraisal of gambling-related stimuli and provided indications to develop new interventions in clinical practice.

High Recreational Gamblers Show Increased Stimulatory Effects of an Acute Laboratory Gambling Challenge

Gambling in moderation is a socially acceptable behavior and over 60% of the Swedish population gambles every year. It has been seen that slot machines are one of the most addictive and problematic forms of gambling and contribute highly to an addictive behavior. It is unclear why some individuals intensify their gambling behavior over time to extreme levels while others do not. Initial positive response of a drug or as in this case a gambling behavior, most likely influences the likelihood of continuing use in non-addicted individuals. Therefore, we wanted to investigate if recreational gamblers show an altered subjective response to an online gambling challenge, e.g. to casino gambling. The present study was designed to examine the subjective effects after an acute gambling challenge, in healthy recreational gamblers compared with non-gamblers. Eighty-two subjects participated in the study. They were challenged with an acute online slot machine gambling challenge and self-report questionnaires of mood and blood pressure were taken before and after gambling. The gamblers, and more specifically the high recreational gamblers, reported increased stimulative effects after the gambling challenge in comparison to the non-gamblers. Findings suggests that gamblers experience significantly higher arousal effects to an acute online slot machine challenge. This response may be a uniquely predictive behavior for increased risk of gambling addiction.

Genome-wide association study of pathological gambling

Background

Pathological gambling is a behavioural addiction with negative economic, social, and psychological consequences. Identification of contributing genes and pathways may improve understanding of aetiology and facilitate therapy and prevention. Here, we report the first genome-wide association study of pathological gambling. Our aims were to identify pathways involved in pathological gambling, and examine whether there is a genetic overlap between pathological gambling and alcohol dependence.

Methods

Four hundred and forty-five individuals with a diagnosis of pathological gambling according to the Diagnostic and Statistical Manual of Mental Disorders were recruited in Germany, and 986 controls were drawn from a German general population sample. A genome-wide association study of pathological gambling comprising single marker, gene-based, and pathway analyses, was performed. Polygenic risk scores were generated using data from a German genome-wide association study of alcohol dependence.

Results

No genome-wide significant association with pathological gambling was found for single markers or genes. Pathways for Huntington's disease (P-value = 6.63 × 10−3); 5′-adenosine monophosphate-activated protein kinase signalling (P-value = 9.57 × 10−3); and apoptosis (P-value = 1.75 × 10−2) were significant. Polygenic risk score analysis of the alcohol dependence dataset yielded a one-sided nominal significant P-value in subjects with pathological gambling, irrespective of comorbid alcohol dependence status.

Conclusions

The present results accord with previous quantitative formal genetic studies which showed genetic overlap between non-substance- and substance-related addictions. Furthermore, pathway analysis suggests shared pathology between Huntington's disease and pathological gambling. This finding is consistent with previous imaging studies.

Polygenic Risk Scores for Psychiatric Disorders Reveal Novel Clues About the Genetics of Disordered Gambling

Disordered gambling (DG) is a rare but serious condition that results in considerable financial and interpersonal harms. Twin studies indicate that DG is heritable but are silent with respect to specific genes or pathways involved. Existing genomewide association studies (GWAS) of DG have been substantially underpowered. Larger GWAS of other psychiatric disorders now permit calculation of polygenic risk scores (PRSs) that reflect the aggregated effects of common genetic variants contributing risk for the target condition. The current study investigated whether gambling and DG are associated with PRSs for four psychiatric conditions found to be comorbid with DG in epidemiologic surveys: major depressive disorder (MDD), attention-deficit hyperactivity disorder (ADHD), bipolar disorder (BD) and schizophrenia (SCZ). Genotype data and survey responses were analyzed from the Wave IV assessment (conducted in 2008) of the National Longitudinal Study of Adolescent to Adult Health, a representative sample of adolescents recruited in 1994-1995 and followed into adulthood. Among participants classified as having European ancestry based on genetic analysis (N = 5215), 78.4% reported ever having gambled, and 1.3% reported lifetime DG. Polygenic risk for BD was associated with decreased odds of lifetime gambling, OR = 0.93 [0.87, 0.99], p = .045, pseudo-R2(%) = .12. The SCZ PRS was associated with increased odds of DG, OR = 1.54 [1.07, 2.21], p = .02, pseudo-R2(%) = .85. Polygenic risk scores for MDD and ADHD were not related to either gambling outcome. Investigating features common to both SCZ and DG might generate valuable clues about the genetically influenced liabilities to DG.

The paradoxical relationship between emotion regulation and gambling-related cognitive biases

Background

Gambling behavior presents substantial individual variability regarding its severity, manifestations, and psychological correlates. Specifically, differences in emotion regulation, impulsivity, and cognitive distortions have been identified as crucial to describe individual profiles with implications for the prevention, prognosis, and treatment of gambling disorder (GD).

Aims and method

The aim of the present study was to investigate the associations of gambling-related cognitions (measured according to the GRCS model) with impulsivity (UPPS-P model) and emotion regulation (CERQ model), in a sample of 246 gamblers with different levels of gambling involvement, using mixed-effects modelling to isolate theoretically relevant associations while controlling for the potentially confounding effects of sociodemographic and clinical covariates.

Results

Affective/motivational dimensions of UPPS-P impulsivity positive urgency and sensation seeking, on the one hand, and CERQ emotion regulation strategies reappraisal, rumination and blaming others, on the other, independently and significantly predicted distorted gambling-related cognitions.

Conclusions

These results (a) reinforce the ones of previous studies stressing the relevance of emotional and motivational processes in the emergence of gambling-related cognitive distortions; and (b) replicate the seemingly paradoxical finding that gamblers use emotion regulation strategies customarily considered as adaptive (i.e. reappraisal) to strengthen and justify their biased beliefs about gambling outcomes and controllability.

Where Do Gambling Problems Fit in the Structure of Psychopathology During Emerging Adulthood?

Research suggests major mental disorders co-occur at higher than chance levels. In adult samples, a two factor structure emerges when modeling the higher order structure of psychopathology. Specifically, disorders tend to co-aggregate into two dimensions: Internalizing (depression and anxiety) and Externalizing (acting out, impulsive, and addictive) disorders. Despite this large body of evidence, few studies have integrated problem gambling into this overall model. We used confirmatory factor analysis to model how the symptom count of gambling fits into the structure of psychopathology in a large, community based young adult twin sample of men and women (age 24; N=1329). Twins were assessed via in-person, structured diagnostic interviews on disorders including: Major Depression, Phobias, Post-Traumatic Stress Disorder and Anxiety Disorders (internalizing) and Substance Use Disorders, Gambling Problems (self-report), and Antisocial Behaviors (externalizing). The data were fit to a two-factor structure, with gambling symptoms loading most highly on externalizing, rather than internalizing. The problem gambling loadings did not differ by sex. Implications of these findings suggest that during emerging adulthood gambling problems are best classified and conceptualized in the realm of externalizing disorders for both males and females. Results also suggest prevention and intervention efforts be aimed at young adults who exhibit commonly co-occurring psychopathology.

The Intergenerational Association Between Parents' Problem Gambling and Impulsivity-Hyperactivity/Inattention Behaviors in Children

Despite the well-established association between problem gambling and ADHD core categories of impulsivity-hyperactivity and inattention, the link between parents' problem gambling and impulsivity-hyperactivity/inattention (IH/I) behaviors in children has not been investigated. This study investigated the association between parents' problem gambling and children's IH/I behaviors while controlling for potential confounding variables. A population-based prospective cohort followed-up from kindergarten to age 30, the Quebec Longitudinal Study of Kindergarten Children (QLSKC), provided data over three generations. Among 1358 participants at age 30, parents with a child aged 1 year or older (N = 468; Mean age = 4.65 years; SD = 2.70) were selected. Generalized Linear Models included measures of grandparents' and parents' problem gambling, parents' IH/I behaviors in childhood, and a host of risk factors and comorbidities to predict IH/I in children. Intergenerational bivariate associations were observed between grandparents' problem gambling, parents' IH/I in childhood and problem gambling at age 30, and between parents' IH/I, problem gambling, and children's IH/I behaviors. Parents' problem gambling predicted children's IH/I behaviors above and beyond the effects of covariates such as family and socioeconomic characteristics, alcohol and drug use, depression symptoms and parents' gambling involvement. Parents' IH/I behaviors in childhood also predicted children's IH/I and had a moderating, enhancing effect on parents' problem gambling association with their offspring's IH/I behaviors. Problem gambling is a characteristic of parents' mental health that is distinctively associated with children's IH/I behaviors, above and beyond parents' own history of IH/I and of typically related addictive, psychopathological or socioeconomic risk factors and comorbidities.

Genetic and environmental influences on gambling disorder liability: a replication and combined analysis of two twin studies

BACKGROUND

Gambling disorder (GD), recognized in Diagnostic and Statistical Manual of Mental Disorders, Version 5 (DSM-5) as a behavioral addiction, is associated with a range of adverse outcomes. However, there has been little research on the genetic and environmental influences on the development of this disorder. This study reports results from the largest twin study of GD conducted to date.

METHODS

Replication and combined analyses were based on samples of 3292 (mean age 31.8, born 1972-79) and 4764 (mean age 37.7, born 1964-71) male, female, and unlike-sex twin pairs from the Australian Twin Registry. Univariate biometric twin models estimated the proportion of variation in the latent GD liability that could be attributed to genetic, shared environmental, and unique environmental factors, and whether these differed quantitatively or qualitatively for men and women.

RESULTS

In the replication study, when using a lower GD threshold, there was evidence for significant genetic (60%; 95% confidence interval (CI) 45-76%) and unique environmental (40%; 95% CI 24-56%), but not shared environmental contributions (0%; 95% CI 0-0%) to GD liability; this did not significantly differ from the original study. In the combined analysis, higher GD thresholds (such as one consistent with DSM-5 GD) and a multiple threshold definitions of GD yielded similar results. There was no evidence for quantitative or qualitative sex differences in the liability for GD.

CONCLUSIONS

Twin studies of GD are few in number but they tell a remarkably similar story: substantial genetic and unique environmental influences, with no evidence for shared environmental contributions or sex differences in GD liability.

Alcohol use, psychiatric disorders and gambling behaviors: A multi-sample study testing causal relationships via the co-twin control design

Human laboratory studies and twin research investigating relationships between alcohol use/pathology and gambling generally have yielded contradictory results, sometimes suggesting causal relationships and common genetic risk factors. 2860 individuals (mean age: 25.60, s.d = 3.21, 50.62% female) from separate clinical (n = 636) and community based (twin) samples (n = 2224) were used to assess associations between past year alcohol use and frequency of past year gambling behaviors (gambling frequency). After adjustment for demographic and psychiatric covariates, individual-level analyses detected that increased alcohol use was associated with more frequent gambling behaviors in twin and clinical samples. Co-twin control models were then used to test potential causal (direct) relationships between alcohol use and gambling frequency. Controlling for all covariates and shared genetic/environmental factors, we found increased alcohol use directly predicted more frequent gambling behaviors (consistent with causality). Our study also suggests shared genetic and/or environmental risk factors contribute to the association between increased alcohol use and frequent gambling behavior, a finding that may be more pronounced in males. The present study helps bridge the gap between twin research and human laboratory studies on gambling and alcohol use and corroborates findings across community and clinical samples. Overall, our findings support both common risk factors between alcohol use and gambling as well as a direct relationship between alcohol use and gambling frequency. Recognizing these dual processes could prove useful for gambling-related prevention/intervention programs.

Determinants of Gambling Disorders in Elderly People-A Systematic Review

Background: Despite the growth in the number of studies on gambling disorders (GDs) and the potentially severe harm it may cause, problem gambling in older adults is rarely apparent in literature. Driven by the need to overcome this limitation, a broad systematic review is essential to cover the studies that have already assessed the determinants of GD in the elderly. Objectives: The aim of this systematic review is to understand the determinants related to GDs in elderly people. Methods: A total of 51 studies met the inclusion criteria, and data were synthesized. Results: Three major types of determinants were identified in this review: individual, socio-financial and environmental. Conclusions: This review explored the determinants influencing GDs in older people. The findings are relevant to academics, policymakers, patients, and practitioners interested in the identification and prevention of GD in older people.

Is Internet Addiction a Clinical Symptom or a Psychiatric Disorder? A Comparison With Bipolar Disorder

The general purpose of this review is to present an updated literature overview of neurobiological/clinical aspects of Internet addiction (IA), particularly of overlaps and differences with bipolar affective disorder (BPAD). Articles with clinical/neurobiological aspects of IA or similarities/differences with BPAD as main topics, from 1990 to present and written in English language, were included. Comorbidity between IA and other psychiatric disorders, including BPAD, is common. Dysfunctions in dopaminergic pathways have been found both in IA and in mood disorders. Most of investigations in IA support a chronic hypodopaminergic dysfunctional state in brain reward circuit and an excessive reward experience during mood elevation. Neuroimaging studies show prefrontal cortex abnormalities shared between addictive and bipolar patients. BPAD and IA present numerous overlaps, such as polymorphisms in nicotinic receptors genes, anterior cingulate/prefrontal cortex abnormalities, serotonin/dopamine dysfunctions, and good response to mood stabilizers. The future is to clarify diagnostic criteria to better define the IA/BPAD relationship.

Understanding the Relationship Between Subjective Wellbeing and Gambling Behavior

This paper examines the relationship between gambling behavior and subjective wellbeing. It is often asserted that populations consist of different types of gamblers: those for whom gambling is a harmless leisure activity and those (pathological/problem gamblers) for whom the activity has harmful effects. One might, therefore, assume that subjective wellbeing will be negativity associated with an individual's level of gambling addiction. Alternatively, gamblers may choose to gamble because they derive utility from participating in this activity and so the relationship between happiness and gambling might be positively correlated. In this paper we test this association, empirically, using data from the 2010 British Gambling Prevalence Survey. The statistically significant findings from this analysis support the hypothesis that individual wellbeing falls as gambling disorder increases.

Genetic and environmental origins of gambling behaviors from ages 18 to 25: A longitudinal twin family study

Gambling behaviors tend to increase in prevalence from late adolescence to young adulthood, and the underlying genetic and environmental influences during this period remain largely understudied. We examined the genetic and environmental influences on gambling behaviors contributing to stability and change from ages 18 to 25 in a longitudinal, behavioral genetic mixed-sex twin study design. Participants were enrolled in the Minnesota Twin Family Study. A range of gambling behaviors (maximum frequency, average frequency, money lost, and gambling problems) were assessed at ages 18 and 25. The results of our study support the following conclusions: (a) the genetic and environmental factors impacting a range of gambling behaviors are largely similar in men and women, (b) genetic factors increase in influence from 18 to 25 (21% at age 18 to 57% at age 25), (c) shared environmental factors are influential at age 18, but tend to decrease from ages 18 to 25 (55% at age 18 to 10% at age 25), and (d) nonshared environmental influences are similarly significant and are small to moderate in magnitude at both ages. The findings add to a small yet important research area regarding determinants of youth gambling behaviors and have the potential to inform prevention and intervention efforts. (PsycINFO Database Record

Caffeine's influence on gambling behavior and other types of impulsivity

BACKGROUND

Young adulthood is a developmental period frequently associated with occurrence of impulsive behaviors including gambling. It is estimated that 73% of children and 87% of adults in the United States regularly use caffeine. Questions remain, however, concerning the role of caffeine in the development and maintenance of impulsive behaviors such as gambling.

METHODS

Sixty-one young adults with at least some degree of disordered gambling were recruited from two Mid-Western university communities in the United States using media advertisements. Caffeine intake over the preceding month was quantified using the Caffeine Use Questionnaire. Clinician rating scales, questionnaires, and cognitive tests germane to impulsivity were completed. Relationships between caffeine intake and demographic, gambling symptom, and neurocognitive measures were evaluated using the statistical technique of partial least squares (PLS).

RESULTS

Average weekly caffeine intake in the gamblers was 1218.5mg (a figure higher than previously reported in the general population). PLS yielded an optimal model with one latent factor, which explained 14.8% of variation in demographic/clinical/cognitive measures and 32.3% of variation in caffeine intake. In this model, higher caffeine intake was significantly associated with earlier age at first gambling, higher personality-related impulsiveness, more nicotine consumption, older age, and more impulsive decision-making.

CONCLUSIONS

These data suggest a particularly strong relationship between caffeine intake, earlier age of first gambling, and certain types of impulsivity in gamblers. Providing education about healthy caffeine use may be especially valuable in gamblers. Future work should explore whether the relationship between caffeine use and gambling is due to a common predisposing factor (impulsive tendencies) or, rather, constitutes a form of self-medication in gamblers (or a means of sustaining gambling habits for longer).

A Baseline Study of Past-Year Problem Gambling Prevalence Among Ohioans

Historically, the scope of legalized gambling was limited in Ohio, but everything changed when a new constitutional amendment allowed four casinos to open. To better understand the impact of gambling expansion, a household survey was commissioned to determine the baseline estimate of problem gambling behaviours in the state before casinos opened. Participants were selected through multi-stage probability sampling, with over 3,500 respondents completing valid surveys. Nearly 60% of Ohioans gambled in the past year, but the statewide prevalence of problem gambling was relatively low; only 1.4% of persons scored high enough on the Problem Gambling Severity Index to be classified as a potential problem gambler (score >3). Regional estimates of problem gambling were highest for Franklin and Hamilton counties (both 5.0%) and lowest for Lucas and Cuyahoga counties (3.2% and 2.1%, respectively). Exploratory logistic regression modelling found that race, employment, education, family history of problem gambling, and feelings of depression increased the odds of being a problem gambler. Results will inform the discussion about current gambling problems and enable policy makers to design prevention strategies.La présente étude portait sur la relation entre le prix des billets de loterie instantanée (à gratter) et la « récupération des pertes » dans un seul épisode de jeu. Pendant plusieurs mois, chaque fois qu’un billet de loterie instantanée était acheté (N = 1081), les commis de dépanneur consignaient le sexe des joueurs et le prix des billets de loterie instantanée, et indiquaient si le consommateur avait acheté un autre billet avant de quitter les lieux. L’analyse de régression logistique a montré une corrélation importante entre le prix des billets et le rachat (rapport de cotes = 0,842, p < 0,0001), ce qui suggère que la récupération au cours d’un même épisode de jeu est courante pour les billets de loterie instantanée à plus bas prix et que de plus faibles coûts ne réduisent pas nécessairement les risques.

Food Addiction in Gambling Disorder: Frequency and Clinical Outcomes

Background: The food addiction (FA) model is receiving increasing interest from the scientific community. Available empirical evidence suggests that this condition may play an important role in the development and course of physical and mental health conditions such as obesity, eating disorders, and other addictive behaviors. However, no epidemiological data exist on the comorbidity of FA and gambling disorder (GD), or on the phenotype for the co-occurrence of GD+FA.

Objectives: To determine the frequency of the comorbid condition GD+FA, to assess whether this comorbidity features a unique clinical profile compared to GD without FA, and to generate predictive models for the presence of FA in a GD sample.

Method: Data correspond to N = 458 treatment-seeking patients who met criteria for GD in a hospital unit specialized in behavioral addictions.

Results: Point prevalence for FA diagnosis was 9.2%. A higher ratio of FA was found in women (30.5%) compared to men (6.0%). Lower FA prevalence was associated with older age. Patients with high FA scores were characterized by worse psychological state, and the risk of a FA diagnosis was increased in patients with high scores in the personality traits harm avoidance and self-transcendence, and low scores in cooperativeness (R² = 0.18).

Conclusion: The co-occurrence of FA in treatment-seeking GD patients is related to poorer emotional and psychological states. GD treatment interventions and related behavioral addictions should consider potential associations with problematic eating behavior and aim to include techniques that aid patients in better managing this behavior.

Gambling disorder: an integrative review of animal and human studies

Gambling disorder (GD), previously called pathological gambling and classified as an impulse control disorder in DSM-III and DSM-IV, has recently been reclassified as an addictive disorder in the DSM-5. It is widely recognized as an important public health problem associated with substantial personal and social costs, high rates of psychiatric comorbidity, poor physical health, and elevated suicide rates. A number of risk factors have been identified, including some genetic polymorphisms. Animal models have been developed in order to study the underlying neural basis of GD. Here, we discuss recent advances in our understanding of the risk factors, disease course, and pathophysiology. A focus on a phenotype-based dissection of the disorder is included in which known neural correlates from animal and human studies are reviewed. Finally, current treatment approaches are discussed, as well as future directions for GD research.

Genetic and Environmental Influences on Gambling: A Meta-Analysis of Twin Studies

Disentangling the genetic and environmental influences of gambling is important for explaining the roots of individual differences in gambling behavior and providing guidance for precaution and intervention, but we are unaware of any comprehensive and systematic quantitative meta-analysis. We systematically identified 18 twin studies on gambling in the meta-analysis. The correlation coefficients within monozygotic (MZ) and dizygotic (DZ) twins, along with the corresponding sample size, were used to calculate the proportion of the total variance accounted for by additive genes (A), dominant genes (D), the shared environment (C), and the non-shared environment plus measurement error (E). We further assessed the moderating effects of gambling assessment (symptom oriented assessment vs. behavior oriented assessment), age, and sex. The whole sample analyses showed moderate additive genetic (a² = 0.50) and non-shared environmental influences (e² = 0.50) on gambling. The magnitude of the genetic influence (a²) was higher for disordered gambling assessed with symptom oriented assessment (53%) than for general gambling assessed with behavior oriented assessment (41%). Additionally, the magnitude of the genetic influence (a²) was higher for adults (53%) than adolescents (42%). Genetic influence (a²) was greater for male (47%) gambling than female (28%) gambling. Shared environment had noticeable effects on female gambling (c² = 14%) but zero effect on male gambling. In conclusion, gambling behavior was moderately heritable and moderately influenced by non-shared environmental factors. Gambling assessment, age, and sex significantly moderated the magnitude of genetic and environmental influences on gambling. Note that the number of studies might serve as a limitation.

Local area disadvantage and gambling involvement and disorder: Evidence for gene-environment correlation and interaction

Previous research has demonstrated that local area characteristics (such as disadvantage and gambling outlet density) and genetic risk factors are associated with gambling involvement and disordered gambling. These 2 lines of research were brought together in the present study by examining the extent to which genetic contributions to individual differences in gambling involvement and disorder contributed to being exposed to, and were also accentuated by, local area disadvantage. Participants were members of the national community-based Australian Twin Registry who completed a telephone interview in which the past-year frequency of gambling and symptoms of disordered gambling were assessed. Indicators of local area disadvantage were based on census data matched to the participants' postal codes. Univariate biometric model-fitting revealed that exposure to area disadvantage was partially explained by genetic factors. Bivariate biometric model-fitting was conducted to examine the evidence for gene-environment interaction while accounting for gene-environment correlation. These analyses demonstrated that: (a) a small portion of the genetic propensity to gamble was explained by moving to or remaining in a disadvantaged area, and (b) the remaining genetic and unique environmental variation in the frequency of participating in electronic machine gambling (among men and women) and symptoms of disordered gambling (among women) was greater in more disadvantaged localities. As the gambling industry continues to grow, it will be important to take into account the multiple contexts in which problematic gambling behavior can emerge-from genes to geography-as well as the ways in which such contexts may interact with each other.

Towards a comprehensive developmental model of pathological gambling

AIMS

To develop a comprehensive etiological model of pathological gambling (PG) for men and women based on Kendler's development model for major depression, which groups 22 risk factors into five developmental tiers (childhood, early adolescence, late adolescence, adulthood, last year). We hypothesized that: (1) all risk factors would be associated significantly with PG; (2) the effect of risk factors in earlier developmental tiers would be accounted for by later tiers; and (3) there would be few gender differences.

DESIGN

Separate models were built for life-time gambling and for 12-month PG among those with life-time gambling.

SETTING

Data drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) in the United States.

PARTICIPANTS

Respondents to NESARC wave 1 (n = 43 093).

MEASUREMENTS

Odds ratios (OR) and adjusted OR (AOR) were used to determine the risk factors in multiple models.

FINDINGS

After mutually adjusting for other risk factors, family history of substance use disorders (SUD) or depression, impulsivity, childhood-onset anxiety, number of Axis I and II disorders, history of SUD, nicotine dependence, social deviance in adulthood, and past-year history of SUD, nicotine dependence and independent stressful life events predicted life-time gambling. Past history of PG, number of personality disorders and past year nicotine dependence were associated significantly with 12-month PG (all P < 0.05). There were no significant gender interactions for 12-month PG.

CONCLUSIONS

A modification of Kendler's model for major depression provides a foundation for the development of a comprehensive developmental model of pathological gambling. Life-time history of gambling and 12-month pathological gambling appear to be determined by risk factors in several developmental levels, with the effect of earlier development tiers accounted for by later ones.

Should pathological gambling and obesity be considered addictive disorders? A factor analytic study in a nationally representative sample

OBJECTIVE

Pathological gambling (PG) is now aligned with substance use disorders in the DSM-5 as the first officially recognized behavioral addiction. There is growing interest in examining obesity as an addictive disorder as well. The goal of this study was to investigate whether epidemiological data provide support for the consideration of PG and obesity as addictive disorders.

METHOD

Factor analysis of data from a large, nationally representative sample of US adults (N=43,093), using nicotine dependence, alcohol dependence, drug dependence, PG and obesity as indicators. It was hypothesized that nicotine dependence, alcohol dependence and drug use dependence would load on a single factor. It was further hypothesized that if PG and obesity were addictive disorders, they would load on the same factor as substance use disorders, whereas failure to load on the addictive factor would not support their conceptualization as addictive disorders.

RESULTS

A model with one factor including nicotine dependence, alcohol dependence, drug dependence and PG, but not obesity, provided a very good fit to the data, as indicated by CFI=0.99, TLI=0.99 and RMSEA=0.01 and loadings of all indicators >0.4.

CONCLUSION

Data from this study support the inclusion of PG in a latent factor with substance use disorders but do not lend support to the consideration of obesity, as defined by BMI, as an addictive disorder. Future research should investigate whether certain subtypes of obesity are best conceptualized as addictive disorders and the shared biological and environmental factors that account for the common and specific features of addictive disorders.

Gambling disorder and other behavioral addictions: recognition and treatment

Addiction professionals and the public are recognizing that certain nonsubstance behaviors--such as gambling, Internet use, video-game playing, sex, eating, and shopping--bear resemblance to alcohol and drug dependence. Growing evidence suggests that these behaviors warrant consideration as nonsubstance or "behavioral" addictions and has led to the newly introduced diagnostic category "Substance-Related and Addictive Disorders" in DSM-5. At present, only gambling disorder has been placed in this category, with insufficient data for other proposed behavioral addictions to justify their inclusion. This review summarizes recent advances in our understanding of behavioral addictions, describes treatment considerations, and addresses future directions. Current evidence points to overlaps between behavioral and substance-related addictions in phenomenology, epidemiology, comorbidity, neurobiological mechanisms, genetic contributions, responses to treatments, and prevention efforts. Differences also exist. Recognizing behavioral addictions and developing appropriate diagnostic criteria are important in order to increase awareness of these disorders and to further prevention and treatment strategies.

Reward pathway dysfunction in gambling disorder: A meta-analysis of functional magnetic resonance imaging studies

Recent emerging functional magnetic resonance imaging (fMRI) studies have identified many brain regions in which gambling cues or rewards elicit activation and may shed light upon the ongoing disputes regarding the diagnostic and neuroscientific issues of gambling disorder (GD). However, no studies to date have systemically reviewed fMRI studies of GD to analyze the brain areas activated by gambling-related cues and examine whether these areas were differentially activated between cases and healthy controls (HC). This study reviewed 62 candidate articles and ultimately selected 13 qualified voxel-wise whole brain analysis studies to perform a comprehensive series of meta-analyses using the effect size-signed differential mapping approach. Compared with HC, GD patients showed significant activation in right lentiform nucleus and left middle occipital gyrus. The increased activities in the lentiform nucleus compared to HC were also found in both GD subgroups, regardless of excluding or not excluding any kind of substance use disorder. In addition, the South Oaks Gambling Screen scores were associated with hyperactivity in right lentiform nucleus and bilateral parahippocampus, but negatively related to right middle frontal gyrus. These results suggest dysfunction within the frontostriatal cortical pathway in GD, which could contribute to our understanding of the categories and definition of GD and provide evidence for the reclassification of GD as a behavioral addiction in the DSM-5.

An overview of and rationale for changes proposed for pathological gambling in DSM-5

The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is scheduled for publication in 2013. It will include several changes to the diagnosis of pathological gambling: the name of the disorder will be altered, the threshold for diagnosis will decrease, and one criterion will be removed. This paper reviews the rationale for these changes and addresses how they may impact diagnosis and treatment of the disorder, as well as potential for future research in the field.

Ventral striatal dopamine synthesis capacity is associated with individual differences in behavioral disinhibition

Pathological gambling, alongside addictive and antisocial disorders, forms part of a broad psychopathological spectrum of externalizing disorders, which share an underlying genetic vulnerability. The shared externalizing propensity is a highly heritable, continuously varying trait. Disinhibitory personality traits such as impulsivity and novelty seeking (NS) function as indicators of this broad shared externalizing tendency, which may reflect, at the neurobiological level, variation in the reactivity of dopaminergic (DAergic) brain reward systems centered on the ventral striatum (VS). Here, we examined whether individual differences in ventral striatal dopamine (DA) synthesis capacity were associated with individual variation in disinhibitory personality traits. Twelve healthy male volunteers underwent 6-[¹⁸F]Fluoro-L-DOPA (FDOPA) positron emission tomography (PET) scanning to measure striatal DA synthesis capacity, and completed a measure of disinhibited personality (NS). We found that levels of ventral, but not dorsal, striatal DA synthesis capacity were significantly correlated with inter-individual variation in disinhibitory personality traits, particularly a propensity for financial extravagance and irresponsibility. Our results are consistent with preclinical models of behavioral disinhibition and addiction proneness, and provide novel insights into the neurobiology of personality based vulnerability to pathological gambling and other externalizing disorders.

Towards a comprehensive developmental model of cannabis use disorders

AIMS

To develop a comprehensive risk-factor model of cannabis use disorders (CUD) based on Kendler's development model for major depression.

DESIGN

Risk factors were divided into five developmental tiers based on Kendler's model of depression (childhood, early adolescence, late adolescence, adulthood, past year). Hierarchical logistic regression models were used to examine the independent contribution of each risk factor. Separate models were built to predict the lifetime risk of cannabis use and the risk of CUD among those with a history of lifetime risk of cannabis use.

SETTING

Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) in the United States.

PARTICIPANTS

Participants consisted of wave 2 of the NESARC (n = 34 653).

MEASUREMENTS

Odds ratios (OR), Adjusted OR (AOR) and confidence intervals (95% CI) were used to determine the risk factors in each tier and with multiple models.

FINDINGS

After mutually adjusting for the effect of other risk factors, lifetime history of drug use disorder (AOR = 4.78, 95% CI = 1.53-14.91), past year alcohol use disorders (AOR = 6.55, 95% CI = 2.54-16.89) and independent (AOR = 1.57, 95% CI = 1.15-2.14) and dependent (AOR = 1.25, 95% CI = 1.01-1.55) stressful life events predicted lifetime cannabis use. Impulsivity (AOR = 2.18, 95% CI = 1.34-3.53), past year alcohol use disorders (AOR = 4.09, 95% CI = 2.29-7.31), greater number of Axis I disorders (AOR = 1.56, 95% CI = 1.01-2.40) and social deviance (AOR = 1.19, 95% CI = 1.08-1.32) independently increased the risk of the development of CUD, whereas religious service attendance (AOR = 0.50, 95% CI = 0.30-0.85) decreased this risk. In both models, the effect of earlier development tiers was mediated by more proximal ones. There were few gender differences in both models.

CONCLUSIONS

A modification of Kendler's risk factor model for major depression which stratifies risk factors into five groups (childhood, early adolescence, late adolescence, adulthood, past year) provides a useful foundation for a comprehensive developmental model of cannabis use and cannabis use disorders.

A closer look at the evidence for sex differences in the genetic and environmental influences on gambling in the national longitudinal study of adolescent health: from disordered to ordered gambling

BACKGROUND AND AIMS

To reconcile an inconsistency in the disordered gambling literature by revisiting a previous study that claimed to find evidence for large gender differences in the magnitude of genetic and environmental influences.

DESIGN

Univariate structural equation twin models were fitted to decompose the variation in gambling behavior into additive genetic, shared environmental and unique environmental influences.

SETTING

United States.

PARTICIPANTS

Participants were 1196 same-sex and unlike-sex twins (18-28 years of age, 49% male, 51% female) from the National Longitudinal Study of Adolescent Health (Add Health).

MEASUREMENTS

Eight questions about normative and problematic gambling involvement were assessed by in-person interview. Although disordered gambling symptoms were assessed, the number of individuals who were administered these questions precluded twin analysis, including analysis of potential gender differences. Of the eight questions, only three were deemed usable for twin analysis-these were all questions about normative gambling involvement.

FINDINGS

Individual differences in (non-disordered) gambling involvement were explained completely by family [C = 38% (30-46%)] and unique environmental factors [E = 62% (54-70%)]. There was no evidence for genetic factors (A = 0), nor was there evidence for sex differences (Δχ(2) = 1.23, d.f. = 2, P = 0.54).

CONCLUSIONS

There appears to be no evidence for gender differences in the genetic contributions to disordered gambling. Family environment appears to play a significant role in explaining individual differences in (non-disordered) gambling involvement among emerging adults.

The use of clinical trials in comparative effectiveness research on mental health

OBJECTIVES

A large body of comparative effectiveness research (CER) focuses on the use of observational and quasi-experimental approaches. We sought to examine the use of clinical trials as a tool for CER, particularly in mental health.

STUDY DESIGN AND SETTING

Examination of three ongoing randomized clinical trials in psychiatry addressing issues that would pose difficulties for nonexperimental CER methods.

RESULTS

Existing statistical approaches to nonexperimental data appear insufficient to compensate for biases that may arise when the pattern of missing data cannot be properly modeled such as when there are no standards for treatment, when affected populations have limited access to treatment, or when there are high rates of treatment dropout.

CONCLUSION

Clinical trials should retain an important role in CER, particularly in cases of high disorder prevalence, large expected effect sizes, difficult-to-reach populations, or when examining sequential treatments or stepped-care algorithms. Progress in CER on mental health will require careful consideration of appropriate selection between clinical trials and nonexperimental designs and on allocation of research resources to optimally inform key treatment decisions for each patient.

A targeted review of the neurobiology and genetics of behavioural addictions: an emerging area of research

This review summarizes neurobiological and genetic findings in behavioural addictions, draws parallels with findings pertaining to substance use disorders, and offers suggestions for future research. Articles concerning brain function, neurotransmitter activity, and family history and (or) genetic findings for behavioural addictions involving gambling, Internet use, video game playing, shopping, kleptomania, and sexual activity were reviewed. Behavioural addictions involve dysfunction in several brain regions, particularly the frontal cortex and striatum. Findings from imaging studies incorporating cognitive tasks have arguably been more consistent than cue-induction studies. Early results suggest white and grey matter differences. Neurochemical findings suggest roles for dopaminergic and serotonergic systems, but results from clinical trials seem more equivocal. While limited, family history and genetic data support heritability for pathological gambling and that people with behavioural addictions are more likely to have a close family member with some form of psychopathology. Parallels exist between neurobiological and genetic and family history findings in substance and nonsubstance addictions, suggesting that compulsive engagement in these behaviours may constitute addictions. To date, findings are limited, particularly for shopping, kleptomania, and sexual behaviour. Genetic understandings are at an early stage. Future research directions are offered.

An empirical evaluation of proposed changes for gambling diagnosis in the DSM-5

AIMS

Recommendations related to pathological gambling for the fifth edition of the Diagnostic and statistic manual for mental disorders (DSM) are to eliminate the criterion related to committing illegal acts and reduce the threshold for diagnosis from five to four criteria. This study evaluated the impact of these changes on prevalence rates and classification accuracy.

DESIGN

Data were analyzed from five samples, varying in severity of gambling problems.

SETTINGS AND PARTICIPANTS

Surveys of randomly selected household residents in the United States (US) (n = 2417), gambling patrons (n = 450), individuals in brief intervention studies (n = 375), patients in community-based gambling treatment programs (n = 149) and participants in randomized intervention studies (n = 319).

MEASUREMENTS

The national opinion research center DSM-IV screen for gambling problems (NODS) was administered to all participants. Internal consistency and factor structure were evaluated using both 10 and nine criteria. Base rates, hit rates, sensitivity, specificity and overall agreement were compared across classification systems, using DSM-IV classification as the standard.

FINDINGS

Eliminating the illegal acts criterion did not impact internal consistency and modestly improved variance accounted for in the factor structure. In comparing a classification system using four of 10 criteria versus one using four of nine, the four of nine system yielded equal or slightly better classification accuracy in all comparisons and across all samples.

CONCLUSIONS

The inclusion of the illegal acts criterion in the proposed DSM-V pathological gambling diagnosis does not appear necessary for diagnosis of pathological gambling and, if it is eliminated, reducing the cut-point to four results in more consistent diagnoses relative to the current classification system.

Ventral striatal dopamine synthesis capacity predicts financial extravagance in Parkinson's disease

Impulse control disorders (ICDs), including disordered gambling, can occur in a significant number of patients with Parkinson’s disease (PD) receiving dopaminergic therapy. The neurobiology underlying susceptibility to such problems is unclear, but risk likely results from an interaction between dopaminergic medication and a pre-existing trait vulnerability. Impulse control and addictive disorders form part of a broader psychopathological spectrum of disorders, which share a common underlying genetic vulnerability, referred to as externalizing. The broad externalizing risk factor is a continuously varying trait reflecting vulnerability to various impulse control problems, manifested at the overt level by disinhibitory symptoms and at the personality level by antecedent traits such as impulsivity and novelty/sensation seeking. Trait “disinhibition” is thus a core endophenotype of ICDs, and a key target for neurobiological investigation. The ventral striatal dopamine system has been hypothesized to underlie individual variation in behavioral disinhibition. Here, we examined whether individual differences in ventral striatal dopamine synthesis capacity predicted individual variation in disinhibitory temperament traits in individuals with PD. Eighteen early-stage male PD patients underwent 6-[¹⁸F]Fluoro-l-DOPA (FDOPA) positron emission tomography scanning to measure striatal dopamine synthesis capacity, and completed a measure of disinhibited personality. Consistent with our predictions, we found that levels of ventral, but not dorsal, striatal dopamine synthesis capacity predicted disinhibited personality, particularly a propensity for financial extravagance. Our results are consistent with recent preclinical models of vulnerability to behavioral disinhibition and addiction proneness, and provide novel insights into the neurobiology of potential vulnerability to impulse control problems in PD and other disorders.

The structure of common and uncommon mental disorders

BACKGROUND

Co-morbidity patterns in epidemiological studies of mental illness consistently demonstrate that a latent internalizing factor accounts for co-morbidity patterns among unipolar mood and anxiety disorders, whereas a latent externalizing factor underlies the covariation of substance-use disorders and antisocial behaviors. However, this structure needs to be extended to include a broader range of disorders.

METHOD

Exploratory and confirmatory factor analyses were used to examine the structure of co-morbidity using data from the Collaborative Psychiatric Epidemiological Surveys (n = 16 233).

RESULTS

In the best-fitting model, eating and bipolar disorders formed subfactors within internalizing, impulse control disorders were indicators of externalizing, and factor-analytically derived personality disorder scales split between internalizing and externalizing.

CONCLUSIONS

This was the first large-scale nationally representative study that has included uncommon mental disorders with sufficient power to examine their fit within a structural model of psychopathology. The results of this study have important implications for conceptualizing myriad mental disorders.

The genetic and environmental etiology of decision-making: a longitudinal twin study

The present study examined the genetic and environmental etiology of decision-making (Iowa Gambling Task; Bechara, Damásio, Damásio, & Anderson, 1994), in a sample of twins at ages 11-13, 14-15, and 16-18 years. The variance across five 20-trial blocks could be explained by a latent "decision-making'' factor within each of the three times of IGT administration. This latent factor was modestly influenced by genetic factors, explaining 35%, 20% and 46% of the variance within each of the three times of IGT administration. The remaining variance was explained by the non-shared environment (65%, 80% and 54%, respectively). Block-specific non-shared environmental influences were also observed. The stability of decision-making was modest across development. Youth showed a trend to choose less risky decks at later ages, suggesting some improvement in task performance across development. These findings contribute to our understanding of decision-making by highlighting the particular importance of each person's unique experiences on individual differences.

Conduct disorder and adult psychiatric diagnoses: associations and gender differences in the U.S. adult population

The authors' objective was to examine the presence of Axis I and II psychiatric disorders among adult males and females with a history in childhood and/or adolescence of conduct disorder (CD). Data were derived from a large national sample of the U.S. population. Face-to-face interviews of more than 34,000 adults ages 18 years and older were conducted during 2004-2005 using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version. After adjusting for sociodemographic characteristics and psychiatric comorbidity, CD was associated with all Axis I and II disorders, particularly substance use disorders (SUD), bipolar disorder, and histrionic personality disorders. After adjusting for gender differences in the general population, men had significantly greater odds of social anxiety disorder and paranoid personality disorder, whereas women were more likely to have SUD. Furthermore, there was dose-response relationship between number of CD symptoms and risk for most psychiatric disorders. From a clinical standpoint, knowledge of the gender differences in associations of CD with other psychiatric disorders in adulthood may be informative of developmental pathways of the disorder, and of possible gender-specific risk factors. Early recognition and treatment of CD may help prevent the development of adult-onset disorders.