Neurobiology of gambling behaviors

Decomposition of Reinforcement Learning Deficits in Disordered Gambling via Drift Diffusion Modeling and Functional Magnetic Resonance Imaging

Gambling disorder is associated with deficits in reward-based learning, but the underlying computational mechanisms are still poorly understood. Here, we examined this issue using a stationary reinforcement learning task in combination with computational modeling and functional resonance imaging (fMRI) in individuals that regular participate in gambling (n = 23, seven fulfilled one to three DSM 5 criteria for gambling disorder, sixteen fulfilled four or more) and matched controls (n = 23). As predicted, the gambling group exhibited substantially reduced accuracy, whereas overall response times (RTs) were not reliably different between groups. We then used comprehensive modeling using reinforcement learning drift diffusion models (RLDDMs) in combination with hierarchical Bayesian parameter estimation to shed light on the computational underpinnings of this performance deficit. In both groups, an RLDDM in which both non-decision time and decision threshold (boundary separation) changed over the course of the experiment accounted for the data best. The model showed good parameter and model recovery, and posterior predictive checks revealed that, in both groups, the model accurately reproduced the evolution of accuracies and RTs over time. Modeling revealed that, compared to controls, the learning impairment in the gambling group was linked to a more rapid reduction in decision thresholds over time, and a reduced impact of value-differences on the drift rate. The gambling group also showed shorter non-decision times. FMRI analyses replicated effects of prediction error coding in the ventral striatum and value coding in the ventro-medial prefrontal cortex, but there was no credible evidence for group differences in these effects. Taken together, our findings show that reinforcement learning impairments in disordered gambling are linked to both maladaptive decision threshold adjustments and a reduced consideration of option values in the choice process.

Neural fingerprints of gambling disorder using diffusion tensor imaging

Gambling disorder (GD) is a behavioral addiction associated with personal, social and occupational consequences. Thus, examining GD's clinical relationship with its neural substrates is critical. We compared neural fingerprints using diffusion tensor imaging (DTI) in GD subjects undergoing treatment relative to healthy volunteers (HV). Fifty-three (25 GD, 28 age-matched HV) males were scanned with structural magnetic resonance imaging (MRI) and DTI. We applied probabilistic tractography based on DTI scanning data, preprocessed and analyzed using permutation testing of individual connectivity weights between regions for group comparison. Permutation-based comparisons between group-averaged connectomes highlighted significant structural differences. The GD group demonstrated increased connectivity, and striatal network reorganisation, contrasted by reduced connectivity within and to frontal lobe nodes. Modularity analysis revealed that the GD group had fewer hubs integrating information across the brain. We highlight GD neural changes involved in controlling risk-seeking behaviors. The observed striatal restructuring converges with previous research, and the increased connectivity affects subnetworks highly active in gambling situations, although these findings are not significant when correcting for multiple comparisons. Modularity analysis underlines that, despite connectivity increases, the GD connectome loses hubs, impeding its neuronal network coherence. Together, these results demonstrate the feasibility of using whole-brain computational modeling in assessing GD.

Computational models of behavioral addictions: State of the art and future directions

Non-pharmacological behavioral addictions, such as pathological gambling, videogaming, social networking, or internet use, are becoming major public health concerns. It is not yet clear how behavioral addictions could share many major neurobiological and behavioral characteristics with substance use disorders, despite the absence of direct pharmacological influences. A deeper understanding of the neurocognitive mechanisms of addictive behavior is needed, and computational modeling could be one promising approach to explain intricately entwined cognitive and neural dynamics. This review describes computational models of addiction based on reinforcement learning algorithms, Bayesian inference, and biophysical neural simulations. We discuss whether computational frameworks originally conceived to explain maladaptive behavior in substance use disorders can be effectively extended to non-substance-related behavioral addictions. Moreover, we introduce recent studies on behavioral addictions that exemplify the possibility of such extension and propose future directions.

Fluoxetine combined with risperidone in treatment of online gambling disorder-case report

Pathological gambling leaves seriously negative impacts on individuals, families, and society. With the universal use of internet, online gambling disorder is also increasing worldwide. However, there is currently a lack of effective treatments, especially medical treatments, for online gambling disorder. This study shared 3 cases of online gambling disorder that was treated with combined fluoxetine and risperidone to provide an option for the treatment of online gambling.

Serotonergic and dopaminergic control of impulsivity in gambling disorder

Gambling disorder (GD) is major public health issue. The disorder is often characterized by elevated impulsivity with evidence from analogous substance use disorders underlining prominent roles of brain monoamines in addiction susceptibility and outcome. Critically, GD allows the study of addiction mechanisms without the confounder of the effects of chronic substances. Here, we assessed the roles of striatal dopamine transporter binding and extrastriatal serotonin transporter binding in GD as a function of impulsivity using [¹²³ I]FP-CIT SPECT imaging in 20 older adults with GD (DSM-5 criteria; mean age 64 years) and 40 non-GD age- and sex-matched controls. We focused on GD in older individuals because there are prominent age-related changes in neurotransmitter function and because there are no reported neuroimaging studies of GD in older adults. Volume-of-interest-based and voxelwise analyses were performed. GD patients scored clearly higher on impulsivity and had higher tracer binding in the ventromedial prefrontal cortex than controls (p < 0.001), likely reflecting serotonin transporter activity. The binding in the medial prefrontal cortex positively correlated with impulsivity over the whole sample (r = 0.62, p < 0.001) as well as separately in GD patients (r = 0.46, p = 0.04) and controls (r = 0.52, p < 0.001). Striatal tracer binding, reflecting dopamine transporter activity was also positively correlated with impulsivity but showed no group differences. These findings highlight the role of prefrontal serotonergic function in GD and impulsivity. They identify cerebral coordinates of a potential target for neuromodulation for both GD and high impulsivity, a core phenotypic dimensional cognitive marker in addictions.

Drug-Induced Gambling Disorder: Epidemiology, Neurobiology, and Management

Problematic gambling has been suggested to be a possible consequence of dopaminergic medications used mainly in neurological conditions, i.e. pramipexole and ropinirole, and possibly by one antipsychotic compound, aripiprazole. Patients with Parkinson's disease, restless legs syndrome and other conditions potentially treated with dopamine agonists, as well as patients treated for psychotic disorders, are vulnerable patient groups with theoretically increased risk of developing gambling disorder (GD), for example due to higher rates of mental ill-health in these groups. The aim of the present paper is to review the epidemiological, clinical, and neurobiological evidence of the association between dopaminergic medications and GD, and to describe risk groups and treatment options. The neurobiology of GD involves the reward and reinforcement system, based mainly on mesocorticolimbic dopamine projections, with the nucleus accumbens being a crucial area for developing addictions to substances and behaviors. The addictive properties of gambling can perhaps be explained by the reward uncertainty that activates dopamine signaling in a pathological manner. Since reward-related learning is mediated by dopamine, it can be altered by dopaminergic medications, possibly leading to increased gambling behavior and a decreased impulse control. A causal relationship between the medications and GD seems likely, but the molecular mechanisms behind this association have not been fully described yet. More research is needed in order to fully outline the clinical picture of GD developing in patient groups with dopaminergic medications, and data are needed on the differentiation of risk in different compounds. In addition, very few interventional studies are available on the management of GD induced by dopaminergic medications. While GD overall can be treated, there is need for treatment studies testing the effectiveness of tapering of the medication or other gambling-specific treatment modalities in these patient groups.

Pharmacological interventions for the treatment of disordered and problem gambling

BACKGROUND

Pharmacological interventions for disordered and problem gambling have been employed in clinical practice. Despite the availability of several reviews of the efficacy of pharmacological interventions for disordered or problem gambling, few have employed systematic search strategies or compared different categories of pharmacological interventions. Systematic reviews of high-quality evidence are therefore essential to provide guidance regarding the efficacy of different pharmacological interventions for disordered or problem gambling.

OBJECTIVES

The primary aims of the review were to: (1) examine the efficacy of major categories of pharmacological-only interventions (antidepressants, opioid antagonists, mood stabilisers, atypical antipsychotics) for disordered or problem gambling, relative to placebo control conditions; and (2) examine the efficacy of these major categories relative to each other.  SEARCH METHODS: We searched the Cochrane Common Mental Disorders Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Embase, and PsycINFO (all years to 11 January 2022).

SELECTION CRITERIA

We included randomised trials evaluating a pharmacological intervention for the treatment of disordered or problem gambling. Eligible control conditions included placebo control groups or comparisons with another category of pharmacological intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures, including systematic extraction of included study characteristics and results and risk of bias assessment. Our primary outcome was reduction in gambling symptom severity. Our secondary outcomes were reduction in gambling expenditure, gambling frequency, time spent gambling, depressive symptoms, anxiety symptoms, and functional impairment; and responder status. We evaluated treatment effects for continuous and dichotomous outcomes using standardised mean difference (SMD) and risk ratios (RR), respectively, employing random-effects meta-analyses. A minimum of two independent treatment effects were required for a meta-analysis to be conducted (with only meta-analytic findings reported in this abstract).

MAIN RESULTS

We included 17 studies in the review (n = 1193 randomised) that reported outcome data scheduled for end of treatment. Length of treatment ranged from 7 to 96 weeks.  Antidepressants: Six studies (n = 268) evaluated antidepressants, with very low to low certainty evidence suggesting that antidepressants were no more effective than placebo at post-treatment: gambling symptom severity (SMD -0.32, 95% CI -0.74 to 0.09, n = 225), gambling expenditure (SMD -0.27, 95% CI -0.60 to 0.06, n = 144), depressive symptoms (SMD -0.19, 95% CI -0.60 to 0.23, n = 90), functional impairment (SMD -0.15, 95% CI -0.53 to 0.22, n = 110), and responder status (RR 1.24, 95% CI 0.93 to 1.66, n = 268). Opioid antagonists: Four studies (n = 562) evaluated opioid antagonists, with very low to low certainty evidence showing a medium beneficial effect of treatment on gambling symptom severity relative to placebo at post-treatment (SMD -0.46, 95% CI -0.74 to -0.19, n = 259), but no difference between groups in responder status (RR 1.65, 95% CI 0.86 to 3.14, n = 562). Mood stabilisers: Two studies (n = 71) evaluated mood stabilisers (including anticonvulsants), with very low certainty evidence suggesting that mood stabilisers were no more effective than placebo at post-treatment: gambling symptom severity (SMD -0.92, 95% CI -2.24 to 0.39, n = 71), depressive symptoms (SMD -0.15, 95% CI -1.14 to 0.83, n = 71), and anxiety symptoms (SMD -0.17, 95% CI -0.64 to 0.30, n = 71). Atypical antipsychotics:Two studies (n = 63) evaluated the atypical antipsychotic olanzapine, with very low certainty evidence showing a medium beneficial effect of treatment on gambling symptom severity relative to placebo at post-treatment (SMD -0.59, 95% CI -1.10 to -0.08, n = 63). Comparative effectiveness: Two studies (n = 62) compared antidepressants with opioid antagonists, with very low certainty evidence indicating that antidepressants were no more effective than opioid antagonists on depressive symptoms (SMD 0.22, 95% CI -0.29 to 0.72, n = 62) or anxiety symptoms (SMD 0.21, 95% CI -0.29 to 0.72, n = 62) at post-treatment. Two studies (n = 58) compared antidepressants with mood stabilisers (including anticonvulsants), with very low certainty evidence indicating that antidepressants were no more effective than mood stabilisers on depressive symptoms (SMD 0.02, 95% CI -0.53 to 0.56, n = 58) or anxiety symptoms (SMD 0.16, 95% CI -0.39 to 0.70, n = 58) at post-treatment. Tolerability and adverse events: Several common adverse effects were reported by participants receiving antidepressants (e.g. headaches, nausea, diarrhoea/gastrointestinal issues) and opioid antagonists (e.g. nausea, dry mouth, constipation). There was little consistency in the types of adverse effects experienced by participants receiving mood stabilisers (e.g. tiredness, headaches, concentration difficulties) or atypical antipsychotics (e.g. pneumonia, sedation, increased hypomania). Discontinuation of treatment due to these adverse events was highest for opioid antagonists (10% to 32%), followed by antidepressants (4% to 31%), atypical antipsychotics (14%), and mood stabilisers (13%).

AUTHORS' CONCLUSIONS

This review provides preliminary support for the use of opioid antagonists (naltrexone, nalmefene) and atypical antipsychotics (olanzapine) to produce short-term improvements in gambling symptom severity, although a lack of available evidence precludes a conclusion regarding the degree to which these pharmacological agents can improve other gambling or psychological functioning indices. In contrast, the findings are inconclusive with regard to the effects of mood stabilisers (including anticonvulsants) in the treatment of disordered or problem gambling, and there is limited evidence to support the efficacy of antidepressants. However, these conclusions are based on very low to low certainty evidence characterised by a small number of included studies, high risk of bias, modest pooled sample sizes, imprecise estimates, moderate between-study heterogeneity, and exclusion of participants with psychiatric comorbidities. Moreover, there were insufficient studies to conduct meta-analyses on many outcome measures; to compare efficacy across and within major categories of interventions; to explore dosage effects; or to examine effects beyond post-treatment. These limitations suggest that, despite recommendations related to the administration of opioid antagonists in the treatment of disordered or problem gambling, pharmacological interventions should be administered with caution and with careful consideration of patient needs. A larger and more methodologically rigorous evidence base with longer-term evaluation periods is required before definitive conclusions can be drawn about the effectiveness and durability of pharmacological treatments for disordered or problem gambling.

Update on Gambling Disorder

Gambling disorder (GD) is estimated to be experienced by about 0.5% of the adult population in the United States. The etiology of GD is complex and includes genetic and environmental factors. Specific populations appear particularly vulnerable to GD. GD often goes unrecognized and untreated. GD often co-occurs with other conditions, particularly psychiatric disorders. Behavioral interventions are supported in the treatment of GD. No medications have a formal indication for the GD, although clinical trials suggest some may be helpful. Noninvasive neuromodulation is being explored as a possible treatment. Improved identification, prevention, and treatment of GD are warranted.

Cognitive boosting interventions for impulsivity in addiction: a systematic review and meta-analysis of cognitive training, remediation and pharmacological enhancement

AIMS

To evaluate and compare the effects of three cognitive boosting intervention approaches (computerised cognitive training, cognitive remediation and pharmacological cognitive enhancers) on measures of impulsive action and impulsive choice.

DESIGN

Systematic review and meta-analysis of publications that reported original controlled trials of cognitive boosting interventions.

SETTING

Studies conducted anywhere in the world. No language restrictions were applied.

PARTICIPANTS

Treatment-seeking adults with substance use disorder or gambling disorder.

MEASUREMENTS

Our primary outcome was a reduction in impulsive action or choice on a validated cognitive measure post-intervention. We assessed risk of bias using the Cochrane Collaboration tool and determined pooled estimates from published reports. We performed random-effects analyses for impulsive action and impulsive choice outcomes and planned moderator analyses.

FINDINGS

Of 2204 unique studies identified, 60 were included in the full-text review. Twenty-three articles were considered eligible for inclusion in the qualitative synthesis and 16 articles were included in our meta-analysis. Articles eligible for pooled analyses included five working memory training (computerised cognitive training) studies with 236 participants, three goal management training (cognitive remediation) studies with 99 participants, four modafinil (cognitive enhancer) studies with 160 participants and four galantamine (cognitive enhancer) studies with 131 participants. Study duration ranged from 5 days to 13 weeks, with immediate follow-up assessments. There were no studies identified that specifically targeted gambling disorder. We only found evidence for a benefit on impulsive choice of goal management training, although only in two studies involving 66 participants (standardised mean difference (SMD) = 0.86; 95% CI = 0.49-1.23; P = 0.02; I²  = 0%, P = 0.95).

CONCLUSION

Cognitive remediation, and specifically goal management training, may be an effective treatment for addressing impulsive choice in addiction. Preliminary evidence does not support the use of computerised cognitive training or pharmacological enhancers to boost impulse control in addiction.

The Relationship Between Affective and Obsessive-Compulsive Symptoms in Internet Use Disorder

We investigated the relationships and diagnostic power of symptoms associated with affective disorders, obsessive-compulsive disorder, and drug addictions on Internet use disorder. Moreover, we tested whether Internet use disorder is characterized by a specific network of symptoms. One-hundred-and-four young adults (78 women) were assessed in laboratory using self-report measures of Internet addiction, alcohol use disorder, cannabis abuse, depression, anxiety, and stress symptoms, impulsiveness, and obsessive-compulsive symptoms. Only hoarding, obsessing, and depression symptoms were positively linked to Internet use disorder severity, with hoarding having greater power and accuracy than other obsessive-compulsive and affective symptoms. Only individuals with mild-moderate Internet use disorder were characterized by a network of strong and positive associations of affective and obsessive-compulsive symptoms. These findings may encourage future longitudinal studies aimed at identifying potential clinical criteria for the diagnosis of Internet use disorder and treatment targets.

Increased risk for developing gambling disorder under the treatment with pramipexole, ropinirole, and aripiprazole: A nationwide register study in Sweden

Gambling Disorder (GD) has recently been reclassified from an impulse-control disorder to a behavioural addiction and, as in other addictive disorders, the dopaminergic reward system is involved. According to neuroimaging studies, alterations within the striatal dopaminergic signalling can occur in GD. However, the findings to date are controversial and there has been no agreement yet on how the reward system is affected on a molecular basis. Within the last 20 years, there has been growing evidence for a higher risk to develop GD in response to certain dopaminergic medication. Especially the dopamine agonists pramipexole and ropinirole, and the dopamine modulator aripiprazole seem to increase the likelihood for GD. The goal of this study was to examine the association between a prescription for either of the three pharmaceuticals and a GD diagnosis in a large cross-sectional study of the Swedish population. Compared to patients with any other dopaminergic drug prescription (38.7% with GD), the diagnosis was more common in patients with a dopamine agonist prescription (69.8% with GD), resulting in an odds ratio of 3.2. A similar association was found between aripiprazole prescriptions and GD diagnoses, which were analysed within the subgroup of all patients with schizophrenia or a schizotypal, delusional, or another non-mood psychotic disorder. An aripiprazole prescription increased the likelihood of GD (88.8%) in comparison to patients without an aripiprazole prescription (71.2%) with an odds ratio of 3.4. This study contributes to the increasingly reliable evidence for an association between several dopaminergic drugs and a higher risk for developing GD. Therefore, one future research goal should be a better understanding of the neurobiology in GD to be able to design more selective dopaminergic medication with less severe side effects. Additionally, this knowledge could enable the development of pharmacotherapy in GD and other addictive disorders.

Caudate nucleus volume mediates the link between glutamatergic neurotransmission and problematic smartphone use in youth

BACKGROUND AND AIMS

Problematic smartphone use (PSU) is growing rapidly among teens. It has similar presentations as other behavioral addictions in terms of excessive use, impulse control problems, and negative consequences. However, the underlying neurobiological mechanisms remain undiscovered. We hypothesized that structural changes in the striatum might serve as an important link between alteration in glutamate signaling and development of PSU.

METHODS

Among 88 participants, twenty (F:M, 12:8; age 16.2 ± 1.1) reported high scores in the smartphone addiction proneness scale (SAPS) with a cut-off score of 42; the other 68 (F:M, 19:49; age 15.3 ± 1.7) comprised the control group. Sociodemographic data and depression, anxiety, and impulsivity traits were measured. Striatal volumes (caudate, putamen, and nucleus accumbens) were estimated from T1 imaging data. Serum glutamate levels were estimated from peripheral blood samples. Group comparisons of each data were performed after controlling for age and gender. Mediation analyses were conducted to test the indirect effects of glutamate level alteration on PSU through striatal volumetric alteration.

RESULTS

The PSU group showed a decrease in both caudate volumes than the control group. Left caudate volume was positively correlated with serum glutamate level, and negatively with impulsivity traits and SAPS scores. The mediation model revealed a significant indirect effect of serum glutamate on SAS scores through the reduced left caudate volume.

DISCUSSION AND CONCLUSIONS

This study suggests that altered glutamatergic neurotransmission may be associated with PSU among teens, possibly through reduced left caudate volume. Current findings might support neural mechanisms of smartphone addiction.

A casino in my pocket: Gratifications associated with obsessive and harmonious passion for mobile gambling

Mobile gambling differs from land-based and traditional forms of gambling in that the opportunity to place bets and engage with casinos is constantly present and easily accessible. Instead of going to a physical bookmaker or casino, mobile gambling is done quickly and swiftly, anytime, anywhere, with a few taps on a mobile device. Previous studies reveal mobile gambling has managed to reach new audiences especially amongst younger people. Gambling harms can have severe adverse effects on individuals, families and society. However, for a subgroup of highly involved individuals, gambling can be considered a harmonious passion that permits frequent gambling without elevating individual's risks of experience problem gambling manifestations. Combining the Uses and Gratifications (U&G) and Dualistic Model of Passion (DMP) frameworks, the present study aims to determine if and how the different gratifications sought from mobile gambling are susceptible to explaining non-problematic versus problematic patterns in highly involved gamblers. Data were collected over two waves from a global sample of mobile gamblers (N = 327). Results emphasize that the motivational underpinnings of mobile gambling (as measured by the U&G) differ in obsessive versus harmonious passion. Obsessive passion is associated with poor mood and problematic gambling. In contrast, harmonious passion for mobile gambling is associated with positive mood but is unrelated to problematic gambling. Based on these findings, and given that problematic gambling is an internationally relevant public health issue (the prevalence of problem gambling is estimated to range from 0.1% to 5.8% in different countries), we suggest interventions focusing on specific uses and gratifications associated with an obsessive passion for mobile gambling may be effective in reducing problematic usage patterns.

On the stability and the progression of gambling problems: longitudinal relations between different problems related to gambling

BACKGROUND AND AIMS

In psychiatric diagnosis, different symptoms of gambling problems are usually aggregated into a single indicator of disorder severity, which has resulted in a knowledge gap on the specific roles of the different issues with which some gamblers struggle. This study estimated the association between baseline symptoms of gambling problems and (i) other symptoms, (ii) the overall severity of gambling problems after 12 months, and the estimated stability rates of various gambling problems after (iii) 12 months and (iv) 5 years. Design and Setting Secondary analysis of data derived from the Swedish Longitudinal Gambling Study (SWELOGS), a prospective representative cohort study conducted between 2008 and 2014 in Sweden.

PARTICIPANTS

A total of 8165 respondents from 16-84 years of age recruited in a stratified random sampling procedure. Among them, 6021 answered the 1-year follow-up survey and 3559 answered the 5-year follow-up survey.

MEASUREMENTS

Nine symptoms related to gambling were assessed using the Problem Gambling Severity Index (excessive gambling, tolerance, chasing, loans, insight, health problems, criticism, financial problems, and guilt).

FINDINGS

Excessive gambling, tolerance, chasing, loans and guilt significantly increased the risk of a range of other symptoms. Chasing and tolerance also tripled the risk of transitioning to more severe gambling problems (OR = 2.9, 95% CI = [1.5-5.5], P = 0.001 and OR = 2.7, 95% CI = [1.6-4.5], P < 0.001, respectively). Stability rates of the different symptoms ranged between 22% (95% CI = [12-31%]) and 42% (95% CI = [35-48%]) after 1 year and 3% (95% CI = [0-10%]) and 19% (95% CI = [7-30%]) after 5 years with chasing being the most stable problem (42% [95% CI = (35-48%)] after 1 year and 17% [95% CI = (6-28%)] after 5 years).

CONCLUSIONS

In psychiatric diagnosis, four symptoms of problem gambling (chasing, tolerance, excessive gambling and guilt) appear to have prognostic validity in assessing gambling-related risk. The symptoms of tolerance and chasing appear to increase the risk of progressing to more severe gambling problems.

Sensation Seeking and Gambling Behavior in Adolescence: Can Externalizing Problems Moderate This Relationship?

Gambling is a widespread phenomenon during adolescence. Among different risk factors involved in the onset of adolescent gambling behaviors, one factor that is studied is the sensation seeking personality trait. However, the literature is heterogeneous and a direct relationship between sensation seeking and gaming behaviors has not always been highlighted. This suggests that the relationship can be influenced by other factors. In particular, we explored the moderating role of externalizing problems in this relationship. A total of 363 adolescents (232 males and 131 females) aged 14 to 20 (M = 16.35, SD = 1.36) completed a battery of questionnaires aimed to assess their gambling behaviors, as well as the levels of externalizing problems and sensation seeking. The results showed that sensation seeking was associated with gambling severity, but this relationship was significant when externalizing problems were high and medium. On the contrary, when externalizing problems were low, the relationship between sensation seeking and gambling severity was not significant. Overall, sensation seeking in adolescence can favor the implementation of risk behaviors, such as gambling, but only in association with the presence of externalizing problems. Limitations, strengths, and social and clinical implications of the present study are discussed.

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.

Dopaminergic activity and exercise behavior in anorexia nervosa

Driven exercise (i.e., the tendency to exercise in excess to influence weight/shape or regulate emotion) is difficult to manage in the context of anorexia nervosa, and is associated with poorer treatment outcomes, and psychological and medical severity. Driven exercise is observed in a considerable number of those diagnosed with anorexia nervosa; however, to date, this hallmark symptom remains poorly understood. Dopamine signaling is implicated in motivating and maintaining appetitive behavior among patients with eating disorders; but, much less is known about the role of dopamine signaling specific to the symptom of driven exercise. An improved understanding of this biobehavioral mechanism may inform the etiology of driven exercise in anorexia nervosa, with the potential to impact future research and treatment efforts. This review describes the role that dopamine serves in maintaining symptoms in the context of anorexia nervosa, and synthesizes current relevant evidence on exercise in AN and related dopaminergic activity. Throughout, theoretical implications are discussed, along with critical directions for future research.

Compulsive exercise or exercise dependence? Clarifying conceptualizations of exercise in the context of eating disorder pathology

OBJECTIVE

Maladaptive exercise relates to eating disorder (ED) pathology and impairment in clinical and non-clinical populations. At present, two different conceptualizations of maladaptive exercise are often studied in relation to ED pathology: compulsive exercise and exercise dependence. Compulsive exercise functions to avoid negative affect (e.g., guilt and anxiety) associated with not exercising, whereas exercise dependence is associated with tolerance to exercise benefits and avoidance of exercise withdrawal. At present, clinicians and researchers struggle to determine the most appropriate term for describing problematic exercise in individuals with ED pathology. This study aimed to directly compare these conceptualizations of maladaptive exercise in relation to severity of ED pathology.

DESIGN

This study examined cross-sectional data.

METHOD

Undergraduate participants (N =235, 78% female) with elevated ED pathology completed the Eating Disorder Examination Questionnaire (EDE-Q), Compulsive Exercise Test (CET), and Exercise Dependence Scale (EDS). Multiple linear regression analyses evaluated associations between EDE-Q and CET and EDS scores and dominance analysis determined which qualities of exercise were uniquely associated with EDE-Q scores.

RESULTS

Results suggest that compulsive qualities of exercise, including exercise to control shape and weight and to avoid negative affect are more strongly associated with severity of ED pathology than qualities of exercise dependence.

CONCLUSIONS

Clinicians and researchers working with ED populations can benefit from prioritizing assessments that capture compulsive qualities of exercise. Additionally, these results suggest that interventions that effectively target other compulsive behaviors (e.g., exposure and response prevention) may be promising treatment options for problematic exercise in the context of EDs.

Gambling involvement and problem gambling correlates among European adolescents: results from the European Network for Addictive Behavior study

PURPOSE

Worldwide, concern has grown over the expansion of gambling among adolescents, who have an increased likelihood of developing risk-taking behaviors. This study aimed to increase knowledge of problem gambling among adolescents in seven European countries and to assess the effect of demographic and lifestyle factors recorded in the European Network for Addictive Behavior survey (https://www.eunetadb.eu).

METHODS

A cross-sectional school-based study (n = 13,284) was conducted in Germany, Greece, Iceland, The Netherlands, Poland, Romania and Spain. Anonymous self-completed questionnaires included socio-demographic data, internet usage characteristics, school achievement, parental control, the Internet Addiction Test, the South Oaks Gambling Screen-Revised for Adolescents Test and Achenbach's Youth Self-Report.

RESULTS

12.5% of the participants reported last year gambling activities either online or offline. 3.6% of the study participants and 28.1% of gamblers (either online or offline) were at risk or had a gambling problem. The study results showed that a higher proportion of adolescents was either at risk or had a gambling problem among males, in the older age group, when the parental educational level was lower/middle, and in the absence of siblings. Furthermore, being at risk or having a gambling problem was associated with lower age at first use of the internet, lower school grades, using the internet 6-7 days per week, and problematic internet use. At risk or problem gamblers had higher scores on all scales of problem behavior and lower scores (lower competence) on activities and academic performance.

CONCLUSIONS

Our findings underline the need for better gambling legislation and suggest the importance of developing social responsibility tools that may help diminish adolescent gambling involvement, with special attention to males.

Gambling disorder

Gambling disorder is characterized by a persistent, recurrent pattern of gambling that is associated with substantial distress or impairment. The prevalence of gambling disorder has been estimated at 0.5% of the adult population in the United States, with comparable or slightly higher estimates in other countries. The aetiology of gambling disorder is complex, with implicated genetic and environmental factors. Neurobiological studies have implicated cortico-striato-limbic structures and circuits in the pathophysiology of this disorder. Individuals with gambling disorder often go unrecognized and untreated, including within clinical settings. Gambling disorder frequently co-occurs with other conditions, particularly other psychiatric disorders. Behavioural interventions, particularly cognitive-behavioural therapy but also motivational interviewing and Gamblers Anonymous, are supported in the treatment of gambling disorder. No pharmacological therapy has a formal indication for the treatment of gambling disorder, although placebo-controlled trials suggest that some medications, such as opioid-receptor antagonists, may be helpful. Given the associations with poor quality of life and suicide, improved identification, prevention, policy and treatment efforts are needed to help people with gambling disorder.

The Interaction of Person-Affect-Cognition-Execution (I-PACE) model for addictive behaviors: Update, generalization to addictive behaviors beyond internet-use disorders, and specification of the process character of addictive behaviors

We propose an updated version of the Interaction of Person-Affect-Cognition-Execution (I-PACE) model, which we argue to be valid for several types of addictive behaviors, such as gambling, gaming, buying-shopping, and compulsive sexual behavior disorders. Based on recent empirical findings and theoretical considerations, we argue that addictive behaviors develop as a consequence of the interactions between predisposing variables, affective and cognitive responses to specific stimuli, and executive functions, such as inhibitory control and decision-making. In the process of addictive behaviors, the associations between cue-reactivity/craving and diminished inhibitory control contribute to the development of habitual behaviors. An imbalance between structures of fronto-striatal circuits, particularly between ventral striatum, amygdala, and dorsolateral prefrontal areas, may be particularly relevant to early stages and the dorsal striatum to later stages of addictive processes. The I-PACE model may provide a theoretical foundation for future studies on addictive behaviors and clinical practice. Future studies should investigate common and unique mechanisms involved in addictive, obsessive-compulsive-related, impulse-control, and substance-use disorders.

Escalation of Gambling Associated With Aripiprazole: A Case Report and Literature Review

Impulse-control problems such as gambling, increased spending, hypersexuality, and compulsive eating are thought to be influenced by temperamental, genetic, and physiological risk factors. In addition, dopamine receptor agonists have been implicated in some cases. It is postulated that aripiprazole may cause impulse-control problems because it can produce a hyperdopaminergic state in the mesolimbic pathway (reward system) through its predominant action on dopamine D3 receptors. We present the case of a patient with bipolar disorder and previous gambling behavior, in whom the gambling behavior escalated with the introduction of aripiprazole and its upward titration. The patient's gambling problems were alleviated with a decrease in aripiprazole dosage. Clinicians should be vigilant for possible gambling and other impulse-control behaviors in patients taking aripiprazole. Our literature review suggests cariprazine and brexpiprazole, which have mechanisms of action similar to that of aripiprazole, may also be associated with possible risks of impulse-control problems and pathologic gambling.

Review: brain neurobiology of gambling disorder based on rodent models

Different literature reviews of gambling disorder (GD) neurobiology have been focused on human studies, others have focused on rodents, and others combined human and rodent studies. The main question of this review was: which are the main neurotransmitters systems and brain structures relevant for GD based on recent rodent studies? This work aims to review the experimental findings regarding the rodent´s neurobiology of GD. A search in the Pub Med database was set (October 2012-October 2017) and 162 references were obtained. After screening, 121 references were excluded, and only 41 references remained from the initial output. More, other 25 references were added to complement (introduction section, neuroanatomical descriptions) the principal part of the work. At the end, a total of 66 references remained for the review. The main conclusions are: 1) according to studies that used noninvasive methods for drug administration, some of the neurotransmitters and receptors involved in behaviors related to GD are: muscarinic, N-methyl-D-aspartate (NMDA), cannabinoid receptor 1 (CB₁), cannabinoid receptor 2 (CB₂), dopamine 2 receptor (D₂), dopamine 3 receptor (D₃), and dopamine 4 receptor (D₄); 2) moreover, there are other neurotransmitters and receptors involved in GD based on studies that use invasive methods of drug administration (eg, brain microinjection); example of these are: serotonin 1A receptor (5-HT_1A), noradrenaline receptors, gamma-aminobutyric acid receptor A (GABA_A), and gamma-aminobutyric acid receptor B (GABA_B); 3) different brain structures are relevant to behaviors linked to GD, like: amygdala (including basolateral amygdala (BLA)), anterior cingulate cortex (ACC), hippocampus, infralimbic area, insular cortex (anterior and rostral agranular), nucleus accumbens (NAc), olfactory tubercle (island of Calleja), orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), prefrontal cortex (PFC) - subcortical network, striatum (ventral) and the subthalamic nucleus (STN); and 4) the search for GD treatments should consider this diversity of receptor/neurotransmitter systems and brain areas.

Suicidal ideation and history of suicide attempts in treatment-seeking patients with gambling disorder: The role of emotion dysregulation and high trait impulsivity

BACKGROUND AND AIMS

Gambling disorder (GD) presents high rates of suicidality. The combined influences of emotion dysregulation and trait impulsivity are crucially important (albeit understudied) for developing strategies to treat GD and prevent suicide attempts. The aim of this study is to investigate the association between trait impulsivity, emotion dysregulation, and the dispositional use of emotion regulation (ER) strategies with suicidal ideation and psychopathological symptom severity in GD.

METHODS

The sample composed of 249 patients with GD (166 with suicidal ideation) who underwent face-to-face clinical interviews and completed questionnaires to assess psychopathological symptoms, impulsive traits, and ER.

RESULTS

Patients with GD who presented suicidal ideation were older and had a later age of GD onset and higher GD severity. Analyses of variance showed higher comorbid symptoms, emotion dysregulation, and trait impulsivity in patients with suicidal ideation. Still, no significant differences were found in the use of ER strategies. SEM analysis revealed that a worse psychopathological state directly predicted suicidal ideation and that both emotion dysregulation and GD severity indirectly increased the risk of suicidal ideation through this state. High trait impulsivity predicted GD severity. Finally, a history of suicide attempts was directly predicted by suicidal ideation.

CONCLUSIONS

Patients with GD are at risk of presenting suicidal behaviors. The results of this study revealed the importance of comorbid psychopathology in the occurrence of suicidal ideation and the indirect effect of trait impulsivity and emotion dysregulation on suicidality. Thus, suicidal rates in GD could possibly be reduced by specifically targeting these domains during treatment.

Hungry to gamble? Ghrelin as a predictor of persistent gambling in the face of loss

Ghrelin, a peptide hormone associated with appetite, is also linked to increased reward seeking behaviors, including food, sex, and drug seeking behaviors through the stimulation of the mesolimbic dopaminergic system. Moreover, plasma ghrelin concentrations are increased by cues that predict rewards, suggesting that cues could facilitate cravings and ultimately relapse. In this project we examined the effects of an overnight fast, a manipulation known to increase ghrelin concentrations, on gambling behaviors. We also examined if cues associated with gambling would also increase ghrelin and, if so, we examined if these increases were associated with gambling behavior. One hundred and one (37 females) participants were asked to fast overnight or after breakfast and then asked to complete food and gambling craving questionnaires. Participants were then presented with gambling cues (a casino like environment in the lab) or a control cue (a cubicle with a computer). After the cue, subjects filled gambling craving questionnaires, and were allowed to gamble. Following 25 practice spins, the slot machines were fixed so that all subsequent spins were losses, and the number of spins in spite of losses were quantified. Blood samples were collected throughout the experiment. Results showed that the gambling cues significantly increased ghrelin concentrations particularly in fasted individuals, and that ghrelin concentrations 20 min after the cue were the best predictor for gambling persistence in the face of continued loss (p < 0.05). Our results suggest that cues that predict the opportunity to gamble have an acute effect on ghrelin concentrations that is facilitated by fasting, and that ghrelin concentrations are a significant predictor of gambling persistence.

Improving patient education about tobacco withdrawal and nicotine gum use by registered nurses in inpatient psychiatry: A feasibility study

WHAT IS KNOWN ON THE SUBJECT?: Many psychiatric inpatients use tobacco, but most psychiatric hospital units prohibit tobacco use. Psychiatric nurses do not receive adequate education about how to teach patients to best manage tobacco withdrawal symptoms. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: Psychiatric nurses who receive a brief educational intervention about tobacco withdrawal symptoms and best practices for using nicotine gum may be more prepared to teach patients about these topics. In turn, patients may use nicotine gum more often during their hospitalization, leading to improved outcomes for them as well as for staff. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: A simple educational intervention aimed at psychiatric nurses can result in positive outcomes for psychiatric inpatients who use tobacco. Patients who have a positive experience with stopping tobacco use while hospitalized may be more likely to commit to lifelong tobacco cessation afterwards. The results of this feasibility study demonstrate that additional research that builds on the work presented here is warranted.

ABSTRACT

Introduction Tobacco use is prohibited in most psychiatric facilities in the United States, yet many psychiatric inpatients are tobacco users. Psychiatric nurses have reported inadequate education about best practices for managing tobacco dependence. Aim To explore the feasibility of an educational intervention for psychiatric nurses designed to improve their ability to educate patients about best practices for managing tobacco dependence, as well as effective use of nicotine gum. Method Fourteen nurses on a psychiatric inpatient unit at a community hospital were educated about the targeted topics. Chart reviews of nonequivalent pre-intervention and post-intervention patient groups were conducted to explore the outcomes of the intervention. Results Patients received more teaching, and used nicotine gum more often, following the intervention. However, no statistically significant differences between the pre-intervention and post-intervention patient groups were found. Discussion Educating nurses about best practices for managing tobacco withdrawal symptoms may have positive outcomes. Existing research suggests that such interventions may be most effective when support and structure are provided to ensure long-term practice changes. Implications for practice This feasibility study demonstrates that a brief nurse education intervention has the potential to improve the experience of tobacco withdrawal for psychiatric inpatients. Future research that expands upon the current project is warranted.

The effect of methylphenidate on decision making in patients with borderline personality disorder and attention-deficit/hyperactivity disorder

Impaired decision making in patients with borderline personality disorder (BPD) has been reported in several studies. Although methylphenidate (MPH) is known to ameliorate impaired decision making in patients with attention-deficit/hyperactivity disorder (ADHD), it has not yet been examined in patients with BPD. We therefore assessed the efficacy of a single dose of MPH on cognitive functions and decision making in patients with BPD. Twenty-two patients diagnosed with BPD participated in the study. The study was a randomized, double-blind placebo-controlled, random block order cross-over trial. Patients participated in two sessions and performed the Test of Variables of Attention, a digit-span test, and the computerized Iowa Gambling Task, after they had been administered either the MPH or a placebo. ADHD symptoms were assessed using the Adult ADHD Self-Report Scale-18. Lower scores on the inattention symptoms scale were associated with a greater improvement in decision making following the administration of MPH when compared with improvements in patients with higher ADHD scores [F(1,17)=5.63, P=0.030]. We conclude that MPH may improve decision making in patients with BPD, although this effect is mediated by the level of ADHD symptoms. Further studies are needed to assess whether a prolonged beneficial effect of MPH on decision making in patients with BPD might also be present in 'real life'.

Smoking, ADHD, and Problematic Video Game Use: A Structural Modeling Approach

Problematic video game use (PVGU), or addiction-like use of video games, is associated with physical and mental health problems and problems in social and occupational functioning. Possible correlates of PVGU include frequency of play, cigarette smoking, and attention deficit hyperactivity disorder (ADHD). The aim of the current study was to explore simultaneously the relationships among these variables as well as test whether two separate measures of PVGU measure the same construct, using a structural modeling approach. Secondary data analysis was conducted on 2,801 video game users (M_age = 22.43 years, standard deviation [SD]_age = 4.7; 93 percent male) who completed an online survey. The full model fit the data well: χ² (2) = 2.017, p > 0.05; root mean square error of approximation (RMSEA) = 0.002 (90% CI [0.000-0.038]); comparative fit index (CFI) = 1.000; standardized root mean square residual (SRMR) = 0.004; and all standardized residuals <|0.1|. All freely estimated paths were statistically significant. ADHD symptomatology, smoking behavior, and hours of video game use explained 41.8 percent of variance in PVGU. Tracking these variables may be useful for PVGU prevention and assessment. Young's Internet Addiction Scale, adapted for video game use, and the Problem Videogame Playing Scale both loaded strongly onto a PVGU factor, suggesting that they measure the same construct, that studies using either measure may be compared to each other, and that both measures may be used as a screener of PVGU.

Alterations in the Emotional Regulation Process in Gambling Addiction: The Role of Anger and Alexithymia

This study aims at the assessment of alexithymia and anger levels in 100 treatment-seeking pathological gamblers compared with controls, who were matched for age, gender and education. Furthermore a positive correlation between alexithymia, anger and severity of gambling disorder and a relationship between gambling behaviour and anger after controlling for alexithymia, are investigated. Finally the role that gender plays in anger in pathological gamblers was also evaluated. Psychological assessment includes the South Oaks Gambling Screen, State-Trait Anger Expression Inventory-2 and the twenty-item Toronto Alexithymia Scale. Statistical analysis of the results shows a higher level of anger in pathological gamblers than in controls, together with alterations in emotional processing. Severity of gambling behaviour positively correlates with alexithymia scores, state-anger and trait-anger. Moreover, a significant contribution of anger in predicting gambling behaviour was suggested after controlling for alexithymia. In conclusion, anger and alexithymia must be regarded as relevant components of the assessment of pathological gamblers, in order to select the best therapeutical strategies to prevent self-defeating behaviours and to reduce drop-out from treatments.

Exploring the Relationship between Reward and Punishment Sensitivity and Gambling Disorder in a Clinical Sample: A Path Modeling Analysis

Most individuals will gamble during their lifetime, yet only a select few will develop gambling disorder. Gray's Reinforcement Sensitivity Theory holds promise for providing insight into gambling disorder etiology and symptomatology as it ascertains that neurobiological differences in reward and punishment sensitivity play a crucial role in determining an individual's affect and motives. The aim of the study was to assess a mediational pathway, which included patients' sex, personality traits, reward and punishment sensitivity, and gambling-severity variables. The Sensitivity to Punishment and Sensitivity to Reward Questionnaire, the South Oaks Gambling Screen, the Symptom Checklist-Revised, and the Temperament and Character Inventory-Revised were administered to a sample of gambling disorder outpatients (N = 831), diagnosed according to DSM-5 criteria, attending a specialized outpatient unit. Sociodemographic variables were also recorded. A structural equation model found that both reward and punishment sensitivity were positively and directly associated with increased gambling severity, sociodemographic variables, and certain personality traits while also revealing a complex mediational role for these dimensions. To this end, our findings suggest that the Sensitivity to Punishment and Sensitivity to Reward Questionnaire could be a useful tool for gaining a better understanding of different gambling disorder phenotypes and developing tailored interventions.

Decision making measured by the Iowa Gambling Task in alcohol use disorder and gambling disorder: a systematic review and meta-analysis

BACKGROUND AND AIMS

Gambling disorder (GD) and alcohol use disorder (AD) have similar features, such as elevated impulsivity and decision-making deficits, which are directly linked to relapse and poor therapeutic outcomes. Our aim was to assess decision-making characteristics in GD and AD patients compared to healthy controls (HC) based on one of the most frequently used measures of decision-making: the Iowa Gambling Task (IGT).

METHODS

In our systematic literature search of three databases, we identified 1198 empirical articles that mentioned decision-making deficits with the use of the IGT in patients diagnosed with either AD or GD. Possible effects were calculated using meta-analysis. In the end, 17 studies (including 1360 participants) were suitable for inclusion in the meta-analysis reporting data for 23 group contrasts.

RESULTS

The random effects estimate indicated impaired IGT performance in both AD patients (N=500; d=-0.581, CI:-89.5<δ<-26.6%) and an even greater deficit in GD patients (N=292; d=-1.034, CI:-156.1<δ<50.7%) compared to HCs. Sampling variances were calculated for both AD (v₁=0.0056) and GD groups (v₂=0.0061), from which the z-score was calculated (z=-21.0785; p<0.05), which indicates a statistically significant difference between AD and GD groups. No significant moderating effects of age, gender or education were found.

CONCLUSIONS

There is enough evidence to support that decision-making deficit associated with addictive disorders, and that the deficit is more expressed in gambling disorder than in alcohol use disorder. Impaired decision-making plays an important part in poor therapeutic outcomes, thus provides a promising opportunity for cognitive intervention.

Risk factors for pathological gambling along a continuum of severity: Individual and relational variables

This study’s aim was to identify characteristics with higher odds of distinguishing a group of pathological gamblers (PG) from (1) a group of gamblers without a gambling problem (NP) and 2) a sub-clinical group (SP). An additional aim was to investigate those characteristics as risk/protective factors along the continuum of problem-gambling severity. Sociodemographic (gender, age, marital status, and educational level), individual (psychopathological symptoms) and relational (family functioning, dyadic adjustment, and differentiation of self) variables were considered. The sample consisted of 331 participants: 162 NP, 117 SP and 52 PG. The main results indicate that the characteristics with higher odds of distinguishing among the groups were gender, educational level, age, differentiation of self, and psychopathological symptoms. The odds of being a PG were higher for men with a low educational level and less adaptive psycho-relational functioning. Conversely, the odds of being a NP were higher for women with a high educational level and more adaptive psycho-relational functioning. Gender and educational level stood out with respect to their relevance as risk/protective factors, and their role was found to be dynamic and interdependent with the severity of problem gambling and/or the investigated psycho-relational characteristics. The risk/protective value was more remarkable when gamblers already exhibited SP.L’objectif de cette étude était d'identifier les caractéristiques présentant une probabilité plus élevée de distinguer un groupe de joueurs pathologiques (PG) d'un groupe de joueurs sans problème de jeu (NP) et un groupe sous-clinique (SP). Un autre objectif consistait à étudier ces caractéristiques en tant que facteurs de risque / protection dans le continuum de la gravité du jeu problématique. Les variables sociodémographiques (sexe, âge, état matrimonial et niveau d'instruction), individuelles (symptômes psychopathologiques) et relationnelles (fonctionnement familial, ajustement dyadique et différenciation de self) ont été prises en considération. L'échantillon comprenait 331 participants: 162 NP, 117 SP et 52 PG. Les principaux résultats indiquent que les caractéristiques ayant une plus grande probabilité de distinction entre les groupes étaient le sexe, le niveau d'instruction, l'âge, la différenciation de self et les symptômes psychopathologiques. Les probabilités d'être un PG étaient plus élevées chez les hommes ayant un faible niveau d'instruction et moins adaptative au fonctionnement psycho-relationnel. À l'inverse, les probabilités d'être NP étaient plus élevées chez les femmes ayant un niveau d'instruction élevé et un fonctionnement psycho-relationnel plus adaptatif. Le sexe et le niveau de scolarité se distinguent par leur pertinence en tant que facteurs de risque / protection et leur rôle est jugé dynamique et interdépendant de la gravité du jeu problématique et / ou des caractéristiques psycho-relationnel étudiées. La valeur risque / protection était plus remarquable lorsque les joueurs présentaient déjà SP.

The placebo effect and its clinical associations in gambling disorder

BACKGROUND

Although gambling disorder is prevalent and functionally impairing, no FDA-approved medications exist for its treatment. The ability of clinical trials to detect the benefits of active treatment has been hindered by an unusually high placebo response. Virtually nothing is known about baseline clinical characteristics that might predict placebo response in those with gambling disorder.

METHODS

Participants (N = 152) assigned to placebo were pooled from multiple double-blind trials of gambling disorder. Participants were classified as placebo responders or non-responders based on a cut-off of 35% reduction in symptom severity on the Gambling Symptom Assessment Scale. Baseline group differences were characterized using t tests and equivalent non-parametric tests as appropriate.

RESULTS

Fifty-one percent of individuals assigned to placebo showed a significant clinical response. Compared with non-responders, placebo responders remained in treatment for significantly longer, were more likely to report "enjoyment" as a trigger for gambling, and were less likely to state that "boredom" or "loneliness" triggered their gambling. Placebo responders and non-responders did not differ significantly in age, sex, age at symptom onset, baseline symptom severity, comorbidities, or likelihood of having received a previous treatment.

CONCLUSIONS

Predictors of placebo response for gambling disorder appear markedly different from those reported for other mental illnesses.

Mirtazapine and ketanserin alter preference for gambling-like schedules of reinforcement in rats

Drug and behavioral addictions have overlapping features, e.g., both manifest preference for larger, albeit costlier, reinforcement options in cost/benefit decision-making tasks. Our prior work revealed that the mixed-function serotonergic compound, mirtazapine, attenuates behaviors by rats motivated by abused drugs. To extend this work to behavioral addictions, here we determined if mirtazapine and/or ketanserin, another mixed-function serotonin-acting compound, can alter decision-making in rats that is independent of drug (or food)-motivated reward. Accordingly, we developed a novel variable-ratio task in rats wherein intracranial self-stimulation was used as the positive reinforcer. Using lever pressing for various levels of brain stimulation, the operant task provided choices between a small brain stimulation current delivered on a fixed-ratio schedule (i.e., a predictable reward) and a large brain stimulation delivered following an unpredictable number of responses (i.e., a variable-ratio schedule). This task allowed for demonstration of individualized preference and detection of shifts in motivational influences during a pharmacological treatment. Once baseline preference was established, we determined that pretreatment with mirtazapine or ketanserin significantly decreased preference for the large reinforcer presented after gambling-like schedules of reinforcement. When the rats were tested the next day without drug, preference for the unpredictable large reinforcer option was restored. These data demonstrate that mirtazapine and ketanserin can reduce preference for larger, costlier reinforcement options, and illustrate the potential for these drugs to alter behavior.

Pathological gambling: a review of the neurobiological evidence relevant for its classification as an addictive disorder

In light of the upcoming eleventh edition of the International Classification of Diseases (ICD-11), the question arises as to the most appropriate classification of 'Pathological Gambling' ('PG'). Some academic opinion favors leaving PG in the 'Impulse Control Disorder' ('ICD') category, as in ICD-10, whereas others argue that new data especially from the neurobiological area favor allocating it to the category of 'Substance-related and Addictive Disorders' ('SADs'), following the decision in the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders. The current review examines important findings in relation to PG, with the aim of enabling a well-informed decision to be made with respect to the classification of PG as a SAD or ICD in ICD-11. Particular attention is given to cognitive deficits and underlying neurobiological mechanisms that play a role in SADs and ICDs. These processes are impulsivity, compulsivity, reward/punishment processing and decision-making. In summary, the strongest arguments for subsuming PG under a larger SAD category relate to the existence of similar diagnostic characteristics; the high co-morbidity rates between the disorders; their common core features including reward-related aspects (positive reinforcement: behaviors are pleasurable at the beginning which is not the case for ICDs); the findings that the same brain structures are involved in PG and SADs, including the ventral striatum. Research on compulsivity suggests a relationship with PG and SAD, particularly in later stages of the disorders. Although research is limited for ICDs, current data do not support continuing to classify PG as an ICD.

Trait and neurobiological underpinnings of negative emotion regulation in gambling disorder

BACKGROUND AND AIMS

Gambling disorder is characterized by poor regulation of negative emotions and impulsive behaviours. This study aimed to (1) compare gambling disorder patients (GDPs) and healthy controls (HCs) in self-report and brain activation measures of emotion regulation; and (2) establish its relationship with negative emotion-driven impulsivity.

DESIGN

Two cross-sectional case-control studies including GDPs and HCs.

SETTING AND PARTICIPANTS

GDPs and HCs were recruited from specialized gambling clinics in Andalusia (Spain), where they were following out-patient treatment, and from the community, respectively. Study 1 included 41 GDPs and 45 HCs [All males; M_age  = 35.22, 33.22; standard deviation (SD) = 11.16, 8.18; respectively]. Study 2 included 17 GDPs and 21 HCs (16/20 males; M_age  = 32.94, 31.00; SD = 7.77, 4.60; respectively).

MEASUREMENTS

In study 1, we compared both groups on suppression and re-appraisal emotion regulation strategies [Emotion Regulation Questionnaire (ERQ)]. In study 2, we compared GDPs with HCs on brain activation associated with down-regulation of negative emotions in a cognitive re-appraisal task, measured with functional magnetic resonance imaging (fMRI). In both studies, we correlated the measures of emotion regulation with mood-related impulsivity indicated by negative urgency (UPPS-P impulsive behaviour scale).

FINDINGS

GDPs relative to HCs showed higher levels of emotional suppression [F = 4.525; P = 0.036; means difference M_HCs -M_GDPs  = -2.433, 95% confidence interval (CI) = -4.706, -0.159] and higher activation of the premotor cortex and middle frontal gyrus during negative emotion regulation in the fMRI task [P ≤ 0.005, cluster size (CS) > 50 voxels]. Negative urgency correlated positively with emotional suppression (r = 0.399, 95% CI = 0.104, 0.629, one-tailed P = 0.005) and middle frontal gyrus activation during negative emotion regulation (P ≤ 0.005, CS > 50) in GDPs.

CONCLUSIONS

Gambling disorder is associated with greater use of emotional suppression and stronger pre-motor cortex and middle frontal gyrus activation for regulating negative emotions, compared with healthy controls. Emotional suppression use and middle frontal gyrus activation during negative emotion regulation are linked with negative emotion-driven impulsivity in this disorder.

Which Diagnostic Criteria are Most Useful in Discriminating Between Social Gamblers and Individuals with Gambling Problems? An Examination of DSM-IV and DSM-5 Criteria

The current study sought to identify which diagnostic criteria for gambling disorder have the greatest ability to differentiate between social and problem gamblers. This study was conducted on a sample of male and female college student athletes across the U.S. (n = 8674). Classification and regression tree analysis represents an appropriate technique when addressing the question of an item's diagnostic value, as it sequentially selects variables to isolate sets of observations with similar outcomes. The current results suggest that the item related to preoccupation ("Have there been periods in the past year where you spent a lot of time thinking about gambling?") was the DSM-5 item best able to differentiate between male and female social and problem gamblers in this sample. When considering only the nine criteria retained in the DSM-5, three criteria were identified as key for distinguishing between social and disordered gamblers among men, and one criterion was identified for distinguishing between groups of women. In addition, these results do not support the notion that the illegal acts criterion has a particularly low base rate and found that it can be an important indicator of disordered gambling in a college-aged sample.

Bright-light intervention induces a dose-dependent increase in striatal response to risk in healthy volunteers

Bright-light interventions have successfully been used to reduce depression symptoms in patients with seasonal affective disorder, a depressive disorder most frequently occurring during seasons with reduced daylight availability. Yet, little is known about how light exposure impacts human brain function, for instance on risk taking, a process affected in depressive disorders. Here we examined the modulatory effects of bright-light exposure on brain activity during a risk-taking task. Thirty-two healthy male volunteers living in the greater Copenhagen area received 3weeks of bright-light intervention during the winter season. Adopting a double-blinded dose-response design, bright-light was applied for 30minutes continuously every morning. The individual dose varied between 100 and 11.000lx. Whole-brain functional MRI was performed before and after bright-light intervention to probe how the intervention modifies risk-taking related neural activity during a two-choice gambling task. We also assessed whether inter-individual differences in the serotonin transporter-linked polymorphic region (5-HTTLPR) genotype influenced the effects of bright-light intervention on risk processing. Bright-light intervention led to a dose-dependent increase in risk-taking in the L_A/L_A group relative to the non-L_A/L_A group. Further, bright-light intervention enhanced risk-related activity in ventral striatum and head of caudate nucleus in proportion with the individual bright-light dose. The augmentation effect of light exposure on striatal risk processing was not influenced by the 5-HTTLPR-genotype. This study provides novel evidence that in healthy non-depressive individuals bright-light intervention increases striatal processing to risk in a dose-dependent fashion. The findings provide converging evidence that risk processing is sensitive to bright-light exposure during winter.

At-Risk/Problematic Shopping and Gambling in Adolescence

Elevated levels of both pathological gambling (PG) and problem shopping (PS) have been reported among adolescents, and each is associated with a range of other negative health/functioning measures. However, relationships between PS and PG, particularly during adolescence, are not well understood. In this study, we explored the relationship between different levels of problem-gambling severity and health/functioning characteristics, gambling-related social experiences, gambling behaviors and motivations among adolescents with and without at-risk/problematic shopping (ARPS). Survey data from Connecticut high school students (n = 2,100) were analyzed using bivariate analyses and logistic regression modeling. Although at-risk/problematic gambling (ARPG) was not increased among adolescents with ARPS, adolescents with ARPG (vs non-gamblers) were more likely to report having experienced a growing tension or anxiety that could only be relieved by shopping and missing other obligations due to shopping. In comparison to the non-ARPS group, a smaller proportion of respondents in the ARPS group reported paid part-time employment, whereas a greater proportion of respondents reported excessive gambling by peers and feeling concerned over the gambling of a close family member. In general, similar associations between problem-gambling severity and measures of health/functioning and gambling-related behaviors and motivations were observed across ARPS and non-ARPS adolescents. However, associations were weaker among ARPS adolescents for several variables: engagement in extracurricular activities, alcohol and caffeine use and gambling for financial reasons. These findings suggest a complex relationship between problem-gambling severity and ARPS. They highlight the importance of considering co-occurring risk behaviors such as ARPS when treating adolescents with at-risk/problem gambling.

Behavioral addictions in addiction medicine: from mechanisms to practical considerations

Recent progress has been made in our understanding of nonsubstance or "behavioral" addictions, although these conditions and their most appropriate classification remain debated and the knowledge basis for understanding the pathophysiology of and treatments for these conditions includes important gaps. Recent developments include the classification of gambling disorder as a "Substance-Related and Addictive Disorder" in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and proposed diagnostic criteria for Internet Gaming Disorder in Section 3 of DSM-5. This chapter reviews current neuroscientific understandings of behavioral addictions and the potential of neurobiological data to assist in the development of improved policy, prevention, and treatment efforts.

Neuroscience of Internet Pornography Addiction: A Review and Update

Many recognize that several behaviors potentially affecting the reward circuitry in human brains lead to a loss of control and other symptoms of addiction in at least some individuals. Regarding Internet addiction, neuroscientific research supports the assumption that underlying neural processes are similar to substance addiction. The American Psychiatric Association (APA) has recognized one such Internet related behavior, Internet gaming, as a potential addictive disorder warranting further study, in the 2013 revision of their Diagnostic and Statistical Manual. Other Internet related behaviors, e.g., Internet pornography use, were not covered. Within this review, we give a summary of the concepts proposed underlying addiction and give an overview about neuroscientific studies on Internet addiction and Internet gaming disorder. Moreover, we reviewed available neuroscientific literature on Internet pornography addiction and connect the results to the addiction model. The review leads to the conclusion that Internet pornography addiction fits into the addiction framework and shares similar basic mechanisms with substance addiction. Together with studies on Internet addiction and Internet Gaming Disorder we see strong evidence for considering addictive Internet behaviors as behavioral addiction. Future research needs to address whether or not there are specific differences between substance and behavioral addiction.

Brain Imaging in Gambling Disorder

Gambling disorder recently was reclassified under the category “substance-related and addictive disorders.” With regard to the diagnostic criteria, it overlaps a great deal with substance use disorder, i.e., loss of control, craving/withdrawal, and neglect of other areas of life. However, the gambling disorder symptom “chasing one’s losses” is the only criterion absent from substance use disorder. Therefore, special forms of reward (i.e., gain/loss) processing, such as the processing of loss avoidance and loss aversion, have just recently attracted attention among gambling disorder researchers. Because gambling disorder might be considered an addiction in its “pure” form, i.e., without the influence of a drug of abuse, investigating brain volume changes in people with this behavioral addiction is an important task for neuroimaging researchers in exploring the neural signatures of addiction. Because the brain is a complex network, investigation of alterations in functional connectivity has gained interest among gambling disorder researchers in order to get a more complete picture of functional brain changes in people with gambling disorder. However, only a few studies on brain structure and functional connectivity in gambling disorder have been performed so far. This review focuses on brain imaging studies of reward and loss processing, with an emphasis on loss avoidance and aversion as well as brain volume and functional connectivity in gambling disorder.

A latent class analysis of pathological-gambling criteria among high school students: associations with gambling, risk and health/functioning characteristics

OBJECTIVES

To identify subtypes of adolescent gamblers based on the 10 Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria for pathological gambling and the 9 Diagnostic and Statistical Manual of Mental Disorders, fifth edition criteria for gambling disorder and to examine associations between identified subtypes with gambling, other risk behaviors, and health/functioning characteristics.

METHODS

Using cross-sectional survey data from 10 high schools in Connecticut (N = 3901), we conducted latent class analysis to classify adolescents who reported past-year gambling into gambling groups on the basis of items from the Massachusetts Gambling Screen. Adolescents also completed questions assessing demographic information, substance use (cigarette, marijuana, alcohol, and other drugs), gambling behaviors (relating to gambling formats, locations, motivations, and urges), and health/functioning characteristics (eg, extracurricular activities, mood, aggression, and body mass index).

RESULTS

The optimal solution consisted of 4 classes that we termed low-risk gambling (86.4%), at-risk chasing gambling (7.6%), at-risk negative consequences gambling (3.7%), and problem gambling (PrG) (2.3%). At-risk and PrG classes were associated with greater negative functioning and more gambling behaviors. Different patterns of associations between at-risk and PrG classes were also identified.

CONCLUSIONS

Adolescent gambling classifies into 4 classes, which are differentially associated with demographic, gambling patterns, risk behaviors, and health/functioning characteristics. Early identification and interventions for adolescent gamblers should be sensitive to the heterogeneity of gambling subtypes.

Gamble While You Gamble: Electronic Games in Ontario Charitable Gaming Centres

Electronic Bingo games have recently appeared in Ontario Charitable Gaming Centres. Here we summarize the characteristics of this novel form of electronic gambling, and give a detailed characterization of one game. We contend that these games have structural characteristics that make them similar to modern Electronic Gaming Machines (EGMs) that feature multiline slots games. These features include a fast and continuous gaming experience, with player adjustable win size and reinforcement rate, a high frequency of losses disguised as wins, and highly salient near misses. Some of these games also have bonus rounds and provide players with a list of recent wins. We conclude that provincial and state gaming authorities should be aware that the placement of Bingo EGMs in existing Bingo facilities may increase problem gambling among an already well-established community of Bingo enthusiasts.

Involvement of the rostral agranular insular cortex in nicotine self-administration in rats

Our prior work demonstrated the involvement of the caudal granular subregion of the insular cortex in a rat model of nicotine self-administration. Recent studies in various animal models of addiction for nicotine and other drugs have identified a role for the rostral agranular subregion (RAIC). The current research was undertaken to examine the involvement of the RAIC in a rat model of nicotine self-administration. We investigated the inactivating effects of local infusions of a γ-aminobutyric acid agonist mixture (baclofen/muscimol) into the RAIC on nicotine self-administration under a fixed-ratio 5 (FR-5) schedule and on reinstatement of nicotine seeking induced by nicotine-associated cues in rats. We also evaluated the effects of RAIC inactivation on food self-administration under an FR5 schedule as a control. Inactivation of the RAIC decreased nicotine, but not food, self-administration. RAIC inactivation also prevented the reinstatement, after extinction, of nicotine seeking induced by nicotine-associated cues. Our study indicates that the RAIC is involved in nicotine-taking and nicotine-seeking in rats. Modulating insular cortex function appears to be a promising approach for nicotine dependence treatment.