Pharmacological treatments in gambling disorder: a qualitative review

Gambling disorder comorbidity a narrative review

Introduction: Problematic and pathological gambling (PG) lead to major adverse consequences for individuals, their families, and society and is highly comorbid with numerous other mental health disorders.

Methods: This narrative review summarized population-based, cross-sectional, treatment and prospective studies on gambling disorder and comorbidity over the past 14 years.

Results: These studies show a high rate of comorbidity of PG and substance and alcohol use disorders, mood and anxiety disorders. Prospective studies indicate that, in some cases, gambling precedes the onset of the comorbid disorder, while in other instances, the temporal relationship is reversed. Women face greater psychiatric comorbidity and are more likely to have mood disorders, suicidality, mania, anxiety and alcohol dependence. Treatment of PG can be effective by improving the gambling and depressive symptoms of PG.

Conclusions: Over the past 15 years, significant progress has been made in understanding and treating GD and its psychiatric comorbidities, with evidence highlighting the reciprocal relationships between GD and conditions like substance use, mood and anxiety disorders.

Pharmacotherapy and gambling disorder: a narrative review

BACKGROUND

Gambling disorder (GD) is a psychiatric disorder classified in the DSM-5 as a non-substance-related and addictive disorder with extensive health and socioeconomic impacts. Its chronic and high-relapsing nature makes it essential to find treatment strategies that improve functioning and reduce impairment associated with it. The purpose of this narrative review is to evaluate and summarize the available evidence on the effectiveness and safety of pharmacotherapy in GD.

METHODS

An electronic literature search of Medline, Embase, and Cochrane Central was conducted to identify systematic reviews, meta-analyses, and reviews on pharmacological interventions in patients with gambling disorder. A similar search of these databases and of Prospero, Clinicaltrials.gov, and Epistemonikos was conducted to identify clinical trials that were published since 2019.

RESULTS

The initial search identified 1925 articles. After screening and duplicate removal, 18 articles were included in the review (11 studies were systematic reviews and meta-analyses, 6 were reviews, and 1 was an open-label trial). Eight pharmacological agents (naltrexone, nalmefene, paroxetine, fluvoxamine, citalopram, escitalopram, lithium, and topiramate) that were studied in randomized controlled trials and open-label trials showed small to moderate effect sizes in reducing GD symptoms in some studies during post-hoc analyses.

CONCLUSION

The overall sum of evidence in the literature on the use of pharmacotherapy in GD is conflicting and inconclusive. Some studies have shown that pharmacotherapy's role in GD is promising, especially when the choice of the agent is guided by comorbid psychiatric disorders. However, significant limitations exist in the study designs, which need to be addressed in future research on the topic. Conducting future and more rigorous trials that address the limitations in the existing literature is necessary to establish more accurate efficacy data on the use of pharmacotherapy in this population.

Frontal white and gray matter abnormality in gambling disorder: A multimodal MRI study

Background

Changes in brain structural connections appear to be important in the pathophysiology of substance use disorders, but their role in behavioral addictions, such as gambling disorder (GD), is unclear. GD also offers a model to study addiction mechanisms without pharmacological confounding factors. Here, we used multimodal MRI data to examine the integrity of white matter connections in individuals with GD. We hypothesized that the affected areas would be in the fronto-striatal-thalamic circuit.

Methods

Twenty individuals with GD (mean age: 64 years, GD duration: 15.7 years) and 40 age- and sex-matched healthy controls (HCs) underwent detailed clinical examinations together with brain 3T MRI scans (T1, T2, FLAIR and DWI). White matter (WM) analysis involved fractional anisotropy and lesion load, while gray matter (GM) analysis included voxel- and surface-based morphometry. These measures were compared between groups, and correlations with GD-related behavioral characteristics were examined.

Results

Individuals with GD showed reduced WM integrity in the left and right frontal parts of the corona radiata and corpus callosum (pFWE < 0.05). WM gambling symptom severity (SOGS score) was negatively associated to WM integrity in these areas within the left hemisphere (p < 0.05). Individuals with GD also exhibited higher WM lesion load in the left anterior corona radiata (pFWE < 0.05). GM volume in the left thalamus and GM thickness in the left orbitofrontal cortex were reduced in the GD group (pFWE < 0.05).

Conclusions

Similar to substance addictions, the fronto-striatal-thalamic circuit is also affected in GD, suggesting that this circuitry may have a crucial role in addictions, independent of pharmacological substances.

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.

Psychiatric Drug Prescription and Temporal Associations with a First Diagnosis of Gambling Disorder—Results from a National Register Study

Psychiatric comorbidity is common in gambling disorder (GD), but there are few studies on larger nationwide samples of treatment-seeking patients. Also, temporal associations between GD and other psychiatric disorders are often difficult to study. To address the prevalence and the temporal associations of prescriptions for psychiatric disorders — both in specialized care and primary care — in patients with a GD diagnosis (ICD-10 F63.0). Data was derived from national health registers in Sweden. All patients who were diagnosed with GD in specialized health care in 2005–2016 were included and run against the nationwide database on prescription of pharmaceuticals aimed for psychiatric disorders (n = 2018). Prevalence of psychiatric drug prescription was used as a proxy for psychiatric comorbidity and studied for two 2-year periods (period 1 and 2) prior to GD and one 2-year period (period 3) after the diagnosis. Controlling for gender, age, and time periods, for eight drug categories (anti- epileptics, anti-psychotics, benzodiazepine derivatives, anxiolytics, hypnotics, anti- depressants and drugs used in addictive disorders), significant increases in drug prescription were seen. For central stimulants, a significant increase was seen upon receiving the GD diagnosis (from period 2 to 3), and for benzodiazepines, an increase was seen prior to the GD diagnosis (from period 1 to 2), but not upon diagnosis (from period 2 to 3). Psychiatric comorbidity in GD is common. Drug prescription for psychiatric problems increased markedly in the years temporarily associated with a first diagnosis of GD. The findings may call for early screening for problem gambling in patients with treatment contacts for increasingly poor mental health.

Interventions to reduce the public health burden of gambling-related harms: a mapping review

Recognition is growing that gambling, although highly profitable for corporations and governments, is a source of serious and unevenly distributed harm. This recognition has led to demands for public health strategies at the local, national, and international levels. We aimed to identify review-level evidence for interventions to address or prevent gambling-related harms and explore policy implications, using stakeholder consultation to assess the evidence base, identify gaps, and suggest key research questions. We opted for a systematic mapping review and narrative synthesis for all forms of gambling in any setting. We included participants from the whole population, identified gamblers including self-defined, and specific populations at risk (eg, children and young people). We included all outcome measures relating to prevention or treatment of gambling-related harms that were reported by review authors. After duplication, the searches generated 1080 records. Of 43 potential papers, 13 were excluded at the full paper stage and 30 papers were included in the Review. We identified whole-population preventive interventions, such as demand reduction (n=3) and supply reduction (n=4) interventions, and targeted treatment interventions for individuals addicted to gambling, such as therapeutic (n=12), pharmacological (n=5), and self-help or mutual support (n=4) interventions. We also reviewed studies (n=2) comparing these approaches. Interventions to screen, identify, and support individuals at risk of gambling-related harms and interventions to support ongoing recovery and prevent relapse for individuals with a gambling addiction were not represented in the review-level evidence. A public health approach suggests that there are opportunities to reduce gambling-related harms by intervening across the whole gambling pathway, from regulation of access to gambling to screening for individuals at risk and services for individuals with an identified gambling problem. The dearth of evidence for some interventions means that implementation must be accompanied by robust evaluation.

Non-invasive brain stimulation targets and approaches to modulate gambling-related decisions: A systematic review

INTRODUCTION

Despite intense neuroscience research on the neurobiological underpinnings of Gambling Disorder (GD) and gambling-related decision-making, effective treatments targeting these dysfunctions are still lacking. Non Invasive Brain Stimulation (NIBS) techniques, such as transcranial Direct Current Stimulation (tDCS) and Transcranial Magnetic Stimulation (TMS), selectively modulate activity of brain circuits and have the potential to reverse alterations sustaining GD symptoms. Therefore, the aim of this systematic review was to determine the impact of different NIBS interventions on gambling-related decision processes.

METHODS

We conducted a comprehensive and translational search in three online databases (MEDLINE via PubMed, Scopus, Web of Science), in accordance with the PRISMA guidelines. We included studies applying neuromodulation (TMS, tDCS) techniques in GD patients or assessing gambling-related decision-making in healthy subjects. In addition, we explored the potential impact of NIBS in drug-induced GD (e.g., Parkinson's Disease).

RESULTS

Twenty-seven studies have been included. We summarized results to detect the impact of different targets and stimulation/inhibition protocols in terms of gambling-related decision-making. The majority of both tDCS and TMS studies targeted the dorsolateral prefrontal cortex. Although heterogeneous in protocols and parameters, results from tDCS and TMS studies converge in indicating that the stimulation (instead of inhibition) of prefrontal regions could be beneficial to contrast dysfunctional gambling-related decision processes.

CONCLUSION

NIBS interventions show promise to be further tested in controlled clinical settings for the treatment of behavioral addictions. Further studies are also necessary to investigate connectivity changes and laterality issues (unilateral versus bilateral; left versus right) of NIBS application in GD.

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.

Topiramate Pharmacotherapy for Alcohol Use Disorder and Other Addictions: A Narrative Review

: Topiramate is a non-benzodiazepine anticonvulsant medication with multi-faceted pharmacologic action. It has emerged as an efficacious pharmacotherapeutic option for the treatment of addiction, especially alcohol use disorder (AUD). We present a broad narrative review of the putative mechanism of action and clinical utility of topiramate with regard to AUD and other substance use disorders. Collective evidence suggests topiramate is an effective treatment option in AUD, with notable efficacy in reducing harmful drinking patterns in AUD. Though not currently approved by the United States Food and Drug Administration for the indication of AUD, topiramate should be considered as a pharmacological treatment option with high utility among AUD patients. Early pharmacogenetic studies raise the intriguing possibility of identifying patients likely to respond to topiramate using genetic testing, and initial studies show that topiramate may also be useful in treating cocaine use disorder, smoking cessation and behavioral addictions. However, further research is needed in all these areas.

Dopaminergic and clinical correlates of high-frequency repetitive transcranial magnetic stimulation in gambling addiction: a SPECT case study

Repetitive Transcranial Magnetic Stimulation (rTMS) shows the potential to modulate local brain activity, thus resulting in a modulatory action on neurocircuitries implicated in the pathophysiology of Gambling Disorder (GD). We report the case of a GD patient treated with two weeks of high frequency (15 Hz) rTMS over the dorsolateral prefrontal cortex (DLPFC). At baseline and after rTMS treatment the patient underwent a SPECT examination with (123)I-FP-CIT tracer, to test changes in dopamine transporter (DAT) availability. The patient was followed up for six months, to explore safety and clinical correlates of a weekly high frequency rTMS maintenance treatment. Over the six-month follow-up the patient reported no episodes of gambling relapse. Also, the patient did not report craving for gambling or gambling-related symptoms. After two weeks of left DLPFC-rTMS treatment, we found a decrease in DAT availability in striatal regions, that represents a putative neurobiological substrate of dopaminergic pathways modulation. This study suggests that high frequency DLPFC-rTMS deserves further investigations in larger samples, using controlled study designs, to assess its real potential as a treatment for GD.

Pharmacological Treatments for Disordered Gambling: A Meta-analysis

Disordered gambling is a public health concern associated with detrimental consequences for affected individuals and social costs. Currently, opioid antagonists are considered the first-line treatments to reduce symptoms of uncontrolled gambling. Only recently, glutamatergic agents and combined pharmacological and psychological treatments have been examined appearing promising options for the management of gambling disorder. A multilevel literature search yielded 34 studies including open-label and placebo-controlled trials totaling 1340 participants to provide a comprehensive evaluation of the short- and long-term efficacies of pharmacological and combined treatments. Pharmacological treatments were associated with large and medium pre-post reductions in global severity, frequency, and financial loss (Hedges's g: 1.35, 1.22, 0.80, respectively). The controlled effect sizes for the outcome variables were significantly smaller (Hedges's g: 0.41, 0.11, 0.22), but robust for the reduction of global severity at short-term. In general, medication classes yielded comparable effect sizes independent of predictors of treatment outcome. Of the placebo controlled studies, results showed that opioid antagonists and mood stabilizers, particularly the glutamatergic agent topiramate combined with a cognitive intervention and lithium for gamblers with bipolar disorders demonstrated promising results. However, more rigorously designed, large-scale randomized controlled trials with extended placebo lead-in periods are necessary. Moreover, future studies need to monitor concurrent psychosocial treatments, the type of comorbidity, use equivalent measurement tools, include outcome variables according to the Banff, Alberta Consensus, and provide follow-up data in order to broaden the knowledge about the efficacy of pharmacological treatments for this disabling condition.

Gambling disorder and bilateral transcranial direct current stimulation: A case report

INTRODUCTION

Gambling disorder (GD) is a major public health concern with currently no validated and efficacious treatments approved. In this single case study, we report the short- and long-term effect of bilateral transcranial direct current stimulation (tDCS) of dorsolateral prefrontal cortex (DLPFC) on craving and impulse control in a subject with GD.

METHODS

The patient is a 26-year-old Caucasian male with an 8-year history of GD as well as alcohol and cocaine misuse. Treatment consisted of twice-a-day stimulation for 10 days. According to the literature, both the left (to control craving) and the right (to control emotional impulses) DLPFC were stimulated. Patients subsequently received tDCS once a week for 3 months and then once every 2 weeks for another 3 months.

RESULTS

After 10 days of treatment, the subject reported improved psychiatric symptoms (depression, anxiety, and impulsivity), as well as reduced gambling craving symptom severity. After 3 and 6 months of treatment, the clinical picture further improved.

DISCUSSION

This is the first report of tDCS effectiveness in a single case study of GD. Therapeutic effects, both on the addictive behavior and on psychiatric comorbid symptomatology, were lasting and continued over 6 months of tDCS maintenance treatment. Future case-control studies are required to test the efficacy of this tool in patients with GD.

Problem Gambling among Young People in Sub-Saharan Africa

Gambling is a cross-cultural and global activity which typically involves the wagering of money or an item of monetary value on an outcome that is governed by chance. Although gambling is positioned as a legitimate recreational and leisure activity within sub-Saharan Africa (SSA), there is widespread recognition among healthcare professionals and policy-makers that gambling has the capacity to become dysfunctional in a minority. Emerging knowledge suggests that problem gambling is rapidly evolving in to a public health concern in SSA, especially among youth. This article focuses on problem gambling among young people in SSA with an emphasis on three key themes: (1) gambling behavior and patterns in SSA; (2) public health and socioeconomic implications of gambling in SSA; and (3) public health policies and interventions for addressing this issue. We believe that collaborative efforts between government, prevention specialists, legislators, researchers, treatment providers, and other stake holders can influence the uptake of research findings necessary to implement social policies and design effective public health intervention options to combat problem gambling and its associated implications among young people in SSA.

Online effects of transcranial direct current stimulation on prefrontal metabolites in gambling disorder

Gambling disorder is characterized by persistent maladaptive gambling behaviors and is now considered among substance-related and addictive disorders. There is still unmet therapeutic need for these clinical populations, however recent advances indicate that interventions targeting the Glutamatergic/GABAergic system hold promise in reducing symptoms in substance-related and addictive disorders, including gambling disorder. There is some data indicating that transcranial direct current stimulation may hold clinical benefits in substance use disorders and modulate levels of brain metabolites including glutamate and GABA. The goal of the present work was to test whether this non-invasive neurostimulation method modulates key metabolites in gambling disorder. We conducted a sham-controlled, crossover, randomized study, blinded at two levels in order to characterize the effects of transcranial direct current stimulation over the dorsolateral prefrontal cortex on neural metabolites levels in sixteen patients with gambling disorder. Metabolite levels were measured with magnetic resonance spectroscopy from the right dorsolateral prefrontal cortex and the right striatum during active and sham stimulation. Active as compared to sham stimulation elevated prefrontal GABA levels. There were no significant changes between stimulation conditions in prefrontal glutamate + glutamine and N-acetyl Aspartate, or in striatal metabolite levels. Results also indicated positive correlations between metabolite levels during active, but not sham, stimulation and levels of risk taking, impulsivity and craving. Our findings suggest that transcranial direct current stimulation can modulate GABA levels in patients with gambling disorder which may represent an interesting future therapeutic avenue.

Common and differential brain abnormalities in gambling disorder subtypes based on risk attitude

Studying brain abnormalities in behavioral addiction including GD enables us to exclude possible confounding effects of exposure to neurotoxic substances, which should provide important insight that can lead to a better understanding of addiction per se. There have been a few brain structural magnetic resonance imaging studies for GD, although the results have been inconsistent. On the other hand, GD was suggested to be a heterogeneous disorder in terms of risk attitude. We aimed to examine the heterogeneity of GD by combining a behavioral economics task and voxel-based morphometry. Thirty-six male GD patients and 36 healthy male control subjects underwent a task for estimation of loss aversion, which can assess risk attitude in real-life decision-making. The GD patients were divided into two groups based on their level of loss aversion, low and high. While both groups showed common gray matter volume reduction in the left supramarginal gyrus and bilateral posterior cerebellum, high loss-aversion GD showed pronounced reduction in the left posterior cerebellum and additional reduction in the bilateral medial orbitofrontal cortex. Our study suggests that the heterogeneity of GD is underpinned at the brain structural level. This result might be useful for understanding neurobiological mechanisms and for the establishment of precise treatment strategies for GD.

A single session of repetitive transcranial magnetic stimulation of the prefrontal cortex reduces cue-induced craving in patients with gambling disorder

BACKGROUND

Gambling disorder (GD) is common and disabling addictive disorder. In patients with substance use disorders, the application of repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) offers promise to alleviate craving. We hypothesized that applying real compared to sham rTMS over the left DLPFC would reduce gambling craving in patients with GD.

METHODS

In a randomized sham-controlled crossover design, 22 treatment-seeking patients with GD received real or sham treatment with high frequency rTMS over the left DLPFC followed a week later by the other type of treatment. Before and after each rTMS session, participants rated their gambling craving (from 0 to 100) before and after viewing a gambling video used as a cue. We used the Yale-Brown Obsessive Compulsive Scale adapted for Pathological Gambling to assess gambling behavior before and 7 days after each rTMS session.

RESULTS

As compared to sham (mean +0.74; standard deviation±3.03), real rTMS significantly decreased cue-induced craving (-2.12±3.39; F_(1,19)=4.87; P=0.04; partial η²=0.05; 95% CI: 0.00-0.21). No significant effect of rTMS was observed on gambling behavior.

CONCLUSIONS

Patients with GD reported decreased cue-induced craving following a single session of high frequency rTMS applied over the left DLPFC. Further large randomized controlled studies are needed to determine the usefulness of rTMS in GD.

Gambling Disorder Due to Brazilian Animal Game ("Jogo do bicho"): Gambling Behavior and Psychopathology

Gambling is currently widespread across the globe and despite legally restricted, it is significantly common in Brazil. A traditional and common form of gambling in Brazil is the Brazilian animal game (BAG)--"Jogo do bicho" in Portuguese. In 2013, BAG activities collected approximately 19 billion Brazilian reais--equivalent to more than 8 billon American dollars, a figure almost 60 % higher than legal lotteries. Although a common form of gambling, the gambling behavior and psychopathology of gambling disorder (GD) associated with BAG has never been systematically studied. The aim of this study is to conduct, the first research approaching GD due to BAG. We assessed 897 participants of whom 63 subjects (7.0 %) presented with GD due to BAG and 834 with GD associated with other forms of gambling. After comparing these two groups, major differences were found in demographics, gambling behavior elements and psychopathological variables. This research reinforces the need for further research on BAG and the need for specific approaches in GD. The particularities of BAG may affect treatment strategies as, for example, suggest some adaptations in social and psychotherapeutic approaches. We also highlight the need to acknowledge the "hidden" BAG as a potential addictive game.

Pharmacotherapy and group cognitive behavioral therapy enhance follow-up treatment duration in gambling disorder patients

BACKGROUND

Longer treatment duration is important for the successful treatment of gambling disorder (GD). This retrospective study investigated the factors and interventions that might enhance treatment duration in GD patients in South Korea.

METHODS

A total of 758 outpatients with a primary diagnosis of GD, who were treated in a clinical practice from 2002 to 2011, were assessed by retrospective chart review. We compared the treatment duration according to pharmacotherapy and group cognitive behavioral therapy (CBT).

RESULTS

Pharmacotherapy contributed to a longer duration of treatment maintenance, despite the patients' gambling severity (p < 0.001). Participation in group CBT (p < 0.001) and antidepressants (p = 0.009) were associated with a longer treatment duration after adjusting for age, depression, and gambling severity. The treatment maintenance duration was the longest in those receiving combined antidepressant pharmacotherapy and group CBT (F = 35.79, p < 0.001).

CONCLUSIONS

Group CBT and antidepressants seem to enhance treatment follow-up duration in GD patients. Additional studies are needed to advance GD prevention and treatment strategies.

[The use of agomelatine (valdoxan) in gambling therapy: a pilot study]

OBJECTIVE

To study the antidepressant agomelatine (M1/M2 agonist and 5-HT2C antagonist) in pathological gambling (PG) (ICD-10 item F63.0).

MATERIAL AND METHODS

An open label 8-week trial was carried out in 22 outpatients (17 male and 5 female, mean age 38±7). PG severity was assessed by the Yale-Brown Obsessive-Compulsive Scale adapted for Pathological Gambling (PG-YBOCS). Anxiety and depression level was measured by the Hospital Anxiety Depression Scale (HADS).

RESULTS

Agomelatine significantly decreased PG-YBOCS scores from the second week of the trial (12.6±3.0 compared to 24.2±2.1 at baseline, p<0.05). In the end of the trial, PG-YBOCS score decreased to 5.3. The total HADS score decreased significantly in the end of the study (from 23.6±2.9 to 11.4±1.9, p<0.05). There was an improvement in behavior as well.

CONCLUSION

Thus, agomelatine has demonstrated efficacy in PG patients.

Translational Models of Gambling-Related Decision-Making

Gambling is a harmless, recreational pastime that is ubiquitous across cultures. However, for some, gambling becomes a maladaptive and compulsive, and this syndrome is conceptualized as a behavioural addiction. Laboratory models that capture the key cognitive processes involved in gambling behaviour, and that can be translated across species, have the potential to make an important contribution to both decision neuroscience and the study of addictive disorders. The Iowa gambling task has been widely used to assess human decision-making under uncertainty, and this paradigm can be successfully modelled in rodents. Similar neurobiological processes underpin choice behaviour in humans and rats, and thus, a preference for the disadvantageous "high-risk, high-reward" options may reflect meaningful vulnerability for mental health problems. However, the choice behaviour operationalized by these tasks does not necessarily approximate the vulnerability to gambling disorder (GD) per se. We consider a number of psychological challenges that apply to modelling gambling in a translational way, and evaluate the success of the existing models. Heterogeneity in the structure of gambling games, as well as in the motivations of individuals with GD, is highlighted. The potential issues with extrapolating too directly from established animal models of drug dependency are discussed, as are the inherent difficulties in validating animal models of GD in the absence of any approved treatments for GD. Further advances in modelling the cognitive biases endemic in human decision-making, which appear to be exacerbated in GD, may be a promising line of research.