Pathological Gambling Group Research Articles

Interrelation between subjective assessment of mental state and perception of family relations by relatives caring for patients with addiction

The addictive disorder often becomes a difficult experience for the all family. Studying the factors influencing the level of psychological distress of addicted patients’ relatives is necessary to create an effective system of psychological assistance for them.Purpose: to reveal the interrelations between the subjective assessment of the mental state and the perception of family relationships among relatives of patients with pathological gambling (PG) and relatives of patients with stimulant use disorder (SUD).Materials and methods. In a cross-sectional study 100 and 41 patients’ relatives were included in the PG and SUD groups respectively. The Symptom Checklist-90-Revised (SCL-90-R) and the Family Environment Scale (FES) was used as an assessment tools. Socio-demographic and clinical data were also collected.Results. The analysis of interrelations between the severity of psychopathological symptoms and the perception of family relationships in the studied groups determined both general and specific correlations. In both groups there are multiple negative correlations between the majority of SCL-90-R scales and the “Cohesion” scale (FES). The specific interrelations included, for example, multidirectional correlations between the “Expressiveness” scale (FES) and psychopathological symptoms scales of the SCL-90-R. Increased expressiveness in the PG group was associated with less severity of psychopathological symptoms and level of distress, and, on the contrary, a greater severity of psychological distress in respondents of the SUD group. Analysis of the correlations in PG compared to SUD showed greater predictability of the connections between psychopathological symptoms and perception of family relationships in the PG group. Thus, the indicators of psychopathological symptoms and psychological distress are negatively associated with parameters reflecting the perception of family cohesion, trust in intrafamily relations, social activity and family organization and, at the same time, have positive interrelations with the indicator of conflict in family relationships.Conclusion. The perception of the family cohesion function as the intrapsychic protection that facilitate the relatives’ adaptation in the emerging life situation, regardless of the form of patients’ addiction.

대학생의 몰입상태, 정서인식명확성, 자살위험성 간 구조적관계

Objectives The purpose of this study is to examine the differences among college students' flow, emotional clarity, and suicide risk variables according to the level of gambling addiction, and to verify the difference in influence between the variables according to the level of gambling addiction. Methods The To this end, after selecting 633 students from 7 universities located in Daegu, Gyeongbuk, and Busan, research analysis was conducted using F-test and multigroup analysis. Statistical significance was verified at a significance probability of .05. Results First, there were significant differences in flow, emotional clarity, and suicide risk of college students according to the level of gambling addiction. In other words, the pathological gambling group showed a higher flow state and suicide risk than the low-risk gambling group, and showed a lower emotional clarity. Second, in the verification of the difference in influence between flow, emotional clarity, and suicide risk, it was found that there was a significant difference according to the level of gambling addiction in all pathways. Conclusions It was found that the pathological gambling group showed a higher suicide risk based on a higher flow state than the low-risk gambling group, and showed a lower emotional clarity based on a higher flow state. The low-risk gambling group showed a lower suicide risk based on higher emotion clarity compared to the pathological gambling group. Therefore, it can be suggested that a program for emotional and behavioral control needs to be applied to a group with gambling addiction problems.

A Multi-Method Investigation of Normative and Pathological Personality Across the Spectrum of Gambling Involvement.

Pathological Gambling (PG) has been linked to both specific personality traits and personality disorders (PDs). However, previous studies have used a wide variety of research designs that preclude clear conclusions about the personality features that distinguish adults with PG from other groups. The current investigation seeks to advance this research by using a sample including adults who do not gamble, who gamble socially, and who exhibit PG, using self-report, informant-report, and interview-rated measures of personality traits and disorders. A total of 245 adults completed measures of gambling behaviour and problems, as well as normative and pathological personality over two assessment visits. A multivariate ANCOVA was conducted to investigate differences between groups. Analyses supported numerous group differences including differences between all groups on the Neuroticism facet of Impulsivity, and between non-gambling/socially gambling and PG groups on the Conscientiousness facet of Self-Discipline. Adults with PG exhibited more symptoms of Borderline, Paranoid, Schizotypal, Avoidant, and Dependent PDs than adults who gamble socially or not at all. The current investigation provides a comprehensive survey of personality across a wide range of gambling involvement, using a multi-method approach. Our findings help to clarify the most pertinent personality risk factors for PG.

Distinct Response Inhibition Patterns in Obsessive Compulsive Disorder Patients and Pathological Gamblers.

Background: Obsessive-compulsive disorder (OCD) and pathological gambling (PG) are common disorders. The cognitive models of OCD and PG focus on abnormalities in response inhibition. Although, these functions have been studied in different PG and OCD samples, no study has compared the response inhibition in both.Methods: Medication-naïve OCD (n = 61) and PG subjects (n = 109) and healthy controls (n = 131) performed CPT and Go/NoGo tasks.Results: Compared to healthy controls (HC), PG and OCD groups underperformed on speed and exhibited larger time variability on the CPT and Go/NoGo task. Only in OCD patients, a positive correlation between omission errors and response time (RT) was observed in the CPT. At the Go/NoGo task, a negative correlation between false alarms and RT (a fast-errors trade-off) was significant only in the PG group. The HC group had greater sensitivity values (d') than the OCD and PG groups in the Go/NoGo task. The PG group displayed lower d' values and more conservative response criterion in the CPT. In addition, only the OCD group expressed a high switching cost compared to both the PG and HC groups in terms of the RT and d' values.Conclusions: Both the PG and OCD groups demonstrated impaired response inhibition compared to the HC group. On several measures, the OCD and PG groups showed comparable impairments, and in others these were distinct. Thus, it appears that distinct neurocognitive patterns are involved in performance of the CPT and the Go/NoGo tasks among OCD and PG subjects whose cognitive status is currently under intensive investigation.

Effects of Gambling Diagnostic Criteria Changes from DSM-IV to DSM-5 on Mental Disorder Comorbidity Across Younger, Middle-Aged, and Older Adults in a Nationally Representative Sample.

Changes in Diagnostic and Statistical Manual (DSM) criteria for a gambling disorder from DSM-IV to DSM-5 included a drop in the minimum number of criteria required to qualify for a diagnosis. This threshold reduction resulted in a near doubling of prevalence in non-gambling focused populations. However, the impact of this change on psychiatric comorbidity with gambling is unknown. The current study aimed to: (a) examine whether the diagnostic change affected the severity of those diagnosed with a gambling disorder with respect to mental disorder comorbidity, and (b) determine whether this relationship differed across younger (18-34years old), middle-aged (35-54years old), and older (55years old and over) age groups. This study utilized data from the National Epidemiological Survey for Alcohol and Related Conditions. Results indicated that the prevalence of comorbid mental health/substance use disorders did not significantly change between the DSM-IV pathological gambling group and DSM-5 gambling disorder group in the overall sample. However, among older adults, the DSM-5 gambling disorder were more likely to exhibit any anxiety disorder as well as any comorbid mental health/substance-use disorder compared to the DSM-IV pathological gamblers. No other significant differences were observed in mental health or substance-use disorders within age-specific groupings. Findings suggest that the new, less restrictive DSM-5 criteria for gambling addiction capture older gamblers with more severe clinical presentations in terms of co-occurring mental disorders, contrary to our expectation that the lowered threshold for diagnosis would result in less severe clinical cases.

An Analysis of Treatment-Seeking Behavior in Individuals with Gambling Disorder.

Gambling disorder affects approximately 1.1-3.5% of the population, with the rates being higher in young adults. Despite this high prevalence, little is known regarding which pathological gamblers decide to seek treatment. This study sought to examine the differences in three groups of pathological gamblers: those who did not seek treatment (n=94), those who sought therapy (n=106) and those who sought medication therapy (n=680). All subjects were assessed on a variety of measures including demographics, family history, gambling history, comorbid psychiatric disorders and an assortment of clinical variables such as the Quality of Life Inventory, Hamilton Depression and Anxiety Rating Scales, Yale Brown Obsessive Compulsive Scale for Pathologic Gambling (PG-YBOCS), Barratt Impulsiveness Scale, Eysenck Impulsiveness Questionnaire and select cognitive tasks. Those seeking treatment were more likely to be Caucasian, have lost more money in the past year due to gambling, andwere more likely to have legal and social problems as a result of their gambling. Those seeking therapy or medical treatment also scored significantly higher on the PG-YBOCS. This study suggests that pathologic gamblers seeking treatment were more likely to exhibit obsessive-compulsive tendencies likely leading to the increased legal and social problems that exist in this group.

Reduced Risk-Taking After Prior Losses in Pathological Gamblers Under Treatment and Healthy Control Group but not in Problem Gamblers

A group of pathological gamblers and a group of problem gamblers (i.e., gamblers at risk of becoming pathological) were compared to healthy controls on their risk-taking propensity after prior losses. Each participant played both the Balloon Analogue Risk Taking task (BART) and a modified version of the same task, where individuals face five repeated predetermined early losses at the onset of the game. No significant difference in risk-taking was found between groups on the standard BART task, while significant differences emerged when comparing behaviors in the two tasks: both pathological gamblers and controls reduced their risk-taking tendency after prior losses in the modified BART compared to the standard BART, whereas problem gamblers showed no reduction in risk-taking after prior losses. We interpret these results as a sign of a reduced sensitivity to negative feedback in problem gamblers which might contribute to explain their loss-chasing tendency.

Episodic Tags Enhance Striatal Valuation Signals during Temporal Discounting in pathological Gamblers.

Similar to many addiction disorders, pathological gambling is associated with an increased preference for immediate rewards (steep temporal discounting). In healthy participants, episodic future thinking has been shown to reduce impulsivity during intertemporal choice. Here, we examine for the first time a modulation of temporal discounting via episodic future thinking in a group of pathological gamblers. We investigated a sample of 24 pathological gamblers and 24 matched healthy controls with functional magnetic resonance imaging (fMRI). Participants made intertemporal choices in two experimental conditions. In the control condition, delayed monetary rewards were offered with the respective amount and delay. In the episodic condition, rewards were additionally associated with participant-specific personal future events. We replicated previous findings of increased temporal discounting in pathological gambling. On a trend level, episodic future thinking attenuated discounting across all participants. We found that pathological gamblers could successfully recruit a prospection related network during decision-making in the presence of episodic information. The episodic condition modulated the functional connection between ventromedial prefrontal cortex (vmPFC) and ventral striatum, a mechanism that might support the increase in striatal value coding observed in the episodic condition in gamblers. However, in controls, but not in gamblers, valuation signal changes in the hippocampus were associated with less impulsive behavior. We provide first evidence that by episodic cues during intertemporal decision-making striatal valuation signals can be enhanced in pathological gamblers. Further research is needed to explore interventions that reliably reduce impulsive choice behavior in pathological gambling.

Latent class analysis of gambling subtypes and impulsive/compulsive associations: Time to rethink diagnostic boundaries for gambling disorder?

BackgroundGambling disorder has been associated with cognitive dysfunction and impaired quality of life. The current definition of non-pathological, problem, and pathological types of gambling is based on total symptom scores, which may overlook nuanced underlying presentations of gambling symptoms. The aims of the current study were (i) to identify subtypes of gambling in young adults, using latent class analysis, based on individual responses from the Structured Clinical Interview for Gambling Disorder (SCI-GD); and (ii) to explore relationships between these gambling subtypes, and clinical/cognitive measures. MethodsTotal 582 non-treatment seeking young adults were recruited from two US cities, on the basis of gambling five or more times per year. Participants undertook clinical and neurocognitive assessment, including stop-signal, decision-making, and set-shifting tasks. Data from individual items of the Structured Clinical Interview for Gambling Disorder (SCI-GD) were entered into latent class analysis. Optimal number of classes representing gambling subtypes was identified using Bayesian Information Criterion and differences between them were explored using multivariate analysis of variance. ResultsThree subtypes of gambling were identified, termed recreational gamblers (60.2% of the sample; reference group), problem gamblers (29.2%), and pathological gamblers (10.5%). Common quality of life impairment, elevated Barratt Impulsivity scores, occurrence of mainstream mental disorders, having a first degree relative with an addiction, and impaired decision-making were evident in both problem and pathological gambling groups. The diagnostic item ‘chasing losses’ most discriminated recreational from problem gamblers, while endorsement of ‘social, financial, or occupational losses due to gambling’ most discriminated pathological gambling from both other groups. Significantly higher rates of impulse control disorders occurred in the pathological group, versus the problem group, who in turn showed significantly higher rates than the reference group. The pathological group also had higher set-shifting errors and nicotine consumption. ConclusionsEven problem gamblers who had a relatively low total SCI-PG scores (mean endorsement of two items) exhibited impaired quality of life, objective cognitive impairment on decision-making, and occurrence of other mental disorders that did not differ significantly from those seen in the pathological gamblers. Furthermore, problem/pathological gambling was associated with other impulse control disorders, but not increased alcohol use. Groups differed on quality of life when classified using the data-driven approach, but not when classified using DSM cut-offs. Thus, the current DSM-5 approach will fail to discriminate a significant fraction of patients with biologically plausible, functionally impairing illness, and may not be ideal in terms of diagnostic classification. Cognitive distortions related to ‘chasing losses’ represent a particularly important candidate treatment target for early intervention.

Post-traumatic stress symptoms in pathological gambling: Potential evidence of anti-reward processes.

BackgroundExcessive gambling is considered to be a part of the addiction spectrum. Stress-like emotional states are a key feature both of pathological gambling (PG) and of substance addiction. In substance addiction, stress symptomatology has been attributed in part to “anti-reward” allostatic neuroadaptations, while a potential involvement of anti-reward processes in the course of PG has not yet been investigated.MethodsTo that end, individuals with PG (n = 22) and mentally healthy subjects (n = 13) were assessed for trauma exposure and post-traumatic stress symptomatology (PTSS) using the Life Events Checklist and the Civilian Mississippi Scale, respectively.ResultsIn comparison with healthy subjects, individuals with PG had significantly greater PTSS scores including greater physiological arousal sub-scores. The number of traumatic events and their recency were not significantly different between the groups. In the PG group, greater gambling severity was associated with more PTSS, but neither with traumatic events exposure nor with their recency.ConclusionsOur data replicate prior reports on the role of traumatic stress in the course of PG and extend those findings by suggesting that the link may be derived from the anti-reward-type neuroadaptation rather than from the traumatic stress exposure per se.

Mapping brain volumetric abnormalities in never-treated pathological gamblers

Several magnetic resonance imaging (MRI) studies to date have investigated brain abnormalities in association with the diagnosis of pathological gambling (PG), but very few of these have specifically searched for brain volume differences between PG patients and healthy volunteers (HV). To investigate brain volume differences between PG patients and HV, 30 male never-treated PG patients (DSM-IV-TR criteria) and 30 closely matched HV without history of psychiatric disorders in the past 2 years underwent structural magnetic resonance imaging with a 1.5-T instrument. Using Freesurfer software, we performed an exploratory whole-brain voxelwise volume comparison between the PG group and the HV group, with false-discovery rate correction for multiple comparisons (p<0.05). Using a more flexible statistical threshold (p<0.01, uncorrected for multiple comparisons), we also measured absolute and regional volumes of several brain structures separately. The voxelwise analysis showed no clusters of significant regional differences between the PG and HV groups. The additional analyses of absolute and regional brain volumes showed increased absolute global gray matter volumes in PG patients relative to the HV group, as well as relatively decreased volumes specifically in the left putamen, right thalamus and right hippocampus (corrected for total gray matter). Our findings indicate that structural brain abnormalities may contribute to the functional changes associated with the symptoms of PG, and they highlight the relevance of the brain reward system to the pathophysiology of this disorder.

Increased impulsivity in pathological gambling: Considering nicotine dependence

Introduction: It has been highlighted that increased impulsivity is an important etiological factor in pathological gambling (PG). However, the role of the highly prevalent comorbid mental disorders in PG remains unclear. This is of special concern as the highest comorbidity was found between PG and nicotine dependence (ND), which, in turn, has also been associated with heightened impulsivity. This study aimed to find out whether increased impulsivity in PG is a specific characteristic related to comorbid mental disorders in general or especially to ND. Method: A cross-sectional study was designed that included a healthy control group and three disorder groups with comorbid PG excluding ND, comorbid PG including ND, and ND alone according to the Diagnostic and Statistical Manual of Mental Disorders–Fourth Edition. Impulsivity was assessed according to the dimensions response and choice impulsivity applying behavioral and self-report measures. Results: We found (a) increased response impulsivity in the comorbid PG group when compared to the control group. Furthermore, increased choice impulsivity was found (b) in comorbid PG excluding ND and (c) in comorbid PG including ND when compared to ND alone. Other group differences did not reach significance. Conclusions: Our findings highlight that comorbid PG shares deficits in inhibitory control with ND. In contrast, maladaptive choices are a specific disorder characteristic of comorbid PG when compared to ND. If replicated in further studies, intervention strategies strengthening cognitive control skills might be effective for comorbid PG as well as ND whereas strategies enhancing maladaptive valuation of rewards might be specifically effective in comorbid PG.

Psychodiagnostic Assessment of Pathological Gamblers: A Focus on Personality Disorders, Clinical Syndromes and Alexithymia

Comorbid psychopathological syndromes are common in pathological gamblers (PGs), but the contribution of alexithymia, as a disorder of affect regulation, has not been fully explored yet. This study sought to examine the association between personality disorders, clinical syndromes and alexithymia levels in a group of PGs and to highlight a relationship between gambling behaviour and alexithymia scores, apart from the relationship between other disorders and gambling behaviour. Psychological assessment included the South Oaks Gambling Screen, Millon Clinical Multiaxial Inventory (MCMI-III) and Toronto Alexithymia Scale (TAS-20) performed on 70 treatment seeking PGs and 70 healthy controls. Statistical analysis on the results shows a greater presence of mental disorders in PGs together with alterations in emotional processing. Moreover, a significant contribution of alexithymia in predicting gambling behaviour has been revealed. In conclusion, even though the assessment of personality disorders and clinical syndromes in PGs should be considered as an essential diagnostical step, alexithymia must be regarded as a relevant psychological feature, in order to produce the most accurate diagnosis available and select the correct therapeutical choice.

Dimensions and disorder specificity of impulsivity in pathological gambling

Impulsivity is a core characteristic of pathological gambling (PG), even though the underlying structure and disorder specificity is unclear. This study aimed to explore different dimensions of impulsivity in a clinical sample including PG. Furthermore, we aimed to test which alterations of the impulsivity-related dimensions are disorder specific for PG. Participants were individuals diagnosed with PG (n=51) and two groups also characterized by various impulsive behaviors: an alcohol dependence (AD; n=45) and a Gilles de la Tourette syndrome (GTS; n=49) group. A healthy control (HC; n=53) group was recruited as comparison group. A comprehensive assessment was used including impulsivity-related and antipodal parameters of the Stop Signal Task, Stroop Task, Tower of London Task, Card Playing Task, Iowa Gambling Task and the Barratt Impulsiveness Scale-11. Principal axis factor analysis revealed four impulsivity-related dimensions that were labeled ‘self-reported impulsivity’, ‘prepotent response impulsivity’, ‘choice impulsivity’ and ‘motor impulsivity’. The PG group scored significantly higher on all four dimensions compared to the HC group. In contrast, the PG group did not differ on any of the dimensions from the AD or the GTS group, except for ‘choice impulsivity’ where the PG group exhibited higher factor scores compared to the GTS group. Altogether, PG is associated with generally heightened impulsivity profiles compared to a HC group, which may be further used for intervention strategies. However, heightened scores in the impulsivity dimensions are not disorder specific for PG. Further research on shared or different underlying mechanisms of these overlapping impulsivity impairments is necessary.

The Impact of Alexithymia on Pathological Gamblers’ Decision Making

We investigated whether alexithymia is at the root of the decision-making deficit classically reported in pathological gamblers. Alexithymia has been shown to be a recurrent personality trait of pathological gamblers and to impair the decision-making abilities of nonpathological gamblers, but no previous studies have investigated whether alexithymia significantly affects pathological gamblers' decision making. Although investigations of pathological gamblers typically have studied those seeking treatment, most pathological gamblers do not seek treatment. Thus, to study people representative of the general population of pathological gamblers, we conducted our study in "sportsbook" casinos with a small sample of gamblers who were not seeking treatment. We recruited gamblers in sportsbooks and classified them based on their scores on the South Oaks Gambling Screen and the Toronto Alexithymia Scale: 3 groups of pathological gamblers (6 alexithymic, 8 possibly alexithymic, and 6 nonalexithymic) and 8 healthy controls. All of the participants completed an adaptation of the Iowa Gambling Task. The alexithymic group chose less advantageously on the task than the other groups. The severity of the deficit in decision-making abilities was related to the severity of alexithymia, even when we controlled for the effects of anxiety and depression. Our findings provide preliminary evidence that alexithymia might be a critical personality trait underlying pathological gamblers' decision-making deficits.

Contingency learning in alcohol dependence and pathological gambling: learning and unlearning reward contingencies.

BackgroundPatients with alcohol dependence (AD) and pathological gambling (PG) are characterized by dysfunctional reward processing and their ability to adapt to alterations of reward contingencies is impaired. However, most neurocognitive tasks investigating reward processing involve a complex mix of elements, such as working memory, immediate and delayed rewards, and risk-taking. As a consequence, it is not clear whether contingency learning is altered in AD or PG. Therefore, the current study aimed to examine performance in a deterministic contingency learning task, investigating discrimination, reversal, and extinction learning.MethodsThirty-three alcohol-dependent patients (ADs), 28 pathological gamblers (PGs), and 18 healthy controls (HCs) performed a contingency learning task in which they learned stimulus–reward associations that were first reversed and later extinguished while receiving deterministic feedback throughout. Accumulated points, number of perseverative errors and trials required to reach a criterion in each learning phase were compared between groups using nonparametric Kruskal–Wallis rank-sum tests. Regression analyses were performed to compare learning curves.ResultsPGs and ADs did not differ from HCs in discrimination learning, reversal learning, or extinction learning, on the nonparametric tests. Regression analyses, however, showed differences in the initial speed of learning: PGs were significantly faster in discrimination learning compared to ADs, and both PGs and ADs learned slower than HCs in the reversal learning and extinction phases of the task.ConclusionsLearning rates for reversal and extinction were slower for the alcohol-dependent group and PG group compared to HCs, suggesting that reversing and extinguishing learned contingencies require more effort in ADs and PGs. This implicates a diminished flexibility to overcome previously learned contingencies.

Almost winning: Induced MEG theta power in insula and orbitofrontal cortex increases during gambling near-misses and is associated with BOLD signal and gambling severity

In slot machine gambling, the “near-miss effect” (when a losing display physically resembles an actual win display) has been implicated in pathological gambling (PG). Functional magnetic resonance imaging (fMRI) with PG and non-PG participants shows that near-misses recruit reward-related circuitry, but little is known about the temporal dynamics and oscillatory changes underlying near-misses. The present multi-modal imaging study investigated the near-miss effect by combining the spatial resolution of blood oxygen-level dependent (BOLD)-fMRI with the spatial and temporal resolution of magnetoencephalography (MEG) during a slot machine task in PG and non-PG groups. Given previous findings on outcome (win and near-miss) processing, functional overlap was hypothesized between induced changes in temporal oscillations and BOLD response to wins and near-misses in PG. We first validated our task in a sample of varying gambling severity using BOLD-fMRI and then compared PG and non-PG participants using MEG to investigate changes in induced oscillatory power associated with win and near-miss, relative to loss, outcomes. Across both modalities, near-misses recruited similar brain regions to wins, including right inferior frontal gyrus and insula. Using MEG, increased theta-band (4–7Hz) oscillations to near-misses were observed in the insula and right orbitofrontal cortex (OFC). Furthermore, this theta-band activity was positively associated with gambling severity. These findings demonstrate that the near-miss effect in insula and OFC is associated with induced theta oscillations. The significance of these findings for theories of PG and the development of potential biomarkers and therapeutic targets is discussed.

Increased Functional Connectivity between Prefrontal Cortex and Reward System in Pathological Gambling

Pathological gambling (PG) shares clinical characteristics with substance-use disorders and is thus discussed as a behavioral addiction. Recent neuroimaging studies on PG report functional changes in prefrontal structures and the mesolimbic reward system. While an imbalance between these structures has been related to addictive behavior, whether their dysfunction in PG is reflected in the interaction between them remains unclear. We addressed this question using functional connectivity resting-state fMRI in male subjects with PG and controls. Seed-based functional connectivity was computed using two regions-of-interest, based on the results of a previous voxel-based morphometry study, located in the prefrontal cortex and the mesolimbic reward system (right middle frontal gyrus and right ventral striatum). PG patients demonstrated increased connectivity from the right middle frontal gyrus to the right striatum as compared to controls, which was also positively correlated with nonplanning aspect of impulsiveness, smoking and craving scores in the PG group. Moreover, PG patients demonstrated decreased connectivity from the right middle frontal gyrus to other prefrontal areas as compared to controls. The right ventral striatum demonstrated increased connectivity to the right superior and middle frontal gyrus and left cerebellum in PG patients as compared to controls. The increased connectivity to the cerebellum was positively correlated with smoking in the PG group. Our results provide further evidence for alterations in functional connectivity in PG with increased connectivity between prefrontal regions and the reward system, similar to connectivity changes reported in substance use disorder.

Commentary on Boileau et al. (2013): Distinguishing D2/D3 dopaminergic contributions to addictions

Commentary on <scp>B</scp>oileau <i>et al</i>. (2013): Distinguishing <scp>D2/D3</scp> dopaminergic contributions to addictions

Striatal dopamine release codes uncertainty in pathological gambling

Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain—striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear function of expected reward and an inverse U-shaped function of uncertainty. In this study, we investigated the dopaminergic coding of reward and uncertainty in 18 pathological gambling sufferers and 16 healthy controls. We used positron emission tomography (PET) with the tracer [11C]raclopride to measure dopamine release, and we used performance on the Iowa Gambling Task (IGT) to determine overall reward and uncertainty. We hypothesized that we would find a linear function between dopamine release and IGT performance, if dopamine release coded reward in pathological gambling. If, on the other hand, dopamine release coded uncertainty, we would find an inversely U-shaped function. The data supported an inverse U-shaped relation between striatal dopamine release and IGT performance if the pathological gambling group, but not in the healthy control group. These results are consistent with the hypothesis of dopaminergic sensitivity toward uncertainty, and suggest that dopaminergic sensitivity to uncertainty is pronounced in pathological gambling, but not among non-gambling healthy controls. The findings have implications for understanding dopamine dysfunctions in pathological gambling and addictive behaviors.