The impact of eating disorders on idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) occurs more frequently in obese females of childbearing age. A link between eating disorders and poor outcome has been suggested but remains unproven. METHODS: This prospective field study at two tertiary headache centers included patients with clinically suspected IIH after standardized diagnostic work-up. Eating disorders were evaluated using validated questionnaires (EDQs). Primary outcome was the impact of eating disorders on IIH severity and outcome, secondary outcome was the prevalence and type of eating disorders in IIH compared to controls. RESULTS: We screened 326 patients; 143 patients replied to the EDQs and were classified as 'IIH' or 'non-IIH' patients. The demographic profile of EDQ-respondents and non-respondents was similar. Presence of an eating disorder did not impact IIH severity (lumbar puncture opening pressure (p = 0.63), perimetric mean deviation (p = 0.18), papilledema (Frisén grad 1-3; p = 0.53)) nor IIH outcome (optic nerve atrophy (p = 0.6), impaired visual fields (p = 0.18)). Moreover, we found no differences in the prevalence and type of eating disorders when comparing IIH with non-IIH patients (p = 0.09). CONCLUSION: Eating disorders did not affect IIH severity or outcome. We found the same prevalence and distribution pattern of eating disorders in IIH and non-IIH patients advocating against a direct link between IIH and eating disorders.

Low quality of life in binge eating disorder compared to healthy controls.

INTRODUCTION: Patients with binge eating disorder (BED) tend to report a lower quality of life (QoL) than patients with other eating disorders. However, most research on QoL in eating disorders include generic rather than disease-specific measures. Depression and obesity are frequent comorbid conditions in patients with BED affecting QoL. In the present study, we aimed to assess disease-specific QoL in BED and to investigate the impact of obesity and depression. METHODS: Adult patients who met the DSM-5 criteria for BED (N = 98) were recruited from a newly established specialised online treatment programme for BED and completed the following questionnaires: the Eating Disorder Quality of Life Questionnaire (EDQLS), the Major Depression Inventory (MDI) and the newly introduced Binge Eating Disorder Questionnaire for measuring BED severity. Healthy, normal-weight individuals were recruited through online invitations on social media, n = 190. RESULTS: QoL in BED individuals was significantly lower than in healthy individuals. No relationship was found between BMI and EDQLS, whereas significant, negative correlations were found between depression and all subscales of the EDQLS. CONCLUSION: Disease-specific QoL in BED was associated with depression but not with BMI. FUNDING: none. CLINICALTRIALS: gov NCT05010798.

Days between sessions predict attrition in text-based internet intervention of Binge Eating Disorder.

Background: The number of days between treatment sessions is often overlooked as a predictor of attrition in psychotherapy. In text-based Internet interventions, days between sessions may be a simple yet powerful predictor of attrition. Objective: We hypothesized that a larger number of days between sessions increased the likelihood of attrition among participants with Binge Eating Disorder (BED) in a 12-session Internet-based cognitive behavioral therapy (iCBT) program. Participants could work on the sessions whenever convenient for them and received written support from a psychologist. Material and methods: We compared 201 adult participants with mild to moderate BED (85 non-completers and 116 completers) on the number of days between sessions to predict attrition rates. Results: Mixed model binomial logistic regression showed that non-completers spent significantly more days between sessions across the first four treatment sessions (1-4) when controlling for age, gender, and intake measures of BMI, BED, overall health status (EQ VAS), and depression symptoms (MDI) (OR = 1.042, p < .001). Age (OR = 0.976, p < .001) and EQ VAS (OR = 0.984, p < .001) were also significant. The risk of attrition increased by 4.2 % for each additional day participants spent completing a session.A receiver operating characteristic (ROC) curve analysis showed that classification accuracy increased across sessions from 61.1 % in session 1 and 65.7 % in session 2 to 68.8 % in session 3 and 73.2 % in session 4. The optimal cut-off point in session 4 was 17.5 days, which detected 60.4 % of non-completers (sensitivity) and 78.4 % of completers (specificity).An exploratory repeated measures of ANOVA of days between sessions showed a significant within-subjects effect, where both non-completers and completers spent more days between sessions as they progressed from sessions 1 through 4 (F = 20.54, df = 3, p < .001). There was no interaction effect, suggesting that the increase in slope did not differ between non-completers and completers. Conclusions: Participants spending more days between sessions are at increased risk of dropping out of treatment. This may have important implications for identifying measures to reduce attrition, e.g., intensifying interventions through automated reminders or therapist messages. Our findings may have important transdiagnostic implications for text-based Internet interventions. Further studies should investigate the predictive value of days between sessions in other diagnoses.

An analysis of patient motivation for seeking online treatment for binge eating disorder-A mixed methods study combining systematic text condensation with sentiment analysis.

Objective: Online treatment for binge eating disorder (BED) is an easily available option for treatment compared to most standard treatment procedures. However, little is known about how motivation types characterize this population and how these impact treatment adherence and effect in an online setting. Therefore, we aimed to investigate a sample of written motivation statements from BED patients, to learn more about how treatment and online treatment in particular, presents in this population. Methods: Using self-determination theory in a mixed methods context, we investigated which types of motivation were prevalent in our sample, how this was connected with patient sentiment, and how these constructs influence treatment and adherence. Results: Contrary to what most current literature suggests, we found that in our sample (n = 148), motivation type was not connected with treatment outcome. We did find a strong association between sentiment scores and motivation types, indicating the model is apt at detecting effects. We found that when comparing an adult and young adult population, they did not differ in motivation type and the treatment was equally effective in young adults and adults. In the sentiment scores there was a difference between sentiment score and adherence in the young adult group, as the more positive the young adults were, the less likely they were to complete the program. Discussion: Because motivation type does not influence online treatment to the same degree as it would in face-to-face treatment it indicates that the typical barriers to treatment may be less crucial in an online setting. This should be considered during intake; as less motivated patients may be able to adhere better to online treatment, because the latter imposes fewer barriers of the kind that only strong motivation can overcome. The fact that motivation type and sentiment score of the written texts are strongly associated, indicate a potential for automated models to detect motivation based on sentiment.

Early development of treatment motivation predicts adherence and symptom reduction in an internet-based guided self-help program for binge eating disorder.

Objective: Lack of motivation is widely acknowledged as a significant factor in treatment discontinuity and poor treatment outcomes in eating disorders. Treatment adherence is lower in internet-based treatment. The current study aimed to assess the relationship between treatment motivation and treatment outcomes in an internet-based therapist-guided intervention for Binge Eating Disorder (BED). Method: Adults (N = 153) with mild to moderate symptoms of BED participated in a 10-session internet-based treatment program. Baseline and between-session scores of "Readiness to change" and "Belief in change" were used to predict treatment completion and eating disorder symptom reduction (EDE-Q Global, BED-Q, and weekly number of binge eating episodes) at post-treatment. Results: Baseline treatment motivation could not predict treatment completion or symptom reduction. Early measures of treatment motivation (regression slope from sessions 1-5) significantly predicted both treatment completion and post-treatment symptom reduction. "Belief in change" was the strongest predictor for completing treatment (OR = 2.18, 95%-CI: 1.06, 4.46) and reducing symptoms (EDE-Q Global: B = -0.53, p = 0.001; number of weekly binge eating episodes: B = 0.81, p < 0.01). Discussion: The results indicated that patients entering online treatment for BED feel highly motivated. However, baseline treatment motivation could not significantly predict treatment completion, which contradicts previous research. The significant predictive ability of early measures of treatment motivation supports the clinical relevance of monitoring the development of early changes to tailor and optimize individual patient care. Further research is needed to examine treatment motivation in regard to internet-based treatment for BED with more validated measures.

Text based internet intervention of Binge Eating Disorder (BED): Words per message is associated with treatment adherence.

Background: Some evidence suggests that in internet-based cognitive behavioral therapy (iCBT) the likelihood of adherence is increased when patients write longer messages to the therapist in the program. This association has not previously been investigated in iCBT for Binge Eating Disorder (BED). Objective: In this study, we hypothesized that the number of words written by patients with mild to moderate BED was associated with increased likelihood of treatment completion in a text-based iCBT program. Material and methods: We compared 143 BED patients (92 completers and 51 non-completers) on the number of messages and words written to their therapist during the treatment. Results: Completers wrote significantly more words per message (words/message) than non-completers. The results remained significant after controlling for gender, age, educational level, marital status, children, source of income and intake measures of BED, BMI and depression symptoms (Wald = 14.48, p < .001). The odds ratio of completion increased by 1.5% for each additional word patients wrote per message (OR = 1.015). The model showed a 72.4% classification accuracy, and an optimal cut-off point of 68.99 words/message for differentiating completers and non-completers. The model accurately identified 80.9% of completers (sensitivity) and 54.9% of non-completers (specificity). Conclusions: The number of words/message patients write may have important implications for ascertaining likelihood of adherence and improving adherence rates. From a clinical perspective, therapists should encourage patients to use the option of writing messages to the therapist. Words/message may prove to be a transdiagnostic predictor of treatment adherence in text based iCBT.

On the learning of addictive behavior: Sensation-seeking propensity predicts dopamine turnover in dorsal striatum.

We asked if sensation-seeking is linked to premorbid personality characteristics in patients with addictive disorders, or the characteristics follow the sensation-seeking activity. We interpreted the former as a state associated with normal rates of dopamine synthesis, and the latter as a trait of individuals with abnormally high rates of synthesis. We previously determined dopaminergic receptor density in striatum, and we now tested the hypothesis that an elevated dopaminergic condition with increased extracellular dopamine and receptor density follows increased dopamine synthesis capacity in highly sensation-seeking individuals, as measured by positron emission tomography of 18 men with tracer fluorodopa (FDOPA). We detected a site in left caudate nucleus where the volume of distribution of FDOPA-derived metabolites correlated negatively with FDOPA metabolite turnover, consistent with decreased metabolite breakdown in highly sensation-seeking subjects. High rates of sensation-seeking attenuated the dopamine turnover in association with a low rate of dopamine recycling, low dopamine oxidation, and elevated extracellular dopamine and receptors in caudate nucleus. In contrast, low rates of sensation-seeking were associated with rapid dopamine recycling, rapid dopamine oxidation, low extracellular dopamine, and low receptor density. We conclude that the modulation of dopaminergic neurotransmission associated with sensation-seeking is a state of sensation-seeking, rather than a trait of personality following abnormal regulation of dopaminergic neurotransmission.

Validation of the Eating Disorder Examination Questionnaire in Danish Eating Disorder Patients and Athletes.

The Eating Disorder Examination Questionnaire (EDE-Q) is a gold standard questionnaire to identify eating disorder symptoms but has not yet been validated in Danish. The scale consists of four theoretical constructs of disordered eating: Restraint eating, Eating concerns, Shape concerns and Weight concerns. However, the four-factor structure has been difficult to replicate across cultures. This study aimed to examine the factor structure and psychometric properties of the EDE-Q in Danish. The study consisted of four samples (aged 15-70): Patients with anorexia, bulimia and unspecified eating disorders (n = 101), patients with symptoms of binge-eating disorder (n = 300), recreational athletes (n = 404), and elite athletes (n = 526). Depending on the analysis performed, participants had to complete the EDE-Q, the SCOFF questionnaire for eating disorders or the Binge Eating Disorders Questionnaire. In accordance with international research, we found no evidence for a four-factor structure in the EDE-Q among patients or among athletes. But our results showed significant, positive associations between EDE-Q and SCOFF, BED-Q and MDI in all samples. We conclude that the internal structure of EDE-Q is low, while construct validity is high, making EDE-Q useful as an instrument to identify individuals with eating disorder symptoms, including recreational, and elite athletes.

Effectiveness of internet-based guided self-help for binge-eating disorder and characteristics of completers versus noncompleters.

OBJECTIVE: Binge-eating disorder (BED) is characterized by recurrent episodes of binge eating, accompanied by a lack of control and feelings of shame. Online intervention is a promising, accessible treatment approach for BED. In the current study, we compared completers with noncompleters in a 10-session guided internet-based treatment program (iBED) based on cognitive behavioral therapy. METHODS: Adults (N = 75) with mild to moderate BED participated in iBED with weekly written support from psychologists. Participants were compared on the Eating Disorder Examination Questionnaire (EDE-Q), diagnostic criteria for BED (BED-Q), major depression inventory (MDI), quality of life (EQ-5D-5L), body mass index (BMI) and sociodemographic variables. RESULTS: Minor differences were observed between completers and noncompleters on depression. No differences were found in BED-symptoms, BMI, and sociodemographic variables. Participants who completed treatment showed large reductions in eating disorder pathology. DISCUSSION: More research is needed to determine risk factors for attrition or treatment outcome in internet-based interventions for BED. It is suggested that iBED is an efficient intervention for BED. However, more studies of internet-interventions are needed.

The anticipatory dopamine response in addiction: A common neurobiological underpinning of gambling disorder and substance use disorder?

The dopamine system is associated with reward processes in both gambling disorder and substance use disorder, and may constitute a common neurobiological underpinning in addiction. The present review examines differences and similarities of dopaminergic reward processes in gambling disorder and substance use disorder. First, it is suggested that baseline binding potentials of the dopamine system may not be a common pathway, since substance use disorder is associated with reduced binding potentials, whereas gambling disorder is not. Second, it is suggested that dopaminergic reward response may be not a common pathway, since substance use disorder is associated with a blunted dopamine response toward drugs, while conflicting findings of reward response has been reported in gambling disorder. Instead, it is suggested that the anticpatory dopamine response may constitute a common underpinning of gambling disorder and substance use disorder, which may be associated with increased dopamine activity in both types of disorder, and does not involve the intake of substances. The notion of the anticipatory dopamine response as a common underpinning of gambling disorder and substance use disorder is consistent with dopaminergic models of addictions such as the incentive-sensitization model, the ingrative neurodevelopmental model of vulnerability toward addiction and the reward prediction error model.

Relating neural processing of reward and loss prospect to risky decision-making in individuals with and without Gambling Disorder.

Neuroimaging studies demonstrate alterations in fronto-striatal neurocircuitry in gambling disorder (GD) during anticipatory processing, which may influence decision-making impairments. However, to date little is known about fronto-striatal anticipatory processing and emotion-based decision-making. While undergoing neuroimaging, 28 GD and 28 healthy control (HC) participants performed the Monetary Incentive Delay Task (MIDT). Pearson correlation coefficients assessed out-of-scanner Iowa Gambling Task (IGT) performance with the neural activity during prospect (A1) processing on the MIDT across combined GD and HC groups. The HC and GD groups showed no significant difference in out-of-scanner IGT performance, although there was a trend for higher IGT scores in the HC group on the last two IGT trial blocks. Whole-brain correlations across combined HC and GD groups showed that MIDT BOLD signal in the ventral striatum/caudate/ventromedial prefrontal cortex and anterior cingulate regions during the prospect of winning positively correlated with total IGT scores. The GD group also contained a higher proportion of tobacco smokers, and correlations between neural activations in prospect on the MIDT may relate in part to gambling and/or smoking pathology. In this study, fronto-striatal activity during the prospect of reward and loss on the MIDT was related to decision-making on the IGT, with blunted activation linked to disadvantageous decision-making. The findings from this work are novel in linking brain activity during a prospect-of-reward phase with performance on a decision-making task in individuals with and without GD.

Routine blood tests are associated with short term mortality and can improve emergency department triage: a cohort study of >12,000 patients.

BACKGROUND: Prioritization of acutely ill patients in the Emergency Department remains a challenge. We aimed to evaluate whether routine blood tests can predict mortality in unselected patients in an emergency department and to compare risk prediction with a formalized triage algorithm. METHODS: A prospective observational cohort study of 12,661 consecutive admissions to the Emergency Department of Nordsjælland University Hospital during two separate periods in 2010 (primary cohort, n = 6279) and 2013 (validation cohort, n = 6383). Patients were triaged in five categories by a formalized triage algorithm. All patients with a full routine biochemical screening (albumin, creatinine, c-reactive protein, haemoglobin, lactate dehydrogenase, leukocyte count, potassium, and sodium) taken at triage were included. Information about vital status was collected from the Danish Central Office of Civil registration. Multiple logistic regressions were used to predict 30-day mortality. Validation was performed by applying the regression models on the 2013 validation cohort. RESULTS: Thirty-day mortality was 5.3%. The routine blood tests had a significantly stronger discriminative value on 30-day mortality compared to the formalized triage (AUC 88.1 [85.7;90.5] vs. 63.4 [59.1;67.5], p < 0.01). Risk stratification by routine blood tests was able to identify a larger number of low risk patients (n = 2100, 30-day mortality 0.1% [95% CI 0.0;0.3%]) compared to formalized triage (n = 1591, 2.8% [95% CI 2.0;3.6%]), p < 0.01. CONCLUSIONS: Routine blood tests were strongly associated with 30-day mortality in acutely ill patients and discriminatory ability was significantly higher than with a formalized triage algorithm. Thus routine blood tests allowed an improved risk stratification of patients presenting in an emergency department.

Treatment of gambling disorder patients with comorbid depression.

OBJECTIVE: This study was conducted to investigate and clinically assess comorbid depression and its relevance in individuals suffering from gambling disorders. The DSM-V defines the condition of gambling disorder as a persistent and recurrent problematic gambling behaviour leading to clinically significant impairment or distress. METHOD: A total of 61 subjects with gambling disorders were assessed using the Structured Clinical Interview for the DSM-IV (SCID-I), the South Oaks Gambling Screen (SOGS) and the Major Depression inventory (MDI). RESULTS: Two-way analysis of variance showed highly significant treatment outcomes associated with reductions in SOGS, F(1,60)=84.79, p<0.0001, MDI, F(1,60)=38.13, p<0.0001, craving, F(1,60)=29.59, p<0.0001, and gambling control, 47.65, p<0.0001. There was also a highly significant outcome associated with comorbidity in MDI, F(1,60)=9.17, p<0.0001. Finally, there was a significant interaction effect between treatment outcome and comorbidity, F(1,60)=3.90, p<0.005, suggesting that both treatment and comorbidity contributed to reductions in depressive symptoms. CONCLUSION: These results suggest and highlights the importance and benefits of integrated treatment of gambling disorders and its comorbidity, but also stresses the importance of adequate screening and detection of these two variables.

Neurobiological underpinnings of reward anticipation and outcome evaluation in gambling disorder.

Gambling disorder is characterized by persistent and recurrent maladaptive gambling behavior, which leads to clinically significant impairment or distress. The disorder is associated with dysfunctions in the dopamine system. The dopamine system codes reward anticipation and outcome evaluation. Reward anticipation refers to dopaminergic activation prior to reward, while outcome evaluation refers to dopaminergic activation after reward. This article reviews evidence of dopaminergic dysfunctions in reward anticipation and outcome evaluation in gambling disorder from two vantage points: a model of reward prediction and reward prediction error by Wolfram Schultz et al. and a model of "wanting" and "liking" by Terry E. Robinson and Kent C. Berridge. Both models offer important insights on the study of dopaminergic dysfunctions in addiction, and implications for the study of dopaminergic dysfunctions in gambling disorder are suggested.

The Iowa Gambling Task and the three fallacies of dopamine in gambling disorder.

Gambling disorder sufferers prefer immediately larger rewards despite long term losses on the Iowa Gambling Task (IGT), and these impairments are associated with dopamine dysfunctions. Dopamine is a neurotransmitter linked with temporal and structural dysfunctions in substance use disorder, which has supported the idea of impaired decision-making and dopamine dysfunctions in gambling disorder. However, evidence from substance use disorders cannot be directly transferred to gambling disorder. This article focuses on three hypotheses of dopamine dysfunctions in gambling disorder, which appear to be "fallacies," i.e., have not been supported in a series of positron emission tomography (PET) studies. The first "fallacy" suggests that gambling disorder sufferers have lower dopamine receptor availability, as seen in substance use disorders. However, no evidence supported this hypothesis. The second "fallacy" suggests that maladaptive decision-making in gambling disorder is associated with higher dopamine release during gambling. No evidence supported the hypothesis, and the literature on substance use disorders offers limited support for this hypothesis. The third "fallacy" suggests that maladaptive decision-making in gambling disorder is associated with higher dopamine release during winning. The evidence did not support this hypothesis either. Instead, dopaminergic coding of reward prediction and uncertainty might better account for dopamine dysfunctions in gambling disorder. Studies of reward prediction and reward uncertainty show a sustained dopamine response toward stimuli with maximum uncertainty, which may explain the continued dopamine release and gambling despite losses in gambling disorder. The findings from the studies presented here are consistent with the notion of dopaminergic dysfunctions of reward prediction and reward uncertainty signals in gambling disorder.

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 [(11)C]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.

Impaired probability estimation and decision-making in pathological gambling poker players.

Poker has gained tremendous popularity in recent years, increasing the risk for some individuals to develop pathological gambling. Here, we investigated cognitive biases in a computerized two-player poker task against a fictive opponent, among 12 pathological gambling poker players (PGP), 10 experienced poker players (ExP), and 11 inexperienced poker players (InP). Players were compared on probability estimation and decision-making with the hypothesis that ExP would have significantly lower cognitive biases than PGP and InP, and that the groups could be differentiated based on their cognitive bias styles. The results showed that ExP had a significantly lower average error margin in probability estimation than PGP and InP, and that PGP played hands with lower winning probability than ExP. Binomial logistic regression showed perfect differentiation (100%) between ExP and PGP, and 90.5% classification accuracy between ExP and InP. Multinomial logistic regression showed an overall classification accuracy of 23 out of 33 (69.7%) between the three groups. The classification accuracy of ExP was higher than that of PGP and InP due to the similarities in probability estimation and decision-making between PGP and InP. These impairments in probability estimation and decision-making of PGP may have implications for assessment and treatment of cognitive biases in pathological gambling poker players.

Dopamine release in ventral striatum during Iowa Gambling Task performance is associated with increased excitement levels in pathological gambling.

AIMS: Gambling excitement is believed to be associated with biological measures of pathological gambling. Here, we tested the hypothesis that dopamine release would be associated with increased excitement levels in Pathological Gamblers compared with Healthy Controls. DESIGN: Pathological Gamblers and Healthy Controls were experimentally compared in a non-gambling (baseline) and gambling condition. MEASUREMENTS: We used Positron Emission Tomography (PET) with the tracer raclopride to measure dopamine D 2/3 receptor availability in the ventral striatum during a non-gambling and gambling condition of the Iowa Gambling Task (IGT). After each condition participants rated their excitement level. SETTING: Laboratory experiment. PARTICIPANTS: 18 Pathological Gamblers and 16 Healthy Controls. FINDINGS: Pathological Gamblers with dopamine release in the ventral striatum had significantly higher excitement levels than Healthy Controls despite lower IGT performance. No differences in excitement levels and IGT performance were found between Pathological Gamblers and Healthy Controls without dopamine release. Pathological Gamblers showed a significant correlation between dopamine release and excitement level, while no such interaction was found in Healthy Controls. CONCLUSIONS: In pathological gamblers dopamine release in the ventral striatum appears to be associated with increased excitement levels despite lower IGT performance. The results might suggest a 'double deficit' function of dopamine in pathological gambling, where dopamine release reinforces maladaptive gambling through increasing excitement levels, reducing inhibition of risky decisions, or a combination of both. These findings may have implications for the understanding of dopamine in pathological gambling and other forms of addiction.

Inverse association between dopaminergic neurotransmission and Iowa Gambling Task performance in pathological gamblers and healthy controls.

The dopamine system is believed to affect gambling behavior in pathological gambling. Particularly, dopamine release in the ventral striatum appears to affect decision-making in the disorder. This study investigated dopamine release in the ventral striatum in relation to gambling performance on the Iowa Gambling Task (IGT) in 16 Pathological Gamblers (PG) and 14 Healthy Controls (HC). We used Positron Emission Tomography (PET) to measure the binding potential of [(11)C] raclopride to dopamine D2/3 receptors during a baseline and gambling condition. We hypothesized that decreased raclopride binding potentials in the ventral striatum during gambling (indicating dopamine release) would be associated with higher IGT performance in Healthy Controls, but lower IGT performance in Pathological Gamblers. The results showed that Pathological Gamblers with dopamine release in the ventral striatum had significantly lower IGT performance than Healthy Controls. Furthermore, dopamine release was associated with significantly higher IGT performance in Healthy Controls and significantly lower IGT performance in Pathological Gamblers. The results suggest that dopamine release is involved both in adaptive and maladaptive decision-making. These findings may contribute to a better understanding of dopaminergic dysfunctions in pathological gambling and substance related addictions.

Pathological gambling: relation of skin conductance response to dopaminergic neurotransmission and sensation-seeking.

Absent Skin Conductance Response (SCR) in pathological gambling (PG) may relate to dopaminergic mechanisms. We recruited equal numbers of PG subjects and healthy control (HC) subjects, and then tested the claim that SCR is less conditioned by dopaminergic activity in PG subjects. During active gambling, SCR differed in PG and HC subjects (P < 0.05), but positron emission tomography revealed the same dopamine receptor availability. However, highly sensation-seeking (HS) PG subjects had lower dopamine receptor availability (P < 0.0001) in the baseline, compared to normal sensation-seeking (NS) PG subjects. We find that HS versus NS controls had the same observation of significant increase of binding potential (BP(ND)) in high compared to normal sensation seekers. In both groups, PG and HC, highly sensation-seeking subjects had significant increase of receptor availability in striatum, compared to normally sensation-seeking subjects, separately (P < 0.05 and P = 0.02, respectively) and together (P < 0.0005). We conclude that SCR is less conditioned by dopaminergic activity in highly sensation-seeking subjects, regardless of PG status.