An eight component decision-making model for problem gambling: a systems approach to stimulate integrative research

Learning and memory processes in behavioural addiction: A systematic review

Similar to addictive substances, addictive behaviours such as gambling and gaming are associated with maladaptive modulation of key brain areas and functional networks implicated in learning and memory. Therefore, this review sought to understand how different learning and memory processes relate to behavioural addictions and to unravel their underlying neural mechanisms. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched four databases - PsycINFO, PubMed, Scopus, and Web of Science using the agreed-upon search string. Findings suggest altered executive function-dependent learning processes and enhanced habit learning in behavioural addiction. Whereas the relationship between working memory and behavioural addiction is influenced by addiction type, working memory aspect, and task nature. Additionally, long-term memory is incoherent in individuals with addictive behaviours. Consistently, neurophysiological evidence indicates alterations in brain areas and networks implicated in learning and memory processes in behavioural addictions. Overall, the present review argues that, like substance use disorders, alteration in learning and memory processes may underlie the development and maintenance of behavioural addictions.

Functionality versus dimensionality in psychological taxonomies, and a puzzle of emotional valence

This paper applies evolutionary and functional constructivism approaches to the discussion of psychological taxonomies, as implemented in the neurochemical model Functional Ensemble of Temperament (FET). FET asserts that neurochemical systems developed in evolution to regulate functional-dynamical aspects of construction of actions: orientation, selection (integration), energetic maintenance, and management of automatic behavioural elements. As an example, the paper reviews the neurochemical mechanisms of interlocking between emotional dispositions and performance capacities. Research shows that there are no specific neurophysiological systems of positive or negative affect, and that emotional valence is rather an integrative product of many brain systems during estimations of needs and the capacities required to satisfy these needs. The interlocking between emotional valence and functional aspects of performance appears to be only partial since all monoamine and opioid receptor systems play important roles in non-emotional aspects of behaviour, in addition to emotionality. This suggests that the Positive/Negative Affect framework for DSM/ICD classifications of mental disorders oversimplifies the structure of non-emotionality symptoms of these disorders. Contingent dynamical relationships between neurochemical systems cannot be represented by linear statistical models searching for independent dimensions (such as factor analysis); nevertheless, these relationships should be reflected in psychological and psychiatric taxonomies.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

Evidence for GABA-A receptor dysregulation in gambling disorder: correlation with impulsivity

As a behavioural addiction, gambling disorder (GD) provides an opportunity to characterize addictive processes without the potentially confounding effects of chronic excessive drug and alcohol exposure. Impulsivity is an established precursor to such addictive behaviours, and GD is associated with greater impulsivity. There is also evidence of GABAergic dysregulation in substance addiction and in impulsivity. This study therefore investigated GABA_A receptor availability in 15 individuals with GD and 19 healthy volunteers (HV) using [¹¹C]Ro15‐4513, a relatively selective α5 benzodiazepine receptor PET tracer and its relationship with impulsivity. We found significantly higher [¹¹C]Ro15‐4513 total distribution volume (V_T) in the right hippocampus in the GD group compared with HV. We found higher levels of the ‘Negative Urgency’ construct of impulsivity in GD, and these were positively associated with higher [¹¹C]Ro15‐4513 V_T in the amygdala in the GD group; no such significant correlations were evident in the HV group. These results contrast with reduced binding of GABAergic PET ligands described previously in alcohol and opiate addiction and add to growing evidence for distinctions in the neuropharmacology between substance and behavioural addictions. These results provide the first characterization of GABA_A receptors in GD with [¹¹C]Ro15‐4513 PET and show greater α5 receptor availability and positive correlations with trait impulsivity. This GABAergic dysregulation is potential target for treatment.

Effects of GABAB receptors in the insula on recognition memory observed with intellicage

BACKGROUND

Insular function has gradually become a topic of intense study in cognitive research. Recognition memory is a commonly studied type of memory in memory research. GABA_BR has been shown to be closely related to memory formation. In the present study, we used intellicage, which is a new intelligent behavioural test system, and a bilateral drug microinjection technique to inject into the bilateral insula, to examine the relationship between GABA_BR and recognition memory.

METHODS

Male Sprague-Dawley rats were randomly divided into control, Sham, Nacl, baclofen and CGP35348 groups. Different testing procedures were employed using intellicage to detect changes in rat recognition memory. The expression of GABA_BR (GB1, GB2) in the insula of rats was determined by immunofluorescence and western blotting at the protein level. In addition, the expression of GABA_BR (GB₁, GB₂) was detected by RT-PCR at the mRNA level.

RESULTS

The results of the intellicage test showed that recognition memory was impaired in terms of position learning, punitive learning and punitive reversal learning by using baclofen and CGP35348. In position reversal learning, no significant differences were found in terms of cognitive memory ability between the control groups and the CGP and baclofen groups. Immunofluorescence data showed GABA_BR (GB1, GB2) expression in the insula, while data from RT-PCR and western blot analysis demonstrated that the relative expression of GB1 and GB2 was significantly increased in the baclofen group compared with the control groups. In the CGP35348 group, the expression of GB1 and GB2 was significantly decreased, but there was no significant difference in GB1 or GB2 expression in the control groups.

CONCLUSIONS

GABA_BR expression in the insula plays an important role in the formation of recognition memory in rats.

Similarities and Differences in Neurobiology

Substance addiction is a chronic, relapsing brain disease characterized by compulsive drug seeking and use despite harmful consequences. Non-substance addiction is defined recently that people may compulsively engage in an activity despite any negative consequences to their lives. Despite differences with respect to their addictive object, substance addiction and non-substance addiction may share similarities with respect to biological, epidemiological, clinical, genetic and other features. Here we review the similarities and differences in neurobiology between these two addictions with a focus on dopamine, serotonin, opioid, glutamate and norepinephrine systems. Studies suggest the involvement of all these systems in both substance addiction and non-substance addiction while differences may exist with respect to their contributions.

Neural and psychological underpinnings of gambling disorder: A review

Gambling disorder affects 0.4 to 1.6% of adults worldwide, and is highly comorbid with other mental health disorders. This article provides a concise primer on the neural and psychological underpinnings of gambling disorder based on a selective review of the literature. Gambling disorder is associated with dysfunction across multiple cognitive domains which can be considered in terms of impulsivity and compulsivity. Neuroimaging data suggest structural and functional abnormalities of networks involved in reward processing and top-down control. Gambling disorder shows 50-60% heritability and it is likely that various neurochemical systems are implicated in the pathophysiology (including dopaminergic, glutamatergic, serotonergic, noradrenergic, and opioidergic). Elevated rates of certain personality traits (e.g. negative urgency, disinhibition), and personality disorders, are found. More research is required to evaluate whether cognitive dysfunction and personality aspects influence the longitudinal course and treatment outcome for gambling disorder. It is hoped that improved understanding of the biological and psychological components of gambling disorder, and their interactions, may lead to improved treatment approaches and raise the profile of this neglected condition.

Alterations of neurotransmitter norepinephrine and gamma-aminobutyric acid correlate with murine behavioral perturbations related to bisphenol A exposure

AIM

Humans are commonly exposed to endocrine-disrupting chemical bisphenol A (BPA), giving rise to concern over the psychobehavioral effects of BPA. The aim of this study was to investigate the effects of prenatal and lactational BPA exposure on neurotransmitters, including norepinephrine (NE), gamma-aminobutyric acid (GABA) and glutamate (Glu), and to assess the association with behavioral phenotypes.

METHODS

C57BL/6J mice were orally administered with BPA (500 μg/bwkg/day) or vehicle daily from embryonic day 0 to postnatal week 3 (P3W), through their dams. The IntelliCage behavioral experiments were conducted from P11W to P15W. At around P14-16W, NE, GABA and Glu levels in nine brain regions were measured by high performance liquid chromatography. Furthermore, the associations between the neurotransmitter levels and the behavioral indices were statistically analyzed.

RESULTS

In females exposed to BPA, the GABA and Glu levels in almost all regions, and the NE levels in the cortex, hypothalamus and thalamus were higher than those in the controls. In males exposed to BPA, the GABA levels in the amygdala and hippocampus showed lower values, while Glu levels were higher in some regions, compared with the controls. In regard to the associations, the number of "diurnal corner visits without drinking" was correlated with the NE levels in the cortex and thalamus in females. The "nocturnal corner visit duration without drinking" was correlated with the GABA level in the hippocampus in males.

CONCLUSION

These results suggest that prenatal and lactational exposure to low doses of BPA might modulate the NE, GABA and Glu systems, resulting in behavioral alterations.

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

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

An 8-week stress management program in pathological gamblers: a pilot randomized controlled trial

Stress plays a major role at the onset and relapse of pathological gambling (PG), but at the same time it can also be the aftermath of gambling behavior, thus revealing a reciprocal relationship. Although the role of stress has been well-documented, there is a paucity of studies investigating the effect of an adjunctive stress management program on PG. In this 8-week parallel randomized waitlist controlled trial pathological gamblers, already in the gamblers anonymous (GA) group, were assigned randomly in two groups, with the intervention group (n = 22) receiving an additional stress management program (consisting of education on diet and exercise, stress coping methods, relaxation breathing -RB- and progressive muscle relaxation -PMR). Self-reported measures were used in order to evaluate stress, depression, anxiety, sleep quality/disturbances, life-satisfaction and daily routine. The statistical analyses for the between group differences concerning the main psychosocial study outcomes revealed a statistically significant amelioration of stress, depression, anxiety symptoms and an increase of life-satisfaction and a better daily routine in participants of the intervention group. We hope that these will encourage researchers and clinicians to adopt stress management in their future work.

An Expert Map of Gambling Risk Perception

The purpose of the current study was to investigate the moderating or mediating role played by risk perception in decision-making, gambling behaviour, and disordered gambling aetiology. Eleven gambling expert clinicians and researchers completed a semi-structured interview derived from mental models and grounded theory methodologies. Expert interview data was used to construct a comprehensive expert mental model 'map' detailing risk-perception related factors contributing to harmful or safe gambling. Systematic overlapping processes of data gathering and analysis were used to iteratively extend, saturate, test for exception, and verify concepts and emergent themes. Findings indicated that experts considered idiosyncratic beliefs among gamblers result in overall underestimates of risk and loss, insufficient prioritization of needs, and planning and implementation of risk management strategies. Additional contextual factors influencing use of risk information (reinforcement and learning; mental states, environmental cues, ambivalence; and socio-cultural and biological variables) acted to shape risk perceptions and increase vulnerabilities to harm or disordered gambling. It was concluded that understanding the nature, extent and processes by which risk perception predisposes an individual to maintain gambling despite adverse consequences can guide the content of preventative educational responsible gambling campaigns.

Risk perception in gambling: a systematic review

Perception of the consequences of risk affects motivation and behaviour. In gambling, distorted expectations and preferences towards outcomes are associated with significant social and clinical harms. A systematic review was conducted to examine the relationship between gambling risk perception and behaviour. Sixteen studies met inclusion criteria. Studies provided evidence that disordered gamblers hold both more optimistic overall perceptions of risk, and a mixture of more positive and more negative specific outcome expectations. Preliminary evidence suggests a range of contextual and individual differences moderate risk perception affecting decision-making. Disordered gamblers appear to sustain motivation to gamble, despite more negative expectations and experiences, via cognitive processes that result in preferential emphasis on positive over negative outcomes. Given potential differences in the perception of risk between various categories of gamblers, clinicians should take into account how gamblers in treatment view gambling as a risky behaviour. Improving the accuracy of such perceptions may reduce the propensity for risk-taking behaviours.

Cross-species approaches to pathological gambling: a review targeting sex differences, adolescent vulnerability and ecological validity of research tools

Decision-making plays a pivotal role in daily life as impairments in processes underlying decision-making often lead to an inability to make profitable long-term decisions. As a case in point, pathological gamblers continue gambling despite the fact that this disrupts their personal, professional or financial life. The prevalence of pathological gambling will likely increase in the coming years due to expanding possibilities of on-line gambling through the Internet and increasing liberal attitudes towards gambling. It therefore represents a growing concern for society. Both human and animal studies rapidly advance our knowledge on brain-behaviour processes relevant for understanding normal and pathological gambling behaviour. Here, we review in humans and animals three features of pathological gambling which hitherto have received relatively little attention: (1) sex differences in (the development of) pathological gambling, (2) adolescence as a (putative) sensitive period for (developing) pathological gambling and (3) avenues for improving ecological validity of research tools. Based on these issues we also discuss how research in humans and animals may be brought in line to maximize translational research opportunities.

The role of memantine in the treatment of psychiatric disorders other than the dementias: a review of current preclinical and clinical evidence

Memantine, a non-competitive NMDA receptor antagonist approved for Alzheimer's disease with a good safety profile, is increasingly being studied in a variety of non-dementia psychiatric disorders. We aimed to critically review relevant literature on the use of the drug in such disorders. We performed a PubMed search of the effects of memantine in animal models of psychiatric disorders and its effects in human studies of specific psychiatric disorders. The bulk of the data relates to the effects of memantine in major depressive disorder and schizophrenia, although more recent studies have provided data on the use of the drug in bipolar disorder as an add-on. Despite interesting preclinical data, results in major depression are not encouraging. Animal studies investigating the possible usefulness of memantine in schizophrenia are controversial; however, interesting findings were obtained in open studies of schizophrenia, but negative placebo-controlled, double-blind studies cast doubt on their validity. The effects of memantine in anxiety disorders have been poorly investigated, but data indicate that the use of the drug in obsessive-compulsive disorder and post-traumatic stress disorder holds promise, while findings relating to generalized anxiety disorder are rather disappointing. Results in eating disorders, catatonia, impulse control disorders (pathological gambling), substance and alcohol abuse/dependence, and attention-deficit hyperactivity disorder are inconclusive. In most psychiatric non-Alzheimer's disease conditions, the clinical data fail to support the usefulness of memantine as monotherapy or add-on treatment However, recent preclinical and clinical findings suggest that add-on memantine may show antimanic and mood-stabilizing effects in treatment-resistant bipolar disorder.

Pathological gambling: a systematic review of biochemical, neuroimaging, and neuropsychological findings

Pathological gambling is an emerging psychiatric disorder that has recently gained much attention because of its increasing prevalence and devastating personal, familial, and social consequences. Although its pathophysiology is largely unknown, the shared similarities with both addiction and obsessive-compulsive spectrum disorders have suggested the possibility of common psychobiological substrates. As with many other psychiatric disorders, it is believed that pathological gambling may result from the interplay between individual vulnerability and environmental factors. The aim of this article is to offer a comprehensive review of the main neurobiological aspects of pathological gambling, with particular attention to neuropsychological and related findings. A deeper understanding of the biological correlates of pathological gambling is required in order to develop effective treatment strategies.

Variations in the GRIN2B gene are associated with risky decision-making

The dopaminergic system is known to modulate decision-making. As N-methyl-D-aspartate (NMDA) receptors strongly influence dopaminergic function, it is conceivable that the glutamatergic system is also involved in decision-making. We examined whether polymorphisms in the N-methyl-d-aspartate receptor 2B subunit gene (GRIN2B) influence decision-making using the Iowa Gambling Task (IGT). In total, 245 (n = 245, 127 female) healthy German students were included in the analysis. Two synonymous SNPs in exon 13, rs1806191 (H1178H) and rs1806201 (T888T) showed the strongest association with aspects of IGT performance. Females with a CC allele in rs1806201 made less use both of a win-stay strategy and demonstrated more exploratory behaviour during task execution. For rs1806191, we found a strong additive effect in usage of a win-stay strategy. This, partly sex-dependent, correlation of the win-stay/lose-shift behaviour with GRIN2B genotypes suggests that healthy individuals with certain GRIN2B variations respond differently to ambiguous conditions, possibly by altered perception of wins and losses. These findings underline the necessity to integrate the glutamatergic system when examining decision-making processes.