Stress and compulsive buying-shopping disorder: A scoping review.

INTRODUCTION: Theoretical frameworks of behavioral addictions mostly acknowledge the role of stress in the development and maintenance of these disorders, models of compulsive buying-shopping disorder (CBSD) however rarely incorporated stress. The association between stress and CBSD has not been reviewed yet. METHODS: A scoping review was conducted to evaluate empirical results on the association between stress and CBSD. A comprehensive search string was employed in three databases. RESULTS: 16 studies were included. Correlative studies suggested significant correlations between general perceived stress and CBSD symptom severity. Studies involving mean comparisons found higher general perceived stress levels in persons with problematic buying-shopping behavior/CBSD compared to control participants (large effects). Mixed results were found in studies involving regression/structural equation models and ecological momentary assessments. One study with a stress/negative mood induction observed more CBSD symptoms in a high stress group compared to a low stress group. DISCUSSION: The studies are heterogeneous concerning design, samples and measures. Only very few studies surpass the level of cross-sectional correlative data which limits the ability to draw clear conclusions. Future research should study the impact of experimentally induced stress on CBSD symptoms, examine the relationship between stress and CBSD longitudinally and assess objective stress markers.

Modelling dataset bias in machine-learned theories of economic decision-making.

Normative and descriptive models have long vied to explain and predict human risky choices, such as those between goods or gambles. A recent study reported the discovery of a new, more accurate model of human decision-making by training neural networks on a new online large-scale dataset, choices13k. Here we systematically analyse the relationships between several models and datasets using machine-learning methods and find evidence for dataset bias. Because participants' choices in stochastically dominated gambles were consistently skewed towards equipreference in the choices13k dataset, we hypothesized that this reflected increased decision noise. Indeed, a probabilistic generative model adding structured decision noise to a neural network trained on data from a laboratory study transferred best, that is, outperformed all models apart from those trained on choices13k. We conclude that a careful combination of theory and data analysis is still required to understand the complex interactions of machine-learning models and data of human risky choices.

Cue-reactivity to distal cues in individuals at risk for gaming disorder.

BACKGROUND: Gaming disorder (GD) is a disorder due to addictive behaviors (ICD-11). Cue-reactivity and craving are relevant mechanisms in the development and maintenance of addictive behaviors. When confronted with cues showing in-game content (proximal cues) individuals with higher symptom severity show increased cue-reactivity. Based on conditioning and addiction theories on incentive sensitization, cue-reactivity responses may generalize to more distal cues, e.g. when individuals at risk of developing a GD are confronted with a starting page of an online game. In cue-reactivity paradigms so far, only proximal gaming cues have been used. METHODS: We investigated the effect of distal gaming cues compared to gaming-unrelated control cues on cue-reactivity and craving in 88 individuals with non-problematic use of online games (nPGU) and 69 individuals at risk for GD (rGD). The distal cues showed the use of an electronic device (e.g., desktop PC or smartphone) whose screen showed starting pages of either games (target cues), shopping- or pornography sites (control cues) from a first-person perspective. FINDINGS: We found significantly higher urge and arousal ratings as well as longer viewing times for gaming-related compared to gaming-unrelated control cues in rGD compared to nPGU. Valence ratings did not differ between groups. INTERPRETATION: The results demonstrate that already distal gaming-specific cues lead to cue-reactivity and craving in rGD. This finding indicates that based on conditioning processes, cue-reactivity and craving develop during the course of GD and generalize to cues that are only moderately related to the specific gaming activity.

Update on treatment studies for compulsive buying-shopping disorder: A systematic review.

Background and aims: Compulsive buying-shopping disorder (CBSD) is mentioned as an example of other specified impulse control disorders in the ICD-11 coding tool, highlighting its clinical relevance and need for treatment. The aim of the present work was to provide a systematic update on treatment studies for CBSD, with a particular focus on online CBSD. Method: The preregistered systematic review (PROSPERO, CRD42021257379) was performed in accordance with the PRISMA 2020 statement. A literature search was conducted using the PubMed, Scopus, Web of Science and PsycInfo databases. Original research published between January 2000 and December 2022 was included. Risk of reporting bias was evaluated with the CONSORT guideline for randomized controlled trials. Effect sizes for primary CBSD outcomes were calculated. Results: Thirteen studies were included (psychotherapy: 2 open, 4 waitlist control design; medication: 2 open, 3 placebo-controlled, 2 open-label phase followed by a double-blind discontinuation phase; participants treatment/control 349/149). None of the studies addressed online CBSD. Psychotherapy studies suggest that group cognitive-behavioral therapy is effective in reducing CBSD symptoms. Pharmacological studies with selective serotonin re-uptake inhibitors or topiramate did not indicate superiority over placebo. Predictors of treatment outcome were rarely examined, mechanisms of change were not studied at all. Risk of reporting bias was high in most studies. Discussion: Poor methodological and low quality of reporting of included studies reduce the reliability of conclusions. There is a lack of studies targeting online CBSD. More high-quality treatment research is needed with more emphasis on the CBSD subtype and mechanisms of change.

Finding the Right Balance: A Social Norms Intervention to Reduce Heavy Drinking in University Students.

Introduction: Heavy alcohol consumption constitutes a major health risk among University students. Social relationships with peers strongly affect University students' perception of the drinking behavior of others, which in turn plays a crucial role in determining their own alcohol intake. University students tend to overestimate their peers' alcohol consumption - a belief that is associated with an increase in an individual's own consumption. Therefore, we implemented a social norms intervention with personalized normative feedback at a major University in Germany to reduce and prevent excessive drinking among University students. Methods: Our intervention was part of a regular health monitoring survey. We invited all enrolled University students to take part in this survey on two occasions. A total of 862 University students completed the questionnaire, 563 (65.3%) of which received e-mail-based feedback upon request concerning their peers' and their own alcohol consumption. For the intervention group (n = 190) as well as the control group (no feedback requested; n = 101), we included only University students in the evaluation who overestimated their peers' alcohol use and indicated above average consumption of the peers. We applied analyses of variance to assess intervention effects with regard to the correction of overestimated group norms as well as University students' drinking behavior. Results: Within the intervention group, we observed a significantly larger reduction of the previously overestimated behavioral norms compared to the control group (p < 0.001; ηp2 = 0.06). With regard to behavioral outcomes the intervention group showed a significantly larger reduction in the AUDIT-C score (p = 0.020; ηp2 = 0.03). Discussion: Our study confirms previous research whereupon personalized, gender-specific and selective normative feedback is effective for alcohol prevention among University students. However, University students still overestimated their peers' alcohol intake after the intervention. Furthermore, we did not reach high-risk groups (University students with the highest alcohol intake) since no feedback was requested. Future studies should address factors influencing the impact of the intervention and reachability of selective groups.

MK2 and Fas receptor contribute to the severity of CNS demyelination.

Models of inflammatory or degenerative diseases demonstrated that the protein-kinase MK2 is a key player in inflammation. In this study we examined the role of MK2 in MOG35-55-induced experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. In MK2-deficient (MK2-/-) mice we found a delayed onset of the disease and MK2-/- mice did not recover until day 24 after EAE induction. At this day a higher number of leukocytes in the CNS of MK2-/- mice was found. TNFα was not detectable in serum of MK2-/- mice in any stage of EAE, while high TNFα levels were found at day 16 in wild-type mice. Further investigation revealed an increased expression of FasR mRNA in leukocytes isolated from CNS of wild-type mice but not in MK2-/- mice, however in vitro stimulation of MK2-/- splenocytes with rmTNFα induced the expression of FasR. In addition, immunocomplexes between the apoptosis inhibitor cFlip and the FasR adapter molecule FADD were only detected in splenocytes of MK2-/- mice at day 24 after EAE induction. Moreover, the investigation of blood samples from relapsing-remitting multiple sclerosis patients revealed reduced FasR mRNA expression compared to healthy controls. Taken together, our data suggest that MK2 is a key regulatory inflammatory cytokines in EAE and multiple sclerosis. MK2-/- mice showed a lack of TNFα and thus might not undergo TNFα-induced up-regulation of FasR. This may prevent autoreactive leukocytes from apoptosis and may led to prolonged disease activity. The findings indicate a key role of MK2 and FasR in the regulation and limitation of the immune response in the CNS.

MAP-kinase-activated protein kinase 2 expression and activity is induced after neuronal depolarization.

Mitogen-activated protein kinase-activated protein kinase (MK)2 is one of several downstream targets of p38 mitogen-activated protein kinase and has a well documented role in inflammation. Here, we describe a possible new function of MK2. We show that triggering depolarization by potassium chloride or increasing the cellular cAMP by forskolin treatment led to elevated levels of expression and activity of mouse MK2. In both treatments, the kinase inhibitor H89 completely prevented the up-regulation of MK2 at the transcript level. By the use of different cell lines we demonstrated that the induction of MK2 expression is characteristic of neuronal cells and is absent in fibroblasts, macrophages and kidney cells. In vivo, induction of a status epilepticus by systemic administration of the chemoconvulsant kainic acid resulted in markedly reduced neurodegeneration in the pyramidal layer of the hippocampus, dentate gyrus and hilus of MK2-deficient mice compared with wild-type mice. Together, our data suggest a possible role of MK2 in the cellular response after neuronal depolarization, in particular in excitotoxicity.

MAPKAP kinase 2-deficiency prevents neurons from cell death by reducing neuroinflammation--relevance in a mouse model of Parkinson's disease.

The inflammatory response in the brain is closely associated with the pathogenesis of degenerative neurological disorders. A role for the p38 stress-activated protein kinase/MAPK-activated protein kinase 2 (MK2) axis in inflammation and apoptosis is well documented. Here, we provide evidence that neurodegeneration can be prevented by eliminating MK2. In primary mesencephalic neuron-glia co-cultures dopaminergic neurons from MK2-deficient (MK2-/-) mice were significantly more resistant to lipopolysaccharide-induced neurotoxicity compared with cells from wild-type mice. This neuroprotection in MK2-deficient cultures was associated with a reduced inflammatory response, especially with reduced production of the inflammatory mediators tumor necrosis factor alpha, keratinocyte-derived chemokine, interleukin-6, and nitric oxide (NO). Interestingly, in primary neuron-enriched cell cultures p38 MAPK, but not MK2, also participates in NO-mediated neuronal cell death. In the MPTP mouse model for Parkinson's disease, MK2-deficient mice show a reduced neuroinflammation and less degeneration of dopaminergic neurons in the substantia nigra after MPTP lesion compared with wild-type mice. In conclusion, our results reveal that MK2 does not directly participate in neuronal cell death, but indirectly contributes to neurodegeneration by the production of neurotoxic substances, such as NO or tumor necrosis factor alpha, from activated glia cells.

Nucleofection is the most efficient nonviral transfection method for neuronal stem cells derived from ventral mesencephali with no changes in cell composition or dopaminergic fate.

Neuronal progenitor cells (NPCs) play an important role in potential regenerative therapeutic strategies for neurodegenerative diseases, such as Parkinson disease. However, survival of transplanted cells is, as yet, limited, and the identification of grafted cells in situ remains difficult. The use of NPCs could be more effective with regard to a better survival and maturation when transfected with one or more neurotrophic factors. Therefore, we investigated the possibility of transfecting mesencephalic neuronal progenitors with different constructs carrying neurotrophic factors or the expression reporters enhanced green fluorescence protein (EGFP) and red fluorescent protein (DsRed). Different techniques for transfection were compared, and the highest transfection rate of up to 47% was achieved by nucleofection. Mesencephalic neuronal progenitors survived the transfection procedure; 6 hours after transfection, viability was approximately 40%, and the transfected cells differentiated into, for example, tyrosine hydroxylase-positive neurons. Within the group of transfected cells, many progenitors and several neurons were found. To provide the progenitor cells with a neurotrophic factor, different isoforms of fibroblast growth factor-2 were introduced. To follow the behavior of the transfected cells in vitro, functional tests such as the cell viability assay (water-soluble tetrazolium salt assay [WST-1]) and the cell proliferation assay (5-bromo-2'-deoxyuridine-enzyme-linked immunosorbent assay) were performed. In addition, these transfected NPCs were viable after transplantation, expressed tyrosine hydroxylase in vivo, and could easily be detected within the host striatum because of their EGFP expression. This study shows that genetic modification of neural progenitors could provide attractive perspectives for new therapeutic concepts in neurodegenerative diseases.