Effects of serotonin and dopamine depletion on neural prediction computations during social learning

We have previously shown that individuals with high depression scores demonstrate impaired behavioral and neural responses during social learning. Given that depression is associated with altered dopamine (DA) and serotonin (5-HT) functioning, the current study aimed to elucidate the role of these neurotransmitters in the social learning process using a dietary depletion manipulation. In a double-blind design, 70 healthy volunteers were randomly allocated to a 5-HT depletion (N=24), DA depletion (N = 24), or placebo (N = 22) group. Participants performed a social learning task during fMRI scanning, as part of which they learned associations between name cues and rewarding (happy faces) or aversive (fearful faces) social outcomes. Behaviorally, 5-HT depleted subjects demonstrated impaired social reward learning compared to placebo controls, with a marginal effect in the same direction in the DA depletion group. On the neural level, computational modelling-based fMRI analyses revealed that 5-HT depletion altered social reward prediction signals in the insula, temporal lobe, and prefrontal cortex, while DA depletion affected social reward prediction encoding only in the prefrontal cortex. These results indicate that 5-HT depletion impairs learning from social rewards, on both the behavioral and the neural level, while DA depletion has a less extensive effect. Interestingly, the behavioral and neural responses observed after 5-HT depletion in the current study closely resemble our previous findings in individuals with high depression scores using the same task. It may thus be the case that decreased 5-HT levels contribute to social learning deficits in depression

Processes controlling the vertical aerosol distribution in marine stratocumulus regions - a sensitivity study using the climate model NorESM1-M

The vertical distribution of aerosols plays an important role in determining the effective radiative forcing from aerosol–radiation and aerosol–cloud interactions. Here, a number of processes controlling the vertical distribution of aerosol in five subtropical marine stratocumulus regions in the climate model NorESM1-M are investigated, with a focus on the total aerosol extinction. A comparison with satellite lidar data (CALIOP, Cloud–Aerosol Lidar with Orthogonal Polarization) shows that the model underestimates aerosol extinction throughout the troposphere, especially elevated aerosol layers in the two regions where they are seen in observations. It is found that the shape of the vertical aerosol distribution is largely determined by the aerosol emission and removal processes in the model, primarily through the injection height, emitted particle size, and wet scavenging. In addition, the representation of vertical transport related to shallow convection and entrainment is found to be important, whereas alterations in aerosol optical properties and cloud microphysics parameterizations have smaller effects on the vertical aerosol extinction distribution. However, none of the alterations made are sufficient for reproducing the observed vertical distribution of aerosol extinction, neither in magnitude nor in shape. Interpolating the vertical levels of CALIOP to the corresponding model levels leads to better agreement in the boundary layer and highlights the importance of the vertical resolution

The silent epidemic of falls from buildings: analysis of risk factors

This study wanted to search for potential risk factors associated with falls from windows and balconies in order to eventually improve prevention. All children under the age of 16years suffering from head injuries/multiple trauma due to falls from windows or balconies treated over the last 7years at the intensive care unit (ICU) of the University Children's Hospital Zürich were analysed retrospectively (group A). Fifty patients out of all children suffering from head injuries/multiple trauma due to other types of accidents in the same period were selected at random as controls (group B). Out of a total of 241 children with head injury and/or multiple trauma, 31 (13%) fell out of a building. Twenty-seven of these victims (87%) fell from the third floor or lower. Twenty-one of the falls (68%) occurred at home. Fifteen children (49%) climbed on a piece of furniture before falling. In almost 20% of the accidents dangerous balcony or house constructions led to the fall. Parents did not witness the fall, except for three cases (10%) with direct parental involvement (one mother jumped out with her child, two mothers threw their child out of the window). Two children (6%) attempted suicide. Children aged 0-5years were predominantly represented (84%), and all six children who died were in this age group. There were significantly more patients with foreign nationalities and lower socio-professional categories in group A than in group B. In both groups, the accidents concerned the youngest child of the family in approximately 50% and happened mostly during summer evenings. There were no significant differences in injured systems and in injury severity between the two groups. This study identified young age, an immigrant family setting, low socio-professional category of the parents, dangerous house constructions, inappropriate furniture placement, and summertime evenings as risk factors for serious building falls in children. This information may foster focused preventio

Impaired social learning predicts reduced real-life motivation in individuals with depression: a computational fMRI study

Background: Major depressive disorder is associated with altered social functioning and impaired learning, on both the behavioural and the neural level. These deficits are likely related, considering that successful social interactions require learning to predict other people’s emotional responses. Yet, there is little research examining this relation. Methods: Forty-three individuals with high (HD; N=21) and low (LD; N=22) depression scores answered questions regarding their real-life social experiences and performed a social learning task during fMRI scanning. As part of the task, subjects learned associations between name cues and rewarding (happy faces) or aversive (fearful faces) social outcomes. Using computational modelling, behavioural and neural correlates of social learning were examined and related to real-life social experiences. Results: HD participants reported reduced motivation to engage in real-life social activities and demonstrated elevated uncertainty about social outcomes in the task. Moreover, HD subjects displayed altered encoding of social reward predictions in the insula, temporal lobe and parietal lobe. Interestingly, across all subjects, higher task uncertainty and reduced parietal prediction encoding were associated with decreased motivation to engage in real-life social activities. Limitations: The size of the included sample was relatively small. The results should thus be regarded as preliminary and replications in larger samples are called for. Conclusion: Taken together, our findings suggest that reduced learning from social outcomes may impair depressed individuals’ ability to predict other people’s responses in real life, which renders social situations uncertain. This uncertainty, in turn, may contribute to reduced social engagement (motivation) in depression

Social reinforcement learning as a predictor of real-life experiences in individuals with high and low depressive symptomatology

Background: Several studies have reported diminished learning from non-social outcomes in depressed individuals. However, it is not clear how depression impacts learning from social feedback. Notably, mood disorders are commonly associated with deficits in social functioning, which raises the possibility that potential impairments in social learning may negatively affect real-life social experiences in depressed subjects. Methods: Ninety-two participants with high (HD; N=40) and low (LD; N=52) depression scores were recruited. Subjects performed a learning task, during which they received monetary outcomes or social feedback which they were told came from other people. Additionally, participants answered questions about their everyday social experiences. Computational models were fit to the data and model parameters were related to social experience measures. Results: HD subjects reported a reduced quality and quantity of social experiences compared to LD controls, including an increase in the amount of time spent in negative social situations. Moreover, HD participants showed lower learning rates than LD subjects in the social condition of the task. Interestingly, across all participants, reduced social learning rates predicted higher amounts of time spent in negative social situations, even when depression scores were controlled for. Conclusion: These findings indicate that deficits in social learning may affect the quality of everyday social experiences. Specifically, the impaired ability to use social feedback to appropriately update future actions, which was observed in HD subjects, may lead to suboptimal interpersonal behavior in real life. This, in turn, may evoke negative feedback from others, thus bringing about more unpleasant social encounters

Investigating subtypes of reward processing deficits as trait markers for depression

Background: Anhedonia, the loss of pleasure in usually enjoyable activities, is a central feature of major depressive disorder (MDD). The aim of the present study was to examine whether young people at a familial risk of depression display signs of anticipatory, motivational or consummatory anhedonia, which would indicate that these deficits may be trait markers for MDD. Methods: The study was completed by 22 participants with a family history of depression (FH+) and 21 controls (HC). Anticipatory anhedonia was assessed by asking participants to rate their anticipated liking of pleasant and unpleasant foods which they imagined tasting when cued with images of the foods. Motivational anhedonia was measured by requiring participants to perform key presses to obtain pleasant chocolate taste rewards or to avoid unpleasant apple tastes. Additionally, physical consummatory anhedonia was examined by instructing participants to rate the pleasantness of the acquired tastes. Moreover, social consummatory anhedonia was investigated by asking participants to make preference-based choices between neutral facial expressions, genuine smiles, and polite smiles. Results: It was found that the FH+ group’s anticipated liking of unpleasant foods was significantly lower than that of the control group. By contrast, no group differences in the pleasantness ratings of the actually experienced tastes or in the amount of performed key presses were observed. However, controls preferred genuine smiles over neutral expressions more often than they preferred polite smiles over neutral expressions, while this pattern was not seen in the FH+ group. Conclusion: These findings suggest that FH+ individuals demonstrate an altered anticipatory response to negative stimuli and show signs of social consummatory anhedonia, which may be trait markers for depression

Convergent evidence for validity of a performance-based ICT skills test

The goal of this study was to investigate sources of evidence of convergent validity supporting the construct interpretation of scores on a simulation-based ICT skills test. The construct definition understands ICT skills as reliant on ICT-specific knowledge as well as comprehension and problem-solving skills. On the basis of this, a validity argument comprising three claims was formulated and tested. (1) In line with the classical nomothetic span approach, all three predictor variables explained task success positively across all ICT skills items. As ICT tasks can vary in the extent to which they require construct-related knowledge and skills and in the way related items are designed and implemented, the effects of construct-related predictor variables were expected to vary across items. (2) A task-based analysis approach revealed that the item-level effects of the three predictor variables were in line with the targeted construct interpretation for most items. (3) Finally, item characteristics could significantly explain the random effect of problem-solving skills, but not comprehension skills. Taken together, the obtained results generally support the validity of the construct interpretation

Quality of Digital Health Interventions Across Different Health Care Domains: Secondary Data Analysis Study

BackgroundThere are more than 350,000 digital health interventions (DHIs) in the app stores. To ensure that they are effective and safe to use, they should be assessed for compliance with best practice standards. ObjectiveThe objective of this paper was to examine and compare the compliance of DHIs with best practice standards and adherence to user experience (UX), professional and clinical assurance (PCA), and data privacy (DP). MethodsWe collected assessment data from 1574 DHIs using the Organisation for the Review of Care and Health Apps Baseline Review (OBR) assessment tool. As part of the assessment, each DHI received a score out of 100 for each of the abovementioned areas (ie, UX, PCA, and DP). These 3 OBR scores are combined to make up the overall ORCHA score (a proxy for quality). Inferential statistics, probability distributions, Kruskal-Wallis, Wilcoxon rank sum test, Cliff delta, and Dunn tests were used to conduct the data analysis. ResultsWe found that 57.3% (902/1574) of the DHIs had an Organisation for the Review of Care and Health Apps (ORCHA) score below the threshold of 65. The overall median OBR score (ORCHA score) for all DHIs was 61.5 (IQR 51.0-73.0) out of 100. A total of 46.2% (12/26) of DHI’s health care domains had a median equal to or above the ORCHA threshold score of 65. For the 3 assessment areas (UX, DP, and PCA), DHIs scored the highest for the UX assessment 75.2 (IQR 70.0-79.6), followed by DP 65.1 (IQR 55.0-73.4) and PCA 49.6 (IQR 31.9-76.1). UX scores had the least variance (SD 13.9), while PCA scores had the most (SD 24.8). Respiratory and urology DHIs were consistently highly ranked in the National Institute for Health and Care Excellence Evidence Standards Framework tiers B and C based on their ORCHA score. ConclusionsThere is a high level of variability in the ORCHA scores of DHIs across different health care domains. This suggests that there is an urgent need to improve compliance with best practices in some health care areas. Possible explanations for the observed differences might include varied market maturity and commercial interests within the different health care domains. More investment to support the development of higher-quality DHIs in areas such as ophthalmology, allergy, women’s health, sexual health, and dental care may be needed

A literature review to identify effective web- and app-based mHealth interventions for stress management at work

Background: Persistent job-related stress can be harmful to physical and mental health and has a sizable financial burden on society. Face-to-face interventions are effective in reducing stress but have the disadvantage of high costs and time requirements. mHealth solutions may be an effective alternative to provide stress management interventions at work. Occupational health professionals need information on which mHealth apps are effective for employees to manage job-related stress. The aim of this review is to provide an overview of effective web- and app-based interventions for reduction of job-related stress and stress-related symptoms. Method: A literature review was conducted in the databases PubMed, PsycINFO, CINAHL Complete, and IEEEXplore. Findings: A total of 24 articles describing 19 products were found. All products showed effectiveness in trials in improving mental and/or physical health and reducing stress. Most products have a course-like structure with a duration from 1 to 8 weeks. The products use various methods such as psychoeducation and education on stress, cognitive restructuring, emotional regulation, problem-solving, goal setting, gratitude, breathing, or mindfulness techniques. Most products use more than one method and most mixed material such as text on web pages, text messages, videos, reading and audio material, and games. Conclusion/Application to Practice: Overall, effective mHealth products were identified for the intervention of acute and chronic stress. Occupational health practitioners can use these 19 evidence-based mHealth products when advising organizations on health promotion of employees to reduce stress symptoms and promote health and well-being

Meaning in life mediates the effects of sense of self and prosocial behaviours on anhedonia: a path analysis

Background Anhedonia, the loss of interest and pleasure, is a core symptom of depression that is resistant to treatment. Anhedonic young people describe a weakened sense of self and reduced meaning in life. Knowing if these experiences predict anhedonia could reveal novel targets for intervention development. Methods We recruited young people (N = 429, mean age: 20 years) with a range of depression scores. Using path analysis, we examined anhedonia, sense of self, meaning in life, and prosocial behaviours cross-sectionally and longitudinally at ~5-month follow-up (N = 160). Results Cross-sectionally, sense of self (β =. 81, p < .001) and prosocial behaviours (β = 0.37, p < .001) had direct effects on meaning in life, and meaning in life had a direct effect on anhedonia (β = −0.11, p < .001). Sense of self (β = −0.09, p < .001) and prosocial behaviours (β = −0.04, p < .001) had indirect effects on anhedonia, mediated by meaning in life. In the longitudinal analysis, sense of self at T1 had a direct effect on meaning in life at T2 (β = 0.36, p < .01) and an indirect effect on anhedonia at T2 (β = −0.05, p < .01), mediated by meaning in life. Limitations Approximately 70 % of the participants were female. Future studies should include equal numbers of males and females. Conclusion We provide novel evidence that targeting meaning in life, sense of self, or prosocial behaviours in psychotherapeutic interventions could be effective in alleviating anhedonia